Station ID.

[skidplate]

Are the digital radio systems and cellular radio sites exempt from identifying the station call letters? If not, do they use cw to ID?

 

[mmckenna]

Digital and trunked radio systems do ID.
On a trunked system, the site is usually required to ID on the lowest assigned frequency at the specific site. ID is done in CW.

Cellular systems don't ID like you are thinking. Also, their licenses are usually done by market area and not individual site.

If you are not hearing them, it's usually because the digital systems will ID in analog FM using low deviation CW.
Analog sites usually send CW ID from the repeater without a CTCSS or DCS.

 

[W9WSS]

Matt, that was something I was thinking of, but you made it crystal clear. Thanks for the thorough explanation!

 

[popnokick]

Part 97 (Amateur Radio) digital systems ID as follows -
System Fusion - FCC callsign in digital data stream
D-STAR - FCC callsign in digital data stream
DMR - No FCC callsign in digital data stream, only DMR ID. Most stations use separate CW ID to remove any doubt regarding compliance

 

[RU55]

I know that I'm splitting hairs, but...

Technically, The transmission mode is frequency modulation (FM) not continuous wave (CW).

I think everyone knows what is meant by CW in reference to identification, but it would be more accurate to say that the stations identify using morse code.

I'm curious why they don't use digital ID, other than morse code (which is technically also digital.)

 

[skidplate]

Digital and trunked radio systems do ID.
On a trunked system, the site is usually required to ID on the lowest assigned frequency at the specific site. ID is done in CW.

Cellular systems don't ID like you are thinking. Also, their licenses are usually done by market area and not individual site.

If you are not hearing them, it's usually because the digital systems will ID in analog FM using low deviation CW.
Analog sites usually send CW ID from the repeater without a CTCSS or DCS.

Thanks for explaining it. 🙂

 

[GTR8000]

Modern P25 systems can ID digitally, by encoding the call sign over the control/traffic channels. This is now an acceptable form of ID'ing in most bands per the FCC, instead of the old school analog Morse code ID. MSI calls it "Digital BSI" on ASTRO 25 systems @ system release 7.16 or newer.

 

[mmckenna]

I know that I'm splitting hairs, but...

Technically, The transmission mode is frequency modulation (FM) not continuous wave (CW).

I think everyone knows what is meant by CW in reference to identification, but it would be more accurate to say that the stations identify using morse code.

Yes. Kenwood, however, still refers to it as CWID. We do know that Morse is the preferred method and what is called for by the FCC.

I'm curious why they don't use digital ID, other than morse code (which is technically also digital.)

The idea is that any of the LMR radios out there will work on analog, so having it in FM makes it easier for someone to identify a source of possible interference. Having to figure out what digital mode it is, then decode the ID isn't something that would be consider "easy".

 

[RU55]

The idea is that any of the LMR radios out there will work on analog, so having it in FM makes it easier for someone to identify a source of possible interference. Having to figure out what digital mode it is, then decode the ID isn't something that would be consider "easy".

That makes perfect sense.

 

[wa8pyr]

Digital and trunked radio systems do ID.
On a trunked system, the site is usually required to ID on the lowest assigned frequency at the specific site. ID is done in CW.

IIRC the rules for trunked systems were changed a few years ago to allow ID to be sent as part of system data, and I think it can use any licensed frequency. I can't hear it any more, but I see "BSI" pop up on various channels on Genwatch and ZoneWatch.

Update: I just saw the response from @GTR8000 earlier in the thread. What he said....

 

[mmckenna]

IIRC the rules for trunked systems were changed a few years ago to allow ID to be sent as part of system data, and I think it can use any licensed frequency. I can't hear it any more, but I see "BSI" pop up on various channels on Genwatch and ZoneWatch.

Yeah, no doubt it's changed. Entirely possible my "lowest frequency at the site" may be off/outdated. I know our old smartnet system was set up that way when I took it over. When I set up the NexEdge system as its replacement, I did the same thing.

 

[mmckenna]

90.425, 90.627 and others show what a difference there is for ID'ing depending on frequency, usage, etc.

90.627 for the 800MHz band still shows the lowest frequency for ID'ing.

90.559 for 700MHz systems allows rolling the ID into the digital signal.

90.735 for 220-222MHz systems

For cellular systems:

§ 22.313 Station identification.
The licensee of each station in the Public Mobile Services must ensure that the transmissions of that station are identified in accordance with the requirements of this section.

(a) Station identification is not required for transmission by:
(1) Stations in the Cellular Radiotelephone Service;

 

[GTR8000]

90.627 for the 800MHz band still shows the lowest frequency for ID'ing.

90.559(c) for 700 MHz and 90.647(c) for 800 MHz

 

[mmckenna]

90.559(c) for 700 MHz and 90.647(c) for 800 MHz

Thanks, number dyslexia on my part.

 

[wa8pyr]

90.627 for the 800MHz band still shows the lowest frequency for ID'ing.
90.559 for 700MHz systems allows rolling the ID into the digital signal.

90.559(c) for 700 MHz and 90.647(c) for 800 MHz

Interesting. The system we're a partner on has a mix, some 700 sites and some 800 sites (and some mixed with both 700 and 800); our site is all 800 MHz yet BSI shows up on any available channel. Must be a systemwide setting.

 

[GTR8000]

Interesting. The system we're a partner on has a mix, some 700 sites and some 800 sites (and some mixed with both 700 and 800); our site is all 800 MHz yet BSI shows up on any available channel. Must be a systemwide setting.

The ASTRO 25 digital BSI broadcasts continuously over the control channel (this can be seen in more recent Unitrunker 2.1 versions, see below), and the sites can also be setup to broadcast the BSI on the traffic channels during the course of normal transmissions. The call sign lives in the GCM comparators. We also disabled the analog BSI, so now the systems are pure digital BSI via OSP's.

I posted more in depth a while back here: Alternate control channels

 

[tadsmith]

The ASTRO 25 digital BSI broadcasts continuously over the control channel (this can be seen in more recent Unitrunker 2.1 versions, see below), and the sites can also be setup to broadcast the BSI on the traffic channels during the course of normal transmissions. The call sign lives in the GCM comparators. We also disabled the analog BSI, so now the systems are pure digital BSI via OSP's.

I posted more in depth a while back here: Alternate control channels

View attachment 129672

I know this is old, but is this by chance being broadcast in the Motorola, MFID = 0x90 opcode = 0x05? I've seen it referred to as MOT Traffic Chan Stn ID?

 

[tadsmith]

Looks like this confirms it. Thanks!

Decoding FCC Callsign from Motorola P25 Control Channels

Attached is a document that describes how to decode the FCC callsign from a Motorola P25 trunking control channel. All Motorola P25 trunking systems (since the 5.0 system release) will encode the callsign on the control channel using this method, if the system owner has populated the callsign...

forums.radioreference.com

 

[GTR8000]

I know this is old, but is this by chance being broadcast in the Motorola, MFID = 0x90 opcode = 0x05? I've seen it referred to as MOT Traffic Chan Stn ID?

Negative. The BSI opcode is 0B 90. 05 90 is the ASTRO 25 system broadcast.

This is how Unitrunker 2.1 represents the control channel data:

0B 90 B2 69 DA 20 B2 C0 16 08 7C 8B BSI Morse ID channel 1-608(771.65625) WQRE366

05 90 40 80 80 00 00 00 08 00 D1 63 Channel Access Information Broadcast AM N TDMA Y FRA 2 RRA 2 Zone 0 CA 0 PDR 0

 

[merlin]

I know that I'm splitting hairs, but...

Technically, The transmission mode is frequency modulation (FM) not continuous wave (CW).

I think everyone knows what is meant by CW in reference to identification, but it would be more accurate to say that the stations identify using morse code.

I'm curious why they don't use digital ID, other than morse code (which is technically also digital.)

Yea, just a bit. Digital modulation is OPSK, FDMA, or TDMA. CW ID is either embeded in the data stream or a sub carrier OOSK.