Same (trunk) site number, different bands, separate CC

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Jay911

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Hey folks..

Got a kind of a conundrum going on here and wondering if it's addressed in the DB handbook (or if someone just has an opinion on how it should go).

I submitted a VHF frequency last night for the Alberta provincial radio system. This system is still being built out, is mostly 700 MHz P25 Phase 1, and the VHF was supposed to be "conventional" according to the details I received. Yesterday I was picking up "idle voice" P25 CAI on that VHF frequency - something I've encountered on other Harris P25 systems before, on the voice channels - and I submitted it, as I said above, as VHF conventional.

Today, while out on the road, I checked that frequency again, and I am getting CC data off that same frequency. The data I'm getting is the exact same WACN, SysID, RFSS, and Site number as the same location's 700 MHz site. I won't know until I get home tonight and look at the HP1 analyzer logs, what the bandplan (iden 0) is like on the VHF side, but I doubt this is just a simulcast of the 700 MHz CC - I believe there are two different CCs being transmitted here.

So my question is, how should this be represented in the database? They are both 05B-660C5, RFSS 95, site 95. Would you put the VHF frequency on the same RR site entry as the 700 frequency? I'm not sure that's completely appropriate since there are two distinct control channels operating. Would you create two RRDB site entries, each with identical details except the actual frequency(ies) in use? Or would that wreak havoc with scanners/programs that download and use the data, and/or the RRDB data itself? Or, is there a "third option" I'm not thinking of?
 

wa8pyr

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Got a kind of a conundrum going on here and wondering if it's addressed in the DB handbook (or if someone just has an opinion on how it should go).

I submitted a VHF frequency last night for the Alberta provincial radio system. This system is still being built out, is mostly 700 MHz P25 Phase 1, and the VHF was supposed to be "conventional" according to the details I received. Yesterday I was picking up "idle voice" P25 CAI on that VHF frequency - something I've encountered on other Harris P25 systems before, on the voice channels - and I submitted it, as I said above, as VHF conventional.

Today, while out on the road, I checked that frequency again, and I am getting CC data off that same frequency. The data I'm getting is the exact same WACN, SysID, RFSS, and Site number as the same location's 700 MHz site. I won't know until I get home tonight and look at the HP1 analyzer logs, what the bandplan (iden 0) is like on the VHF side, but I doubt this is just a simulcast of the 700 MHz CC - I believe there are two different CCs being transmitted here.

So my question is, how should this be represented in the database? They are both 05B-660C5, RFSS 95, site 95. Would you put the VHF frequency on the same RR site entry as the 700 frequency? I'm not sure that's completely appropriate since there are two distinct control channels operating. Would you create two RRDB site entries, each with identical details except the actual frequency(ies) in use? Or would that wreak havoc with scanners/programs that download and use the data, and/or the RRDB data itself? Or, is there a "third option" I'm not thinking of?
If the system is still being built out, let's let things settle down a bit before we jump to any conclusions.

Without knowing the exact details of the system I suspect you may be seeing a patch or simulcast or some special system development thing.

As I understand it from system administrator classes, every site in the system has to have a unique RFSS (aka Zone) and Site ID; there can be two sites sharing Site #2, but they have to be in separate subsystems/zones. This goes for conventional sites, trunked sites, console sites, etc.

With everything connected to the same system controller, basically all the controller sees is a whole mess of sites.

Unless there are confirmed trunked voice channels being assigned by that control channel we would have to treat it as a conventional frequency.
 

Jay911

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It's definitely a separate control channel, pushing a VHF iden, but with the same sysid etc. To boot, the iden is incorrect (off by 10 kHz) for the channel.

The 700 site is (and has for a long time) shown site trunking, but the VHF site does not.

Clearly there's still some work to be done by the techs in order to put this online.

I do disagree with requiring it to be a conventional frequency if it doesn't grant a dedicated voice channel, though. I know of a number of sites on other P25 systems with a single frequency, control channel in normal operation but VOC (voice on control) functionality when voice traffic is present. The Newfoundland provincial radio system is one such example - around a third to a half of the sites on that system are single-channel VOC.

In any case, there's obviously more monitoring to be done before this gets finalized. Thanks for the reply.
 
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