Hello Adrian

Sorry to say I'm not particularly conversant with DMR; anyone who can furnish more detail is encouraged to jump in here...  Accordingly I'll have to limit this to generalities...

> reached a point where I no longer know how to interpret the ETSI standard

Yes, I know the feeling.  The TIA standards can induce the same feelings...

As for "aligned timing", I assume this to mean the capability of the MS to transmit TDMA fragments whose start and end times are in strict alignment with the slot boundaries demarcated by the outbound data stream transmitted by the BS.  The feasibility of this is more questionable when the MS is implemented in PC software and separated from the hardware radio by a number of software layers and drivers each having its own associated latencies / unpredictable delays.

All of this goes double when the MS also has to retune the radio at precisely the timing needed to acquire reverse channel bursts sandwiched between its own transmitted fragments.

For all the above reasons I decided it's not currently feasible for us to try to implement a TDMA subscriber in terms of GNU Radio blocks.  A proper job would seem to require an implementation at a level much closer to the RF hardware and/or the FPGAs.

> There are a few scenarios where it seems to me these tier 3
> services (power control, priority interrupt) cannot be
> available at all...
> 1. Alternate timeslot is a control channel
> 2. Alternate timeslot is idle
> 3. Alternate timeslot carries something other than voice payloads

In each of these cases I wouldn't be surprised if there might be room enough to also sneak a PDU or two into the alt. timeslot somewhere along the line?

> The standard doesn't clarify these cases