City of Davis rebanded

[selgaran]

City of Davis rebanded today.

Frequencies should now be:

852.2750 (control channel)
852.6625
853.0750
853.6375
858.2375

Submitted to database.

 

[selgaran]

...and now the control channel appears to be on 853.6375

 

[officer_415]

Is 858.2375 active on the rebanded system? I know this was their mobile data frequency prior to the implementation of the trunked radio system, but I never saw it come up on the trunked system in the 4 years I lived in Davis...

 

[selgaran]

Is 858.2375 active on the rebanded system? I know this was their mobile data frequency prior to the implementation of the trunked radio system, but I never saw it come up on the trunked system in the 4 years I lived in Davis...

Yes, it is part of the system. There's rarely enough traffic on the system to light up all 4 voice channels at once. It was definitely in use during the rebanding process as they took the other channels down to convert them.

 

[officer_415]

It's my understanding that SmartNet systems cycle through all available voice channels with each successive transmission. I always saw traffic distributed evenly between 867.5875, 867.0750, and 866.6125 but I never saw traffic come up on 858.2375. Any idea why this would be the case?

 

[selgaran]

I know it is possible in SmartNet to set preferred channels (I think you can even do that on a talkgroup level), and that the system will temporarily skip a channel that it thinks is subject to interference. At any rate it is definitely active now (in fact, it just came up as I was typing this).

 

[officer_415]

Cool. I'm thinking it may have been the Base Station Identifier (BSI) channel, which transmits the FCC callsign. This is usually the lowest frequency in a trunked system, and like you said, there is rarely enough traffic on the Davis system to necessitate use of the BSI channel for voice.

 

[WayneH]

It's my understanding that SmartNet systems cycle through all available voice channels with each successive transmission.

It depends. Generally with message trunking (versus transmission) there's a timer that counts down after a call is complete before the previously used channel is reused by that TG. Otherwise the controller will revert to the lowest channel and then assign in an ascending order. So say a system is 10 channels and follows the general rules in assigning channel numbers. CH 10 would be for BSI and the four (or less) lowest channel numbers would be for Control. IIRC, with SmartZone will CC's and BSI only be assigned when all others are full so that they are free for BSI transmission or for the CC to roll in the event of channel failure. When someone knows the channel number assignments you can see there's some definite logic in their assignment.

I think it's EDACS which will step through them all. EDACS is typically transmission trunking.

 

[jt1331]

bandplan?

Is there a custom bandplan, or will the motorola rebanded preset work?

 

[WayneH]

Is there a custom bandplan, or will the motorola rebanded preset work?

The preset should work fine.