P25/Phase 2 UID Issue?

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werinshades

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Question for anyone monitoring Phase 2/P25 systems. When PT0 is showing in the display, not receiving a Unit/Radio ID, however when PT1 is displayed, Unit/Radio ID is showing. Any idea why this is? I have the TRX-2 running and Unit/Radio ID's display at all times.
 

jonwienke

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The problem is not keyed to timeslot. I'm seeing UID on both timeslots on some calls, and no UID on both timeslots on other calls. It's not keyed to TGID, either. The display of UID is simply intermittent on Phase II P25 systems.
 

werinshades

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The problem is not keyed to timeslot. I'm seeing UID on both timeslots on some calls, and no UID on both timeslots on other calls. It's not keyed to TGID, either. The display of UID is simply intermittent on Phase II P25 systems.

You are correct. After I posted, started seeing this as well. It's a system I normally don't monitor, so thought maybe it was a setting I had to adjust. Thanks for the reply.

UPMan...were you aware of this. Firmware 1.11.31 on a 536hp. I can't say if it was better with previous firmware versions as it's a system that's been around awhile that I normally don't monitor. PT0/PT1 will show in the display and the UID/Radio ID will show, other times it doesn't. Signal strength is good, no decoding issues on the talk groups.
 

UPMan

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If the scanner is a "late entry" to the call, it never sees the UID (which, IIRC, is only on the original channel grant).
 

jonwienke

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Not the case here. The UID won't show up even if there is a conversation going on. What you say would account for the first transmission in the conversation not always having a UID showing, but the reply transmissions should always show UIDs. And they don't.
 
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werinshades

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If the scanner is a "late entry" to the call, it never sees the UID (which, IIRC, is only on the original channel grant).

If I'm understanding you correctly, if the scanner is "scanning" and catches the conversation in mid-stream, the UID will not display? If the scanner catches the initial conversation the UID will display? PT1 PT0 means what exactly in reference to a Phase 2 system? Similar to slots on a MotoTRBO system? I never really tinkered in Phase 2 systems until recently so pardon my inquiry. Are you or the technicians able to duplicate this with a system?
 

UPMan

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PT0 = Conversation is occurring on Slot 0
PT1 = Conversation is occurring on Slot 1

Yes, like MotoTRBO.

Yes, we can duplicate it. There is no way to generate the information if the scanner did not actually receive it. Unlike a system radio, which is almost never doing anything other than monitoring the system, the scanner is doing a bit more (including periodic "housekeeping") that could cause it to miss the original channel grant.
 

jonwienke

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If the scanner happens on the conversation during the middle of Unit A's transmission to Unit B, I can understand the scanner not always getting Unit A's ID. But when Unit B keys up to reply to Unit A while the scanner is still holding on the talkgroup, there's no excuse for the scanner not picking up Unit B's ID during the reply transmission. The same goes when Unit A replies back to B--the scanner has no excuse for not picking up Unit A's ID at that point.
 

werinshades

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PT0 = Conversation is occurring on Slot 0
PT1 = Conversation is occurring on Slot 1

Yes, like MotoTRBO.

Yes, we can duplicate it. There is no way to generate the information if the scanner did not actually receive it. Unlike a system radio, which is almost never doing anything other than monitoring the system, the scanner is doing a bit more (including periodic "housekeeping") that could cause it to miss the original channel grant.

Thanks for the explanation, however I just tried something. I held the System left the scanner in ID Search to see what would happen. I tried to duplicate a system radio holding only on the system and saw the same results. I just held a talk group to duplicate it even further and had the same results. Like it was previously discussed, it occurred on both PT0 and PT1 voice calls so it's not slot dependent. This reminds me of the issues we initially had on MotoTRBO where some conversations were missed if the conversation associated with a different slot on the same frequency.

Would you pass this along to your technicians if it hasn't been addressed already? Phase 2/P25 systems seem to be the culprit. I'm running a TRX-2 for comparison purposes and this is not being duplicated on that scanner.
 

werinshades

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A system radio will be holding (typically) on only one talk group.

Yes...that was one of my tests just now. Held system first to watch the activity, then waited for an active Talk group to watch the activity. PT1 came up on the Talk group without a Radio/UID. Same talk group, PT0 came up with Radio/UID, then conversation ended, picked back up on PT0 no Radio/UID. I'm holding the talk group to duplicate a system radio.

TRX-2 was displaying Radio/UID's throughout conversation. I also set it up to hold the talk group. Very interesting to say the least..
 

troymail

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Yes...that was one of my tests just now. Held system first to watch the activity, then waited for an active Talk group to watch the activity. PT1 came up on the Talk group without a Radio/UID. Same talk group, PT0 came up with Radio/UID, then conversation ended, picked back up on PT0 no Radio/UID. I'm holding the talk group to duplicate a system radio.

TRX-2 was displaying Radio/UID's throughout conversation. I also set it up to hold the talk group. Very interesting to say the least..

I think you need to hold on a talkgroup AND delay the "system housekeeping" (i.e. change the HOLD time) for best results.

Easier to Read BCD436/536HP Digital Scanner Manual

Default is 0 (only as long as is required to check the system for activity).

Perhaps Paul can advise what these "system housekeeping" things really are that would be adversely affected by changing from "0".
 

jonwienke

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A system radio will be holding (typically) on only one talk group.

If you're holding on a site, then the scanner shouldn't be missing any traffic, unless there are multiple simultaneous conversations going on.
 

jonwienke

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Just did a test where I did a site hold on the PA Adams County P25-II "West System" site, and I'm still intermittently missing UIDs. The scanner shouldn't ever be off the control channel, except during "housekeeping". When doing a site hold, there's no reason the scanner should catch the call but not the UID.
 

troymail

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Just did a test where I did a site hold on the PA Adams County P25-II "West System" site, and I'm still intermittently missing UIDs. The scanner shouldn't ever be off the control channel, except during "housekeeping". When doing a site hold, there's no reason the scanner should catch the call but not the UID.

Don't forget the effects of simulcast.... the radio just isn't receiving 100%... even on full hold.
 

jonwienke

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Simulcast is not an issue with this system. I don't live in Adams county.
 

jonwienke

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Here's my ProScan log:

Talk Group ID Frequency Tone RSSI UID Mod. Hits Duration Start Date / Time End Date / Time System / Site - Department - Channel System Type Digital Type
20000 855.7375 426 NFM 20 00:00:03 09/14/17 13:37:30 09/14/17 13:37:34 Adams County Public Safety - West System - Fire/EMS - Fire/EMS Dispatch P25 Trunk PT0
20000 855.7375 425 12204 NFM 19 00:00:05 09/14/17 13:37:12 09/14/17 13:37:17 Adams County Public Safety - West System - Fire/EMS - Fire/EMS Dispatch P25 Trunk PT1
20000 855.7375 431 354205 NFM 18 00:00:06 09/14/17 13:37:02 09/14/17 13:37:08 Adams County Public Safety - West System - Fire/EMS - Fire/EMS Dispatch P25 Trunk PT1
10000 855.7375 427 NFM 13 00:00:02 09/14/17 13:33:36 09/14/17 13:33:39 Adams County Public Safety - West System - Law Enforcement - P-Serv P25 Trunk PT1
10000 855.7375 425 12103 NFM 12 00:00:02 09/14/17 13:33:32 09/14/17 13:33:35 Adams County Public Safety - West System - Law Enforcement - P-Serv P25 Trunk PT1
10000 855.7375 424 NFM 11 00:00:11 09/14/17 13:33:15 09/14/17 13:33:26 Adams County Public Safety - West System - Law Enforcement - P-Serv P25 Trunk PT0
10000 855.7375 427 NFM 10 00:00:06 09/14/17 13:32:56 09/14/17 13:33:03 Adams County Public Safety - West System - Law Enforcement - P-Serv P25 Trunk PT0
10000 855.7375 426 NFM 9 00:00:03 09/14/17 13:32:50 09/14/17 13:32:53 Adams County Public Safety - West System - Law Enforcement - P-Serv P25 Trunk PT0
20000 855.7375 426 354205 NFM 17 00:00:01 09/14/17 13:26:05 09/14/17 13:26:07 Adams County Public Safety - West System - Fire/EMS - Fire/EMS Dispatch P25 Trunk PT0
30005 855.7375 430 12204 NFM 20 00:00:02 09/14/17 13:25:46 09/14/17 13:25:49 Adams County Public Safety - West System - Fire/EMS - EMS Ops 2 P25 Trunk PT0
30005 855.7375 426 354103 NFM 19 00:00:03 09/14/17 13:25:41 09/14/17 13:25:45 Adams County Public Safety - West System - Fire/EMS - EMS Ops 2 P25 Trunk PT0
10038 855.7375 426 150601 NFM 1 00:00:03 09/14/17 13:21:23 09/14/17 13:21:26 Adams County Public Safety - West System - Unknown - TGID:10038 P25 Trunk PT0
10002 855.7375 429 NFM 13 00:00:04 09/14/17 13:07:27 09/14/17 13:07:32 Adams County Public Safety - West System - Law Enforcement - East Police Dispatch P25 Trunk PT1
50037 855.7375 423 473001 NFM 1 00:00:05 09/14/17 13:03:05 09/14/17 13:03:10 Adams County Public Safety - West System - Municipal Govt - Hamilton Township P25 Trunk PT0

UID capture is only about 50%, even though I'm holding on a site with excellent reception and a P25 decode error rate of ZERO.
 
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