How to map a new Phase II P25 system??

Hello RadioReference Forum. Bitting off a big chunk here and asking the following question.

If a local City is moving to a new phase II P25 system, and we know their standard frequencies, how do we start mapping out talk groups? How do we start building a map of the system? Any reference to point me towards?

And what is the best portable battery powered scanner for mapping out this new phase II P25 system?

thanks!

Uniden SDS100 (definitely, if the system uses simulcast) or 436 (excellent scanner, but isn't designed to handle simulcast).

Both have discovery and analysis tools for monitoring a system and logging unknown talkgroups in the scanner. Or if you connect the scanner to ProScan, that has even more logging and recording features.

A Uniden Scanner and PROSCAN.
1. Logs all data
2. Records all data

Do we have a real date for the SDS 100 to be released? Is it worth waiting for the SDS100 if the system is simulcast (it is)? The system has 4 control channels and 7 traffic channels.

In addition to recording audio, what helped me out the most in mapping a new system was UniTrunker. It's a bit difficult to get setup for a first time user but it is incredibly cheap. Maybe $20 to $25 to get a USB dongle.

It will record all trunking activity. Let's say that you have a clear dispatch channel, but NCIC is encrypted. You can piece this together by seeing a radio user's activity. In other words it helps by grouping various agencies that use the system with what talkgroups each of them use. ProScan mentioned above might do much of the same, I haven't used it.

In my area, the reused almost all of the previous talkgroup assignments from the old SmartNet system on the new P25 system. There was a mathematical adjustment, I think dividing by 16.

As for whether to wait for a better scanner, that answer resides in not how many frequencies they have but if they are using simulcast. Are the same set of output frequencies used at multiple tower locations? If so, you wait will be worth it.

If the new system has just gone up, there's likely several months of testing a tweaking ahead before it becomes primary. During that time period of seemingly low activity was some of the most important traffic. I left a scanner dedicated to recording the audio. Came home one day to a slew of very helpful activity... "Radio Shop testing Fire Ops 5"

Chances are also good that if you have other "less critical" users, they will be migrated to the new system first. This includes the dog catcher, public works and sanitation crews.

Chance said:

ProScan mentioned above might do much of the same, I haven't used it.

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I have, and it has very robust recording and TGID & UID logging.

If your current system is Harris EDACS system and moving to Harris P25 P2 it could be really easy to map the new system. My city did this a couple years ago and all they did was add one or two extra digits to the beginning of talkgroups. They did something similar to radio IDs but the State of Texas has a coordination system for assigning radio ID blocks to new or upgraded systems.

Chance said:

If the new system has just gone up, there's likely several months of testing a tweaking ahead before it becomes primary. During that time period of seemingly low activity was some of the most important traffic. I left a scanner dedicated to recording the audio. Came home one day to a slew of very helpful activity... "Radio Shop testing Fire Ops 5"

Chances are also good that if you have other "less critical" users, they will be migrated to the new system first. This includes the dog catcher, public works and sanitation crews.

Click to expand...

Good point! This early audio will be gold. I will dive a bit deeper quicker as the system is just starting up. I will check out UniTrucker ASAP as I already have a SDR USB stick.

nd5y said:

If your current system is Harris EDACS system and moving to Harris P25 P2 it could be really easy to map the new system. My city did this a couple years ago and all they did was add one or two extra digits to the beginning of talkgroups. They did something similar to radio IDs but the State of Texas has a coordination system for assigning radio ID blocks to new or upgraded systems.

Click to expand...

That makes sense, but it is a generation and vendor change, so it might be better to start from scratch.