P25 Phase 2 - Scanning Input Frequencies

[pb_lonny]

On our EDACS system, I currently scan the input frequencies for my closest tower, I do this to know of any local activity, even if in some cases (Provoice) I can't hear the communications.

We have a new P25 Phase 2 network being rolled out, is it "possible" to scan the input frequencies and will you hear any voice traffic (Using a UBCD436PT)?

 

[waltmitty]

I don't have an answer because I'm too new at this P25 thing but it is my belief that transmissions may also have NAC codes which function as a digital squelch feature.

 

[CqDx]

On our EDACS system, I currently scan the input frequencies for my closest tower, I do this to know of any local activity, even if in some cases (Provoice) I can't hear the communications.

We have a new P25 Phase 2 network being rolled out, is it "possible" to scan the input frequencies and will you hear any voice traffic (Using a UBCD436PT)?

I have used this method to identify some of the unknown / encrypted talk groups on a local Phase 1 and Phase 2 systems. I would say it is more difficult for software like DSDPlus or even scanners to decode Phase 2 input traffic, probably because difference in technology (TDMA vs FDMA)

I have much better success identifying talk group IDs on Phase 1 systems using DSDPlus or scanners on input channels.

 

[wtp]

one article says that the inbound and outbound of a phase 2 system are tow different modes of transmit.

https://www.viavisolutions.com/en-us/literature/understanding-and-testing-p25-phase-2-tdma-application-notes-en.pdf

i do have a phase 1 and 2 system in my county and get digital noise on the inputs which i assume are phase 2 inputs.
i listen to the inputs on a handheld for the "in the neighborhood" listening.
but i still assume it is a phase 1 that is too far away for a good copy.
i will be getting an SDS100 soon as the output freq is choppy.
so i really believe the answer is no, you can't listen in on phase 2.

 

[Randyk4661]

I don't know if this will help or not.
I used my BCD996P2 on custom search (use control channel mode only) between the lowest to highest input frequencies I could find of the So. Calif. Edison system when they were in the area. They are a phase 2 system. I used proscan to log any hits, which I got several. It did tell me what site they were using by cross referencing with the Radio reference database.
Give it a try

 

[CrabbyMilton]

If you program them as P25 individually it will work. I like to go to the airport observation area with the scanner. So I can listen to the airport ops on the county wide system and aircraft frequencies on the same list. I have a 436HP as well.

 

[KevinC]

If you program them as P25 individually it will work. I like to go to the airport observation area with the scanner. So I can listen to the airport ops on the county wide system and aircraft frequencies on the same list. I have a 436HP as well.

For P25 Phase 2? I'm pretty darn sure it won't.

 

[DVINTHEHOUSEMAN]

I don't know of any scanner that can monitor H-CPM (P25 phase II inputs) at all, or H-DQPSK (Phase II output) in conventional mode for that matter.