The state of Tennessee Advanced Communications Network (TACN)

[INDY72]

TDMA is an digital format: It is recognized as the standard format for digital mobile radio (DMR). It supports multiple users simultaneously using multiple "slots" for data/voice transmissions. Current TDMA is 2 slot. The next phase is 4, then 6. P25 Phase II uses 2 slot TDMA. (Trunking ONLY) Currently there is ONLY an P25 Phase II format for TRUNKING.... Conventional repeaters that want to use DMR, must use a commercially offered solution such as MotoTRBO until they can come up with an Phase II P25 for conventional.

Phase I P25 uses FDMA, which only allows one use of a "slot" either data, or voice. (Conventional that means only one user can be on a frequency at a time for FDMA, where as with TDMA you could have two users on the same frequency at the same time, or an data signal and a user. Trunked means you have 2 usable spots per frequency, so say on an 3 frequency site, you can now have up to 4 or 5 users talking with TDMA, as opposed to only 2 users with FDMA... 3 freqs - 6 slots... 1 data chan leaving 4 to 5 possible voice slots,,,, VS 3 freqs - 3 slots... 1 data chan leaving only 2 usable voice slots.)

So imagine if you will, an trunking simulcast mega site with 30 or more freqs.... Using TDMA.... You do the math....

 

[vans113]

Awesome ! Thanks for explaining !! So this basically means if they don't go encrypted a psr-800 will pick up the Clarksville site just fine so I can listen again when they switch !


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[INDY72]

Precisely. Any Phase II capable offering in the scanner market will let you hear P25 Phase II TDMA... The way things have been stated, Whistler may also be offering an scanner capable of ANY Non Encrypted TDMA format. (A true DMR scanner). The November release of an new Uniden, will most likely have Phase II abilities as well...

 

[vans113]

Doesn't dsd decode dmr?


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[INDY72]

Doesn't dsd decode dmr?


Too a point... There have been issues stated about MotoTRBO trunking and DSD.... Do not know if this in BOTH formats, or just one. It works fine on NON ENCRYPTED DMR Conventional. There is also DMRDecode out there I believe?

 

[vans113]

I'll look into that if so, I'd like to use unitruker for the control channel and dsd or that dmrdecode to decode the audio. Thats that i do now for the clarksville system thats on provoice. That would save me spending 500+ on a new scanner.

 

[INDY72]

Um... Pro96Com is best for CC decode and system analysis for an P25 system. But you are going to a lot of trouble by using multiple softwares and taps of a scanner to do what a one time purchase of an capable scanner can do for years.... And all in one package....

 

[vans113]

I am yes, but I already have all of the modded scanner, and everything. The way clarksville goes about stuff honestly if they're out in open. It will be just a matter of time before encryption.

 

[vans113]

UPDATE: They are working on the radios here. Here is a sample of audio i edited where you can hear the officer say " Dispatch can't reach us" which is never a good thing. Again this is the clarksville system audio is edacs provoice and is deocded using unitrunker and dsd https://soundcloud.com/michael-eric-johnson/dispatch-down

 

[mthurmerm]

All I can say is I hope Uniden or Radio Shack will come out with a pre-programmed simple unit. Standing By, Mitch

 

[vans113]

I'm hoping so! I talked to one of the techs and he isn't allowed to speak on any info about the system. So it's just a waiting game from here


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[mthurmerm]

QUESTION, Will this scanner do what I want ?
Uniden® BCD996XT Digital TrunkTracker IV Scanner

It is $ 449, not a minor expense, Please advise M.Thurmer

 

[vans113]

What is it that you want ?


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[davewhall29]

QUESTION, Will this scanner do what I want ?
Uniden® BCD996XT Digital TrunkTracker IV Scanner

It is $ 449, not a minor expense, Please advise M.Thurmer

That scanner will pick up the TACN, including THP (unless they are using Phase II or encrypted). It will also cover everything else that you are currently listening to (Polk, Bradley, etc., based on your previous posts).
Currently THP Districts 1, 2, and 5 are in the clear on their main dispatch channels, however, I have been picking up all encrypted talk on their Ops channels, and some in PII.

 

[davewhall29]

New talkgroup picked up early this morning.

2-fully encrypted on the Lenoir City site. My guess radio tech of some sort. Radio IDs in the 404XXX and 202XXX range, couldn't get to scanner quickly enough to get complete IDs. Just thought I'd pass it along.

 

[davewhall29]

Quick question, As I understand it if a radio has a specific talkgroup programmed in it and associates with a particular site, then I would be able to pick up that talkgroup off that site, correct?

Example, I am picking up TGID 1187 (Chattanooga Hospital Routing) off the Knoxville Sharp's Ridge site and am hearing Medcom and ambulances talking. But only every now and then. So, does that mean someone who has that TGID programmed into their radio is near the Sharp's Ridge tower? Even if they are not using that TGID, would it associate with that tower and thus making it able for me to pick it up?

Next question would be I wonder who that is that is close enough to the Sharp's Ridge tower for the TGID to associate?

Thanks,
David

 

[W4EMS]

I hear that TG and 1320 when Lifeforce is flying near Murfreesboro. Guess having a 3000' AGL antenna covers a lot of turf.

 

[slatescan]

New TG 16004 giving weather cx wind speed etc etc. coming off the Nashville Site



edit 10:52 CDT same tg was ref columns and numbers just now

 

[slatescan]

also heard 15136 talk about new radios another prison coming online?


hearing 15106 hearing a ref to count time. another new prison

 

[K4AOL]

Am in Gibson and Madison County area also noticed a few more new TGs will put the home patrol on discovery mode and see what new ones I get.