hi all, May I ask the follow question. For a single site Voice communication digital repeater operation in identical conditions, which format /system type will work better in multi path signal ,with lager coverage area. FDMA,TDMA (D-Star ,Mototrbo,P25,Nexedge,Idas) ?
TNX & 73s de VR2XVD/W.L.Ho 6 Apr.10 On Tue, Apr 6, 2010 at 12:58 AM, MCH <m...@nb.net> wrote: > > > There are P25 repeaters on the air. Granted, not as many as D-STAR > (strictly talking about ham systems), but I know of nobody giving away > P25 repeaters. Also, I bet there are more P25 receivers owned by hams > than D-STAR since there are several scanners that decode P25, and only a > few that decode D-STAR (not ironically, all made by Icom). > > Anyway, the point is not which format to use, but to make the systems as > flexible as possible so they can be available in emergencies. Simply > put, D-STAR is not as flexible as P25 since a P25 repeater can be made > to pass P25 or analog. Granted, D-STAR does have some format benefits, > but those could easily be added to P25 (or, the P25 benefits could be > added to D-STAR, as has been discussed). > > There are also MotoTRBO repeaters in the ham bands, now. The more > various formats you add to the mix, the less we will be likely to use > them when they are needed. On the other hand, all the radios can use > analog - making it the clear choice for emergency communications. > > Joe M. > > John Szwarc wrote: > > > > > > Okay. I've been reading with some interest the threads on D-STAR. > > There have been some very good points and some pretty amusing ones. P25 > > sounds interesting, but you will have to take note of the fact that it > > has not been widely accepted by the ham community. And considering that > > it (P25) is not compatible with D-STAR's AMBE codec, I doubt that it > > will be accepted by hams anytime soon. Who cares if D-STAR takes up > > repeater pairs that could be used for analog? Have you listened to the > > analog repeaters? They're mostly silent anyway. One comment that I > > read early on (and I don't recall who said this) was that in an > > emergency the analog users would not be able to access a D-STAR > > repeater. Yep, but so what? Do you really mean to tell me that each > > local area is covered by just one analog repeater? It just sounds to me > > like typical human behavior: resistance to change. > > > > There's a good friend of mine that was so ticked off at the institution > > of no-code hams. He calls them "rif-raff". He operates almost > > exclusively on the CW sections of the HF bands to avoid the no-code > > folks. It's sad because there are a lot of no-code hams that are good > > operators and some are very technically knowledgeable. He might learn a > > thing or two from these folks. I wonder if the people in this group > > that are resisting D-STAR are missing the boat as well. Maybe there is > > something they could learn from D-STAR? Maybe they could find ways to > > to improve it? Of course that won't happen if they are too busy trying > > to talk people out of it in favor of P25 or old fashioned analog. > > > > Just my 2 cents. I'll go back to my corner now. > > > > John N3SPW > > > > ---------------------------------------------------------- > > *From:* Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com> > > [mailto:Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com>] > *On Behalf Of *Nate Duehr > > *Sent:* Monday, April 05, 2010 4:01 AM > > *To:* Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com> > > *Subject:* Re: [Repeater-Builder] Re: D-Star (Protocol and Repeaters) > > > > > > > > > > > On Apr 4, 2010, at 2:30 PM, John wrote: > > > > > > > > > > > --- In > > > Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com> > > <mailto:Repeater-Builder%40yahoogroups.com<Repeater-Builder%2540yahoogroups.com>>, > Nate Duehr <n...@...> wrote: > > > > > > > > > > > > I like D-STAR as a not-very-well-designed "first try" and use it... > > but it's seriously technologically flawed. Some of that can be fixed... > > other things like the header information not being interlaced... > > > > > > > > -- > > > > Nate Duehr, WY0X > > > > n...@... > > > > > > > > > > Hmmm... I'm sitting here with my NQMHS Node Adapter (GMSK Modem) and > > watching the binary stream, in both Hex and Char, off of my IC-91AD, > > while transmitting for a few seconds. It seems the callsign information > > is repeated on a pretty continuous basis looking at the trace. I think > > it may just be a repeater/gateway control implementation issue. > > > > I believe if you'll look again, the callsign of the sending station is > > interlaced, but not RPT1/RPT2, and the destination address, which are > > the essential routing information. > > > > Plus, you're correct: Judging by the behavior, the repeater's don't look > > at that data or utilize it anyway. > > > > -- > > Nate Duehr, WY0X > > n...@natetech.com <nate%40natetech.com> > > <mailto:nate%40natetech.com<nate%2540natetech.com> > > > > > > No virus found in this incoming message. > > Checked by AVG - www.avg.com > > Version: 9.0.800 / Virus Database: 271.1.1/2791 - Release Date: 04/04/10 > > 14:32:00 > > > > > > > > > > > -- HKARA website : http://www.hkara.org.hk VR2XVD email : vr2...@yahoo.com,vr2...@gmail.com Please consider the environment before printing the email.
