Sayreville P25 observations

[phillydjdan]

Last night I was floating around testing the programming of my many radios. They include a 996P2 scanner, APX7000 radio, Unication G5 pager, and XTL mobiles in UHF and 800 MHz. While I was able to verify that most systems worked on all of my equipment, Sayreville turned into an oddity. On my G5 pager it locked onto a control channel and gave me all bars (full signal strength). I could not tell if the APX locked on a control channel due to it being programmed for non-affiliate scanning. But the weirdest thing was observed on the scanner. Even though the frequencies programmed were accurate (I double checked), it seemed as if the control channel was only transmitting in spurts. It would put out a burst then nothing for a certain period of time, maybe a minute. But the G5 pager maintained the full scale while the scanner was jumping from full to nothing. I thought maybe I was getting interference so I moved literally into the borough and got the exact same results. So now my question is, why was it doing that? And I guess more importantly, is this system even being used? Maybe I can get some input from a local, as I've never seen any behavior like that from a P25 system...

 

[kd2pm]

I listen to the Middlesex Co P25 daily and have never seen that happen. But then again I am at the far end at the Middlesex/Mercer border. I am also using the SDS100 at the moment. Also, Middlesex Co is a 16 channel simulcast and there is also that slight possibility that you are getting LSM distortion that the scanner is having a hard time with. You could be picking up more than one tower and that slight phasing between the sites may be enough for the 996 to not always see a clean control channel and its bouncing in and out. Just a thought. Like I said, I live on the edge of the system so I only really hear 1 of the simulcast towers and I dont ever have a problem listening to everything on the county system

 

[GM]

Sayreville's P25 system is used, and I believe what you were seeing on the scanner with regards to the Control Channel is how the various scanners interpret the data used on a Harris branded P25 control channel. I have also observed the same activity with my BCD325P2 on the Middlesex County P25 network which also uses a Harris branded Control Channel.

Also another thing to keep in mind is Sayreville's P25 system is tied into the Middlesex County TRS at the core, so if a user's radio falls below a certain signal strength on one system, it automatically switches to the other system, and the voice traffic is simulcast between both systems on the same talkgroup number.

 

[phillydjdan]

I'm not talking about the Middlesex County system, I am talking about the Sayreville Borough P25 700 MHz system.

 

[phillydjdan]

Sayreville's P25 system is used, and I believe what you were seeing on the scanner with regards to the Control Channel is how the various scanners interpret the data used on a Harris branded P25 control channel. I have also observed the same activity with my BCD325P2 on the Middlesex County P25 network which also uses a Harris branded Control Channel.

Also another thing to keep in mind is Sayreville's P25 system is tied into the Middlesex County TRS at the core, so if a user's radio falls below a certain signal strength on one system, it automatically switches to the other system, and the voice traffic is simulcast between both systems on the same talkgroup number.

So, with that design in mind, do I even have to monitor the Sayreville Borough system at all? Could I get away with just scanning the Middlesex County system? I thought they were independent systems and you had to monitor the borough to hear anything in the borough.

 

[W2SJW]

You need to monitor the borough system for the majority of the traffic specific to the town.

The subscriber units will only fall-over to the county system if they lose solid signal with the borough system.

I keep forgetting to add the borough talkgroups to the county system to cover this in my SDS...

 

[mdsxfire]

So, with that design in mind, do I even have to monitor the Sayreville Borough system at all? Could I get away with just scanning the Middlesex County system? I thought they were independent systems and you had to monitor the borough to hear anything in the borough.

Nope u can just listen to them (FD) on the Middlesex county system, that’s how I listen and never have an issue (unication G5)


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[mdsxfire]

You need to monitor the borough system for the majority of the traffic specific to the town.

The subscriber units will only fall-over to the county system if they lose solid signal with the borough system.

I keep forgetting to add the borough talkgroups to the county system to cover this in my SDS...

Fire dept TG is always active on the county system


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[W2SJW]

My question as a follow-up is regards to EMS Dispatch - it shows in the clear on the borough system & encrypted on the county system.

Which is it (for real)?

 

[phillydjdan]

Fire dept TG is always active on the county system


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Sounds good! The less resources that need to be monitored, the better! My scope is generally fire anyway, so that's perfect. Thanks

 

[mdsxfire]

My question as a follow-up is regards to EMS Dispatch - it shows in the clear on the borough system & encrypted on the county system.

Which is it (for real)?

I think unit to dispatch is in the clear but dispatch to unit is encrypted or vice verse from what I’ve listened to.


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[Murenovich]

I know that Sayerville has had nothing but problems with their system since they set it up. Just the other day the fd and ems went out for an overturned and units were reporting issues with the tones and the message sent out from the dispatch. The dispatcher said he was doing everything he’s supposed to do and that some units got the full dispatch, so my guess is the issues haven’t gone away. A few of my buddies on the FD always complain on how horrible reception is and how they always have issues and are usually having to switch over to the county system.

Just another disaster of a system built and maintained by Harris, IMO.