BCD436HP/BCD536HP: Unsupported Patch Type?

[DaveNF2G]

A local agency on a P25 trunked system is using a group ID that shows as "Patch" in DSDPlus and is not received by my 436. Checking the agency's regular talkgroups while this Patch is in use reveals no traffic anywhere. It seems to stand alone.

In the DSDPlus log, transmissions show up starting like this:

P-Group call; TG=121

It seems that the scanner does not recognize "P-Group" calls.

 

[Spitfire8520]

None of Uniden's products has ever supported talkgroup patching on P25 systems. This missing feature (or issue) has known for a long time, but it appears that Uniden is not interested by their constant lack of response for the past decade. You can manually monitor the patched talkgroup by programming it directly.

April, 2009
Patched Talkgroups/Status Bit
April, 2010
Talkgroup Patch Feature
May, 2012
Talkgroup Patches on Motorola P25 systems
February, 2014
Uniden BCD536HP & Patched Talkgroups on Phase II System
April, 2015
P25 Patch Following
July, 2015
Uniden, please fix the P25 system patch issue
September, 2017
BCDx36HP P25 Patch Following...

 

[jonwienke]

If there is a patch between talkgroup X and talkgroup Y, You can hear the patch traffic by monitoring talkgroup X or talkgroup Y. You just can't monitor the patch itself. Try using ID SEARCH instead of ID SCAN.

 

[Spitfire8520]

If there is a patch between talkgroup X and talkgroup Y, You can hear the patch traffic by monitoring talkgroup X or talkgroup Y. You just can't monitor the patch itself. Try using ID SEARCH instead of ID SCAN.

That would depend on the system. For Motorola systems, the traffic will end up on either talkgroup X or talkgroup Y. For Harris systems, the traffic will end up on a completely different talkgroup Z (which is pulled from a large group of talkgroups) and monitoring talkgroup X & Y will not work.

For the OP case, monitoring TG 121 directly will let you hear the patched traffic. With Uniden scanners, anything short of monitoring the the "P-Group" directly will not work.

 

[Ubbe]

If DSD shows a patched talk group then the talkgroups that have been patched are no longer in use and only the patched TG are used.
It would be a huge waste of resources if three talkgroups got activated when someone uses his PTT in any of the patched TG's.

/Ubbe

 

[slicerwizard]

None of Uniden's products has ever supported talkgroup patching on P25 systems.

Well, of course not. As Uniden's shill Voyager put it:

But, if they are using an arbitrary TGID for the supergroup, your only recourse is to use ID SEARCH. There is no practical way for a scanner to know you want to monitor a random TGID.

OMG, what horse manure. So, V-Ger, then how do GRE/Whistler manage to do it?

 

[DaveNF2G]

I was planning to add another Uniden 536 to my station, but if Uniden's scanners have a built-in disability with respect to monitoring a plain old P25 Phase I system P-Group, then maybe I should reconsider Whistler. (I just hate EZ-Scan, which is far from it.)

 

[jonwienke]

Only on Harris P25 systems, and if you have ID Search turned off. Otherwise you will hear patched traffic.

 

[cellphone]

OMG, what horse manure. So, V-Ger, then how do GRE/Whistler manage to do it?

It is rumored that GRE/Whistler owns a patent for monitoring patches on a P25 system, but no one has cited a source.

 

[slicerwizard]

No source because that's more manure. It's not that hard to check their patents.

Besides, patch monitoring is quite straightforward - monitor the proprietary patch announcements and teardowns and tie the patch IDs to the patched groups. Simples and not particularly patentable.

Proprietary because even though patching is a known requirement for PS systems, the vendors, who had every opportunity to bake patches into the P25 standard, instead chose to go with incompatible solutions.

Same deal with DMR - no standard method for deploying encryption. Go figure.

 

[DaveNF2G]

Only on Harris P25 systems, and if you have ID Search turned off. Otherwise you will hear patched traffic.

Hardly a solution on a large system with over 200 talkgroups.

 

[jonwienke]

200 talkgroups is relatively small, compared to SIRN, MARCS, and other statewide or multistate systems.

You can program every known talkgroup in those systems with zero impact on performance, and ID Search only hits on new talkgroups and patches. It's not the most elegant solution, but it works.

 

[DaveNF2G]

ID Search hits on every talkgroup it detects. If the TGID is programmed into the scanner with a label, then that label will be displayed.

 

[jonwienke]

No. ID Search/Scan only affects the way the scanner handles talkgroups that are not programmed. Scan ignores all traffic with unprogrammed talkgroup IDs. Search plays all traffic with unprogrammed talkgroup IDs.

Programmed talkgroups are not affected either way--the decision to play or ignore a transmission is determined by Location Control, active Service Type selections, and Avoids, regardless of whether ID Search or ID scan is selected.

 

[troymail]

For ID Search to work properly, you must have all known talkgroups programmed against a given system with those not of interest locked out in some way. Otherwise, you'll get tons of false hits for "new/unknown" talkgroups.

 

[slicerwizard]

You can program every known talkgroup in those systems with zero impact on performance, and ID Search only hits on new talkgroups and patches. It's not the most elegant solution, but it works.

That's great if you want to be bothered by every patch.

 

[jonwienke]

Generally not an issue. The great majority of traffic is not patched. And if a patch pops up you aren't interested in, an avoid is a single button press away.

 

[troymail]

If you are really sure you don't want to hear patches, you could always create a set of patch talkgroups using something like Excel, etc., cut and paste them into Sentinel and set them to Avoid..... It's probably just some specific range of TGIDs....

 

[mikewazowski]

How about Uniden just fix it?

 

[Ubbe]

That's great if you want to be bothered by every patch.

You probably would like that as a patch are only set up when something big has happened, that you do not want to miss.

/Ubbe