Saturday, June 30, 2012

State VHF TRS Using NTIA Frequencies

On a recent trip to Northwest Arkansas, I was noticing many weak hits on 171.4375 MHz, N1CC. After a while I figured out this was a P-25 trunked control channel. I then monitored the control channel data and discovered that this was a trunked site that was part of the Missouri statewide radio system called MOSWIN. The site I was hearing was Site 12, using the frequencies of 161.8375 & 171.4375 MHz. It is reportedly located in St. Claire County, Missouri (well north of my location at the time). The system data can be found here:

The system consists of both 800 MHz and VHF trunked sites to provide statewide coverage. What is interesting is that the state has taken not only FCC controlled spectrum, but has a number of channels from the federal spectrum as well. My guess is that since VHF public safety allocations are getting difficult to find, they were able to get some VHF federal channels as a cooperative effort with the feds.

There were indications that the next deployment of the now unfunded, federal IWN trunked system would be in the Midwest. So it seems that giving the frequencies over the state of Missouri and letting them build the radio system (probably with federal grants), then getting federal agency access to the system is another method of getting what the Justice Department wanted in the first place.

Also, I have noticed a similar situation with the Nebraska state VHF trunked radio system, called the N-WIN: .

The WYOLINK system in Wyoming has only one site in Cheyenne that is using federal VHF channels, and I assumed that was for interoperability with the F.E. Warren AFB there:

The Montana Statewide Interoperable Public Safety Radio System (MSIPSRS?), a VHF P-25 trunked system, features only 1 site (so far) that is using a single federal allocation - Site 44:

I was advised that the new State of Maine VHF P-25 trunked radio system is planned to utilized frequencies in the federal VHF band. The system is not yet built out, but planners are acquiring VHF frequencies from as many sources as they can.

Also, the State of Wisconsin is utilizing some VHF allocations in the 138 - 150 MHz bands that were given over in a cooperative agreement with the Department of Defense.