chris451rr
Member
We had VIP activity at KCID yesterday. The typical freqs were in use, 165.375, 164.8875, 12.5khz bandwidth.
Whats new are the every 10-30 second beacons from each station. Each freq in use has the short beacons on it while they are active. Before and after this was gone. Sounds like some type of networking.
A series of 4 to 6 stations in rapid secession would transmit 40-100ms of data in sequence.
A continuous stream of data (assumed to be voice) was also occasional but primary during movement was the short bursts. Perhaps this is location data and short messaging (they don't have many messages while they are on the move that could not be stored ahead of time and addressed or short messaged.
The previous visits were P25 encoded. Before that it was DVP encoded. Before that it was analog.
Various websites state they are replacing the entire set of radios and base sites with a newer system that will eliminate dead spots and improve their reliability, and the stories state they consider their radios as obsolete now although they did not complain about the security but that it garbles alot.
THis wave form did not seem to decode as P25 so it must be something else. Does not sound like the military formats I have heard. I have SDRSharp samples of this if anyone needs it.
One of the radios I have is supposed to be p25 phase 2 tdma compatable but it did not decode anything but saw S readings,
Whats new are the every 10-30 second beacons from each station. Each freq in use has the short beacons on it while they are active. Before and after this was gone. Sounds like some type of networking.
A series of 4 to 6 stations in rapid secession would transmit 40-100ms of data in sequence.
A continuous stream of data (assumed to be voice) was also occasional but primary during movement was the short bursts. Perhaps this is location data and short messaging (they don't have many messages while they are on the move that could not be stored ahead of time and addressed or short messaged.
The previous visits were P25 encoded. Before that it was DVP encoded. Before that it was analog.
Various websites state they are replacing the entire set of radios and base sites with a newer system that will eliminate dead spots and improve their reliability, and the stories state they consider their radios as obsolete now although they did not complain about the security but that it garbles alot.
THis wave form did not seem to decode as P25 so it must be something else. Does not sound like the military formats I have heard. I have SDRSharp samples of this if anyone needs it.
One of the radios I have is supposed to be p25 phase 2 tdma compatable but it did not decode anything but saw S readings,
