Spectrum
Policy for the
21st
Century – The
President’s
Spectrum
Policy
Initiative
A Public Safety Sharing
Demonstration
CARLOS M. GUTIERREZ,
SECRETARY
JOHN M. R. KNEUER, ASSISTANT SECRETARY FOR
COMMUNICATIONS AND INFORMATION
June 2007
LEADERSHIP AND
CONTRIBUTORS
National Telecommunications & Information
Administration
The Honorable
John M. R. Kneuer
Assistant Secretary for Communications
and Information
Meredith A.
Baker
Deputy Assistant Secretary for Communications
and Information
Office of Spectrum Management
Karl B. Nebbia
Associate
Administrator
Emergency Planning and Public Safety Division
William A.
Belote
Division
Chief
Richard J. Orsulak
Team Lead
Charles T. Hoffman
The
National Telecommunications and Information Administration (NTIA) would like to
thank the District of Columbia’s Office of the Chief Technology Officer (OCTO),
under the direction and leadership of
This page
intentionally blank
ACRONYMS AND ABBREVIATIONS.................................................................................... xi
EXECUTIVE SUMMARY....................................................................................................... xiii
Section 1 - introduction.............................................................................................. 1-1
BACKGROUND...................................................................................................................... 1-1
OBJECTIVES........................................................................................................................... 1-3
APPROACH............................................................................................................................ 1-3
Section 2 - Selection
Criteria................................................................................... 2-1
Section 3 - the warn pilot............................................................................................ 3-1
BACKGROUND...................................................................................................................... 3-1
SPECTRUM CONSIDERATIONS.......................................................................................... 3-2
WARN overview................................................................................................................ 3-4
Purpose................................................................................................................................. 3-4
Applications........................................................................................................................... 3-4
Timeline................................................................................................................................. 3-7
Users..................................................................................................................................... 3-7
Funding................................................................................................................................. 3-8
Technology/Vendor Selection................................................................................................. 3-8
Network Construction......................................................................................................... 3-10
TECHNICAL ASPECTS........................................................................................................ 3-10
Overview............................................................................................................................. 3-10
Devices............................................................................................................................... 3-13
SYSTEM PERFORMANCE.................................................................................................. 3-14
Overview............................................................................................................................. 3-14
Network Performance......................................................................................................... 3-15
Subscriber Device Performance........................................................................................... 3-17
Application Performance...................................................................................................... 3-18
NETWORK USAGE.............................................................................................................. 3-19
Customer Feedback............................................................................................................ 3-21
SIGNIFICANT WARN DEPLOYMENTS............................................................................ 3-23
Presidential Inauguration, January 2005................................................................................ 3-24
Independence Day, July 2005.............................................................................................. 3-25
Independence Day, July 2006.............................................................................................. 3-27
Section 4 feasIbility of
commercial services............................................... 4-1
BACKGROUND...................................................................................................................... 4-1
COMMERICAL SERVICES IN THE DISTRICT.................................................................... 4-1
Section 5 - observations
and recommendations......................................... 5-1
observations.................................................................................................................... 5-1
Benefits................................................................................................................................. 5-1
The Growing Demand for Public Safety Broadband................................................................ 5-2
Spectrum Issues..................................................................................................................... 5-2
Amount of Spectrum….………………………………………………………………...5-2
Federal
Broadband Spectrum…………………………………………………….……..5-3
Coverage............................................................................................................................... 5-4
Devices................................................................................................................................. 5-4
FUTURE TRENDS AND QUESTIONS.................................................................................. 5-5
RECOMMENDATIONS......................................................................................................... 5-5
Identify Broadband Requirements........................................................................................... 5-5
Begin Planning To Share Spectrum Resources........................................................................ 5-6
Leverage Standardized Economies of Scale............................................................................ 5-7
Improve Buying Power And Public Safety Capabilities............................................................ 5-7
Consider Commercial Services Where Appropriate................................................................ 5-8
SUMMARY.............................................................................................................................5-8
APPENDICES
A - GLOSSARY.......................................................................................................................... A-1
B - SAMPLE MEMORANDUM OF
UNDERSTANDING (MoU)...................................... B-1
C - TECHNICAL INFORMATION......................................................................................... C-1
D - WARN PERFORMANCE
TESTING................................................................................ D-1
E - USER FEEDBACK.............................................................................................................. E-1
LIST OF FIGURES
Figure 1: WARN Spectrum............................................................................................................ 3-3
Figure 2: Flash-OFDM Network Architecture................................................................................ 3-9
Figure 3: WARN Architecture Overview...................................................................................... 3-11
Figure 4: Radio Router................................................................................................................. 3-12
Figure 5: Flash-OFDM PCMCIA Card....................................................................................... 3-13
Figure 6: Portable Access Device
(PAD)...................................................................................... 3-14
Figure 7: Monthly Data Transmission............................................................................................ 3-20
Figure 8: User Survey Result........................................................................................................ 3-22
Figure 9: Daily Total Traffic Transferred....................................................................................... 3-23
Figure 10: Hourly Traffic of January 20, 2005............................................................................... 3-25
Figure 11: Section 6 RR Configurations......................................................................................... C-1
Figure 12: Access Router Cards.................................................................................................... C-2
Figure 13: RF Subsystem High Level Block Diagram..................................................................... C-3
Figure 14: Measured Downlink Received Level............................................................................. D-2
Figure 15: Downlink Signal to Noise Ratio (12 sites)...................................................................... D-3
Figure 16: Downlink Received Data Rate (10 sites)........................................................................ D-3
Figure 17: Uplink Transmitted Data Rate (10 sites)........................................................................ D-4
Figure 18: WARN Performance Parameters.................................................................................. D-4
AAA Accounting, Authentication, & Authorization
A/C Air Conditioning
AIU Alarm Interface Unit
AVL Automatic Vehicle Location
BBU Baseband Unit
BHU Backhaul Unit
bps Bits per second
CAD Computer Aided Dispatch
CDMA Code-Division Multiple Access
CDPD Cellular Digital Packet Data
CMRS Commercial
cPCI Compact Peripheral Component Interconnect
CSU/DSU Channel Service Unit/Data Service Unity
DC DOT District of Columbia Department of Transportation
DC EMA District of Columbia Emergency Management Agency
DC FEMS
DC MPD District of Columbia Metropolitan Police Department
DC PHS
DC
DHS Department of Homeland Security
EVDO Evolution Data Optimized
FCC Federal Communications Commission
FMDM Flarion Mobile Diagnostic Monitor
GIS Geographic Information System
GPS Global Positioning System
IMF International Monetary Fund
IP Internet Protocol
IPSec Internet Protocol Security
IT Information Technology
JPEG joint Photographic Experts Group
LAN Local Area Network
LMR Land
MACC
Mbps Megabits per second
MCU Master Control Unit
MDT
MHz Megahertz
MMCX Micro Miniature Coaxial
MoA Memorandum of Agreement
MoU Memorandum of Understanding
MPEG4 Motion Picture Experts Group Version 4
NCR National Capital Region
NPS National Park Service
NPSTC National Public Safety Telecommunications
Council
NTIA National Telecommunications and
Information Administration
OCTO Office of the Chief Technology Officer
PA Power Amplifier
PAD Portable Access Device
PCMCIA Personal Computer Memory Card International
Association
PCMIA Personal Computer Manufacturer Interface Adapter
PCU Power Control Unit
PDA Personal Digital Assistant
PHY Physical Layer Processing
QoS Quality of Service
RF Radio Frequency
RFP Request for Proposal
RWBN Regional Wireless Broadband Network
RXU Receiver Unit
SNR Signal to Noise Ratio
STA Special Temporary Authorization
TXU Transceiver Unit
UDP User Datagram Protocol
UPS Uninterruptible Power Supplies
USB Universal Serial Bus
USPP
USSS United States Secret Service
VSAT Very Small Aperture Terminal
WARN Wireless Accelerated Responder Network
WLG Working Level Group
WMATA
WMO Wireless
Management Office
WPO Wireless
Programs Office
In May 2003, President Bush established
the Spectrum Policy Initiative to promote the development and implementation of
a
A main goal of the Initiative is to
evaluate the communication needs of public safety agencies and the efficiency
of spectrum use. This report fulfills recommendation 9(b) of the President’s Spectrum
Policy Initiative Report Two of July 2004 which states that the National
Telecommunications and Information Administration (NTIA) should develop and implement one or more demonstration
programs to test the operational and cost effectiveness of sharing spectrum and
communications infrastructure between federal, state, and/or local governments
and private users. After evaluating
programs from across the country, NTIA chose the District of Columbia’s (District)
pilot program, “Wireless Accelerated Responder Network” (WARN), which was
implemented by the District's Office of the Chief Technology Officer (OCTO). NTIA selected the
WARN pilot program because it met NTIA’s evaluation criteria; specifically, it demonstrated
the use of a public safety network on which federal, state, local and private
users share the available bandwidth.
The WARN system is a broadband,
public safety wireless network providing citywide coverage to the District. It was created to
fill a need of first responders to exchange large amounts of data wherever
emergency services are required. WARN
provides high bandwidth access to streaming video, large files and images, specialized
emergency response databases as well as standard desktop applications such as
email and instant messaging. The
system operates in the 700 MHz band using an experimental license provided by
the Federal Communications Commission (FCC).
It includes 12 fixed transmission sites and roughly 200 subscribers.
The system became operational in
January 2005, and has continued to operate throughout the publication of this
report. During the demonstration period
which was from January 2005 through December 2006,[1]
WARN was used by more than a dozen federal, District, and non-federal agencies. WARN bandwidth was
shared during multiple large-scale events, and enabled access to
critical data for federal and non-federal users. It saw significant initial use during the
Presidential Inauguration, International Monetary Fund (IMF) demonstrations, and
Fourth of July celebrations. WARN
improved collaboration between federal and District agencies. The system also demonstrated significant
benefit to users according to user feedback.
The demonstration also revealed several areas to improve future public
safety solutions, including the need for increased broadband coverage.
WARN demonstrated a critical value in supporting federal and non-federal agencies as they work toward a spectrum-sharing solution to meet the increasingly complex, public-safety, wireless, broadband communication needs in the coming decades. Specifically based upon this pilot, NTIA observed and recommended the following:
Observations |
Recommendations |
Spectrum Planning |
|
· WARN demonstrated that in-depth spectrum planning and coordination are required to satisfy emerging broadband requirements. · WARN illustrated a growing need for broadband capabilities within the District. |
· Federal agencies should clearly identify all broadband requirements in their agency strategic spectrum plans submitted to NTIA. · State and local public safety entities should develop spectrum plans that address their emerging broadband requirements. |
Spectrum Use |
|
· WARN demonstrated that the availability of broadband leads to the realization of broadband potential and the creative identification of new applications. · According to the District’s experiences, it appears the amount of spectrum used by WARN (2.5 MHz) under the experimental license within the 700 MHz band may be insufficient for public safety broadband use. |
· The FCC should conclude their revision of the current 700 MHz band plan to provide the capability for public safety entities to deploy broadband services. |
Spectrum Sharing |
|
· The WARN pilot showed that partnerships that share spectrum resources between all levels of government greatly increase interoperable communications. · The District discovered during the WARN pilot that spectrum and communications infrastructure sharing tends to provide operational and cost-effective solutions. |
· Broadband partnerships should be considered by the public safety community to include all levels of government. |
Feasibility of Commercial Services |
|
· The District analyzed the use of commercial services and determined that commercial networks did not meet the requirements of WARN. However, they are available and may be appropriate for non-mission-critical uses if reliability, throughput, coverage, security, and network management issues are addressed. |
· Public safety agencies should use commercial broadband services, where appropriate, if they can satisfy their broadband requirements. |
President
Bush established the Spectrum Policy Initiative in May 2003,[2] to
promote the development and implementation of a
(a) foster economic
growth;
(b) ensure our
national and homeland security;
(c) maintain
(d) satisfy other
vital
To ensure that U.S. spectrum
management policies are capable of harnessing the potential of rapidly changing
technologies, the President charged the Secretary of Commerce to develop
recommendations to: “(a) facilitate a modernized and improved spectrum
management system; (b) facilitate policy changes to create incentives for more
efficient and beneficial use of spectrum and to provide a higher degree of
predictability and certainty in the spectrum management process as it applies
to incumbent users; (c) develop policy tools to streamline the deployment of
new and expanded services and technologies, while preserving national security,
homeland security, and public safety, and encouraging scientific research; and (d)
develop a means to address the critical spectrum needs of national security,
public safety, Federal transportation infrastructure, and science.”[4]
Based on the President’s guidance, [5]
the advice of the Federal Task Force,[6]
and outreach efforts to the public safety and private sector communities,[7]
the Secretary of Commerce, in
June 2004, submitted two reports to the President, titled Spectrum Policy for the 21st Century – The President’s
Spectrum Policy Initiative (Report 1 and 2). The
two reports contained 24 recommendations for assessing spectrum use in the
public safety and government sector. The President requested in an Executive
Memorandum dated November 30, 2004, that the Department of Commerce submit an
Implementation Plan to put the 24 recommendations into practice.[8]
NTIA
published the Implementation Plan in March 2006.[9] A critical
facet of the Implementation Plan is Project D, which addresses the recommendations
related to public safety. The Department
of Homeland Security (DHS) is responsible for addressing all recommendations
related to public safety except for recommendation 9(b) of Report 2, which is NTIA's
responsibility.[10] Recommendation
9(b) states that NTIA should “develop and implement one or more demonstration
programs to test the operational and cost effectiveness of sharing spectrum and
communications infrastructure between federal, state, and/or local governments
and private users.”[11]
Demonstrations or pilots that share
resources and assets between federal, state, and local public safety agencies
are not a new concept, although few include private users. In many instances, a Memorandum of Understanding
(MoU) or Memorandum of Agreement (MoA) between federal and non-federal agencies
outlines sharing and mutual aid arrangements that may never be registered or
known at a national level. Most federal
agencies have numerous such local arrangements.
In recent years, many of these agreements have become more regional in
nature. For example, the Department of
Defense (DoD), through Alaskan Command, formed a partnership with various state
and local public safety agencies to form the Alaska Land Mobile Radio System
(ALMRS), a statewide public safety telecommunications system in which all users
of the system share resources (spectrum, funding, and facilities).[12] Demonstration projects and proofs of concept,
when properly designed and implemented, can show to the public safety
community, elected officials, Congress, and the Administration, the
effectiveness of cooperative solutions in responding to situations where interoperability
may be problematic.
Additionally, these demonstrations
can prove the application of innovative technologies to public safety and speed
their introduction into the public safety community. Demonstrations can help resolve spectrum
policy and regulatory issues among agencies at both the federal and non-federal
level. These demonstrations enable more
flexible rules to allow easier sharing of spectrum and systems among public
safety agencies and between government entities and private networks, including
the critical infrastructure industry and commercial service industry. The lessons learned from these programs are invaluable
tools in helping federal, state, and local agencies perform their jobs in a
more coordinated manner.
The objectives of the Recommendation 9(b) task are for NTIA to: (1) examine the feasibility of sharing spectrum among commercial, federal and local public safety and critical infrastructure applications, including the possibility of leasing services, and (2) develop and implement one or more demonstration programs to test the operational and cost effectiveness of sharing spectrum and communications infrastructure between federal, state, and/or local governments and private users.[13] Since new funding was not available, NTIA met these objectives through the selection of an existing demonstration pilot.
In order to successfully achieve the objectives of Recommendation 9(b), NTIA took the following approach:
· Conduct research on current public safety demonstrations and pilots; compile a list with background information on possible demonstration candidates and select an existing pilot based upon the recommendations and objectives as described above and consistent with established selection criteria;
· Provide Working Level Group (WLG) D members with information on the selected demonstration candidate and seek WLG D concurrence;
· Invite expert demonstration staff to brief WLG D members on the selected demonstration candidate;
· Work with demonstration staff, the DHS and the Federal Communications Commission (FCC), if necessary, during the duration of the pilot;
· Research sources of existing and available information on the feasibility of commercial services for use by public safety services; and
· Research information on the selected demonstration candidate, and compile data from interviews, the Internet, and other sources into a report.
This page intentionally blank
NTIA compiled a list of current and conceptual demonstration programs that NTIA staff knew to exist or that proponents presented to NTIA for consideration as a possible demonstration. Each of the identified projects possessed merits that could demonstrate sharing and interoperability among public safety entities. In addition to the basic and fundamental criteria in Report 2, Recommendation 9b, NTIA established other benchmarks that coincided with the intent or language of the Implementation Plan. These additional benchmarks became part of the requirements to be met in order for the project to be considered and selected. Therefore, the complete criteria required that the chosen project:
NTIA identified conceptual candidates but did not consider them for a demonstration or ranking since there were too many unknown variables to meet the December 2006 deadline. Further, NTIA dismissed from consideration those candidates that used technology-only solutions (e.g., gateway or audio switch solutions to connect disparate frequency bands or systems) since they did not meet the basic recommendation of sharing spectrum. NTIA also dismissed other proposals that did not satisfy the recommendation of sharing spectrum with other private users.
Based upon the above selection criteria, NTIA selected and WLG D approved, the District of Columbia’s Office of the Chief Technology Officer’s (OCTO) Wireless Area Responder Network (WARN) 700 Megahertz broadband pilot program.[15] WARN met the established selection criteria:
· The program was in existence and would likely meet the December 2006 deadline.
·
The project was funded.
·
The project demonstrated sharing between federal,
state, local, and private users, since the Washington Metropolitan Area Transit
Authority (WMATA), as defined under Part 90 Rules,[16]
is a business licensee.
·
The project was cost effective.
o The
WARN system used low-cost wireless Personal Computer Memory Card International
Association (PCMCIA) cards allowing any laptop or computer to become part of
the network.
o The WARN system used the same sites as the current DC Land Mobile Radio (LMR) system (no additional infrastructure costs).
o The
WARN system costs less than twenty percent of the DC LMR system.
·
NTIA would incur no
extra expenses due to the geographic location of WARN, which would also allow
NTIA personnel to attend all planning meetings and actively participate
in the project.
·
All coordination for spectrum was approved, and
the WARN program was granted an experimental license by the FCC (the expiration
of which would extend beyond the December 2006 deadline).
·
The WARN system showcased new technology.
·
Although at the time it was a broadband,
streaming video project, narrowband-like Voice-over-Internet Protocol (VoIP) was
being considered for the project in the future.
·
The Implementation Plan stated that NTIA should
work closely with DHS on the demonstration program, and the DHS Wireless
Management Office (WMO) signed a MoU with the WARN program to become a user on
the network. The WMO stated that they were
willing to share any information that they gained from their testing and use of
the system.
Ultimately, NTIA determined that the DC’s WARN broadband pilot fulfilled the basic recommendation of “sharing spectrum and communications infrastructure between federal, state, and/or local governments and private users.”
This report focuses on the scope,
observations, recommendations, and conclusions drawn within
the shared environment of the DC’s WARN broadband pilot program.
THE WARN PILOT
BACKGROUND
The
The
District is responsible for a significant number of incidents and events that
occur in the nation’s capital, which also includes fire suppression and
emergency medical services for federal structures and property. This responsibility demands coordination and
extensive communication with many jurisdictions. For instance, daily traffic related incidents
on the
Since its establishment in April 2001, the OCTO has been implementing an eight-year, citywide, IT Strategic Plan (IT Plan). The IT Plan is designed to deliver a robust technology infrastructure for the District government, provide systematic technology support for District government functions, create a state-of-the-art public safety/homeland security infrastructure for the nation’s capital, and provide a complete and coherent Website offering a variety of Web services for the public.
In
order to address the District’s needs for wireless communications, the Wireless
Programs Office (WPO) was established at the end of 2001. The WPO is responsible for using wireless
technology to improve District operations.
Because wireless solutions are used extensively by the public safety
community, the WPO focuses primarily on pubic safety wireless needs. In the aftermath of 9/11, the WPO initially
focused on implementing a fully interoperable public safety radio system with
ample in-building coverage for District emergency personnel. While working on the public safety radio
system, it became evident to OCTO and WPO personnel that existing data
communications solutions were not meeting the needs of emergency responders
within the District. For instance,
public safety personnel needed to use real-time broadband data applications
when working in the field (e.g., streaming video, detailed building blueprints,
and high resolution images). These
applications required a large transmission pipe, and the existing LMR systems
and public safety spectrum were insufficient to support these needs over wide
areas. This finding led to the
development of WARN, the pilot network designed to provide wireless broadband
at high speeds to emergency response personnel deployed in the field.
SPECTRUM CONSIDERATIONS
The District recognized the necessity of a public safety broadband wireless data network, but it also recognized that the technologies using existing public safety spectrum did not fulfill its broadband data needs. The private-owned network options offered at the time included narrowband channels in the 150 MHz, 450 MHz, and 800 MHz public safety bands, wideband data channels in the 700 MHz band, or broadband data channels in the 4.9 GHz band.[17]
The District’s analysis of these options showed that:
· Although 150 MHz, 450 MHz, and 800 MHz band propagation allows a small number of sites to provide ubiquitous coverage to a wide area,[18] the narrowband (25 kilohertz) data channels in these bands did not allow for broadband data application use. The throughput provided was less than half that of a typical dial-up connection. Peak achievable throughput was about 20 kilobits per second (kbps), limiting operations to little more than text messaging. Also, the lack of contiguous blocks of spectrum prevents use of the necessary bandwidth to accommodate broadband applications. Furthermore, these bands are heavily used by thousands of licensees, and they would have to be cleared to allow for broadband channels.
· The current 24 MHz of public safety spectrum within the 700 MHz band possesses radio propagation characteristics that are similar to the 800 MHz band. However, the 150 kHz channel size limit in this public safety band does not allow for broadband applications. For example, Scalable Adaptive Modulation (SAM), the technology proposed as the wideband technology standard, was not expected to be cost-effective or to meet the demands of transferring data. Peak throughput is 460 kbps, allowing for only a few streaming video feeds; whereas some applications transmit multi-video feeds and require 1.2 megabits per second (Mbps). Therefore, the high bandwidth demand could not be supported by this technology. Furthermore, the District expected to secure only a few 150 kHz channels in the 700 MHz regional planning process. The result would be 50 times less throughput than what the applications required. Additionally, because the SAM technology is not easily scalable, the only way to increase capacity would have required costly upgrades.
· Even though sufficient bandwidth exists in it, the 4.9 GHz (4940-4990 MHz) band allocated to public safety was not economically viable for deploying and operating a District-wide network. Ubiquitous coverage of the District (68 square miles) would have required more than 1,000 radio sites compared to roughly 10 sites in the 700/800 MHz band because of its short-range propagation characteristics. The District estimated that the deployment and operating costs for this quantity of sites would be prohibitive. The application of this band is more suitable to “hot-spot,” short-range incidents.
After analyzing the available options, the District decided to deploy a pilot network in the 700 MHz band under an experimental license, and to seek permanent broadband spectrum for public safety.[19] An experimental license was necessary because the current FCC Part 90 Rules do not provide channel widths to accommodate high-speed/high-data rate broadband applications and the District intended, in part, to use spectrum not allocated to public safety.[20] Under the authority of an FCC experimental license, the District deployed a 700 MHz pilot network using a commercial technology called Fast Low-latency Access with Seamless Handoff Orthogonal Frequency Division Multiplexing (Flash-OFDM).[21]
The
light yellow areas in Figure 1 show the spectrum
granted to OCTO through the experimental license. Figure 1 identifies the 24 MHz of spectrum
from TV channels 63, 64 (764-776 MHz) and 68, 69 (794-806 MHz) that has been
reallocated for public safety uses.
Figure 1: WARN Spectrum
WARN uses
one 1.25 MHz channel in each of the two 4 MHz bands[22] allocated in the
TV Channel 61 (downlink or base station to mobile terminal), and the TV Channel
69 (uplink or mobile terminal to base station) segments. The OCTO selected these bands since they
afforded the only clear space in the 700 MHz band within the District at the
time of the pilot launch.
After
the experimental license was granted in February 2004, the District learned
that the Flarion equipment to be used in the experimental network would be
available more rapidly if the uplink and downlink frequencies were swapped (e.g.,
if the base stations operated in the lower range of frequencies from 752.65 MHz
to 756 MHz range,[23] and the mobile units operated in the upper
range of frequencies from 800.65 MHz to 804 MHz). Swapping the uplink and downlink frequencies
had no impact on the operations of WARN; however, in order to receive approval
for this license revision, the District had to demonstrate to the FCC that the
operations of Maryland Public TV broadcasting in the adjacent channel were not
disturbed by WARN.[24]
The FCC stipulated that the District
had to coordinate with the Maryland Public TV station (Channel 62) prior to
network deployment to ensure that no harmful interference would be caused to
its television operations.[25] As the license filing describes, the only TV Broadcasting
station on a co-channel or an adjacent channel was a Maryland Public TV located
in
The purpose of the WARN pilot was to determine how a broadband wireless network could address the needs of public safety and to further refine system and application requirements for future public safety data systems. The District designed the WARN program to use the upper 700 MHz band, thereby allowing it to evaluate the impact of interference received from or created by TV stations broadcasting in this band.
Applications
Responding to emergency events such as multiple-alarm building fires, chemical or biological attacks, or other large-scale attacks requires immediate and rapid wireless data communications among multiple first responders, including fire, police, and emergency medical services (EMS) personnel. Broadband applications now are considered essential tools for protecting lives and property. The ability to use these critical public safety data applications, among others, requires ubiquitous wide-area coverage with broadband throughput. The network allowed District first responders to use full-motion, high-resolution video monitoring and other bandwidth-intensive monitoring tools to immediately share time-critical incident and emergency event information with such applications as:
·
Real-time, full-motion video;
·
Digital imaging (e.g., building diagrams, mug
shots);
·
Remote access to databases (e.g., criminal,
hazardous materials) and report management systems;
·
Mapping, Geographic Information Systems (GIS);
·
Remote sensors (e.g., biological, radiological);
·
Automatic Vehicle Location (AVL), automatic
collision notification systems; and
· Emergency Medical Services (EMS) applications.
Specifically, a number of diverse applications requiring varying degrees of data rates evolved over the duration of the pilot. The titles and descriptions of many of the applications are reflected in the following table. Not all of the applications listed have actually been used as of yet, but show the potential for future use on the WARN network.
Title |
Description/Benefit |
PROTECT
(Chemical/biological terrorism detection and information sharing) |
Existing
applications of video and plume projection information to first responders in
the field provides enhanced response time and real-time detailed
information. Providing this
information to the field to qualified personnel avoids missing key information
that an untrained eye might miss. |
Demonstration
video surveillance |
Dissemination
of video from existing overhead traffic cameras provides field officers
important information regarding the demonstration. It also allows law enforcement to locally
identify needed resources before any officer is put in harm’s way. LiveWave, Greenhouse, and KaptureNet are
examples of this type of application that were used with WARN. |
Bomb
squad support |
Local
law enforcement bomb squad personnel can be supported remotely by federal
bomb experts to analyze and incapacitate sophisticated bombs. |
|
|
Building
images, etc. |
Overhead
building images from multiple angles provide firefighters with critical
entry, exit, building vent points, and building vulnerability points. Computer-aided designs of buildings also
provide firefighters with detailed floor plans and building materials. GIS systems provide fire hydrant locations
and aid firefighters in identifying potential water sources while en-route,
saving valuable time. |
Helicopter
video support |
Video
captured above a major building fire provides incident commanders with an
important perspective on how to extinguish the flames and minimize risks to
firefighters battling the fire. |
Interoperable
video |
Police
officers or other government personnel who arrive at an incident early can
convey critical information back to |
Image
or video distribution |
The
distribution of a picture of a missing child, convenience store robbery
video, or criminal-sketch to all equipped vehicles in the field. High-resolution images can be quickly
disseminated to an entire department with broadband networks. These images provide clearer representations
of their subjects and allow first responders to more accurately identify important
information. Video content might show
a suspect with a telling limp. |
Fingerprint
distribution |
A
suspect’s fingerprint can be transmitted from the field for detailed analysis
in the lab or a fingerprint can be disseminated to the field for remote analysis. |
Field
reporting |
Public
safety personnel can prepare and submit reports in the field that include
voice, images, and video. This can
avoid unnecessary trips back to headquarters or the home office. |
Field
training |
Training
or instructional videos can be viewed in the field to minimize the impact on
command, management, and training resources. |
Management
consultation |
Officers
or |
Remote
Roll Call |
Management
can conduct roll calls remotely keeping public safety personnel in the field
and minimizing out-of-service time. |
CapWIN |
An
interoperable public safety application for the NCR. Provides NCR jurisdictions with the ability
to communicate and access multiple law enforcement databases. |
JUSTIS |
The Criminal
Justice Coordinating Council’s information sharing application. Allows sharing of law-enforcement data
among city and federal agencies. |
|
The Washington Area Law
Enforcement System is a real-time, computer-based, police information system
serving the tri-state area of the District. |
The following timeline represents key milestones in the deployment of WARN:
Date |
Event |
August 03 |
Request for Proposal (RFP) for Pilot Network Released |
December 03 |
Contract Awarded to Motorola |
January 04 |
OCTO Files for Experimental License with the FCC |
February 04 |
FCC Grants License |
July 04 |
OCTO Files for a Revision to Experimental License; Original Network Sites Deployed |
August 04 |
FCC Grants Revised License |
August 04 - December 04 |
System Optimization and Testing of Network |
December 31, 04 |
System Acceptance |
January 05 |
Additional Site Added to Network (near White House); First Official Use of Network - Presidential Inauguration |
April 05 |
Additional Site Added to Network (RFK Stadium) |
January 05 - December 06 |
More than 200 Subscriber Devices Operating on the Network |
WARN network users included a vast group of federal and non-federal government agencies and public safety personnel from in and around the District. Their cooperation on the WARN network demonstrated the abilities of agencies to effectively work together. The following is a list of agencies that were users of WARN:
•
City of Alexandria Police Department
• DC Metropolitan Police Department
• DC Child and Family Services Agency
• DC Office of the Chief Technology Officer
• DC Fire and Emergency Medical Services Department
• DC Department of the Environment
• DC Department of Transportation
• DC Department of Corrections
• DC Department of Health
• DC Emergency Management Agency
• DC Office of the Chief Medical Examiner
• DC Office of Unified Communications
•
•
•
•
US Department of Homeland Security
•
US Federal Protective Service
•
US Park Police
•
US Secret Service
All user agencies were required to execute a MoU with the District’s OCTO (see a sample MoU in Appendix B). This MoU required agencies to abide by the District’s computer use policy, to utilize the network extensively, and to report back to OCTO with information that could lead to future requirements and enhancements.
The construction of WARN and its initial operations were funded through the District’s capital funds. A total of $2.8 million enabled the District to build the initial ten-site network covering its 68 square miles, and provided one year of network operations, as well as 200 subscriber devices. For Fiscal Year 2006, the WPO received additional funding through the DHS State Homeland Security Grants, which covered network and customer operations for the WARN network.
WARN
was cost effective in comparison to the upgrades made to the District’s LMR
system. The District spent $6 million on
its original four-site 800 MHz LMR system, and an additional $17 million to
upgrade it to a ten-site 800 MHz and 450 MHz network. However, the LMR network provides
comprehensive in-building coverage to the 95th percentile versus
outdoor coverage for the broadband network at the 95th percentile.
The OCTO sought technologies that would meet the needs and demands of the District’s public safety personnel and be cost effective. The key qualities in technology that were sought for WARN included:
• High uplink speeds capable of supporting multiple video streams from mobile units to the network;
• Support of Quality of Service (QoS) which efficiently managed network capacity through flexible traffic prioritization administration;
• Same frequency reuse at all sites to facilitate scalability and minimize needed spectrum (i.e., spectrum efficient); and
•
Use of existing LMR infrastructure for cost
effectiveness.
The District selected Motorola to deliver WARN which had partnered
with Flarion Technologies, the maker of Flash-OFDM equipment. The District selected the Motorola/Flarion
solution over Lucent’s 1xEVDO (Evolution Data Optimized) Rev 0 due to the
higher uplink speeds enabling streaming video from the field as well as the
support of QoS controls which enabled improved management of scarce wireless
bandwidth. At the time of vendor
selection, Verizon Wirelss had recently deployed a 1xEVDO Rev 0 system in the
Flarion’s technology, Flash-OFDM, is a wireless data
solution that provides high data rates at very low latency.[26] This feature gave WARN users a wireless
connection that was always on, provided upload and download speeds (peak speeds
of 900 kbps and 3 Mbps respectively) comparable to residential broadband
connections, incurred minimal delays in reception of
streaming media, and performed all of these functions in any location covered
by the network. Since Flash-OFDM was
capable of supporting high data rates, it gave WARN users the ability to send
and receive real-time video applications.[27]
Figure 2 illustrates the Flash-OFDM network architecture. At launch, WARN consisted of ten radio
routers, an Internet Protocol (IP) network interface, and a network operations
center. The architecture is based on the
Mobile IP standard and provides seamless connectivity and a single IP address
throughout the coverage area.[28]
Figure
2: Flash-OFDM Network Architecture
The technology uses a 1.25 MHz channel bandwidth and supports re-using the same frequency at each site and sector via random frequency hopping. Interference occurred only if the power from two sites or sectors was relatively equal and then only part of the time because error correction made up for most of the difference. Though throughput was constrained in this scenario, connections were maintained with this advanced, interference-resistant technology.
Though not part of the solicitation, Motorola offered its Greenhouse video, audio, and dispatch software for WARN operations. This unexpected additional offering proved highly beneficial to the District. The Greenhouse software enabled WARN users to share real-time video and audio information at high video resolutions, with full motion, while using little network capacity. Greenhouse can also make use of inexpensive webcams or high-end professional cameras to share video information.
Network Construction
Three
additional antennas, six transmission lines, and three transceivers[29] were
added to the ten LMR sites to provide citywide service. The resulting configuration provided for
three sectors per site that delivered up to three times the capacity of a
single sector. Additionally,
all the sites were interconnected through the District’s fiber optic network,
DC-NET, to redundant central nodes. These
hub sites included Accounting Authentication and Authorization (AAA) servers as
well as elements that provided mobility management. The hub sites also gave network users access
to the District Wide Area Network (DC-WAN) and
the Internet.
Antennas and cables connecting the radio equipment were installed at each site and then activated. The basic function of each site (radio communication with mobile subscribers and routing of data packets) and the connectivity to the other components of the network were then tested. After testing the functionality of all individual sites, the performance of the entire network was verified during the optimization phase.
WARN’s optimization phase was an
iterative process that consisted of evaluating the performance of the network
by driving around the city and testing network operations, modifying the
configuration of the network, and then re-evaluating the network performance
until optimal performance was achieved. During
this phase, the antenna direction was altered to steer signals to where they
were needed most and away from areas where interference caused poor performance. On
TECHNICAL ASPECTS
Overview
WARN is an “all-IP” network using the ubiquitous IP for all network elements, allowing low-cost network elements with simple interconnections to the Internet. WARN’s base stations are IP routers that support the Flash-OFDM radio interface (radio-routers). Each terminal equipment unit, radio site, and sector was assigned an IP address. As an “all-IP” network, it was very easy to integrate WARN into most existing commercial and private data networks because it operated with IP. In particular, the functions of the network could be realized using equipment already deployed on wired networks.[30]
The network includes 12 transceiver
sites interconnected to two redundant data centers via an independent,
District-operated fiber ring. This
interconnection at the data centers provides WARN users access through the DC
WAN to other District agencies and the Internet, making it possible for
agencies and users to share data and video.
In order for WARN to achieve proficient wide-area communications, application servers were placed inside the WARN network, in the District’s data centers, and in the agencies’ WAN. All application servers had significant interconnection and power redundancy to ensure the QoS offered by WARN. The network was further equipped with security policies, firewalls, and dedicated links that limited the access of specific applications to relevant end-users.
As Figure 3 shows, the configuration of the backhaul connections, the central node switches, and the AAA, are all fully redundant.
Figure 3: WARN
Architecture Overview
The central node switch manages the users’ network mobility. Both the switches and the AAAs are located in two different data centers allowing transition of operations from one data center to the other in the event of a failure. The critical network functions (switching that directs calls to the right recipients, AAA, and Mobility Management that ensures reaching users anywhere within the coverage area) are duplicated in each data center. Because of the ring nature of the fiber network, the backhaul offers no single point of failure.
Ten of the twelve WARN sites were already being used by the District’s public safety, LMR, voice, push-to-talk network. They all offer redundant power supplies (including Uninterruptible Power Supplies (UPS) and diesel generators) and redundant air conditioning (A/C) units. The radio routers also have redundant power units and redundant network interface units.
Two
additional sites were deployed to address coverage and capacity (see the
“Network Performance” Section). Because
of the quick deployment requirements and a limited budget, it was not possible
to offer the same level of reliability for these sites. Although power was secured with a UPS and
battery backup at both sites, it was not possible to procure and install
generators and A/C units.
Also, one of the additional sites
did not have access to the fiber ring. For
this site, backhaul was provided through a non-redundant microwave link that
connected this site to the closest WARN site.
These improvements are planned in 2007, when the District plans to
implement a fully operational (non-pilot) broadband service as part of the
National Capital Region Regional Wireless Broadband Network.
Ultimately, the architecture of WARN was designed to provide the best reliability, functionality, capacity, and spectral efficiency to its users. To achieve this goal, each of the network’s radio sites included a three-sector radio router that allowed for maximum throughput of data (see Figure 4).
Additionally, each sector was connected to a cross-polarized panel antenna, which provided for optimal coverage for data throughput. For the sites located at buildings, the panel antennas were mounted on the side of the penthouse for improved shielding between sectors.[31] The selected configuration included receive-diversity, which was used to improve signal reception and was achieved on WARN by having one transmitter, one amplifier and two receivers for each sector.[32] The combination of these characteristics of WARN’s architecture ensured the consistency of coverage for network users. (Appendix C contains more technical details regarding network architecture.)
In order to transmit and receive
data on the network, WARN users were assigned personal computer (PC) cards or Portable
Access Devices (PADs). Some devices were
assigned to agencies for distribution to users within their agencies as needed,
and others were permanently assigned to individuals. The PADs were typically used in command bus
applications and mobile video surveillance, but they also served as DC-WAN
extensions for remote public safety offices.
These remote extensions offered tremendous flexibility for public safety
operations to be established almost anywhere in the District.
The PC cards and PADs served as
communications modems for host computers – no different than a dial-up modem or
Local Area Network (LAN) card inserted into a computer. Users could easily install PC cards in a slot
in most notebook or laptop computers along with the installation of
corresponding software drivers which provided the communications channel to the
operating system and its applications.
Although non-technical personnel could have performed these
installations and used the WARN PC cards with minimal delay, OCTO installed all
software drivers as an additional level of security and customer service. Likewise, a PAD could be installed very
quickly by connecting the PAD to a host computer via a LAN Ethernet connection or Universal Serial Bus
(USB) cable. Both the PC card and the
PAD allowed the host computer to have access to the DC WAN and the Internet.
The District acquired 200 terminal equipment units for network users. The units consisted of 180 PCMCIA cards (Figure 5) that can be installed on most common notebook or laptop PCs, and 20 PADs (see Figure 6) with Ethernet ports that are compatible with all modern notebook, desktop, or network devices. The transmitted power of the terminal equipment is very low (250 milliwatts).
Figure 5: Flash-OFDM PCMCIA Card
The computer system requirements to support the PC card include:
•
Card Slot: 1 Type II PCMCIA Card Slot
•
Memory: 32 Mb
•
Hard Disk Space: 5 Mb
• I/O Resources: 1 IRQ, 256 bytes I/O Space
•
Processor Speed: 600 MHz
•
Operating System: Windows 2000, XP, Me, Pocket
PC
The cards come with a flexible antenna that bends and rotates to reduce breakage. The antenna is removable and connected by a standard Micro Miniature Coaxial (MMCX) connector. For some vehicular configurations, this antenna was removed and a coaxial cable and an external antenna was attached for superior coverage. With the appropriate drivers (provided by Motorola/Flarion), a new computer system can be configured in minutes to secure a connection to the DC WAN and the Internet.
Figure 6: Portable Access Device (PAD)
The PAD (Figure 6) is a small box (3 3/8" x 5 3/8" x 1.5 ") that includes a card and an antenna, and it has a USB port and an Ethernet port for connecting to computing devices. The first iteration of the devices required the user to depress the power button to turn the unit on. Later releases automatically powered up and proved valuable in the event of a power failure. This feature was very useful in the command bus setting where the unit was immediately available when needed. Upon power up, each device was authenticated by the network. The PAD requires no host computer or software and was directly connected to a router, desktop, or notebook computer that supported a USB or Ethernet connection.
Security was provided for both the PAD and the PCMCIA card. If a device or card was lost or stolen, the device or card could be removed from the AAA database and would not be able to gain access to the network. Users employed additional security measures by controlling access to Mobile Data Terminals (MDT) and by using encryption of transmitted data.
The WARN demonstration was positive
and valuable to the
A main reason for the network’s
success, however, was the added value provided to public safety operations and
the resulting positive reception from the user community, as reflected in
Appendix E. In particular, WARN enhanced
capabilities and interoperability of local and federal public safety agencies
in major planned events such as the Presidential Inauguration, the State of the
Union Addresses, the Fourth of July celebrations, the World Bank and IMF demonstrations,
as well as unplanned emergency events, such as the
Additionally, using WARN stimulated creativity in its users who developed further uses of the network. For instance, two such examples include the U.S. Park Police (USPP) and the District’s Fire Department developed a protocol to share USPP helicopter video over WARN to enhance emergency operations (that will be useful in events such as major fires). Also, the District and neighboring jurisdictions recognized the need for regional interoperable data solutions using broadband. As a consequence, the NCR initiated an exhaustive Regional Data Interoperability Program that includes the deployment of a Regional Wireless Broadband Network (RWBN).
WARN provided average speeds of 1 Mbps downlink (base-to-mobile) and 300 kbps on the uplink (mobile-to-base). It achieved these speeds outdoors with a mobile antenna inside a vehicle. These speeds provided the flexibility needed for delivering essential video streams, high-resolution images, and GIS information. The speeds were fast enough that the multiple streams and data information could be shared at the same incident location. The throughput of data improved as the signal level increased relative to the noise level. Throughput was at its weakest where the signal level was low and the noise level was high. Low throughput areas also included those where the signal was strong from other sites.[33] This performance was similar to in-building coverage of the District’s radio network with only ten sites.[34] Detailed coverage maps and performance information can be found in Appendix D.
The implementation of QoS also efficiently managed the capacity of the network to share bandwidth among simultaneous users. Each user was assigned a profile and depending on the users’ role (e.g., commander vs. officer) and the application used (real time or not), the system was able to prioritize traffic. The data transmission rates were also capped based on user needs.
The coverage of the system was less than expected by the District – especially at the edge of the system and at locations equidistant between sites. With the initial ten sites, the system provided outdoor connectivity (greater than 0 kbps throughput) to 95 percent of the city.[35] The District had expected that the system would provide broadband (a minimum of 300 kbps) coverage over 95 percent of the city. In addition to capacity needs in strategic areas, this coverage deficiency led to adding two sites post network acceptance. Two factors contributed to this situation.
First, Flash-OFDM was not able to accept self-interference (cases in which the signal level of two adjacent sites is roughly equal) and maintain good data rates. In these areas, connectivity and throughput was highly variable. The cell edge is the geographic area located at the border between two sites’ coverage areas. At this location, two signals of comparable strength were received from each site at the same location. Because the system used the same frequency at each site, these sites interfered with each other. When this condition occurred, the throughput of the system was very low and connectivity could have been lost. When compared to LMR, however, the use of the same frequency provided far greater spectral efficiency and scalability. Improvements in the ability to resist interference were needed to take advantage of the efficiency while ensuring reliable service for public safety users.
Second, the Flash-OFDM technology operates at lower power levels and antenna heights than the LMR network. Transmitted power levels of the Flash-OFDM technology were much lower than the LMR system, and radio propagation range is directly linked to how much power is transmitted (the more that is transmitted, the longer the range). Similarly, lower antenna heights lead to more obstacles that reduce signal levels, resulting in reduced transmission site range.
On the terminal side, the PC cards were transmitting a power of only 250 milliwatts, or less than one-tenth of the power of the typical handheld LMR unit operating at three Watts, and less than one-hundredth of the power of a mobile unit operating at 35 Watts. However, this tradeoff enables important capabilities such as the use of PC cards.[36] On the base station side, the WARN transmitters operate at one-fifth of the transmitter power of the LMR system. Even in situations where the content is downloaded from a server, the mobile unit must be able to communicate that messages were received properly. Therefore, this reduction in power from the mobile unit results in a smaller footprint per site.
Transmitting antenna height is also
a factor in radio propagation range. Lower
antennas are more impacted by natural obstacles (e.g., buildings and trees) and
thus have reduced coverage footprints. For
example, the
Two additional transceiver sites were added to address coverage/capacity issues in critical areas of the District after the initial ten-site deployment. The first site, in the vicinity of the White House, provided additional capacity for the White House and its grounds, as well as for part of World Bank neighborhood. The load on this site increased significantly, particularly during major public safety related events. This site was added before the 2005 Presidential Inauguration in anticipation of significant traffic in the vicinity of the White House.
The second site was later added
near Robert F. Kennedy Memorial Stadium (RFK) to alleviate coverage issues
around the stadium and along the
The ease of integrating two new sites demonstrated the scalability of the system. The two new sites used the same frequency as the ten initial sites, and their footprints were contained in the coverage area of the initial system. As a consequence, their integration did not necessitate additional coordination with potential interferers, but it required some limited fine tuning of the parameters of WARN’s configuration.
Due to the existing operations on the network at the time, the District could not perform throughput testing, as it could have disturbed public safety emergency communications. However, measurements of the Signal to Noise Ratio (SNR) allowed the District to estimate that the throughput, at the 95th percentile, was 200 kbps for the 12-site system.
The failure rate of the subscriber devices has been very low since WARN operations began. Of the nearly 200 devices, fewer than five cards or PADs were replaced, and only three antennas required replacement as of August 2006. Thus, the failure rate was less than 2.5 percent in one and a half years (or a 1.6 percent overall annual failure rate).
More
problematic, however, was that the PADs did
not automatically power up when power was
available during initial deployment. In
the case of the command bus implementations, operators were
already overloaded with duties; therefore, an automated solution was required. The District worked with Flarion Technologies
to secure a modification to more than half of the PAD inventory to automatically
power up the PAD when power was supplied to it.
As a result, as soon as the command bus power supplies were on, the PAD
provides the bus LAN with a connection to the DC WAN and Internet.
OCTO also identified a need to provide alternative subscriber device sizes and functions for WARN access. For example, many public safety personnel had notebook computers that were capable of embedded wide-area modems. These internal modems were more rugged and lacked the obtrusive WARN antenna. Additionally, the only PDA solutions that could accommodate a WARN PC card required a heavy and bulky expansion pack and a very limiting battery life. Finally, the District is a significant user of Automatic Vehicle Location (AVL). The systems that support AVL include an integrated Global Positioning System (GPS) receiver with a wireless modem; however, no such product was available for WARN compatible devices.
While supporting local and federal agencies in implementing and operating their communication applications, the program continuously fine-tuned the configuration of the available applications and evaluated alternative and creative solutions with vendors to better meet the needs of public safety first responders.
In particular, streaming video was a crucial application for first responders. Those video applications were particularly challenging in terms of data throughput and network load, and therefore drove the dimensioning of the network and the associated public safety spectrum requirements. The demand to enhance the availability and effectiveness of video applications for WARN users required significant efforts to review and evaluate video applications that were available on the market. Evaluating such applications allowed WARN users and OCTO to work closely with vendors to improve their products to match public safety’s mobile communication needs.
Pilot research results showed that an increasing number of video products were maturing and becoming better positioned for the public safety wireless environment. Bandwidth requirements varied widely with the vendors’ solutions, as did the quality of the video itself. A key criterion for evaluating the application was its flexibility to match the quality of the image (and therefore the required bandwidth) to the specific need of the first responder.
For instance, with the addition of the D.C. Department of Corrections (DC DOC) as a user on the network, KaptureNet was added as a video surveillance application to be used over the network. KaptureNet helps provide incident control during the transportation of inmates. In order to provide incident control, video is recorded and downloaded at a designated site, and it is also accessed wirelessly and instantly when necessary. The unique aspect of this product is that it combines a GPS locator with video to provide accurate geographical surveillance to the DC DOC. As a consequence of adding KaptureNet to WARN, the DC DOC was able to locate their vehicles at all times and could essentially “check-in and look” whenever they wanted to do so. To ensure the effective functioning of the application, the DC DOC and OCTO worked closely with the vendor to optimize their algorithms and ensure that adequate service was provided to the end-user.
The pilot program team also extensively evaluated Motorola’s Greenhouse software, which contains streaming video components. It was used by several agencies including the USPP. The major upgrades made to the software are detailed as follows:
· The first upgrade was the addition of new codecs. Motion Joint Photographic Experts Group (JPEG) and H-264 were added to the existing Motion Picture Experts Group version 4 (MPEG4) codec.[37] This variety of codecs enables users to rank the merits of each and select the most appropriate one for their use.
· Second, users were given the option to select not only the codec to be used, but also the transmitted bandwidth. This option brought some flexibility to the users to transmit at a lower quality level when the network is saturated or the radio conditions are not optimal.
· Third, a new version of the software was deployed that used one uplink stream independent of the quantity of users viewing the video. Previously, multiple viewers of a single video source would require as many uplink streams and thus significant amounts of scarce bandwidth. With the previous version, each user downloading the same streaming video transmission would take up additional bandwidth.
Overall, the pilot fulfilled the original purpose for which it was defined, which was to deploy and demonstrate a broadband public safety network used on the 700 MHz spectrum that emphasized sharing among public, private, and government agencies. There were multiple effective deployments of pubic safety applications over the network and no interference issues were documented from the use of the upper 700 MHz band.
Specifically, in regard to the interference issues, it is important to note that since the WARN network base stations began transmitting, Maryland Public TV station (Channel 62) did not report any interference issues. Likewise, WARN did not experience any interference issues from Channel 62.
The planning, deployment, and operations of WARN provided many useful insights about the effectiveness of the wireless broadband solution for public safety. They also highlighted several areas where improvements were needed. Many of these improvements were identified as a result of major events during the demonstration project.
Use of the network was relatively
consistent over time. WARN was used on a
daily basis with very high traffic volume during major events. Figure 7 illustrates comparatively equal
uploads and downloads and notes the high traffic events. The total monthly traffic averaged almost 25
gigabytes of data from January 2005 through August 2006, amounting to an
average of 130 megabytes per month per user (assuming 190 users).
Figure 7: Monthly Data
Transmission
The WARN network was used to support federal and District first responders and their agency command buses (USPP, Metropolitan Police Department, DC FEMS, and the DC EMA) during several large events in the District. For example, these events included the Fourth of July celebrations, the Million and More March, the World Bank and IMF demonstrations, anti-war protest marches, the Jamaican Festival, at the D.C. Armory for Hurricane Katrina evacuees, and the President’s 2005/2006 State of the Union Addresses.
During
these events, user agencies employed a variety of applications that enabled
them to access remote Computer-Aided Dispatch (CAD) features to track vehicle
fleets (I/Netview), transmit and receive across the city multi-streaming video
links (LiveWave, Greenhouse, TrafficLand, KaptureNet), access and share
critical data with other agencies and/or jurisdictions (CapWIN, JUSTIS, WALES),
and remotely access vital information (Internet and GIS).
The
USPP was a very active user of the system.
For example, WARN was utilized by a patrol officer in
Another
key user of the system was the DC FEMS, which actively used the WARN cards in a
variety of functions, such as transmitting pictures from the Public Information
Officer to media outlets, filing real-time reports in the arson department, and
improving responses to chemical alarms in the hazardous materials department. Additionally, DC FEMS equipped their command
bus with the capability to communicate on the WARN network. DC FEMS used the system on site at such
incidents as the mercury spill at
Since August 2005, the District asked WARN users to complete monthly customer surveys in order to assess the value of WARN and to capture needed improvements.[38] The surveys seek user opinions on coverage, reliability, support, benefits, and satisfaction with all aspects of the WARN network, including available technologies, network coverage, speed of communications, and usefulness. The response rate of these customer surveys is typically 30 percent of all users. The customer surveys allow the WARN team to measure how beneficial the network is to public safety operations as well as to obtain a thorough understanding of future technical requirements or items needing improvement.
Overall,
customer satisfaction with all elements has been very high. Average monthly user ratings are shown in
Figure 8: User Survey Results. The
highest scores were support, benefit, and overall satisfaction, while the
lowest-rated elements were mobile terminal antenna reliability and consistent
coverage. This feedback was consistent
with the findings of the coverage differentials between the District LMR system
and WARN and with the lower throughput noted at cell-edge (see section on
“Network Performance”). High scores on
support were largely due to the attentive WARN customer support team. The small user community enabled this team to
provide more personal customer support and quickly address any problems. In fact, the WARN customer support team spent
considerable time working on issues that were unrelated to WARN network or
subscriber device operations. The team
typically helped customers bring new applications onto WARN and provided
troubleshooting support for these applications.
High benefit and overall satisfaction are testament to the usefulness of
a broadband connection for public safety.
For specific user feedback collected by the District regarding WARN use,
see Appendix E.
The District received the most suggested improvements in the coverage category. As noted in Appendix E, the system provided broadband service in most of the city; however, public safety personnel needed and expected connections anywhere they had the potential to respond. Therefore, broadband connections were needed everywhere. Even with two additional sites and 700 MHz operation/propagation, many points in the District had limited connections.[39]
The lessons learned from the users of the network were among the most significant results of the pilot program. The network was not truly valuable unless beneficial data was shared by the WARN users. As seen in the customer survey reports, the users in the pilot program found the network of significant value to their everyday activities, as well as for large-scale incidents or events.
One
of the most significant lessons learned from the user community was that public
safety was unaware that these types of solutions were possible. Additionally, it was recognized that
technology alone was insufficient for delivering useful solutions to public
safety. Technology must accompany training
and development of solutions that fit the public safety operational model. Once applications and systems met the
operational needs of public safety and the user community was able to fully
understand the benefits of the solution, the full benefit derived from a
broadband network was realized.
Furthermore, the WPO customer operations group was instrumental in
ensuring that the users were able to make complete use of a broadband solution
and were able to support ancillary systems.
Since January 2005, WARN was deployed at a number of events throughout the District. The use of WARN during major events demonstrates that WARN was both a critical and effective network for facilitating communications and data exchange among agencies to promote public safety. Furthermore, major events require special attention: they caused the most significant loads on the network and demonstrated the ultimate capabilities and benefits WARN provided. WARN became a resource that the public safety community relied on to facilitate command decisions from a remote location.
Figure 9: Daily Total
Traffic Transferred
Figure 9 shows the five periods of highest WARN traffic. These periods saw public safety employ significant video applications to augment their operations causing spikes in network traffic. Both federal and District law enforcement use of video surveillance were the dominate drivers for these high-demand days. The five periods were:
·
·
·
·
·
Details of a few planned, major
events in which WARN enabled the transmission of high-speed data from remote
locations follow. These events highlight
significant developments during the implementation of WARN and do not
necessarily reflect the five busiest events as noted above. The first official deployment of WARN was the
Presidential Inauguration in January 2005.
The final event of this demonstration,
The geographic scope of the event included the parade route from around the White House up to the U.S. Capitol and back. The participants included the DC MPD, U.S. Secret Service (USSS), DC EMA, DC FEMS, USPP and WMATA. To coordinate the security of this event, agencies were contacted in advance, but most of the implementation occurred within one week or less.
During
the Inauguration, most users planned to run standard Web-based applications
(e.g., Web-based news) though one agency deployed an uplink video system that
enabled command centers to have a view of streaming mobile video signals. Another agency worked with OCTO WPO to deploy
Motorola’s Greenhouse software in order to provide bi-directional audio and
video with the intention to stream video from a command bus and an additional
cruiser to an
The USSS accounted for more than 60 percent of the total
traffic carried by WARN on that day (five gigabytes of a total of eight
gigabytes). The use of real-time
streaming video accounted for this traffic.
The application used by USSS, LiveWave, uses motion JPEG to transfer
video information. Essentially, this
system transmits compressed snapshots in succession. Unfortunately, the motion JPEG system uses
significant bandwidth to send just several frames per second.[41] The system tries to send as many frames as
possible; therefore, it quickly overloaded the network.
OCTO staff worked with participating agencies to ensure the
applications would function as needed. Multiple
modifications of security systems were required to allow these applications to
function. Significant advanced planning
was necessary to ensure the integrity of the District and federal facilities,
to maintain security, and to provide the needed wireless functions.
The
generated traffic on WARN during this event was in the downtown area of the
District, between the surroundings of the Capitol and the neighborhood of the
White House. Three sectors of the WARN
network covered this area.
Figure 10: Hourly
Traffic of
Figure 10 shows the total loading of several highly-utilized
sectors or cells during Inauguration Day.
The measurement of this load was reported every fifteen minutes. This graph shows that for several hours,
several sectors had a load of nearly 100 percent and therefore experienced
overload conditions at some point during the 15 minute measurement period,
especially on the uplink or upload path (mobile terminal to base station noted
as uplink (UL), i.e., uplink in the figure).
The two cells with the highest load, Cell 1 and Cell 3, served the White
House and the U.S. Capitol, respectively.
Note that traffic was highest at the Capitol during the Inauguration
itself and that loading on the White House site continued through the night due
to ongoing events. Only cells with a
significant load are shown, and therefore, Cell 3, serving the Capitol, never
had an appreciable load on the downlink (DL).
Cell 4 covered part of
The first significant use of WARN demonstrated its importance for public and national security, and it demonstrated that agencies can effectively operate on one network while performing different tasks. This initial large-scale use of WARN proved that advance planning is critical to achieving successful operations. Additionally, it was important to implement QoS so that no one agency acquired all of the available bandwidth. The use of applications that were bandwidth-efficient was a key to achieving successful operations. The implementation of an additional temporary site to support the needs of the USSS demonstrated the scalability and flexibility of the technologies. Finally, the system required much greater testing to ensure that upon failure, the system engaged the secondary components.
WARN was used to support a number of agencies during the Independence Day celebrations on the Mall in 2005, which included activities on the Mall between the National Monument and the U.S. Capitol. Although this event was not considered one of the five busiest events, it highlighted a number of issues/applications of importance. There was significant coordination among OCTO and the users for this event. During this event, WARN mainly supported the USPP, the DC EMA, DC FEMS, and the DC MPD.
At this event, the applications deployed were:
During Independence Day 2005, OCTO personnel were stationed at the USPP command bus to assist in the set up and maintenance of the system. With a combination of four agencies heavily using the network, it was vital to ensure the sharing of resources functioned efficiently. According to verbal feedback from the users, the District realized a savings in time, money, and personnel through the sharing of valuable resources such as video.
Moreover, during this event, the network enabled the deployment and the usage of these applications in a wide geographical area. Support of the applications would have been impossible with the traditional wireless technologies available to public safety, as illustrated in the following testimony from Lt. David Mulholland, USPP:
“The
United States Park Police increased its usage of the WARN network commencing
with the National Fourth of July Celebration on the National Mall. The United States Park Police had currently
used WARN to provide high-speed connectivity to its Mobile Command.
On
the Fourth of July, the United States Park Police also expanded usage of the
WARN network to its stationary operation center, functioning as a Multi-Agency Communications
Center for this activity, allowing connectivity to CapWIN, the United States
Park Police helicopter video downlink (real-time), DC DOT traffic cameras, and
the District JUSTIS network.
Additionally,
the United States Park Police deployed WARN as the primary connectivity medium
for two mobile data computers in patrol vehicles. These patrol vehicles tested the reception of
WARN throughout the western half of the District including the Rock Creek area. The tests were met with very positive results. These MDCs[42] were also used to receive real-time video
imagery from the United States Park Police helicopter. They continue to be used as the primary means
of connectivity for these two patrol vehicles.”[43]
WARN was utilized to support a number of agencies during the events of Independence Day 2006 which included activities on the Mall between the National Monument and the U.S. Capitol. Representatives came from a cross-section of agencies, including state, local, federal and non-federal organizations. The agencies included the National Park Service (NPS), USPP, the Red Cross, Smithsonian Institute, WMATA Transit, WMATA Police, DC DOT, DC FEMS, DC EMA, OCTO, the National Weather Service (NWS), and the DC Public Health Service (DC PHS).
For this event, a significant
alteration to the network occurred on
During the July 4, 2006 celebration, the USPP hosted a Multi-Agency Communication Center (MACC) at their Anacostia facility, during which WARN was used to facilitate the transmission of streaming video from multiple remote locations back to the MACC. The purpose of a MACC is to provide a remote location for all agencies to provide assessments and from which to make command decisions.
The MACC was set up with five large
plasma displays. One was dedicated to
the air traffic control radar, one for the NWS, two for TV stations (CNN/FOX),
and one for WARN and Greenhouse. The NWS
feed and traffic information (via TrafficLand) were delivered over WARN. The equipment used for this event included a
Laptop PC with a WARN PCMCIA card and a WARN PAD connected to a router that
provided Internet access to half of the computers in the MACC.
The DC-FEMS command bus at
When a strong line of thunderstorms
entered the NCR, WARN provided a tremendous benefit via its connection to the
NWS. The joint team at the MACC used the
NWS feed to determine that the storms were quite severe and decided to evacuate
the National Mall and take cover. This
proved to be beneficial, as the large tents blew over and could have caused
injury. All of this was visible to the
emergency personnel at the MACC via several DC DOT,
USPP, and DC FEMS cameras situated on or near the Mall.
The careful planning and continued relationship-building demonstrated through the MACC resulted in a smooth execution of the systems and further demonstrated the benefits of the WARN network across agencies. Additionally, they provided insight to the benefits that can be derived among many agencies – even those without wireless broadband connections. For example, DC DOT was able to receive important weather information and traffic camera information at a joint command post. Ultimately, this last significant deployment showed how improvements to WARN increased user education, and how inter-agency communication created a network that was critical to public safety needs.
FEASIBILITY OF COMMERCIAL SERVICES
The
proliferation and deployment of Commercial Mobile Radio Services (CMRS) now
extends beyond the traditional cellular voice communication to include wide-area,
high-speed data communications. Initially,
data service, such as text, was limited to low-speed Cellular Digital Packet
Data (CDPD) services. However, within
the past few years, the technologies and networks that support far greater
speeds have become available and public safety agencies have adopted these
services. Commercial wireless and broadband
services could offer a potential alternative for private public safety networks
to assist in emergency response and preparedness and to improve or augment
existing infrastructure or capabilities.
However, the public safety community identified wider-bandwidth
applications that CDPD services at the time could not support. Additionally, CDPD
has since been phased out in favor of wider-bandwidth applications and solutions. In response to consumer demand, the CMRS
carriers have deployed broadband services in cities across the
Prior to the development of the WARN pilot, the District
examined the use of commercial networks and services to deliver broadband
applications. In February 2003, the
District informed the FCC of its needs during a presentation to the National
Coordinating Committee. In that
presentation, the District stated that its known broadband applications
required:
During the course of 2003, and up until the Request for Proposal (RFP) was issued in August 2003, the District further refined its requirements to include:
At the time, the fastest data service offered by the commercial providers was 1xRTT which had typical speeds of 80 kbps. In October 2003, Verizon Wireless launched 1xEVDO Revision 0, which, for the first time, provided commercial wireless broadband speeds. In discussions with the commercial carriers at the time, the District found that they could provide:
As a result, based upon the District's articulated requirements as noted in their RFP, and the available commercial offerings as stated, the existing technology of the commercial carriers did not meet the expected needs of the District in late 2003. The District quickly recognized the promise of the technologies utilized by the CMRS. However, the District found that the carrier solutions did not provide the level of network management, control, throughput, coverage, security, and reliability desired. The District had just lived through LMR outages during Hurricane Isabelle when it relied on commercial interconnect services that failed. It now operates on a redundant fiber ring it calls DC-NET. Additionally, the throughput offered by the CMRS community did not satisfy the District’s need for streaming video from the field.[45]
The District also recognized that in many scenarios rugged devices were not essential for data communications. The model for data exchange in the District was a vehicle-based solution that did not typically come into contact with harsh environments. The existing commercial subscriber solutions were largely meeting the needs of the public safety community for data communications. More importantly, at the same time, the LMR devices did not provide the throughput demanded by the District’s emergency response personnel.
The District concluded during its studies that the commercial technologies were viable for public safety data, but the commercial services and networks were not. Essentially, the subscriber and network equipment could be public safety grade, but the network needed to be controlled in order to manage priorities and dedicate bandwidth where needed. It was also necessary to have a solution that was built for an event requiring high-speed, high-volume data exchange, such as the 9/11 Pentagon incident.
The District recognized that its broadband network would be an island of coverage for some time. It further recognized that routers could support switching between its private network and commercial networks. Such routers, however, required a large host incapable of supporting handheld configurations and such a host would cost in excess of $2,000 per vehicle – a direction the District was hoping to avoid. In light of these economic realities, the District was optimistic that Nextel (then independent of Sprint) would select Flarion Technologies’ Flash-OFDM technology for its national broadband network. Later, Sprint would purchase Nextel and abandon the Flash-OFDM technology, thereby making roaming to a nationwide commercial network with the same devices very unlikely.
The District recognized that control of the network and the users would prove to be invaluable. Not only would this control lead to improved uptime of service, but it also allowed for improved distribution of capacity to the needed users as well as enhanced security. Through advanced QoS parameters, the District was able to prioritize traffic and cap the throughput available to users. Considering the disparity of usage, from hundreds of bits per seconds for simple text transmission to hundreds of thousands of bits per second for streaming video, managing priorities and overall QoS is very important for broadband data networks. For its broadband network, the Wireless Program Office was able to pre-plan events with significant video usage and use these control mechanisms to ensure the right information was transferred over WARN in a timely manner. Additionally, since WARN was within the DC WAN, it was protected by the same security measures that protect the servers and desktops within the District.
The District currently uses
commercial data services for its other operational public safety needs. These other commercial services are required,
due to the limited scope of the experimental license, therefore a limited
number of subscriber devices were purchased.
The District uses nearly 1,000 commercial AVL modems for public safety
vehicles and an additional number of handheld data devices. The District sees this as an interim solution
until it can build a permanent network operating on a fully operational FCC
license with widely available subscriber devices. The District recognizes that
the commercial carriers represent communications solutions outside the coverage
area of public safety broadband systems, and that they can serve as a redundant
backup to public safety systems. The
District seeks partnerships with the CMRS community by utilizing the commercial
carrier’s existing operations, thereby allowing the District to satisfy its
needs as economically as possible by reducing deployment and operational costs.
Finally, the WARN, as a pilot, enabled the District and its personnel to fully understand the District’s needs as well as its ability to operate such a network, and to determine the overall benefits. A services-based approach from the commercial carriers was not pursued for WARN for the reasons as noted above. The District examined the use of commercial services to fulfill its broadband needs under this pilot, and the specific conclusions of the District in development of the WARN were based on their own analysis of the service offerings at that time. Nonetheless, the capability of commercial services to provide the network management, control, throughput, coverage, security, reliability and applications remains an open issue for the public safety community as a whole. As the District continues the implementation of the WARN, it should reevaluate the evolving offerings of commercial technology and services and take advantage of those that meet the District's requirements.
To fully evaluate the capabilities of the commercial offerings or the ability of proposed commercial systems to meet public safety broadband requirements necessitates a complete and transparent presentation of those requirements. In response, the commercial providers would need to delineate those requirements they can or cannot meet. Furthermore, in the evaluation of options of government-owned versus commercial services, funding, maintenance, and ongoing transition of technology will need to be considered.
OBSERVATIONS
AND RECOMMENDATIONS
By all accounts, the WARN 700 MHz broadband
pilot met the objectives of testing the operational and cost-effectiveness of
sharing spectrum between federal, state, local, and other private users. Considerable interest by the public safety
community at large, Congress and the FCC has shown that there is a real demand
for broadband services. Based on this
pilot, the following observations were identified and recommendations developed
to demonstrate the feasibility of public safety spectrum sharing initiatives
and broadband solutions.
Benefits
Data applications are becoming more important to support response and recovery efforts. The WARN system provided ample benefits to both federal and non-federal users and demonstrated a successful, cost-effective, spectrum-sharing initiative. Importantly, it used only 2.5 MHz of spectrum, yet delivered tens of Mbps of data throughput, demonstrating efficient use of scarce spectrum resources. It delivered sufficient broadband speeds in most situations, but needed improved coverage to allow public safety to reliably use broadband speeds wherever required. The most beneficial aspect of this demonstration project, however, was in the collaboration between federal and District agencies. Such coordination was only possible because of the significant capacity offered by WARN. Without this capacity, the District would not have been able to accommodate the additional demand of the federal agencies. Ultimately, the project demonstrated not only successful spectrum sharing, but also successful spectrum use. WARN could be a model of the future of public safety communications as a result of its high bandwidth capabilities that supported voice, video, text, images, and a host of other critical public safety applications. Similar broadband technologies also harness the economies of scale of commercial markets, and provide far greater capabilities at ever decreasing costs. As such, projects like WARN demonstrate great promise for addressing the next generation of public safety interoperable communications systems.
The
use of WARN provided significant benefits to federal agencies within their
organizations, including interoperability that might not have been possible if
the agencies had used different networks.
The high degree of collaboration between the USPP and the District
afforded tremendous additional opportunities for interoperability. For example, DC F
The WARN pilot demonstrated a diverse set of broadband applications including helicopter video, traffic management support, bomb squad support, and fingerprint distribution. Users on the WARN system found these applications to be useful, and as they became more accustomed to the network, the demand for new applications continued to grow. The applications provided seamless interoperability among all WARN users.
The
Growing Demand for Public Safety Broadband
Just
as consumers are looking for other mobile services and features, such as data
and video imagery, there is a growing interest in public safety operated
broadband networks across the country to augment their current capabilities. The District and the local governments in the
Metropolitan Washington Area are working to implement such a solution for the NCR
– extending the capabilities of WARN into the urban and suburban areas outside
of the District. This region filed a
waiver from current 700 MHz FCC Rules to allow for a regional, interoperable,
and broadband wireless network.[46] This
regional network, while not an expansion of WARN, will draw significantly on
the lessons learned from the WARN pilot.
The WARN pilot used spectrum in the 700 MHz band that is not currently authorized for broadband use in FCC Part 90 Rules.[47] Hence, the pilot needed an experimental license to transmit with broadband channels. This license is set to expire in mid 2007. Thus, a solution is still needed to enable permanent use of this band for broadband operations. Additionally, this band only allows federal government use as an end user in coordination with a state and/or local partner.[48]
Several spectrum issues become clear as a result of this WARN demonstration project. They include:
· Existing amounts of spectrum bandwidths may be insufficient for meeting the growing mobile, wide-area broadband demands of public safety; and
· The federal government does not have spectrum allocated specifically for dedicated mobile public safety-related broadband applications.
Amount of Spectrum. According to the District’s experiences, it appears the amount of spectrum used by WARN (2.5 MHz) — under the experimental license and within the 700 MHz band — is insufficient for broadband public safety use.
With only 20 users on Inauguration
Day, WARN was overloaded in the downtown area, bringing into question the
adequacy of a single broadband channel for a city the size of the District. Though these users were expected to be
super-users (meaning they should generate much more traffic than the average
user), the capacity of the system to support all public safety use in the
District remains questionable. Over
3,800 District police officers, 1400 Fire and
The use of video presented the most significant demand to WARN. OCTO made changes to user profiles after the 2005 Inauguration to prevent excessive bandwidth use by individual users. These changes could degrade the frame rate to the extent that motion representation becomes inadequate. However, despite these changes, subsequent major events resulted in as much or more use with fewer than 200 users.
Furthermore, emerging applications are likely to become available to public safety in the near future and place significant additional demands on data networks. Few would have predicted the wide-scale use of the Internet today as compared to ten years ago and few can predict the capabilities that may be available to public safety in the next five to ten years. Also, other broadband applications such as three-dimensional GIS and high resolution image sharing were used sparingly over WARN, but interest in these applications is increasing. Likewise, smarter technologies are being developed that deliver better applications in more spectrally efficient ways.
The DTV Act directs the FCC to take
all steps necessary to require, by
Federal Broadband Spectrum. By agreement, some federal agencies were
participating users of WARN, however, they cannot presently be licensed to
operate in the 24 MHz public safety 700 MHz band that is expected to support
broadband.[50]
The federal government does not have spectrum identified specifically for mobile public safety-related broadband applications, whereas non-federal public safety services do at 4.9 GHz and the potential exists for such capabilities in the public safety 700 MHz band. If federal agencies identify a need for broadband access, they have, for example, a number of options in the near future: utilizing commercial services; partnering with state or local governments in building and operating broadband private networks; or identifying spectrum for broadband use within the current federally-allocated bands based on specifically identified requirements.
For example, satellite services may be a solution only for command vehicles and other specialized units due to the cost and size of Very Small Aperture Terminals (VSAT) applications with large bandwidth. Satellite services are also frequently unavailable in urban or natural canyons or inside buildings. For reasons mentioned previously, federal agencies should appropriately consider the use of satellite and other commercial services based upon such issues as reliability, coverage, security, and network management.
If spectrum were to be identified for federal broadband use from the federally-allocated bands, it should be near or co-located with state, local, and tribal spectrum so as to easily tie the networks operationally together and build a greater, national, economy-of-scale network that would foster interoperability. Furthermore, the band should contain enough spectrum to accommodate broadband channel widths.
Achieving adequate broadband
coverage is perhaps the biggest challenge to implementing WARN, as indicated by
the need to add two sites to the WARN system.
The inherent lower power of broadband technologies delivered significant
advantages, such as smaller base station equipment and handheld devices, but it
also resulted in less in-building coverage when compared to LMR. Adding sites was an excellent solution to the
coverage dilemma, but they were costly to implement and operate. The challenge is now to match broadband
coverage to LMR coverage, allowing public safety to better leverage existing
infrastructure, saving capital and operating dollars. The District expects that technologies are on
the horizon that can help make up for broadband coverage deficiencies in the
long-term, providing excellent coverage even in the dense granite structures of
downtown
Devices
Additional types of subscriber
devices would help meet public safety needs.
Rugged computing devices are sufficient, and the PC cards have proven to
be sufficiently rugged, with the exception of the antenna. The PC cards and PADs have a small paddle
antenna that can pop off, break, or become an obstruction to the user. Additionally, the cards are custom-made at a
cost of $600 each and they do not allow
roaming on commercial networks. Although
antenna reliability issues were not prevalent in user feedback, using
integrated or fixed antenna technology in the next generation of laptops is a
viable solution to this issue.
Technologies that can support all user needs would be ideal. For example, OCTO could not satisfy requests to provide WARN connections for PDA devices without significant sacrifices of battery power and usefulness of the device due to bulk. Therefore, users requiring a handheld device with WARN access could not be supported. Furthermore, integrated modems with AVL were also not available and could not be supported. With commercial technologies, however, WARN users would have had the opportunity to acquire the necessary solutions and more. For example, voice and data integrated devices in a phone format allow users to read email, use Web sites, and access other information. These features may be attractive for some users who desire limited capabilities in a small, handheld form. Additionally, some commercial handheld devices are built to withstand shock and moisture. This selection of devices would have enabled OCTO to better meet the needs of its user community. Ultimately, the commercial technologies would offer more choices for public safety and address a wider variety of needs.
The initial data collected from the WARN pilot program suggested that a strategy was needed to deal with the long-term trends in technology for wider channels, more data, and higher data throughput. Based on verbal feedback from the user community to the District, it is believed that more data will be required over time (video, biometrics, imagery), requiring an increase in bits per second (bps) throughput to handle the demand. This increase will demand reliable broadband solutions for the entire public safety user community. Leveraging innovation and competition in commercial markets, while providing sufficient economy of scale for customization for public safety, appears critical for maintaining the needed capacity to address these demands. Planning is critical to ensure that a blueprint for regional or national wireless broadband solutions is available when the user community needs them.
The recommendations that stem from this demonstration project include guidance for technological improvements as well as additional short and long-term planning and sharing required among and between government agencies for broadband services.
Agencies that have the need for
broadband applications should identify their requirements in their strategic spectrum
plans submitted to NTIA. State and local
public safety entities should similarly plan and identify their broadband
requirements.[51] Without identifying the requirements, a
viable spectrum plan cannot be developed.
In order to provide a comprehensive view on what spectrum and technical
solutions may satisfy agency requirements, agencies should consider the
following in their spectrum needs planning:
•
Throughput and tolerance: The
throughput of the applications and application tolerance of deviation (e.g.,
streaming media versus transmission of file) that are or will become mission
critical.
•
Latency: The latency
tolerance of the applications, i.e., does the
application need to hear back within a short time frame or will excess latency
cause some degraded quality of service?
•
Device requirements (e.g., small PDA,
embedded in notebook, PC card): Some critical differentiators
include requirements for lightweight, handheld solutions. This will become a driving factor on the
coverage footprint, size of the device, battery life, and the usefulness that
the public has become accustomed to with today’s commercial devices. If this is not a factor, many more options
open up.
•
Coverage requirements and spectrum options: If the public safety mission for
broadband includes areas within foliage, inside buildings, and in urban or
natural canyons, then satellite communications become difficult. On the other hand, building broadband
networks in remote areas is expensive. At
the other extreme, on-scene communications solutions at unlicensed or 4.9 GHz
may provide the needed capacity if the coverage expectations can be met. These may be the main differentiating factors
as to what frequency and architecture are needed to address the requirement.
•
Required scalability: Agencies
will need to estimate demand over time to ensure growing user communities and
usage will be accommodated. Projections
for the growth in data needs are critical in understanding the needed pace for
technological advancements of any data solution. Other solutions, such as cell splitting, may
be an alternative solution to address capacity, especially for same-frequency-reuse
technologies. However, it is critical to
understand the demand curve for individual applications and users, and in
aggregate, to ensure the spectrum and infrastructure solutions can stay ahead
of the curve.
•
Required reliability of the solution: It
is vital to consider the degree to which the data solutions are mission
critical and their impact if lost. Important factors for reliability include the
power, backhaul, and other redundant components. Additionally, the type of priority access may
become an important consideration.
•
Commercial services: Agencies
may consider the trade-offs of using commercial services and networks instead
of private networks in satisfying the identified broadband requirements.
Some may debate the need of public safety broadband capacity. Others may also question the need for public safety operated networks. In any case, these are important issues that will require years of planning to achieve regional or nationwide solutions. In the event that private broadband networks are needed in the coming years, planning must begin to address the need. Regardless of method, public safety must share spectrum at some level in order to accommodate its broadband needs – either with the public or with other public safety agencies or governments. WARN demonstrated the feasibility of spectrum sharing among governments, but considerable efforts are required to make such a solution permanent.
Additionally, it is impractical for individual jurisdictions to go it alone. Both high deployment and operational costs will result. The more entities that work together to deploy similar solutions, the more built-in interoperability will inherently exist. Additionally, regional efforts can share significant costs in the build-out and operations phase. Regional deployments and systems could also reduce the complexity of roaming arrangements.
Partnerships between federal
agencies, regions, states, and their local jurisdictions are an important
component of an effective public safety broadband solution. Partnerships among federal, state and local
public safety entities, as demonstrated by WARN, have shown to improve
coordination and interoperability between federal and non-federal agencies. Interoperability is needed at the borders
between states and regions, and therefore, a more global approach to spectrum
and technology use is required to address these areas. It is also impractical to set up agreements among
every local or county jurisdiction in the nation. State, regional, and national
partnerships are more appropriate.
The lessons learned from the District are to choose standard solutions that are also affordable due to mass commercialization. The WARN pilot provided for lower-cost network and subscriber devices when compared to LMR systems, but subscriber devices were considerably more expensive than commercial cellular devices. Further, the subscriber device options in the commercial markets provide tremendous choices that will benefit public safety as compared to the limited choices offered to WARN users.
These same commercial technologies decrease year-by-year in cost versus an increase in the LMR marketplace. Therefore, over time, the cost disparity between commercial broadband and other solutions will grow even larger. Public safety should leverage commercial wide-area solutions in order to continue to harness the economies of scale. If demand is as significant as presented by WARN, it may also be important to tap the research and development efforts and solutions that deliver exponential growth in capacity and features of the commercial markets.
Additionally, these solutions may inherently deliver built-in roaming solutions. As a result of mass-scale standard technology use, vendors will find it easier to deliver solutions that can support the frequencies of public safety and commercial markets. This will enable roaming on to commercial networks from private public safety networks using inexpensive subscriber devices.
The benefits of the use of standard solutions can also facilitate national interoperability. Such mass-scale solutions are already delivering national commercial networks and can be adopted to address seamless interoperability among private networks. If state and local public safety entities deploy different broadband solutions across the country, then it is likely that federal agencies would have to buy multiple devices (and routers to support seamless operations) to have coverage on each operating network. Whether the federal solution becomes a private one hosted by regional state and local public safety agencies, or a federally-owned network, the devices that are purchased should be compatible with existing nationwide commercial networks. Initially, any private solution will provide an island of coverage. Compatibility with commercial services could then also deliver more cost-effective national solutions to accommodate federal and regional needs through economies of scale.
A significant limitation for deploying this type of broadband solution is the reduction in coverage compared to a LMR system operating on the same frequency band. Agencies will desire network capacity and the ability to support more broadband applications. However, their ability to deploy more sites to address the limited coverage in comparison to 700 MHz or 800 MHz LMR deployments could be problematic. In order for broadband solutions to become viable, they may need to deliver coverage on par with LMR networks. This would allow public safety to fully leverage existing assets such as sites, generators, and backhaul.
Several technologies are on the horizon that could potentially improve coverage and investments in infrastructure, and subscriber devices are needed to bring these technologies to the marketplace. Smart antennas, for one, focus signals where needed and away from areas where they would cause interference. Other techniques such as transmit diversity, whereby the same signal is transmitted from two antennas and at two different points in time, may also deliver improvements in range. More mobile power may also deliver additional range, but at the expense of reduced portability.
A focused effort around broadband solutions will help to energize a public safety broadband marketplace and result in a lower cost, yet customized solution for agencies nationwide.
As discussed previously, it was the District’s decision not to use commercial services for a broadband network because user requirements (reliability, coverage, security, and network management) could not be met. However, in some areas, commercial services may be the only solution in the near term for affordable broadband services. Should commercial services be used, public safety agencies will need to deal with issues like coverage, priority service, redundancy, reliability, and other features (e.g., streaming video, access to GPS information, etc) to ensure that they can perform their missions. Public safety agencies are encouraged to appropriately use commercial services for broadband applications should their requirements dictate.
SUMMARY
WARN demonstrated a critical value in supporting federal and non-federal agencies as they work towards a spectrum sharing solution to meet the increasing complexity of public safety’s wireless broadband communication needs in the coming decades. In these times of heightened awareness and security, public safety agencies are asked to provide more effective vigilance, response, and recovery efforts for its citizens. The WARN pilot demonstrated a new way to approach this demand.
Specifically based upon this pilot, the following observations and recommendations were identified:
Observations |
Recommendations |
Spectrum
Planning |
|
· WARN illustrated a growing need for broadband capabilities within the District. |
|
Spectrum
Use |
|
|
|
Spectrum
Sharing |
|
|
|
Feasibility
of Commercial Services |
|
· The District analyzed the use of commercial services and determined that commercial networks did not meet the requirements of WARN. However, they are available and may be appropriate for non-mission-critical uses if reliability, throughput, coverage, security, and network management issues are addressed. |
· Public safety agencies should use commercial broadband services, where appropriate, if they can satisfy their broadband requirements. |
This
page intentionally blank
APPENDIX A
1xRTT |
A version of CDMA2000 that utilizes a pair of 1.25 MHz
radio channels. 1xRTT (Radio
Transmission Technology) offers high-speed data services and voice capability
and is more efficient due to its use of a pilot signal and more channels
between fixed stations and mobile users.
|
4.9 GHz |
The frequency band 4940-4990 MHz designated by the FCC for
fixed and mobile wireless services and for use in support of public safety. The allocation of this band for public
safety provided public safety users with additional spectrum to support new
broadband applications. |
700 MHz |
The frequency band 764-776 and 794-806 MHz designated by
the FCC for general use and interoperability narrowband channels, narrowband low power channels and wideband general use channels for
public safety. |
800 MHz |
The frequency band designated by the FCC for public safety
use in the 806-869 MHz range. This band is currently in a re-banding process
to alleviate the commercial/public safety interference issues. |
ALMRS |
Alaska Land Mobile Radio System is the shared and
interoperable statewide public safety telecommunications system used by state,
local and federal first responders and public safety agencies in |
AVL |
Automatic Vehicle Location is a technology that monitors
vehicles in real-time and conveys navigational or operational data to the
driver or monitoring center. |
CDMA |
Code-Division Multiple Access is a technology for digital
transmissions of radio signals between a wireless device and a radio base
station. |
DC F |
District Fire Emergency Medical Services is the agency that provides emergency support services in the District. |
DCWAN-VLAN |
District Wide Area Network-Virtual Local Area Network is
the telecommunications network providing coverage to the government agencies
in the District. |
DHS |
U.S. Department of Homeland Security develops and coordinates a comprehensive
national strategy to strengthen and protect against terrorist threats or
attacks in the |
“Direct” Communications |
Short-range, line-of-sight communications directly from
one radio to another without benefit of a repeater to extend the range of the
transmitted communication. |
Downlink |
The downlink (otherwise known as forward or download) path
is the path from the base station to the wireless subscriber device (e.g., computer
modem). |
EVDO |
Evolution Data Optimized, EVDO is a standard for broadband
wireless technology. Initially
developed by Qualcomm, EVDO operates on a CDMA signal with a higher data rate
capability that 1xRTT. It has been
adopted by many CDMA mobile phone service providers as an “always-on” on
wireless connections, similar to DSL. |
FCC |
The Federal Communications Commission was established to
regulate all non-federal government use of radio spectrum, interstate
communications, and international communications that begin or end in the |
IPSec |
Internet Protocol Security is a framework of standards for secure communications over the Internet. |
IT |
Information Technology is the branch of engineering that deals with the use of computers and telecommunications to gather, store, and transmit information. |
LMR |
Land Mobile Radio is a mobile service between fixed base stations and stations capable of surface movement within geographical limits. |
MACC |
A |
MHz |
Megahertz is a unit of frequency equal to one million
cycles per second. |
MoA |
A Memorandum of Agreement sets forth basic principles and
guidelines under which two parties will work together on a given issue or to
meet common needs/goals. |
MoU |
A Memorandum of Understanding sets forth basic principles
and guidelines under which two parties will work together on a given issue or
to meet common needs/goals. |
NCR |
National Capital Region is the geographical area in which
WARN is deployed, covered the |
NTIA |
National Telecommunications and Information Administration
is responsible for telecommunications and information policy in the |
OCTO |
The Office of the Chief Technology Officer. The District’s Agency responsible for the
development, operations and maintenance of the technology infrastructure. |
OSM |
Office of Spectrum Management is responsible for managing
the federal government’s utilization of the radio frequency spectrum and
establishing policy and plans for spectrum regulation. |
PAD |
A Portable Access Device is a mobile data access unit. |
PCMCIA |
Personal Computer Memory Card International Association is a non-profit trade association and standards body consisting of around 500 companies that has developed a standard for small, credit card-sized devices, called PC cards, that are used in notebook computers. |
PCMIA |
A Personal Computer Manufacturer Interface Adapter (PC card) is used to connect a mobile phone to a laptop enabling the user to expand communication abilities while on the move. When a user is connected via the PCMIA he or she can send and receive data and access the Internet. |
PDA |
Personal Digital Assistants are handheld devices, originally used for personal organizers, but are now are used for transmitting data, video and audio recording, accessing the Internet, among other high technology functions. |
SAFECOM |
SAFECOM Program is the communications program of the DHS
providing research, testing, and evaluation to better address the needs of
emergency responders. |
Repeater |
A repeater is a high powered radio generally co-located
with a tower to amplify and extend the geographic coverage area of portable
and mobile radios. |
RWBN |
Regional Wireless Broadband Network is a mobile
communications system created to transmit broadband wireless voice and data communications
in a specified geographic region. |
“Talk-around” Communications |
Short-range (a few miles or less), communications directly
from one radio to another without the benefit of a repeater to extend the
range of the transmitted communication.
Generally limited to a few miles of effective coverage. |
Transceiver |
A transceiver is a device that contains a combined
transmitter and receiver. |
Uplink |
The uplink is the path from the subscriber device to the
base station or other system wireless access point and is also known as the
reverse path or reverse link |
USPP |
The United States Park Police is the security police force
jurisdiction in all National Park Service areas and other government lands. It is the oldest uniformed federal law
enforcement agency in the |
USSS |
United States Secret Service is responsible for protecting
our nation’s leaders, visiting world leaders, and special national security
events. |
VSATs |
Very Small Aperture Terminal is a 2-way satellite ground
station with a dish antenna that is smaller than 3 meters that serves home
and business users and handles data, voice, and video signals. |
WARN |
The Wireless Accelerated Responder Network was the pilot
network in the District providing wireless broadband speeds to law enforcement
and fire personnel while deployed in the field. |
Wireless Broadband |
A technology aimed at providing wireless access to data
networks, with high data rates. In the
public safety sector, wireless broadband applications, such as high-speed
digital technologies and wireless local area networks (LANs) have been
utilized for incident management and dispatch and public safety vehicle
operations. |
WLG |
Working Level Groups established by NTIA to assist in the
implementation of the recommendation of the President's Spectrum Reform
Initiative. |
WMATA |
Washington Metropolitan Area Transit Authority is a non-federal
tri-jurisdictional agency authorized by Congress and funded by the District, |
WMO |
Wireless Management Office is a division of the DHS that ensures the wireless needs of the Department are met. |
SAMPLE MEMORANDUM
OF UNDERSTANDING (MoU)
MEMORANDUM OF UNDERSTANDING
BETWEEN THE
OFFICE OF THE CHIEF TECHNOLOGY OFFICER,
[GOVERNMENT OF THE
AND Agency/Department
I. INTRODUCTION
This
Memorandum of Understanding (“MOU”) is made this ______ day of ___________
2005, by and between the Government of the District of Columbia Office of the
Chief Technology Officer (“OCTO”) and the (Agency/Department), (“XXX”)
concerning providing XXX access to the Pilot Wireless Broadband Network
operated by OCTO, otherwise called the Wireless Accelerated Responder Network
(WARN).
WHEREAS, OCTO will provide access, usage and support of the WARN network, and
WHEREAS, OCTO has identified the objectives of the WARN network during this pilot program as to:
WHEREAS, XXX desires to access and test the WARN network for XXX operations, and
WHEREAS, both parties desire to expedite connection of XXX to the WARN network,
NOW THEREFORE, the parties agree to enter into this MOU to provide XXX access to use and test the pilot WARN network.
II. OBLIGATIONS OF OCTO
OCTO will:
III. OBLIGATIONS OF XXX
XXX will:
IV. USAGE
XXX
warrants that each network device, i.e. PC
card and/or PAD, issued to it by OCTO will be used as much as operationally
required by XXX to provide feedback on network effectiveness to OCTO for the
purposes of the pilot network evaluation.
V. DISCLAIMERS AND
RESERVATIONS
VI. FEES
1. Fees OCTO incurred
significant cost to develop the WARN network and reserves the right to charge
XXX fees for its use of the network, subject to the waiver provided in Section
V.2. OCTO will charge no fees until the
amount of the fees has been determined by agreement of the parties and set
forth in an amendment to this MOU. If
XXX does not agree to pay fees that are reasonable in the judgment of OCTO,
OCTO may choose to terminate this agreement upon seven (7) days’ written notice.
2. Initial waiver
OCTO will waive all fees during the initial
term, until
VII. EFFECTIVE DATE
This agreement is effective on the date of the last signature.
VIII. TERM
The Term of this Memorandum of
Understanding shall be until
IX. MODIFICATION
This agreement may be modified at any time by agreement of the parties.
X. TERMINATION
This agreement may be terminated by either party upon 30 days’ written notice. Notice will be sent to the administrative point of contact.
XI. SIGNATORIES
XXX Agency/Department |
Office of the Chief Technology Officer |
By:
_____________________________ |
By: _____________________________ |
Name: |
Name: Suzanne Peck |
Title:
____________________________ |
Title: Chief Technology Officer |
Date: ____________________________ |
Date: __________________________ |
Exhibit A – Service Level Agreement
SECTION |
SERVICE |
SERVICE LEVELS |
||
1.0 |
Telephone Service |
|
||
|
Hours
of Operation |
24 hours a day; 7 days a week |
||
Time
to Answer |
<
30 seconds |
|||
2.0 |
Response Time |
|
||
|
Response
Time to E-Mail |
The
Help Desk will respond within four hours via email response unless additional
details are required. Then, Help Desk
will contact the customer via phone. |
||
Response
Time (onsite) to Hardware
|
The
Help Desk will dispatch a resource to respond onsite by Next Business Day. |
|||
3.0 |
Help Desk Technical
Support |
|
||
|
Telephone First
Call Resolution Rate |
75% |
Definition – The percentage of calls
that are resolved on the first contact; that is, while the user is still on
the phone. |
|
Telephone Extended
Call Resolution Rate |
90% |
Definition – The percentage of calls
that are resolved within the first 72 hours after the call is logged. The extended call resolution rate is an
extension to the First Call Resolution. |
||
Priority |
Priority |
Definition |
||
High |
Network
connectivity down; system failure; |
|||
Standard |
Routine
problems; minimal impact on job functions; application usage; “how-to”
assistance |
|||
Telephone Resolution
Times |
Priority |
Ticket Type |
Resolution Time* |
|
All |
GDC – OCTO Software –
First Call |
First Call |
||
All |
GDC – OCTO Software –
Extended Call |
72 hours |
||
Priority |
Ticket Types |
Resolution Time* |
||
Standard |
Network Access |
Next Business Day |
||
All |
GDC – OCTO Hardware |
Next Business Day |
||
*
Resolution time is defined as the period of time between the initial ticket
creation (open date/time) and documented problem resolution (closed date). |
Exhibit B – Hardware
and Software
OCTO will provide, manage, and support the following hardware and software. Any hardware and/or software not listed below but is used on the WARN network is the sole responsibility of XXX for maintenance, support and/or replacement.
Hardware
ID |
Type |
Quantity |
1. |
Flarion PC card Network Device |
10 |
2.
|
Network Device Antenna Connector |
10 |
Software
ID |
Type |
License Quantity |
1.
|
Flarion Installation Drivers |
10 |
Exhibit C – Software Application Implementation
OCTO will work with XXX and document the requirements needed to ensure accessibility to the required applications that will be used over the WARN network. A new application will not be deployed if it degrades network performance. The requirement gathering will determine the necessary ports that need to be opened, the expected throughput needed, the configuration of the device, and what security measures are implemented.
It will be required by this MOU that XXX work with OCTO Security to implement new software applications. The WARN network is protected by several firewalls which block all ports except for the ports needed for existing applications or ports requested specifically by XXX and approved by OCTO Security. OCTO reserves the right to prevent the deployment of any application that may be deemed as a security risk and/or may degrade network performance.
Exhibit D – Server
Hardening Policy
Servers are depended upon to deliver data in a secure, reliable fashion. There must be assurance that data integrity, confidentiality and availability will be maintained. One of the required steps to attain this assurance is to ensure that the servers are installed and maintained in a manner that prevents unauthorized access, unauthorized use, and disruptions in service. The purpose of the Server Hardening Policy is to describe the requirements for installing a new server in a secure fashion and maintaining the security integrity of the server and application software.
Policy
·
A
server must not be connected to the WARN network until it is in an accredited
secure state and the network connection is approved by OCTO.
·
The
Server Hardening Procedure provides the detailed information required to harden
a server and must be implemented for OCTO’s accreditation. Some of the general steps included in the
Server Hardening Procedure include:
o Installing the operating system
from an OCTO approved source
o Applying vendor supplied patches
o Removing unnecessary software,
system services, and drivers
o Setting security parameters, file
protections and enabling audit logging
o Disabling or changing the password
of default accounts
·
OCTO
will monitor security issues, both internal to OCTO and externally, and will
manage the release of security patches on behalf of XXX.
·
OCTO
will test security patches against OCTO core resources before release where
practical.
·
OCTO
may make hardware resources available for testing security patches in the case
of special applications.
·
Security
patches must be implemented within the specified timeframe of notification from
OCTO.
This page intentionally blank
APPENDIX C
This
Appendix provides high-level, technical details on the aspects of WARN’s
architecture for those that are interested.
CONFIGURATION
The Radio Access Router on the network was based on a Compact Peripheral Component Interconnect (cPCI) standard compliant chassis platform comprised of a number of hardware and software elements. The Access Router included the Baseband Unit (BBU), which performed the Flash-OFDM waveform processing, the RF system consisting of a Receiver Unit (RXU) and Transmit Unit (TXU) pair, the Master Control Unit (MCU), the Backhaul Unit (BHU), Power Conditioning Unit (PCU), and the Alarm Interface Unit (AIU). The Radio Access Router provided network access control, authentication, routing and mobility management functions, as well as backhaul connectivity interconnecting the Access Router with the rest of the Flash-OFDM system. Configuration options of a radio router are shown in Figure 11:
Subsystem Non Redundant Configuration |
One Carrier Omni |
One Carrier Simulcast |
One Carrier 3 Sectors |
Tx Diversity |
BBU Rev 1 |
1 |
1 |
3 |
1 to 3 |
RFU Rev 1 |
1 |
1 |
3 |
1 to 3 |
MCU |
1 |
1 |
1 |
1 |
Quad T1/E1 |
1 |
1 |
1 |
1 |
AIU |
1 |
1 |
1 |
1 |
cPCI Chassis |
1 |
1 |
1 |
1 |
20 Watt PA |
1 |
1 |
3 |
3 to 6 |
LNA/Duplexer Filter |
1 |
1 |
3 |
3 |
LNA/Rx Filter |
1 |
1 |
3 |
3 |
Combiner/Splitter |
|
1 |
|
|
Figure 11: Section 6 RR Configurations
The Radio Router base station fits in a standard 19” rack for indoor applications and a two-bay cabinet for outdoor applications. The MCU and the BHU are rated for an extended temperature range (up to 65ºC), but are otherwise standard off-the-shelf cards. The BBU, TXU and RXU are proprietary custom circuit cards that generate and receive the Flash-OFDM waveform. The PCU was very similar to standard 24VDC cPCI power supply but outputs a non-standard 5.8VDC that was used by the BBU, TXU and RXUs. The AIU was also a circuit card that was custom developed by Flarion. It provided the alarm collection function for the base station. It also had a role in redundancy swap over of the MCU and BBUs. Some of the cards in the Access Router had options for redundancy and failover as Figure 12 shows.
Off-the-Shelf Cards |
Redundancy |
2 MCUs |
2N |
2 BHUs |
2N |
2 PCUs |
2N |
Custom Cards |
|
4 BBUs |
N+1 |
3 TXUs |
None |
3 RXUs |
None |
2 AIUs |
2N |
Figure
12: Access Router Cards
BBU
Description-Air Interface
The BBU was the baseband modem processor for a sector of the radio router base station (i.e., the air interface). It provided the link layer interface between the MCU (router) running IP protocols and the RF cards (RXU and TXU), which required analog baseband Flash-OFDM signals. Link, MAC, and physical (PHY) layer processing functions for the station are performed by the BBU. The telemetry and control functions for the RF cards were also performed by the BBU. The card’s main components were two FPGAs, a DSP, a Power PC (PPC), PCI interface chip, and DAC and ADC.
The radio router supports N+1 BBU redundancy as an optional feature. In a radio router so equipped, the failure of a BBU would automatically be detected and the failover process initiated, where the redundant BBU would be electronically switched into that sector. Operation would then resume, although all active sessions would experience an interruption to service. The backup BBU could have been switched into any of the three sectors.
The router functions of the access router were implemented in the MCU board. The MCU was a Pentium III-based single board computer (SBC) in a 6U cPCI standard format. The unit was procured as a standard off-the-shelf computer with the main characteristics as follows:[52]
RF SUBSYSTEM DESCRIPTION
The RF part
of the Flarion base station was defined as all the hardware between the digital
section of the BBU and the antennas on the other end. Physically, all the hardware except for
antennas and antenna cables resided in one 19” cabinet together with all other
components of the radio router. The
cabinet accommodated all the hardware needed for up to a 3-sector base station
with receive and transmit diversity.
The major components of the RF subsystems were (see Figure 13):
6. Antennas
Figure
13: RF Subsystem High Level Block Diagram
A/D and D/A sections were located on a BBU cPCI card together with all the physical layer digital circuitry. They convert signals from/to digital and analog formats. There were two identical A/D and D/A sections (main and diversity) per BBU per antenna sector.
TXU and
RXU
TXU and RXU
are cPCI circuit cards that plugged into the cPCI backplane together with all
other base station circuit cards. They
provided up and down frequency conversion and filtering of the analog signals. TXU and RXU interface with BBUs on one end
and with LNA/Duplexers and power amplifiers on the other end. There was one TXU and one RXU per sector, and
up to three of each could have been accommodated in a cPCI chassis. Each TXU and RXU had two identical signal
paths for diversity. The units contained
self-diagnostic capabilities and switch matrices to allow switchover to a
redundant BBU in case of a BBU failure
LNA/Duplexer
LNA/Duplexer was comprised of a depleting filter followed by a low noise amplifier. The duplexer was composed of two frequency filters joined together at a common port that connects to antenna cable. The transmitter filter provided frequency filtering of a signal from a Power Amplifier (PA) before it reached the antenna, and the receiver filter does the same between the antenna and the Low Noise Amplifier (LNA). The LNA was built into the same assembly as the duplexer, while the PA connected to the duplexer through cable. There was one LNA/Duplexer per antenna, so two were needed if diversity was used. However, since transmitter diversity was optional, the second assembly could only have a receiver filter instead of a full duplexer. Up to six LNA/Duplexers could have been accommodated in a cabinet for a 3-sector system with diversity.
Power Amplifier
The PA provided the final high power amplification for the transmitter. The standard PA was rated for 43 dBm (20 Watt) output, which provides approximately 41.3 dBm at the antenna connector after internal losses are accounted for. The radio router used PAs commonly used for existing cellular/PCS CDMA systems.
The PA interface to TXU at the input and to the transmitter port of LNA/Duplexer at the output. PA linearity, together with the transmit part of a duplexing filter and any optional filtering, further determined out-of-band emissions of the system. The PA also included forward/reflected power detectors and other alarm and diagnostic monitors.
RF Operating Characteristics
Operating characteristics include the following:
Signal Format:
MHz Frequency Division Duplex (FDD) (duplex separation is band dependent)
QPSK Transmit; QPSK, 16QAM Receive
Frequencies Supported:
1. 700 MHz: 30 MHz
duplex separation
Receive: 777 MHz to 792 MHz
Transmit: 747 MHz to 762 MHz
2. SMR: 45 MHz duplex separation
Receive: 806 MHz to 821 MHz
Transmit: 851 MHz to 866 MHz
3. 800 MHz Cellular: 45 MHz duplex separation
Receive: 824 MHz to 849 MHz
Transmit: 869 MHz to 894 MHz
4. 1900 MHz PCS: 80 MHz duplex separation
Receive: 1850 MHz to 1910 MHz
Transmit: 1930 MHz to 1990 MHz
5. 2100 MHz UMTS: 190 MHz duplex separation
Receive: 1920 MHz to 1980 MHz
Transmit: 2110 MHz to 2170 MHz
6. 2300 MHz Korean: 70 MHz duplex separation
Receive: 2300 MHz to 2330 MHz
Transmit: 2370 MHz to 2400 MHz
Performance:
The Back
Haul Unit (BHU) featured 4 fully independent line protected T1/E1 Channel
Service Unit/Data Service Unit (CSU/DSU) channels. Each channel supported full, fractional and
56K mode T1/E1 protocols. T1 speeds up
to 1.544 Mbps and E1 speeds up to 2.048 Mbps are supported. The
unit was procured as a standard off-the-shelf TI card with the following
characteristics:
The four supported T1s on two BHUs provided a maximum of eight T1/E1 connections for the Radio Router base station. Any four of the eight T1/E1s could have been active at one time.
Power Control Unit Description
The Power
Control Unit (PCU) was a DC/DC converter that provided power to the cards in
the Access Router shelf. The PCU
accepted an input of 21VDC to 28VDC, and output five voltages: +5.0V, +5.75V, +3.3V, +12V and –12V. Since a standard cPCI supply does not have a
+5.75V output, a custom supply was required in the Access Router shelf. The analog circuitry within the BBU and the RFU
required +5.75V.
Alarm Interface Unit
Description
The Alarm Interface Unit (AIU) had a dual role in the radio router base station. It managed all hardware connections of the base station alarms and communicates alarm status to the MCU. It was also involved in the fail-over of the redundant BBU and the redundant MCU. The AIU handled, or was involved with, the following tasks:
Fail-over facilitation
Alarm monitor and user defined alarms
Maintenance features
Base station clock synchronization and distribution
System reset
Customer defined functions
Inventory and configuration
There are 2 AIU slots in the Access Router shelf. A single AIU card could have handled all of the alarming and fail-over requirements for the base station. The second AIU provided redundancy.
The software and hardware of the base station were able to function without a populated AIU slot. A base station without an AIU would not provide redundancy fail-over for the MCU or BBU and would not provide hardware connectivity for user specified external alarms. Platform management of internal alarms was handled by the MCU in a base station that had no AIU present.
APPENDIX D
TESTING METHODOLOGY
Drive tests were performed by the District with a laptop that included a Flash OFDM card. The antenna was located inside the vehicle. The antenna configuration corresponded to an additional propagation loss of 6 dB to 8 dB. The laptop ran the Flarion Mobile Diagnostic Monitor (FMDM) software. FMDM monitored performance parameters such as data rates and link states for each test session. Concurrently, FMDM collected geographic location data through a GPS receiver connected to the same laptop.
The laptop would receive IP traffic from the core network to evaluate the downlink performance and would transmit IP traffic to the core network to evaluate uplink performance using the Internet Performance (Iperf) application. The “ping” command ran repetitively to evaluate the network latency. Uplink and downlink tests were run on different laptops. Iperf was configured such that data streams were generated on a User Datagram Protocol (UDP), which is a means to broadcast messages over the network. UDP is the protocol used for streaming video.
FMDM collected data twice a second. Through post processing, the data collected by FMDM was aggregated into 400 meter grids. The value attached to each grid was of the median value for all the instances of the parameter collected in that grid.
TESTING RESULTS
Figure 14 represents the field strength received from the site that has the dominant pilot channel.
Figure 14: Measured
Downlink Received Level
Several
poor coverage areas appear on this map, although they did not exist for the
voice network. The two main areas are
the bed of the
More than the received field strength level, the received Signal-to-Noise Ratio (SNR) is the parameter that indicates the performance of the radio link, e.g., the achievable data rate. SNR was not satisfactory when the coverage was not sufficient, but also when the level of interference was too high. Figures 16 and 17 depict the downlink throughput measured throughout the city. The correlation between this map and the pilot field strength level map is high. Figure 18 shows the uplink throughput measured across the city. The technology allowed for peak rates of 2.7 Mbps for the downlink, and 900 kbps on the uplink. About 70% of the locations received more than 300 kbps in the downlink, and 60% of the locations were able to transmit 100 kbps on the uplink.
Figure 15: Downlink
Signal to Noise Ratio (12 sites)
Figure 16: Downlink Received Data Rate (10
sites)
Figure 17: Uplink
Transmitted Data Rate (10 sites)
Based on the results, the District began planning to improve the network coverage and capacity performance further by deploying two additional sites (and amend the experimental license accordingly):
Other key performance parameters are summarized in Figure 18.
Metric |
Value |
Packet delay (Median single user) |
30 ms |
Dropped pings |
2.49% |
Access Failure rate (> 15s) |
1.75% |
System Drop rate (Session Drop and Handover Drop > 2s) |
0.203/100 |
Figure 18: WARN Performance Parameters
APPENDIX E
The District asked WARN users to
complete monthly surveys regarding their satisfaction and opinions with the
coverage, reliability, and benefits WARN provides to their daily and emergency
operations. The survey included a
scoring section and allowed for users to expand upon certain items and
specifically requests opinions on areas of improvement. The following are unedited excerpts from the
District’s monthly user surveys.
WARN BENEFITS
DC
Fire and Emergency Management Agency
“WARN has helped me as an F/EMS planner in numerous ways. I attend many meetings throughout the city. In these meetings, I access files via WARN that allow me to make video and graphic presentations and to access other people’s information in ways that would not be possible without it. This ability has made my work more efficient.
I have also used the WARN network on multiple National Security Events, special events, and emergency responses to track unit status information in real time, to access the METRO Protect System, to compile data, and access the internet and send and receive emails.”—DC Fire and Emergency Services
DC
Emergency Management Agency
“WARN has had a
tremendous impact in our ability to access and transfer critical information to
and from our mobile command center. It
has provided our mobile units with a fast, simple, and reliable means through
which to send and receive digital information.
The ability to transmit live streaming video or access our GIS server
from the field, has proven invaluable to senior management in their decision
making process. We look forward to the
day WARN has expanded throughout the NCR.”[53]
DC Fire and Emergency Medical Service
“For F/EMS users, it should be expanded to all EMS Operations Supervisors.”[54]
“This system continues to be an asset to our agency. Without it, there are times we would be much less efficient in our operations.”—December 2005 User Survey
“Mobile Command HQ
used/relied on our WARN connection HEAVILY during the recent IMF/World Bank and
Anti-War Demonstrations. The system
worked flawlessly in spite of our “difficult” location (adjacent to the West
Wing).”—
“During the month of
January 2006, the United States Park Police, in coordination with the DC Office
of the Chief Technology Officer, installed a WARN connection at the USPP
Anacostia Operations Facility. This
connection now enables the United States Park Police Command Center, designated
as such for large-scale incidents and events, to have direct access into
District of Columbia databases, allows for extensive data interoperability with
District of Columbia government and public safety partners, and provides a
robust platform for continuity of operations should an incident result in the
loss of the United States Park Police backbone.
This is an outstanding partnership.”—
SUGGESTED IMPROVEMENTS
The following represents a comprehensive list of all suggested improvements from the WARN customer surveys:
August 2005
“Wants additional training.”—HSMP
“More coverage or bigger antennas to expand
coverage at the fringes of the covered area.”—F/EMS
“More coverage in the SE toward Bolling AFB.”—MPD
“Better coverage in 400 block of
“Need external antenna.”—F/EMS
“Better in-building coverage.”—DHS
“Lighter PCs (They are using a free but heavy-ML-900).”—EMA
September 2005
“Different antenna options.”—F/EMS
“Stronger signals”—F/EMS
“Provide a better alternative to current
Greenhouse video software”—MPD
October 2005
“Need more coverage in the SW and SE area of
the city. East of the river. Seventh District area” —MPD
“Difficult to say due to short notice of
EMA’s request. Staff was more than
helpful and provided the best possible service.
The process of identifying IP’s, opening ports, etc. is cumbersome,
especially in an emergency situation. Due
to short notice 2 cards were not activated.” —EMA
November 2005
“Again, nice system, needs more coverage in
SW.” —MPD
“Not receiving a signal at 12th
and
“Seems like coverage could be better in
certain areas.” —F/EMS
“The signals are weak and also the connect. If we connect, it works fast.” —F/EMS
December 2005
“No coverage in NE part of the city around
“Better coverage.” —MPD
“Speed and coverage good. Coverage can be improved.” —F/EMS
January 2006
“Wider coverage when system gets more sites. Lower SW part of the city still needs
coverage. How about a tower at
“For F/EMS users, it should be expanded to
all
“Speed and connections.” —F/EMS
“Not sure if I’ve asked for this but a
detailed coverage map (GIS layer).” —EMA
“We are still having coverage and speed
issues in certain areas of NW. I have
provided a map and highlighted the areas of no coverage compared to the old
multicast system.” — USPP
“Get it to work in COG and at my house in MD
:) Keep up the good work guys.” —F/EMS
February 2006
“More Coverage.” —F/EMS
“Speed and area coverage can be improved.”
—F/EMS
“My computer has been down so my usage has
been limited due to some software/hardware issues. I have had problems when logging into Packet
Cluster while the WARN card is connected (locked in). When it is disconnected, I can log in?? Hopefully
once I am up and running, I will have more feedback.” —MPD
“In order to have effective use of
Pictometry we will need to pay to have the Pictometry image library compressed.”
—OCTO
“Allow DCFD (FEMS) VPN users access to
Greenhouse.” —F/EMS
March 2006
“Expand.” —F/EMS
“It will be great if speed can be fast.”
—F/EMS
April 2006
“It is a wonderful system and it should have
a larger area of coverage.” —F/EMS
“Connection Faster.” —F/EMS
May 2006
“A site is needed in lower SE for better
coverage.” —MPD
“Would like to get links to all public video
transmissions under DC Control for special events.” —MPD
June 2006
“Perhaps more antenna strength.” —MPD
“Low signal quality.” —MPD
[1] The
demonstration period of this pilot is from January 2005 through December
2006. The
[2]
Memorandum on Spectrum Policy for the 21st Century, 39 Pub. Papers
23 (
[3]
[4]
[5]
The President directed the Secretary of Commerce
to initiate two courses of action: (a) to establish a Federal Government
Spectrum Task Force (the “Task Force”) consisting of the heads of impacted
executive branch agencies, departments, and offices to address improvements in polices affecting spectrum use
by federal agencies, and, (b) to schedule a series of public meetings to
address improvements in policies affecting spectrum use by state and local
governments and the private sector, as well as improvements in polices for the
spectrum management process as a whole.
[6] National Telecommunication and Information Administration, U.S. Dep’t of Commerce, Spectrum Policy for the 21st Century- The President’s Spectrum Policy Initiative: Report 1, Recommendations of Federal Government Spectrum Task Force (June 2004) at http://www.ntia.doc.gov/reports/specpolini/presspecpolini_report1_06242004.htm (Report 1).
[7] National Telecommunications and Information Administration, U.S. Dep’t of Commerce, Spectrum Policy for the 21st Century- The President’s Spectrum Policy Initiative: Report 2, Recommendations from State and Local Governments and Private Sector Responders, (June 2004) at http://www.ntia.doc.gov/reports/specpolini/presspecpolini_report2_06242004.htm (Report 2).
[8] Memorandum on Improving Spectrum Management
for the 21st Century,_ Pub. Papers _ (
[9] National Telecommunications and Information Administration, U.S. Dep’t of Commerce, Spectrum Management for the 21st Century: Plan to Implement Recommendations of the President’s Spectrum Policy Initiative (March 2006), available at http://www.ntia.doc.gov/osmhome/reports/ImplementationPlan2006.htm (Implementation Plan).
[10] Report 2, supra note 7, at 26.
[11]
[12] See Alaska Land Mobile Radio Project, at
http://www.ak-prepared.com/almr/.
[13] Report 2, supra note 7, at 26.
[14] Implementation Plan, supra note 9, at 23.
[15] NTIA Press Release, NTIA Selects DC Public Safety Network to Monitor Effectiveness in Sharing Radio Spectrum with Federal, State, and Local Government Users, April 25, 2006, available at http://www.ntia.doc.gov/ntiahome/press/2006/publicsafety_042506.htm.
[16] Federal Communications Commission, Private Land Mobile Radio Services, 47 C.F.R. Pt. 90 (FCC’s Part 90 Rules).
[17] The District also looked at the possibility
of using commercial services.
Ultimately, the District decided that commercial services did not meet
all of their requirements. More
information on the feasibility of using commercial services for broadband
applications and the District’s decision not to use them is explained in
Section Four.
[18] A small number of sites results in lower capital and operational costs for the network operator.
[19] To this end, the District worked with Congress and
other stakeholders and decision-makers to heighten awareness of broadband
needs, not only in the District, but across the nation. As part of this effort, the District founded
the Spectrum Coalition for Public Safety (Spectrum Coalition) to address the
broadband spectrum needs for the country in the 700 MHz band. The Spectrum
Coalition is a non-commercial affiliation of over 30 state, county and local
government public safety communications organizations. See http://www.spectrumcoalition.org.
[20] See FCC’s Part 90 Rules, supra note 16, at Section 90.531.
[21] Federal Communications Commission, Experimental Radio Construction Permit and License, Call Sign WD2XHO, File Number 0182-EX-RR-2006 (WARN Experimental License).
[22] The
District initially planned for two technologies with channel bandwidths of 1.25
MHz each and an intermediate guard band to utilize this 4 MHz of spectrum. Ultimately, only one technology was deployed.
[23] This
band is part of the blocks of spectrum to be auctioned no later than
[24]
The FCC Rules regarding such an experimental
license protects TV Broadcasting stations that are co-channel (transmitting on
the same channel) or adjacent channel to WARN. See FCC’s Part 90 Rules, supra
note 16, at Section 90.545.
[25] WARN Experimental License, supra note 21.
[26] Low latency systems deliver data (packets) in shorter periods of time from source to destination.
[27] The OFDM component of the radio link uses technology that can also be found in 802.11a and WiMax solutions. Flarion’s augmentations focused on creating a mobile access and full mobility OFDM solution.
[28] This
single, static IP address enables servers to find mobile devices as they travel
throughout the District.
[29] A transceiver transmits signals to mobile units and receives signals from mobile units as well as translates them for transmission over fixed lines back to the core network.
[30] For instance, the base stations were able to connect directly to the DC WAN at the core and DC-NET at each radio site. Additionally, the equipment and functions of the WARN were the same or similar to those already managed by the District.
[31] The building itself provided some shielding that reduced interference from sector-to-sector.
[32] The
same frequency was transmitted on each sector.
The amplifier transmitted 20 Watts.
The panel antennas have a 12 dBd gain.
[33] The Flarion Flash OFDM technology uses the same frequency at each site; therefore, these other sites will cause noise among themselves.
[34] The District’s LMR network was measured to provide more than 95 percent coverage and various levels of in-building coverage. On average, the system provides good audio quality inside most buildings through the first two walls.
[35] The contract called for 95 percent coverage of the city.
[36] The power consumption and heat output of a three Watt transmitter would not allow for PC card or other small form factors.
[37] The video codec converts the video image to data packets that can be transmitted over a communications link or stored for later use. The codec codes the image on the transmitting end and decodes the image on the receiving end. In general, the higher the transmission rate, the higher the overall quality of the video image. However, the various video codecs are proficient at different tasks and there have been significant improvements to low data rate, yet high video quality codecs on the market. H.264 refers to the jointly developed video standard of the International Telecommunications Union Video Coding Experts Group and the Motion Picture Experts Group.
[38] NTIA did not commission, pay for, or seek to have these customer surveys as part of the WARN pilot. In fact, the surveys were being conducted prior to NTIA’s involvement with and selection of the WARN. The District collected and analyzed the surveys and provided this information to NTIA for inclusion into this report.
[39] These limited connections take the form of low data transmission rates, temporary loss of connection, or both.
[40] A.N.S.W.E.R. refers to the coalition to Act Now to Stop War and End Racism.
[41] Full motion video requires 24 or more frames per second. Lower frame rate solutions cannot accurately portray fast moving objects.
[42] Mobile Data Computers (MDCs) are rugged personal computers that largely serve the same function as standard desktop or notebook PCs and are typically mounted inside vehicles. They are hardened to withstand the vibration and heat of the mobile environment.
[43] E-Mail correspondence from Lt. David Mulholland (USPP) to Guy Jouannelle (Televate), August 21, 2005, quoted in the District of Columbia THIRD PROGRESS REPORT on the Construction and Operation of the Experimental Wireless Accelerated Responders’ Network (August 2005), at 13.
[44] Commercial carriers AT&T, Verizon, and Sprint/Nextel all offer wireless broadband services in the District. See for example http://b2b.vzw.com/broadband/serviceoverview.html and http://powervision.sprint.com/mobilebroadband/.
[45] Verizon Wireless had launched its EVDO Rev 0 network that offered peak uplink data rates of 153 kbps. The rate of the entire channel to an end-user is somewhat lower and is shared with other users on the site.
[46] Federal
Communications Commission, Public
Notice, Public Safety and Homeland Security
Bureau Seeks Comment on Request by National Capital Region for Waiver of Part
90 Rules to Allow Establishment of a 700 MHz Interoperable Broadband Data
Network, DA 06-1973 (September 29, 2006) at http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-06-1973A1.pdf
(Waiver RFC). Subsequently, the FCC has
approved the waiver request.
[47] FCC’s Part 90 Rules, supra note 16, at Section 90.531.
[48]
[49] DTV Act, supra note 23, at Section 3002.
[50] 47 C.F.R. §2.103(a). However, federal government entities are authorized to use channels in the 700 MHz band subject to conditions and agreements in place with non-federal public safety agencies. See 47 C.F.R. §2.103(b).
[51] One of the recommendations of the President’s Spectrum Policy Initiative is to encourage state and local spectrum planning. This planning process will provide a mechanism for state and local entities to identify and plan for their future broadband needs. See Report 2, supra note 7, at 26.
[52] The list describes the characteristics and matching processing options of the unit.
[53]
[54] Id, 12.