GPT Data channel 419.6250

[citabria]

Hi Guys,

I have observed this on pro96com and a P25 analyser, and it seems this channel is running 24/7 with nothing except packet data and terminator units.. Strange that only one channel is being used for this and theres no voice traffic on it either. I would've thought that it would have been rotated around to share the load across the system rather than having one base do all the data work (like a conventional system)

Anyone else noticed this?

Cheers,
Matt

[Bigfella237]

G'day Matt,

Is this system data or is it associated with a talkgroup/user radio?

I seem to remember that Sydney Water used to have a few talkgroups dedicated to data, I think they were used to send sewer and pipe diagrams to MDTs in their vehicles?

Andrew

[citabria]

It's user data - however it all appears to be one way (from the radio to the system) since the only data packets on the repeater output are confirmation response packets - ie they don't contain data, they simply tell the mobile radios that the data sent from the handset has been received by the trunk system OK

Format: Response Packet (0x03)

[Bigfella237]

Any idea of the radio ID? Is it in a group (or from an agency) that's already been identified?

[citabria]

I don't think this is going to be agency specific - anyone using any P25 data feature is probably using this channel - but heres some RIDs I've collected over the past 15 mins or so.

2008026, 2311926, 2009348, 2372874, 2311923, 2311028, 2350008, 2311282, 2310879, 2375987, 2376222, 2311764, 2376173, 2310203, 2310703, 2376458

So that includes Fire & Rescue, Railcorp, Ferries, and the Ambos. I reckon other agencies might pop up too..

[Longreach]

Hi all, I noticed a similar thing off kurrajong too a while back, however I think it's been changed. The main thing I noticed were the private data packets on this single channel, and they were mainly integral (or whatever there known as this week) rid's
Cheers
Matt

[cartman]

Frequency 419.625 is now quiet again a day later
No packet data ... nothing
Just the occasional P25 voice transmission

Grant