Mototrbo question

[davef3138]

I've been looking around for detailed information on how the Mototrbo radios/repeaters can be programmed.

Do the repeatersact like a 2 channel trunked system (ie; can there be multiple talkgroups that utilize both TDMA timeslots) or is each repeater more like having two conventional repeaters (ie; a group of users on each timeslot).

We're looking for a new radio system that can ideally have more than 3 or 4 groups of users (ie; talkgroups) with at least two simutaneous conversations able to be carried on simutaneously. Not sure if a 2 channel LTR system would work (not sure of the costs involved) or if the Mototrbo system can work that way out of the box.

 

[DiGiTaLD]

If you setup a TRBO system in digital mode with a repeater, yes, you can create a maximum of 2 voice channels that operate independently of one another through the one TRBO repeater on one repeater frequency pair using the two TDMA timeslots, basically doubling the traffic capacity that a standard analog repeater would have on the same frequency pair. You could also have one voice channel and one data channel (for instant messaging and/or the integrated GPS position reporting functions of the radios) if you so desire on the same physical frequency pair.

If you go direct radio-to-radio, you lose the advantage of working through the repeater, which provides the time synchronization reference to all the users' radios so they are all synchronized to the same TDMA timeslot. Radio-to-radio without the repeater, you can only have one channel per frequency, just like any conventional analog radio in simplex mode.

 

[N_Jay]

It works more like two conventional community repeaters.

 

[hlferg]

Mototrbo

A single Mototrbo repeater setup would be more efficient due to the TDMA time slots. The dual community repeater analogy is close, but in digital mode (TDMA) can break down the data stream to allow limited multiple conversation on the same time slot, analog cannot due it's characteristics. Also you do not need to monitor a channel for voice activity, the radio xmits the data stream on PTT activation. ...whew, that was mouth full.

 

[davef3138]

Looks like they may have since updated the software to allow for trunking:

MOTOTRBO Capacity Plus
Motorola Announces New Features for MOTOTRBO and Launches Commercial Radio

 

[N_Jay]

A single Mototrbo repeater setup would be more efficient due to the TDMA time slots. The dual community repeater analogy is close, but in digital mode (TDMA) can break down the data stream to allow limited multiple conversation on the same time slot, analog cannot due it's characteristics. Also you do not need to monitor a channel for voice activity, the radio xmits the data stream on PTT activation. ...whew, that was mouth full.

(Assuming conventional) Nope, there is no mixing of conversations on a time slot. You own the slot when your group is active. There is also no automatic switching to the second slot, so even though you don't have to monitor, you will not get the channel if your slot is busy.

It might have been a mouthful of words, but not of facts.

 

[N_Jay]

Looks like they may have since updated the software to allow for trunking:

MOTOTRBO Capacity Plus
Motorola Announces New Features for MOTOTRBO and Launches Commercial Radio

Yep.

Last summer.