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. 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.
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. We did all that before we submitted the petition and actually ran some tests to ensure that this was true. Ultimately, the market will determine product development. Comments made to the FCC on this petition showed support by the industry for the allocation of this spectrum. DOT neither controls nor licenses this.