Problems getting Galveston Phase II to work G4

[maus92]

On the state of Maryland's Motorola P25P2 system (First,),the six packs have only two cch's. Even the 8 channel sites have 2 cch's. Conversely, a Maryland county's brand new Motorola P25P2 simulcast site is (currently) advertising 4 cch's, but it is not officially online yet, and hasn't migrated from its legacy Type II system.

 

[Project25_MASTR]

I'm sitting here looking at several systems, all Motorola, all fairly recent except the TxWARN site:
TxWARN - 2 CCs
2 other systems - 2 CCs
Another system - 6 CCs (much larger system)

The hard-and-fast you-must-advertise-4-control-channels-period died with Type II, I believe. I'm pretty sure TxWARN doesn't advertise 4 per site because of the channel number limitations in the A25/APX platform radios. They simply couldn't enter all of the sites into a single CC list if every one advertised 4.

In all honesty, the channel limitation thing shouldn't be a factor, at least with Astro 25 and APX subscribers. Yes there is a limit to how many control channels that can be programmed into the radio but once the radio affiliates, it will begin to read the control channel info off the control channel itself and begin to store that channel info in the flash memory. It will retain that information until either it needs to be overwritten or a new codeplug is written to the radio.

Likely some other reason (FB8 availability for example, though I seem to see a lot of FB2's on other systems for control channels) and that may be why the some system managers feel comfortable allowing only two advertised control channels at a site.

 

[David628]

So this Phase 2 MARC colorado metro system has only control channels listed: https://www.radioreference.com/apps/db/?sid=6616
Any idea why thats the case?

 

[maus92]

Harris P25 systems can use any frequency as a control channel, so all must be programmed.

 

[David628]

Harris P25 systems can use any frequency as a control channel, so all must be programmed.

So will programming all CC’s on one (1) individual tower site (I.e 5, 6 or 7 for the one tower) work or do you have to enter ALL of the CC’s listed (30 Plus) for all tower sites listed in in the entire system?




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[troymail]

Think of each site as a "mini-system" - if you program any single set of site frequencies, you'll only hear that site. If you want to potentially hear the other sites, you'll need to program them as well.

If "fully" programmed as a 5 site system, your radio will attempt to find the better of the sites (signal strength wise) and lock onto that site. When you travel around Jefferson, the radio will/might/could determine that the current locked on site is of poor quality and look, find, and lock onto a different site.

For the system in question, I'd suspect that the Arvada Simulcast is the main site which would carry most/all of the traffic and the other sites have specific purpose - gap filling, facility based, etc.

Keep in mind that you could potentially hear slightly (or even completely) different traffic/activity on each site and some systems have sites where you'll hear no voice activity.

 

[Spitfire8520]

If "fully" programmed as a 5 site system, your radio will attempt to find the better of the sites (signal strength wise) and lock onto that site. When you travel around Jefferson, the radio will/might/could determine that the current locked on site is of poor quality and look, find, and lock onto a different site.

For this specific system, please do not program Denver's Mount Morrison site in with the rest of the system. It is effectively its own system and should be programmed as such. It is why there are two sites co-located at the same location, each serves a separate community.

For the system in question, I'd suspect that the Arvada Simulcast is the main site which would carry most/all of the traffic and the other sites have specific purpose - gap filling, facility based, etc.

The Arvada Simulcast is the main site for Arvada in the northeast, but most everyone else uses the other sites. The Arvada Simulcast is the one gap filling for Arvada since they joined an already established system in this case .

 

[troymail]

Good to know -- every system is different....

I figured there was something odd given it is a "5 site" P25 system that appears to cover one county per RR (Jefferson). To me, that's pretty unusual but anything is possible. RRDB labeling is a bit confusing (at least to me - not knowing the area or system first hand) given all sites are reporting being in that one county and only one is labeled simulcast (perhaps RRDB limitations). However, one site is clearly marked "Denver only".

I've encountered some multi-site systems that have sites that carry no voice traffic at all - and others where sites appear to be specific to a facility or complex and 99% of the traffic on that given site is encrypted. And other systems I've monitored have two "sites" that cover roughly the exact same area but carry different traffic most of the time.

In this case, I'd recommend programming (or adding programming) that defines each site as a separate system in the PPS and then configuring at least one zone/knob that is specific to each site (you can use TG-Monitor or a "wildcard" group of 65535). Then, attempt to monitor each site to determine what activity is being carried on each.

 

[maus92]

From afar, it looks like a multicast system to me. But like Troy, I'm not familiar with the system or the geography. If it were me, I'd program each site as a separate knob position, and program a few target TGs to test. But then again I'd probably map the system with Unitrunker or eqv. first to get an idea about how the radio traffic is segmented. Bottom line though is all the site freqs for each site need to entered because that is how Harris builds resilience into their systems.

 

[David628]

I’m always learning something new every day from you all on this site. Thanks to everyone who replied back!


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