- What is DSRC?
Dedicated Short Range Communications is a
communications approach to allowing short range communications between
vehicles and the roadside for a variety of purposes, such as intersection
collision avoidance, transit or emergency vehicle signal priority, electronic
parking payments, and commercial vehicle clearance and safety inspections.
- Are DSRC functions implemented now?
Yes. Electronic toll collection and commercial
vehicle operations both utilize DSRC technology. There are currently
about 6 million vehicles with DSRC devices on them across the country.
The current applications operate in the 902-928 megahertz band.
- Why is this allocation needed?
When all of the potential DSRC applications
were examined, it became clear that the existing spectrum could not accommodate
the wide variety of applications. Thus, USDOT, in concert with ITS America,
petitioned the FCC for additional spectrum to allow the growth of DSRC
services in the future. At 900 we have 12 megahertz of spectrum (which
includes cordless phone and garage door openers), and it's not enough
to accommodate the potential uses for DSRC.
- What new applications do you foresee for
DSRC?
New applications would be signal priority
for both emergency services vehicles and public transit vehicles, communication
between the rail crossing and vehicles at highway rail intersections,
electronic parking payment (e.g. Pittsburgh Airport parking garage) and
cooperative safety systems, such as intersection collision avoidance.
- Why do we need so much?
To accommodate some of the key public safety
applications of DSRC such as emergency vehicle priority, there must be
protection for these safety-of-life applications, such that other non-essential
applications could not interfere. So there must be portions of this 75
MHZ allocated to these safety-critical functions. If we ever get to a
point where every vehicle in the US has a DSRC tag on it from the factory,
that will mean that there are a multiplicity of uses for this device.
Therefore the only way they can coexist in a given metropolitan area
is to have frequency separation among the uses. 5.9 was chosen because
of the ability of DSRC applications to coexist with the other users of
that band, which are some military radars and some satellite communications
systems.
- Why did you seek Co Primary status?
Co Primary allows DSRC and only the other
current users of this band to use the frequencies on a non-interference
basis, that is, someone else cannot come in and interfere with you. A
secondary user says "You can use this frequency, but if you interfere
with the primary user, you must change." Primary user has preference.
So we wanted some band for these safety-critical applications that someone
else could not utilize and interrupt and perhaps cause threat to life.
- How do the other users of this band feel
about DSRC?
Before ITS America submitted the petition
to the FCC, ITS America and USDOT coordinated with all the current primary
users of the band to ensure that there would be no interference in their
operations because of DSRC applications, or DSRC applications would agree
to limit their uses, so as not to interfere with the existing users.
We did all that before we submitted the petition and actually ran some
tests to ensure that this was true.
- Do you think industry is ready to develop
products at 5.9?
We believe so; however, that is going to be
driven by how the industry perceives the marketability of these devices.
Ultimately, the market will determine product development. The USDOT
will not mandate its use; however, we want to ensure availability of
this band width for today's and future applications of ITS technology.
- How do existing DSRC users view 5.9?
Comments made to the FCC on this petition
showed support by the industry for the allocation of this spectrum.
- Who will have access to this spectrum?
DOT neither controls nor licenses this. It
will be just like any other portion of the spectrum. Its use will be
limited to DSRC applications in accordance with the service rules that
the FCC will be establishing soon. However, it is likely that some portions
of the spectrum will be reserved for safety-critical applications.
