XPR XPR7550e and TDMA

[dmason04]

Howdy y'all,
I have some questions about conventional operation of the XPR7550e. Is TDMA available on a conventional channel? I assume the XPR is similar to my XTS in the sense that there are digital P25 and analog conventional channels (obviously it's DMR, not P25.) I read that the APX series only do TDMA on a trunking system. We don't have a trunking system operational currently. My question essentially is this: Will I be able to use TDMA voice on a conventional channel?

Thanks,
David

 

[KA0KDW]

If you’re meaning convential DMR the answer is yes. DMR regardless of conventional or trunking is TDMA.

 

[dmason04]

If you’re meaning convential DMR the answer is yes. DMR regardless of conventional or trunking is TDMA.

That was fast, thanks for your help!!

 

[tweiss3]

DMR is by definition TDMA all the time. There are considered 3 tiers, 1 being simplex, 2 being repeater based and 3 is trunked. XPR7550e will do all no problem, but unlike some of the amateur radios, you cannot listen to both timeslots at the same time.

 

[KA0KDW]

No problem. Just happened to see the title of the thread on the RR home page and decided to click it.

 

[KA0KDW]

Although DMR Tier 3 should not be confused with Motorola’s Cap or Connect + trunking methods. in technicality those aren’t tier 3 as specified by ETSI (European Telecommunications Standards Institute) where DMR originated.

 

[clbsquared]

The APX radios will do both TDMA and FDMA for P25. They will not support DMR in any form or fashion. Therefore, an APX can only communicate with an XPR in conventional analog only.

 

[GTR8000]

I read that the APX series only do TDMA on a trunking system.

It has nothing to do with the APX, and everything to do with the P25 standard. TDMA is only available in trunking when it comes to P25, aka Phase II operation. P25 conventional is always FDMA aka Phase I.

 

[PACNWDude]

Great info above....use many TDMA and analog XPR7550e radios, as well as administer a nationwide P25 Phase 1 / 2 and Trbo based network. Everything connects in analog mode, or via Zetron 6300 IP interface into Motorola CCGW's. When you make a channel in the XPR7550e you have a choice of analog or digital, in digital you then set the time slot for TDMA. Great radios (XPR7550/7550e) that hold up well for their price. We have many forklift drivers that run them over, just like their previous XTS1500's.

The biggest problem is when end users that use APX900's (ASTRO) go to a site that is using XPR7550/7550e radios (Trbo) and wonder why they do not work, as the radios themselves look very similar.

 

[KN4EHX]

P25 Phase I and Yaesu Fusion are both FDMA / C4FM. Practically kissing first cousins, but just different enough they aren’t compatible.

P25 Phase II and DMR are both TDMA. Practically kissing first cousins, but just different enough they aren’t compatible. Mind you P25 Phase II is for trunking and although DMR Tier III is trunked they are still different enough they aren’t compatible.

You mentioned the APX, but the Kenwood NX series is worthy of a notable mention due to the fact it is capable of supporting analog, DMR, and P25 all in the same radio. Although as far as I am aware they are single band only. Perhaps in the future they will make a full spectrum multi mode portable, but you gotta pay to play. Whenever they do, it will probably be LTE capable, touch screen, case bejeweled with diamonds, and can be had for the low low price of around $20,000 if you agree to purchase at least 30 units. 5 years down the line they’ll come up with a new certification that will be required for fire use.

Hope that helps.