DSDPlus Beyond the Forest: Hunting for Hyphenated Talkgroups, Bigfoot's Secret Communication Network

[Facsimile]

Relevant system information: HERE

I've been monitoring a lightly documented system in hopes to add to it. I've come across a strange occurrence which has happened a couple of times with this system. As seen below in the log, there is a talkgroup that shows up as "15-1598" and a channel of 12. This would put the frequency at 450.1375 mhz which is not, according to the FCC nor the RRDB, part of anything in this area. Is this just a bug? Or something else? I've never seen a talkgroup with a hyphen. If it weren't for the Channel Activity window I never would have know it happened.

2024/04/08  04:27:23  Freq=452.387500  RAN=1  Registration; RID=14 [UNIT 6]   TG=3    ACCEPTED
2024/04/08  04:28:01  Freq=452.387500  RAN=1  Registration; RID=14 [UNIT 6]   TG=3    ACCEPTED
2024/04/08  04:36:06  Freq=452.387500  RAN=1  Group call; TG=98 [S.W.O.R.N. Security Channel 1]  RID=964 [SWORN HT 20]  Ch=153  2s
2024/04/08  04:51:08  Freq=452.387500  RAN=1  Group call; TG=15-1598  Ch=12
2024/04/08  04:53:21  Freq=452.387500  RAN=1  Registration; RID=217   TG=116    ACCEPTED
2024/04/08  04:56:18  Freq=452.387500  RAN=1  Deaffiliation; RID=964 [SWORN HT 20]    ACCEPTED
2024/04/08  04:58:51  Freq=452.387500  RAN=1  Registration; RID=250   TG=116    ACCEPTED

 

[dave3825]

What is your console log verbosity Level setting set to? It's in the menu under MISC.

 

[Facsimile]

What is your console log verbosity Level setting set to? It's in the menu under MISC.

It's set to the default of 3. Of course I disabled logging a few days ago and forgot to turn it back on. I assume the log would probably contain the answer?

 

[dave3825]

Not exactly sure how it's handled now, as the -E (FMP24) that used to do what's listed below is not a valid switch anymore but know I have my logging set to 4 and it logs more data..

DSD+ v2.5

note: TCP linking will not work with 1.x versions of FMP/FMP24/FMPA

added some ProVoice link control decoding

when a TCP link from FMP24 or FMPA is used,
the -E logging option adds tuned frequency information to DSDPlus.event entries

 

[lwvmobile]

Is this just a bug? Or something else?

Sounds like a bad decode, on NXDN, that frames LICH might have been accidentally decoded as a Type-D Distributed Trunking message, and you got a channel prefix - target value or similar from a VCALL or VCALL_ASSGN.

Type C or Conventional NXDN VCALL (same for VCALL_ASSGN)



Type D Distributed or Icom IDAS Trunking VCALL



Sounds a lot like a random erroneous Type-D message decode. All it would take is for the LICH code to be a bit or two off, but still pass parity.