SF Municipal Transportation Agency (SFMTA) Trunked Systems

Radiobern · Jan 24, 2016

Looks like SF MTA has a new system that I just noticed on the following frequencies:

854.1125
854.2375
854.3875
854.4625
856.5125
856.6875
857.0625

From FCC records (ULS License - PubSafty/SpecEmer/PubSaftyNtlPlan,806-817/851-862MHz,Trunked License - WQVY934 - SAN FRANCISCO, CITY AND COUNTY OF), it appears to be for SF MTA and is associated with Harris. Since this does not sound like P25, DMR/MotoTRBO or NXDN, I concluded it to be Open Sky, since that is a Harris product. I suspect this system is up for those working on the "Super Bowl City" that is going on now.

jland138 · Jan 25, 2016

I seem to remember that the Harris Open Sky part of the SFMTA system upgrade is the data network. The voice system upgrade is 700 MHz P25 Phase II under this license: ULS License - Trunked Public Safety 700 MHz License - WQMJ646 - SAN FRANCISCO METROPOLITAN TRANSPORTATION AGENCY

The system was funded, but ran into construction problems at some sites: https://wireless2.fcc.gov/UlsEntry/...tachmentKey=19676603&attachmentInd=applAttach

Radiobern · Jan 25, 2016

Yes, I have noticed a control channel on 769.60625 but have not detected any voice activity yet. It is also a little weak for me to decode from my location.

Thank goodness there will be no voice on the Open Sky system.

officer_415 · Jan 25, 2016

I was monitoring the San Francisco 700 MHz P25 system this weekend and noticed a couple of talkgroups with SFMTA traffic on them. Has anyone heard about SFMTA using this system? I also noticed the control channel on 769.60625

bharvey2 · Jan 25, 2016

Radiobern, What type of antenna do you use to monitor San Fransciso? I'm in San Leandro as well and usually have a heck of a time with SF although years ago when everyone was analog I had little trouble. And, it seems odd that they'd go to Open Sky. I would have expected P25 to maintain some type of interoperability with SF public service.

Radiobern · Jan 25, 2016

I'm up on the San Leandro hills, about 200' up, so I'm line of sight with San Francisco. I typically can't use any outdoor antennas for 800 MHz as BART will overload my scanners (PSR-500 and Pro-668). I use either the Radio Shack 800 MHz rubber duck or another one I picked up from GRE that swivels to listen to SF.

Being line of sight with everything across the Bay is nice, but I have a very tough time with anything on my own side of the Bay. Anything directly to my north or south is shadowed out, so I have lots of multipath for anything in Oakland or Hayward/Fremont hills.

bharvey2 · Jan 25, 2016

Ah, the hills. That explains it. I'm not far from the marina. I do pretty well from my area with most VHF/UHF HAM, (need to get a HF rig still) but I do have multipath issues with the EBRCS system. I ended up building a narrow corner reflector antenna for the EBRCS system. It works best when mounted low for me.
Receiving SF was much easier when most of there transmissions were in the 400-500MHZ range.

With regard to the shadowing effect of your area, I'm familiar with it. My brother lives in the Hayward hills and has the same problem. Oakland repeaters are tough for him. Although, there are two in San Leandro that he can hit pretty well. We usually look for each other on those.

officer_415 · Jan 25, 2016

I monitored the San Francisco 700 MHz P25 system again today. SFMTA is operating on the following talkgroups, and the traffic sounds like Muni buses:

35110 - buses/dispatch
35111 - buses/dispatch
35113 - announcements ("TMC to all units")

The traffic on this system is NOT patched from the 480 MHz system, and there is still a lot of activity on that system.

Also, the control channel on 769.60625 indicated the following information:

System ID: 00A
WACN: 92732
RFSS: 006
Site: 006
NAC: 00A

Radiobern · Jan 25, 2016

The talk groups you listed, are they on the system with a control channel on 769.60625 or 770.10625? I have only detected an occasional encrypted talk group on the system with 770.10625. For some reason, 769.60625 is very weak at my location.

officer_415 · Jan 25, 2016

Sorry for the confusion, they are on the system with control channel 770.10625. The other control channel is also weak for me.

kma371 · Jan 25, 2016

mlangeveld said:
Also, the control channel on 769.60625 indicated the following information:

System ID: 00A
WACN: 92732
RFSS: 006
Site: 006
NAC: 00A

System added to DB here:

San Francisco Municipal Transportation Agency (SFMTA) Trunking System, San Francisco City/County, California - Scanner Frequencies

I'm also not able to pick up anything on the control channel you mentioned from my remote in San Leandro.

officer_415 · Jan 25, 2016

The control channel has rotated to 771.66875. I went to a better location and ran Unitrunker, and determined the following system frequencies, which match the frequencies licensed under WQMJ646:

769.60625
771.36875
771.66875
772.13125
772.43125
772.73125
773.13125
773.41875
774.64375

No activity on the system, but all of the frequencies were listed as control channels. I had a very strong signal on the scanner but Unitrunker still showed it as weak, possibly due to simulcast distortion (which could explain why you guys are unable to decode it).

Submitted to DB

kma371 · Jan 26, 2016

I've changed the topic of the thread to SF MTA since the discussion has been regarding both systems and not just the OpenSky one, for clarity.

mlangeveld said:
The control channel has rotated to 771.66875. I went to a better location and ran Unitrunker, and determined the following system frequencies, which match the frequencies licensed under WQMJ646:

769.60625
771.36875
771.66875
772.13125
772.43125
772.73125
773.13125
773.41875
774.64375

No activity on the system, but all of the frequencies were listed as control channels. I had a very strong signal on the scanner but Unitrunker still showed it as weak, possibly due to simulcast distortion (which could explain why you guys are unable to decode it).

Submitted to DB

vince48 · Jan 26, 2016

mlangeveld said:
I monitored the San Francisco 700 MHz P25 system again today. SFMTA is operating on the following talkgroups, and the traffic sounds like Muni buses:

35110 - buses/dispatch
35111 - buses/dispatch
35113 - announcements ("TMC to all units")

The traffic on this system is NOT patched from the 480 MHz system, and there is still a lot of activity on that system.

Also, the control channel on 769.60625 indicated the following information:

System ID: 00A
WACN: 92732
RFSS: 006
Site: 006
NAC: 00A

mlangeveld

are you actually hearing voice traffic on this system?

officer_415 · Jan 26, 2016

vince48 said:
mlangeveld

are you actually hearing voice traffic on this system?

Just to clarify, we are actually talking about 3 different systems:

1. The San Francisco County/City P25 system. This system has been active for several years, and recently SFMTA has been operating 3 talkgroups on it.

San Francisco County/City 700 MHz P25 Trunking System

2. The new SFMTA P25 system. Radiobern and I both noticed the control channel for this system recently, but no activity has been observed yet.

San Francisco Municipal Transportation Agency (SFMTA) Trunking System

3. The 800 MHz OpenSky system mentioned by Radiobern at the beginning of this thread. According to jland138, this system will be used for data only.

inigo88 · Jan 27, 2016

Should be easy to confirm the control channel you were hearing is OpenSky (on system #3, the data only network). Here's an audio sample of OpenSky data from the classic "Digital Modes Samples" website.

http://www.kb9ukd.com/digital/opensky-PA.mp3

You should also be able to find some Fedex OpenSky data channels in the 930-940 MHz range for comparison. They have a nationwide system for their portable computers.

I started to write control channel, but apparently according to the wiki OpenSky does not use control channels.
http://wiki.radioreference.com/index.php/OpenSky

In fact, it uses the DVSI AMBE codec and multiple TDMA timeslots per frequency. On first impression it sounds very similar to Motorola iDen formerly used on the NEXTEL network, which is fitting given their technical similarities.

officer_415 · Jan 27, 2016

inigo88 said:
Should be easy to confirm the control channel is OpenSky (on system #3, the data only network). Here's an audio sample of an OpenSky control channel from the classic "Digital Modes Samples" website.

http://www.kb9ukd.com/digital/opensky-PA.mp3

You should also be able to find some Fedex OpenSky control channels in the 940 MHz range for comparison. They have a nationwide system for their portable computers.

Confirmed.

officer_415 · Jul 24, 2017

I've been monitoring the various SFMTA systems over the past few weeks, and I've seen very little activity:

San Francisco P25 System (https://www.radioreference.com/apps/db/?sid=6758)
- No SFMTA activity observed, including on the bus talkgroups which were active last year

SFMTA P25 System (https://www.radioreference.com/apps/db/?sid=8580)
- Some radio testing, but the only active talkgroup seems to be 10595 cable cars

SFMTA Conventional System (480 MHz frequencies)
- Light Rail traffic on 484.6625 "channel 1"
- AVL data on 484.5625 and 484.7625
- Morse Identifier on 488.5625, no traffic

This leads me to believe that SFMTA has moved most of their operations to the OpenSky system. Does anyone have more information about this?

inigo88 · Jul 25, 2017

Thanks for the report. I wonder if OpenSky will be limited to buses only, or all of SF MTA?

SF Municipal Transportation Agency (SFMTA) Trunked Systems

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