P25 phase II

[FMROB]

Since someone was nice enough to lock the preceding thread, I have a question.

Will the new phase two of P25 allow for two simultaneous voice paths much the way that Mototrbo does??

I appoligize in advance if this question causes anyone any undue hardship....

[Wowbagger]

Since someone was nice enough to lock the preceding thread, I have a question.

Will the new phase two of P25 allow for two simultaneous voice paths much the way that Mototrbo does??

I appoligize in advance if this question causes anyone any undue hardship....

No, that is a reasonable question. Yes, both the current Motorola "F2" and the (still a work in progress) TIA Phase II will allow 2 time slots per 12.5 kHz channel. A timeslot can be either a traffic channel (carrying voice or data) or a control channel.

Thus, an F2 or P2 system can use 1 RF channel to carry either 2 conversations, or a conversation and a control channel (or 2 control channels, or 2 halves of the same control channel. Now do you see why writing the protocol stack for these things is a :o?)

If an RF channel carries 2 conversations in 12.5 kHz, that's an effective 6.25kHz per traffic channel.

Also, it is possible to support "full duplex" operation by shifting the inbound timeslots relative to the outbound timeslots. Thus it looks like this:

Inbound: | slot 0 | slot 1 | slot 0 | slot 1 | slot 0 |
Outbound:| slot 1 | slot 0 | slot 1 | slot 0 | slot 1 |

So a mobile subscriber unit (that's "radio" to you) can listen to the outbound, then turn around and transmit on the inbound, then listen on outbound, etc. - talk and listen at the same time WITHOUT having a duplexer in the radio (just an RF switch to allow the TX and RX to alternately connect to the antenna).

In that regard MotoTRBO, Phase II, and Motorola F2 are similar (in the same sense that an Accord, a Crown Vic, and an Impala are similar).

(still doesn't mean you can take parts off on and bolt them onto another, though.)

[FMROB]

I have a friend that is looking to build out a multi user, multi channel radio system on a handful of UHF channels. He was looking into the Kewood nexedge. The kenwood has great features with the trunking and security however is 12.5 fdma which is single user single time slot. To run the 6.25 feature it would require alot of re-license work and the equipment price jumps.

He is setting his eyes on the turbo which essentially will allow two distinct users per channel to operate simultaneously (best bang for the buck theory). I also heard that motorola might be looking to provide internet linking and possibly trunking capabilities to the trbo line. If that is the case it would be truely a great deal.

Any insight on any other systems out there or your thoughts on the trbo equipment.

Thanks, Rob