SF MUNI Data channels?

[samccormack]

Is it possible to decode the data channels used by the MUNI system in San Francisco? I realize the whole idea may be pointless if it is encrypted in some way but it would interesting to at least know what sort of data is being sent over those channels. I've only found info on decoding data in the HF bands that I am not sure applies to data channels found on VHF/UHF radio systems or if I even have the equipment to even attempt it (I have a Uniden BCD396T and am going to pick up a BCD396XT soon)

 

[WayneH]

I know little about how they use their system but typically organizations like these use what's referred to as "transit trunking". This isn't trunking like how you think of it in the traditional sense. Radios are not told which channels to operate on like a standard system. The data is more for signaling at a higher level like authorizing transmission on a dispatch channel. A bus has to request authorization before they can speak over the conventional repeater.

There's really not a lot of info on how these systems operate so with that I don't know of software to decode the info on the data channels. It wouldn't be that interesting.

 

[winglessBat]

This is very old technology provided by Motorola way back in the days. I believe it's called Metrocom or something. TDMA-based 6 slots per second.

 

[bayareascan]

Is it possible to decode the data channels used by the MUNI system in San Francisco? I realize the whole idea may be pointless if it is encrypted in some way but it would interesting to at least know what sort of data is being sent over those channels. I've only found info on decoding data in the HF bands that I am not sure applies to data channels found on VHF/UHF radio systems or if I even have the equipment to even attempt it (I have a Uniden BCD396T and am going to pick up a BCD396XT soon)

I doubt it's encrypted. You probably would be bored to monitor text msgs between the dispatchers and the drivers. Many messages are pre programed. Late-passenger load, restroom stop, farebox jamed ect.
If you have a true organized list of Muni frequencys, i would appreciate.