I did some more research on the new P25 system being built for the county. The county commissioned Mission Critical Partners to study various options for replacing the current radio system that has been judged as inadequate. MCP recommended using the UHF band, and constructing either a 10 channel P25 conventional system, or a 6 channel P25P2 simulcast system with microwave backhaul. An RFP was issued and three vendors responded, all proposing a simulcast system. One proposal did not fulfill the requirements (and was also the most expensive,) thus was not considered. The two remaining proposals were analyzed and rated, with Motorola being awarded the contract.
It appears that the system will be split into two simulcast cells (logical sites) with three subsites each. The North(east) 6 channel Simulcast Cell has tower (sub)sites located at Cottontown (Strasburg,) Fort Valley, and Zepp (Maurertown.) The South(west) 7 channel Simulcast Cell has tower (sub)sites located at Lost River (Bayse,) Rudes Hill (New Market,) and Deerhead (Mt. Jackson.) The talkout frequencies for the North cell are: 451.125, 451.150, 452.475, 452.825 (WRFM581) 453.5125, 460.4625 (WREY641.) The talkout frequencies for the South cell are: 451.1625, 451.250, 451.2625, 452.425, 460.900 (WRFH568) 453.6125, 460.375 (WRHW719.) There is a control point located at the new Sheriff's Office / ECC in Woodstock.
The one thing I find interesting is there are no FCC microwave licenses for the subsite backhaul loops. Maybe they are using another FRN for these devices, or maybe the are using unlicensed frequencies, both which I doubt. Another possibility is that the backhaul is now entirely fiber. A presentation earlier this year mentioned that ShenTel was able to run fiber to every site at no cost to the county, which was not anticipated in the original MCP study or RFP. It is best practice to have two paths to each tower site: a looped microwave ring network can provide this redundancy, and is the lowest latency solution. Another approach would be a network with two different media (mw and fiber is preferred, PSTN is to be avoided if possible.) A fiber run can be made resilient by running multiple fiber cables to a site.
There was a plan to construct a lattice tower at the ECC to host the MW distribution, but now I'm thinking this wasn't built. The FCC license modified in June only mentions a building mounted pole antenna which I would think would not be sufficient to support multiple MW dishes. Someone could roll by the ECC and take a look.
