Future of "x2 tdma" in the dc metro

[RonBon]

I dont follow the forums much. Is it safe to say "x2 tdma" is off everyones table in the DC metro area jurisdictions for at least the near future until the phase 2 shift over starts approaching? I'm just curious when being able to decode phase 2 will matter. More important when will hobbyist types actually have to worry about a scanner with the proper hardware to handle "phase 2 tdma" saying goodbye to IMBE will be nice. Something to look forward to!

 

[ka3jjz]

I don't know what you mean by 'off the table' - the PSR-800 (and MAYBE the upcoming PSR-900) can decode X2. If a jurisidiction went completely Phase 2, then no scanner out of the box can handle it. And if anyone is developing such a beast, it's unlikely we'd hear about it now. Trade secrets, y'know...

Mike

 

[RonBon]

I was trying to avoid this but I thought everyone knew. X2 tdma is fancy for p25 phase one but double the price and a Motorola thing. Phase 2 tdma sounds more like a standard. X2 just has proprietary ring to it.

 

[RonBon]

I hope they have some trade secrets. I can't tell if the home patrol is a GPS unit or what. And I'm on my second P S R 800. The pavement won against my first one. The USB connector and antenna port on my second one are getting looser by the day. I'm not complaining because you're not going to see me build one. I hear selling those trade secrets it's a lot more profitable for everybody.

 

[lep]

I was trying to avoid this but I thought everyone knew. X2 tdma is fancy for p25 phase one but double the price and a Motorola thing. Phase 2 tdma sounds more like a standard. X2 just has proprietary ring to it.

Better re-read the APCO 25 Standards as recently approved by ITU-SG in Geneve. It is not limited to MOT nor is it the same thing as Phase 1.. no, I wasn't there as I retired in 2009 from attending those meetings at ITU HQ in Switzeralnd but I was present when "phase 1" was approved and still recall the discussions in some detail.

 

[ka3jjz]

Correct - as I understand it, X2-TDMA is Motorola's 'beta' implementation of Phase II. It's not a full spec.

It was quite a surprise when folks found out the PSR-800 could handle X2, as it wasn't in the documentation.

Mike

 

[RonBon]

I was surprised to see CQPSK still implemented in x2. Explains a lot.

 

[loco-lee]

a) I don't think there will be any more X2 implementations, now that MOT is shipping Phase II TDMA capable products.

b) Can someone point me to the test results, technical docs (or threads here on RR) that lead you all to believe the PSR-800 will not decode Phase II TDMA?

 

[ka3jjz]

re Question b:

I don't wish to sound rude, but if you use the search functions on this site, you'll come up with your answer...look at the blue toolbar under the sub title of the 'The RadioReference.com Forums' ... Mike

 

[loco-lee]

re Question b:

I don't wish to sound rude, but if you use the search functions on this site, you'll come up with your answer...look at the blue toolbar under the sub title of the 'The RadioReference.com Forums' ... Mike

I have searched within the forums on this site everything from "PSR-800 Phase II" to "IDENup" and can't find what I am looking for. I was hoping someone would be so kind as to post a link to RR or elsewhere.

 

[ka3jjz]

Hmm...I came up with 6 pages of forum items when I searched on 'PSR-800 + TDMA' - live and learn.

Here's a candidate for you - search for TxWarn traffic in the Texas forum - this system uses Phase II, not X2, evidently...

Texas Wide Area Radio Network (TxWARN) Project 25 Trunking System, Various, Texas - Scanner Frequencies

Mike

 

[GTR8000]

I asked GRE directly, and they replied directly to me. I can't link you to anything because it wasn't a public conversation, but here is GRE's reply...straight from the horse's mouth:

Currently the PSR-800 will decode only X2 TDMA. We still do not know if the hardware will be able to handle the Phase II TDMA data at this time.

 

[loco-lee]

Hmm...I came up with 6 pages of forum items when I searched on 'PSR-800 + TDMA' - live and learn.

Here's a candidate for you - search for TxWarn traffic in the Texas forum - this system uses Phase II, not X2, evidently...

Texas Wide Area Radio Network (TxWARN) Project 25 Trunking System, Various, Texas - Scanner Frequencies

Mike

Thanks, I will try 'PSR-800 + TDMA' and see what it found.

 

[ka3jjz]

You might also want to look for trunking in Houston - and in Florida, the following system also appears to be Phase II, not X2

Apopka Public Safety (Project 25) Trunking System, Apopka, Florida - Scanner Frequencies

There aren't, AFAIK, too many pure Phase II systems out there yet - good for us scannists, but that may change down the road as Moto 'pushes the new tech'. How long it will be before someone comes up with a Phase II scanner is anyone's guess, particularly if the standard hasn't been completely ratified yet (at least, last that I had heard - someone better informed would please chime in on that). No one is going to try to develop something against a moving target

Mike

 

[GTR8000]

How long it will be before someone comes up with a Phase II scanner is anyone's guess, particularly if the standard hasn't been completely ratified yet (at least, last that I had heard - someone better informed would please chime in on that). No one is going to try to develop something against a moving target

You heard wrong. The Phase II standard was finalized in November 2010, with the first Phase II systems shipping last summer.

 

[brownlab]

I thought I read that X-2 TDMA was now being used in Jacksonville Fla which I thought was odd since yes, Phase 2 TDMA is available.

 

[GTR8000]

I thought I read that X-2 TDMA was now being used in Jacksonville Fla which I thought was odd since yes, Phase 2 TDMA is available.

Please keep in mind that the XTS series are X2-TDMA capable, but are not Phase II TDMA capable. Only the APX series is Phase II capable. This is a huge determining factor whether a system remains using X2 or upgrades to Phase II. If you have to support XTS radios, while taking advantage of TDMA (effectively doubling your voice paths), you have to remain at X2 instead of upgrading to Phase II.

 

[RonBon]

There are other radios out there. The apx series is not a one man show. Unless a color screen and 2 speakers are what you need...Cough..imbe? Interoperable. There is a reason the psr800 decodes x2 very well. Decoding loudouns control data and some other pieces of signal software was fun. Eye opening.

 

[GTR8000]

There are other radios out there. The apx series is not a one man show. Unless a color screen and 2 speakers are what you need. Cough..imbe?

You missed the point of my direct response to brownlab's comment that he thought it was "odd" that they would stick with X2 when Phase II is available. My point is that a lot of these agencies have a significant investment in XTS radios and can't afford to purchase hundreds or thousands of APX (or whatever your choice of manufacturer is) radios just to implement Phase II. So, they stick with X2-TDMA for the time being, allowing them to take advantage of some form of TDMA without having to spend an enormous amount of money upgrading radios.

By the way, X2 was more than just "fancy for p25 phase one", it actually allowed users to double the amount of voice paths on ASTRO25 systems by leveraging TDMA technology prior to the final Phase II standard being written and adopted. It was a stopgap solution to agencies having limited spectrum available.

 

[RonBon]

Done.I got you.