talkgroup capacity and scan options

[HM1529]

I'm listening to a discussion on OpenSky vs. P25 Phase 1 or 2.

One item tossed out there was that OpenSky provided a more robust talkgroup scanning capability.

On the OpenSky radio I have now at work, you are limited to scanning the current 16 channel profile in the radio and only able to "reliably" scan 3 of those talkgroups (the one your knob is one and whatever you have set as P1 and P2).

I know on the Motorola system (mixed mode analog/digital SmartZone) and EFJ Multinet system that I use for fire service and hazmat organizations I am involved with, you can scan multiple talkgroups throughout the radio banks.

How does this work on pure P25 phase 1 or 2 systems? Are talkgroups stored in banks that are all accessible or are they stored in unique 16 channel profiles (like OpenSky). What are the scanning limitations?

I'm just trying to figure out what information is correct. I was always under the impression that the limit of scanning 3 talkgroups reliably in OpenSky was a limitation that did not exist on other platforms. The way it was exlained in this discussion is that P25 was actually worse because the radio could onl direct the network to drive one talkgroup to it reliably (the on you have selected).

 

[kf8yk]

With P25 multisite trunking only the subscribers current transmit talkgroup is affiliated to the site. Different models of P25 subscriber radios have larger or smaller scan lists, but no matter how many talkgroups are in your scan list or how they are tagged priority/non priority only the TG audio you are set to transmit on will be reliably delivered to your site. Any scan activity you hear is purely by chance that another subscriber is affiliated to the same site as you and parked on one of your scan list TG's

OpenSky systems have a unique ability to not only affiliate the subscribers current transmit talkgroup but also two more priority scan list members (P1 & P2), allowing a total of three TG's to be reliably scanned. Additional scan list members can be added with the same caveat as P25 systems, another OS subscriber must be on your site parked on one of your non-priority scan TG's

P25 systems can be programmed to deliver certain TG's to a group of sites regardless if anyone is affiliated, but widespread use of this feature will destroy your loading capacity.

 

[HM1529]

That's pretty much the same explanation that came up in the meeting later on in the morning after I posted this question. I did not realize that limitation existed on a P25 system.

The primary law enforcement agency using our OpenSky system has previously voiced issues with only being able to reliably scan 3 talkgroups. Looks like the P25 option would not improve upon that limitation.

I guess I was spoiled by the EFJ Multinet system I use at the local level since you can essentially scan every talkgroup in the radio.

 

[talviar]

Ben,

I will e-mail you on that topic in a bit. Work or private email?

Tony
Fayette Co 911

 

[HM1529]

Ben,

I will e-mail you on that topic in a bit. Work or private email?

Tony
Fayette Co 911

Either is fine.