Nice idea, but unworkable in D-Star due to the fact that it's a single carrier system.
If you take a real trunked system like MPT1327, trunked P25 or TETRA, then there multiple carriers per site (or timeslots in the case of TETRA) to allow multiple calls. In D-Star, there can only be one session at a time per repeater. You would need some contention system to handle multiple users. For example, if the repeater you appeared on was linked to D-Plus, would you unlink it ? When would you re-link ? What if a QSO was in progress ? Don't get me wrong - I like the idea. But D-Star uses the wrong radio access method to make it work. David --- In dstar_digital@yahoogroups.com, John Hays <j...@...> wrote: > > > On Jan 22, 2010, at 3:28 PM, Nate Duehr wrote: > > > On 1/22/2010 4:03 PM, Neil wrote: > > > >> > >> > >> Wouldn't it be nice if say, a group of people around the country > >> (or world even), could put a special call in the UR field and > >> everyone in that group would have their traffic automatically > >> routed to all the other members, bit like a multicast I suppose, > >> but not much fun if the local repeater was already in use. > >> (That's where G3 'could' come in handy, sending a message instead > >> to the members radio on that repeater, underneath the QSO without > >> hindering the other users...then you could switch to another > >> repeater/node and continue.) > >> > >> I suppose you could subscribe to a 'multicast group', something > >> like a reflector that handles instantaneous multiple connections. > >> > >> Food for thought... > >> > >> 73 de Neil G7EBY > > > > The commercial digital world calls this "talk groups" and has had it > > for at least a decade. > > > > An Amateur talk group system would need to come up with a way to > > "self-register" with a particular talk group. > > > > Could be done. Interesting concept. > > > > Nate WY0X > > > > > > > Once we have an open source gateway, its pretty easy. My > understanding is that the RP2C sends any transmission with something > in RPT2 to the gateway (doesn't have to just be "call G" --- there > are a couple of syntax that could be used. > > UR: TG00000R (Register) > MY: K7VE > RPT1: NW7DR (Module number isn't required by the protocol, but may be > required for RP2C) > RPT2: GATEWAY > > With UR:TG00000U (UnRegister) > > The gateway would have a list of active talkgroups and register itself > to the talkgroup server (like a reflector) for two way transmission > relay -- no need for a "link" > > Another syntax: > > UR: xxxxxxxx (usually CQCQCQ or -------U to Unregister) > MY: K7VE > RPT1: NW7DR > RPT2: TG00000 (Gateway will register for talkgroup if not already > registered, keep a list of local callsigns in the group and unregister > when the last sends the unregister or times out) > > Arbitration of multiple talk groups on a single repeater frequency is > the main downside. > > > > > John D. Hays > Amateur Radio Station K7VE > PO Box 1223 > Edmonds, WA 98020-1223 VOIP/SIP: j...@... > Email: j...@... >
