Re: [Repeater-Builder] D-Star Was: Molotora Gontor
On Apr 2, 2010, at 11:00 AM, Kris Kirby wrote: There is one issue that needs to be handled. When a D-Star repeater hears another user on the input for a callsign not it's own, the modem is captured, and any input packet that starts or is received in the middle of that transmission is discarded. This, of course, would not be permitted in the Motorola world; something would have to be done with the received information, even if a band-opening allowed a remote digital user to interfere with a digital trunking system's input channel(s). Not sure what you're talking about here Kris. (The squirrel dinner thing was very funny, BTW.) The D-STAR header ONLY... right at the beginning of the transmission, includes the four callsigns embedded in every transmission for source-routing purposes. The user enters them into the rig, and they get transmitted ONCE per transmission. Those callsigns are not INTERLACED throughout the transmission... So what REALLY happens is this... The D-STAR repeater detects a header that's not set to use the repeater's callsign, it's discarded. However, if a station can MANGLE their header, the last known good header is used. We see this on D-STAR on weak-signal users all the time in the logs. It's easy to tailgate in D-STAR. Additionally FM capture effect still stands, and if the bitstream isn't too mangled by the noise created by a double, a station can talk over another. But it takes a VERY strong signal vs. a VERY weak one to pull it off. Additionally in the D-STAR specification, the header/routing information and the embedded 1200 bps simultaneous serial data stream that rides along with each voice transmission are NOT forward-error-corrected, while the VOICE portion (4800 bps) is. This causes all sorts of user confusion when they try out low-speed background data applications, or wonder why the callsigns showing up on the screen are all mangled from other stations, and/or their own transmissions won't route properly. But everyone can HEAR me!... yes, they can. But the repeater can't copy your weak signal well enough to dig out the callsigns in your header. Mix the tailgating and the latter, and you have confusion when weak stations participate in any activity that requires correct callsign routing from all participating stations... such as the almost-worthless Icom Multicast Routing for linking multiple repeaters. Obviously, almost all U.S. D-STAR repeaters also implement HARD linking via the add-on D-PLUS software, which works far better with weak user signals... but kinda defeats the whole purpose of having the callsign header/routing in the first place. So.. with all of that in mind, I don't know why you say the repeater will automatically discard interfering transmissions. It's far more likely that it will PASS them, if the header got mangled, as if it were a continuation of the first transmission... after the double stops occurring. Practically speaking, I think that the earlier data should be thrown out, and the packet decode restarted with the new signal. Of course, short of doing SDR and de/re-coding on the fly, this is not a trivial problem to fix. When your RSSI is measured as BER, it's a different world. STREAM decoding is done continuously, on the fly on all of these systems. FM capture effect still happens. This is the design flaw that data engineers coming over to RF make all the time... and it shows the most in D-STAR. In P-25, the Unit ID information is continuously repeated (interlaced) in the frames, and if two radios key up at the same time... when the double stops, the decoder at the repeater can still figure out who's left transmitting. In D-STAR, the ASSUMPTION (and we all know what assumptions do...) was that the RF/Air interface would behave just like a hard-wired bit-pipe... and it doesn't. I don't have any knowledge of how MotoTRBO or the others handle this. Here's hoping they're interlacing the critical must have identification/authentication/routing information instead of treating it like it's not as important as the voice signal itself... p.s. Before anyone thinks this is a plug or a rant either way for or against any technology mentioned above, be advised that I've been working on bugs like this my entire career, and watching engineers make the same mistakes over and over and over again in the wireline telco world. I gave up picking favorites long ago... almost every data protocol out there sucks, in one way or another. I can explain how to break X.25, Ethernet, Gigabit Ethernet, Token Ring, IPX, IP, Q.931 messages... ahh, pretty much anything -- 'cause I've seen customers do it. Invent a better protocol, someone will invent a better idiot. (My favorite was two weeks ago when a worker for a VERY large telecom company wanted to know the IP endpoints of a hard down T1 voice circuit showing red-alarm at our equipment's end... meaning no
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
On Apr 2, 2010, at 11:32 AM, k7pfj wrote: Unless you have a Aeroflex 3920 with the options you can scan DStar as well as Mototrbo and all others. Well, at least until the P25 guys turn on encryption. :-) A whole new learning curve. -- Nate Duehr, WY0X n...@natetech.com
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
On Apr 2, 2010, at 3:35 PM, Doug Bade wrote: Yes... Icom oversold it.. Actually they did an okay job on the radios, JARL did a really piss-poor job on the streaming standard, and Icom REALLY screwed up the distribution of a Linux server... (Build Apache from SOURCE CODE as a normal way to distribute the software?! Really Icom? Okay, welcome back to the 80s... thanks...) So it's not just about the selling... 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...@natetech.com
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
On Sat, 3 Apr 2010, Nate Duehr wrote: Actually they did an okay job on the radios, JARL did a really piss-poor job on the streaming standard, The radio interface isn't so bad until you get into programming all fourteen menu items that have to be set to make communication happen through a repeater. I still think it needs a beacon channel like APRS which would allow the radio to be aware of what repeaters are around it so the system may route the call according to what repeater the user can hit. But that might make it too much like trunking radio, and would require another duplexer and a second frequency. and Icom REALLY screwed up the distribution of a Linux server... (Build Apache from SOURCE CODE as a normal way to distribute the software?! Really Icom? Okay, welcome back to the 80s... thanks...) Agreed. That and completely NOT understanding NAT and RFC1918 space, as as well as requiring pre-CIDR routing make it a toy. Realisticially, you don't need to know anything about routing, and way they decided to implement it precludes current subnetting practices used in AMPR.ORG (44.x.x.x/8). 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... There's always DSTAR v2.0... If ICOM is willing to release a flash tool for the radios. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
On Sat, 3 Apr 2010, Nate Duehr wrote: p.s. Before anyone thinks this is a plug or a rant either way for or against any technology mentioned above, be advised that I've been working on bugs like this my entire career, and watching engineers make the same mistakes over and over and over again in the wireline telco world. I gave up picking favorites long ago... almost every data protocol out there sucks, in one way or another. This is not limited to data and RF, it's all over anything attached to a computer. I gave up working in computer security because it was always the same thing -- someone would write software wrong, not test it, ship it, and it would be the way that a customer was broken into. Of course, if that customer had followed the recommendations of the security consultant, the break-in wouldn't have occurred, but the CxO made the decision based on cost vs risk to skip implementation of that system. I can explain how to break X.25, Ethernet, Gigabit Ethernet, Token Ring, IPX, IP, Q.931 messages... ahh, pretty much anything -- 'cause I've seen customers do it. Invent a better protocol, someone will invent a better idiot. I've been that better idiot. I'm continually amazed at the bugs I find in exercise equipment, cars, etc. Failure or unexpected situations are not tested for, because testing is expensive and only performed once someone gets hurt or killed. I think we're trying to teach people this stuff so fast these days, they have no idea what you're talking about when you ask them to measure the voltage on a T1 circuit... or try asking someone to measure the voltage on Ethernet sometime. Trying to understand digital RF communications is like drinking from a firehose. And most college students are more interested in graduating and/or doing all of those things that college students do. When it comes to RF digital protocols, the entire classroom full of hams would fall asleep long before you got past the basic framing of the circuit, let alone talking about how a double at the RF/Air interface would affect it. Well, we do this as a hobby... Wireline techs have no concept that ELECTRICITY and all the E=IR and other properties that go with it... are actually traveling down those wires... they do seem to get it that when they replace it with plastic fiber optics it all works faster/better... but then they bend the cable beyond the bend radius allowed for the fiber, and wonder why it all falls apart again. NO CLUE about the physical world, just that you're supposed to plug it in and type some commands and it'll magically work for you. Again, this isn't limited to wireline techs. There's an entire generation of Americans who know only that one thing they do, and have no desire to learn anything else unless the boss tells them they need to know it. In an earlier time, these individuals would find themselves out of a job. Thus, the folks who REALLY know it -- really need to try a little harder to make the on-air interfaces bulletproof, and ALSO to make sure the products are also released with TEST GEAR that any moron could operate. Seriously. We all know from reading here on RB that just understanding all the gotchas of FM analog, and repeaters, is many years of study. Add the requirement that the repeater operator also should magically understand routing protocols, IP, on-air framing formats, and all that jazz? There are many man-centuries of experience on this list. But I agree. I think that Motorola and some of the other companies haven't put thier best talents on writing protocols and designing products. It'll be a while. Ask any agency who deployed P25 when it first came out how many years it took their best techs to really UNDERSTAND what was going on in the system on a day-to-day basis... or if they even really believe they do, yet. I find that the best techs tend to be reverse engineers. Unfortunately for them, they are under-paid and usually unrecognized among thier peers. The company brought in a trainer a few years back to teach logical troubleshooting. Three clues in, I gave the answer. The trainer said, How did you DO that? Before I could reply, my boss (kindly) said, We didn't hire him for his personality! My favorite answer is: I think with both halves of my brain at once. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
I would strongly remind them that they are purchasing a system that has only ONE and only ONE supplier/source. This may not fit some of the bid requirements that some government agencies require. Joe Kris Kirby wrote: On Fri, 2 Apr 2010, Scott Zimmerman wrote: Around here (Western PA) the governments bought Icom D-Star radios for RACES. I had no objection to that since those radios can be used in analog modes with analog repeaters. Now they are wanting to get D-Star repeaters for RACES and emergency use.
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
At 4/3/2010 15:35, you wrote: I would strongly remind them that they are purchasing a system that has only ONE and only ONE supplier/source. This may not fit some of the bid requirements that some government agencies require. Joe A well-written sole source justification memo takes care of that. Bob NO6B
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
Besides, doesn't that assume they will be adding more user units to it? In this case, it's likely a one-shot deal, so they won't care about future sources. Joe M. On Sat 03/04/10 7:00 PM , n...@no6b.com sent: At 4/3/2010 15:35, you wrote: I would strongly remind them that they are purchasing a system that hasonly ONE and only ONE supplier/source. This may not fit some of the bidrequirements that some government agencies require. Joe A well-written sole source justification memo takes care of that. Bob NO6B Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ Your email settings: Individual Email | Traditional To change settings online go to: http://groups.yahoo.com/group/Repeater-Builder/join(Yahoo! ID required) To change settings via email: repeater-builder-dig...@yahoogroups.com repeater-builder-fullfeatu...@yahoogroups.com To unsubscribe from this group, send an email to: repeater-builder-unsubscr...@yahoogroups.com Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
My biggest problem with the D-Star repeaters is that they didn't make them analog compatible. Knowing as little as I do about the D-star hardware, it would seem easy enough for Icom to have done so. All they would have needed to do would have been to look at the incoming signal, see if it was analog or digital, and process it correctly. While you'll pry my analog repeater pairs from my cold dead hands; if D-Star machines were analog capable, I'd swap every pair I have to that format tomorrow. As RB (the company) I have been asked about D-star more times than I can count. I tell people it's nice to play with, but what happens in an emergency? If Icom would have made the D-star machines analog capable, those that wanted to (and had D-star radios) could play with it all they wanted to. When an emergency arose and you had 10x as many people out there with analog rigs, the machine would *still* be useful. As it is at present, if an emergency arises, only those with D-star rigs can use a D-star machine. That concept is fine, as long as ALL of your volunteers have D-Star radios! (How many places is this the case?) Around here (Western PA) the governments bought Icom D-Star radios for RACES. I had no objection to that since those radios can be used in analog modes with analog repeaters. Now they are wanting to get D-Star repeaters for RACES and emergency use. I *strongly* object to that since they CANNOT be used in analog modes for emergencies. In my view, you'd be alienating much of your volunteer base that doesn't have the correct equipment right at the point where you need all the help you can get! Of course with the government in the mentality that they have been in the past few years, maybe that's their way of thinning the heard. I *think* I remember someone saying that some other company had made an analog capable D-Star controller? Do any of you list members know anything about that? Scott Scott Zimmerman Amateur Radio Call N3XCC 474 Barnett Road Boswell, PA 15531 Nate Duehr wrote: On 4/1/2010 9:57 PM, George Henry wrote: I suppose I should clarify: I don't do D-STAR, either. Moral objection to their use of a proprietary codec. You're going to be a while on that soap box. CODECs are almost literally the only way to make any money in the audio streaming, video streaming, and related technology worlds these days... mixed with Patents, you won't see any high-quality free CODECs that can properly encode voice at 4800 bps any time soon. DVSI has ALL of that market locked up until someone hires a pile of PhD's in math and goes after them. And even then, they'd have to make a significant impact on bandwidth utilized or voice quality over either AMBE/AMBE2, or IMBE... to have a chance of dislodging the first player to market... the only player to be written into multiple standards (P25, D-STAR, even the TDMA-based things from Kenwood/Icom... all using DVSI chipsets.) Brilliant of them really... heavily patent-encumbered CODEC, super-high price on using the CODEC in software, sell a $20 (in low-quantity, slightly cheaper in high-quanity) chipset, in a market as small as 2-way radio... they're making a bloody killing. I'd love to know what the development costs of the CODECs were... to see just how lucrative their lock on the market(s) is. But anyway... good luck finding a commercial product that doesn't use their chipset anytime soon. The next CODEC chipset maker is going to be an also-ran forever, unless their mathematicians and algorithms are uber-brilliant. Nate WY0X Yahoo! Groups Links
RE: [Repeater-Builder] D-Star Was: Molotora Gontor
I am in the process of deploying a home built 70cm Mastr III conversion to D-Star. It is quite capable of doing both with existing technology. I do not CHOOSE to do both.. but it can.. It also does analog enough to do diagnostics on it which is a bit of an improvement over Icom's digital only.. I do have a discriminator and cor point to watch when I send an rx signal in.. J Doug KD8B From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Scott Zimmerman Sent: Friday, April 02, 2010 8:54 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] D-Star Was: Molotora Gontor My biggest problem with the D-Star repeaters is that they didn't make them analog compatible. Knowing as little as I do about the D-star hardware, it would seem easy enough for Icom to have done so. All they would have needed to do would have been to look at the incoming signal, see if it was analog or digital, and process it correctly. While you'll pry my analog repeater pairs from my cold dead hands; if D-Star machines were analog capable, I'd swap every pair I have to that format tomorrow. As RB (the company) I have been asked about D-star more times than I can count. I tell people it's nice to play with, but what happens in an emergency? If Icom would have made the D-star machines analog capable, those that wanted to (and had D-star radios) could play with it all they wanted to. When an emergency arose and you had 10x as many people out there with analog rigs, the machine would *still* be useful. As it is at present, if an emergency arises, only those with D-star rigs can use a D-star machine. That concept is fine, as long as ALL of your volunteers have D-Star radios! (How many places is this the case?) Around here (Western PA) the governments bought Icom D-Star radios for RACES. I had no objection to that since those radios can be used in analog modes with analog repeaters. Now they are wanting to get D-Star repeaters for RACES and emergency use. I *strongly* object to that since they CANNOT be used in analog modes for emergencies. In my view, you'd be alienating much of your volunteer base that doesn't have the correct equipment right at the point where you need all the help you can get! Of course with the government in the mentality that they have been in the past few years, maybe that's their way of thinning the heard. I *think* I remember someone saying that some other company had made an analog capable D-Star controller? Do any of you list members know anything about that? Scott Scott Zimmerman Amateur Radio Call N3XCC 474 Barnett Road Boswell, PA 15531 Nate Duehr wrote: On 4/1/2010 9:57 PM, George Henry wrote: I suppose I should clarify: I don't do D-STAR, either. Moral objection to their use of a proprietary codec. You're going to be a while on that soap box. CODECs are almost literally the only way to make any money in the audio streaming, video streaming, and related technology worlds these days... mixed with Patents, you won't see any high-quality free CODECs that can properly encode voice at 4800 bps any time soon. DVSI has ALL of that market locked up until someone hires a pile of PhD's in math and goes after them. And even then, they'd have to make a significant impact on bandwidth utilized or voice quality over either AMBE/AMBE2, or IMBE... to have a chance of dislodging the first player to market... the only player to be written into multiple standards (P25, D-STAR, even the TDMA-based things from Kenwood/Icom... all using DVSI chipsets.) Brilliant of them really... heavily patent-encumbered CODEC, super-high price on using the CODEC in software, sell a $20 (in low-quantity, slightly cheaper in high-quanity) chipset, in a market as small as 2-way radio... they're making a bloody killing. I'd love to know what the development costs of the CODECs were... to see just how lucrative their lock on the market(s) is. But anyway... good luck finding a commercial product that doesn't use their chipset anytime soon. The next CODEC chipset maker is going to be an also-ran forever, unless their mathematicians and algorithms are uber-brilliant. Nate WY0X Yahoo! Groups Links image001.jpgimage002.jpg
RE: [Repeater-Builder] D-Star Was: Molotora Gontor
I would be glad to elaborate about D-Star Repeater conversions as there are multiple ways to do it now and Any EDACS capable or Smartnet Capable repeater would do D-Star as both fundamentally have the parts to transmit and receive GMSK type waveforms There are several Yahoogroups that are focused on alternate D-Star hardware and software devices. Doug KD8B From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Scott Zimmerman Sent: Friday, April 02, 2010 8:54 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] D-Star Was: Molotora Gontor My biggest problem with the D-Star repeaters is that they didn't make them analog compatible. Knowing as little as I do about the D-star hardware, it would seem easy enough for Icom to have done so. All they would have needed to do would have been to look at the incoming signal, see if it was analog or digital, and process it correctly. While you'll pry my analog repeater pairs from my cold dead hands; if D-Star machines were analog capable, I'd swap every pair I have to that format tomorrow. As RB (the company) I have been asked about D-star more times than I can count. I tell people it's nice to play with, but what happens in an emergency? If Icom would have made the D-star machines analog capable, those that wanted to (and had D-star radios) could play with it all they wanted to. When an emergency arose and you had 10x as many people out there with analog rigs, the machine would *still* be useful. As it is at present, if an emergency arises, only those with D-star rigs can use a D-star machine. That concept is fine, as long as ALL of your volunteers have D-Star radios! (How many places is this the case?) Around here (Western PA) the governments bought Icom D-Star radios for RACES. I had no objection to that since those radios can be used in analog modes with analog repeaters. Now they are wanting to get D-Star repeaters for RACES and emergency use. I *strongly* object to that since they CANNOT be used in analog modes for emergencies. In my view, you'd be alienating much of your volunteer base that doesn't have the correct equipment right at the point where you need all the help you can get! Of course with the government in the mentality that they have been in the past few years, maybe that's their way of thinning the heard. I *think* I remember someone saying that some other company had made an analog capable D-Star controller? Do any of you list members know anything about that? Scott Scott Zimmerman Amateur Radio Call N3XCC 474 Barnett Road Boswell, PA 15531 Nate Duehr wrote: On 4/1/2010 9:57 PM, George Henry wrote: I suppose I should clarify: I don't do D-STAR, either. Moral objection to their use of a proprietary codec. You're going to be a while on that soap box. CODECs are almost literally the only way to make any money in the audio streaming, video streaming, and related technology worlds these days... mixed with Patents, you won't see any high-quality free CODECs that can properly encode voice at 4800 bps any time soon. DVSI has ALL of that market locked up until someone hires a pile of PhD's in math and goes after them. And even then, they'd have to make a significant impact on bandwidth utilized or voice quality over either AMBE/AMBE2, or IMBE... to have a chance of dislodging the first player to market... the only player to be written into multiple standards (P25, D-STAR, even the TDMA-based things from Kenwood/Icom... all using DVSI chipsets.) Brilliant of them really... heavily patent-encumbered CODEC, super-high price on using the CODEC in software, sell a $20 (in low-quantity, slightly cheaper in high-quanity) chipset, in a market as small as 2-way radio... they're making a bloody killing. I'd love to know what the development costs of the CODECs were... to see just how lucrative their lock on the market(s) is. But anyway... good luck finding a commercial product that doesn't use their chipset anytime soon. The next CODEC chipset maker is going to be an also-ran forever, unless their mathematicians and algorithms are uber-brilliant. Nate WY0X Yahoo! Groups Links image001.jpgimage002.jpg
RE: [Repeater-Builder] D-Star Was: Molotora Gontor
D-STAR may not be adopted by the majority of VHF/UHF users until the end-user gear prices drop significantly. I think there will be too few users to justify the efforts of a trustee or club to migrate to D-STAR/digital. One D-STAR follower noted 12,000 units sold globally. That number of unit sales over a period of five years or more is a product line waiting to be dropped. D-STAR is no IPOD ;-) What is holding D-STAR adoption back is pretty obvious; no competition from Kenwood or Yasue that might help drive the prices down as has been the case with all previous technology evolutions. Kenwood actually offers D-STAR re-selling ICOM's units with a stick-on Kenwood label.doesn't look like Kenwood is going to adopt this technology as a viable alternative to analog systems. Without competition there is a dead-end coming around the bend for D-STAR travelers, IMHO. The digital repeaters are also very expensive. The new hardware/software workarounds for the repeater side make migrating to the digital mode less expensive for the trustees and clubs that are interested in the mode but users make a repeater system and without the users why bother. This isn't one of those build-it-and-they-will-come scenarios. Perhaps an analogy might be why tone a repeater in a vacation spot when most of the users are from out of town and won't know the tone. Sure you can tone but you'll reduce the number of users, at least that was the case before receivers were smart and could detect the tone for us. But you get idea. So, I suspect those considering digital are thinking about adding a new repeater rather than converting an existing system. That approach is also going to lead to that dead-end for ICOM D-STAR. I think it is great that repeaters can now be enhanced with bolt-on applications running on PCs but I can't imagine hand-held owners enjoying the few if any tangible benefits of D-STAR if they have to lug a lap-top around with them so their existing mobile or hand-held can operate the mode... Linking analog repeaters via the Internet may be a better approach then trying to force or wait for 99% of the user community to migrate to the new mode. I give ICOM D- for implementation. They totally misread the marketplace IMHO. Please flame direct ;-) Best, Dave WA3GIN/W4AVA/W4KGC _ From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Doug Bade Sent: Friday, April 02, 2010 9:50 AM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] D-Star Was: Molotora Gontor I would be glad to elaborate about D-Star Repeater conversions as there are multiple ways to do it now and Any EDACS capable or Smartnet Capable repeater would do D-Star as both fundamentally have the parts to transmit and receive GMSK type waveforms There are several Yahoogroups that are focused on alternate D-Star hardware and software devices. Doug KD8B From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Scott Zimmerman Sent: Friday, April 02, 2010 8:54 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] D-Star Was: Molotora Gontor My biggest problem with the D-Star repeaters is that they didn't make them analog compatible. Knowing as little as I do about the D-star hardware, it would seem easy enough for Icom to have done so. All they would have needed to do would have been to look at the incoming signal, see if it was analog or digital, and process it correctly. While you'll pry my analog repeater pairs from my cold dead hands; if D-Star machines were analog capable, I'd swap every pair I have to that format tomorrow. As RB (the company) I have been asked about D-star more times than I can count. I tell people it's nice to play with, but what happens in an emergency? If Icom would have made the D-star machines analog capable, those that wanted to (and had D-star radios) could play with it all they wanted to. When an emergency arose and you had 10x as many people out there with analog rigs, the machine would *still* be useful. As it is at present, if an emergency arises, only those with D-star rigs can use a D-star machine. That concept is fine, as long as ALL of your volunteers have D-Star radios! (How many places is this the case?) Around here (Western PA) the governments bought Icom D-Star radios for RACES. I had no objection to that since those radios can be used in analog modes with analog repeaters. Now they are wanting to get D-Star repeaters for RACES and emergency use. I *strongly* object to that since they CANNOT be used in analog modes for emergencies. In my view, you'd be alienating much of your volunteer base that doesn't have the correct equipment right at the point where you need all the help you can get! Of course with the government in the mentality that they have been in the past few years, maybe that's their way of thinning the heard
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
On Fri, 2 Apr 2010, Scott Zimmerman wrote: Around here (Western PA) the governments bought Icom D-Star radios for RACES. I had no objection to that since those radios can be used in analog modes with analog repeaters. Now they are wanting to get D-Star repeaters for RACES and emergency use. I *strongly* object to that since they CANNOT be used in analog modes for emergencies. In my view, you'd be alienating much of your volunteer base that doesn't have the correct equipment right at the point where you need all the help you can get! Of course with the government in the mentality that they have been in the past few years, maybe that's their way of thinning the heard. There's also a substantial base of users who like D-STAR because there isn't a scanner that can decode it. This provides the benefits of an encrypted channel without the encryption. IMO, any use of this mode for that purpose is strictly against the rules. I'll take my analog Motorola Saber with a 2700mAH battery any day over a ham HT for being out in the sticks or having to transmit/receive for eight or more hours. When the battery dies, I can at least bludgeon a squirrel to death with it and get a meal out of the radio. Disaster situations are about survival. Individuals who go into a disaster situation need to have basic survival skills, plan to carry everything in that they need, and to have a way out. Skip the air-conditioner for the shack, pack an extra water tank, and pick the most effective radios you can for the job. They should all be MIL-810E tested or higher. -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] D-Star Was: Molotora Gontor
On Fri, 2 Apr 2010, Doug Bade wrote: I would be glad to elaborate about D-Star Repeater conversions as there are multiple ways to do it now and Any EDACS capable or Smartnet Capable repeater would do D-Star as both fundamentally have the parts to transmit and receive GMSK type waveforms There is one issue that needs to be handled. When a D-Star repeater hears another user on the input for a callsign not it's own, the modem is captured, and any input packet that starts or is received in the middle of that transmission is discarded. This, of course, would not be permitted in the Motorola world; something would have to be done with the received information, even if a band-opening allowed a remote digital user to interfere with a digital trunking system's input channel(s). Practically speaking, I think that the earlier data should be thrown out, and the packet decode restarted with the new signal. Of course, short of doing SDR and de/re-coding on the fly, this is not a trivial problem to fix. When your RSSI is measured as BER, it's a different world. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
If you don't count the Icom scanning receivers. They CAN decode D-STAR. Joe M. Kris Kirby wrote: There's also a substantial base of users who like D-STAR because there isn't a scanner that can decode it.
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
Unless you have a Aeroflex 3920 with the options you can scan DStar as well as Mototrbo and all others. Mike Mullarkey K7PFJ 6886 Sage Ave Firestone, CO 80504 303-736-9693 k7...@skybeam.com On Apr 2, 2010, at 11:24 AM, MCH wrote: If you don't count the Icom scanning receivers. They CAN decode D-STAR. Joe M. Kris Kirby wrote: There's also a substantial base of users who like D-STAR because there isn't a scanner that can decode it.
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
I do not know that it needs to be handled... The day we have enough D-Star repeaters and users on the air that an out of town DX signal trips mine I will be tickled to death... not complainBecause JRRL did not put an equivalent to CTCSS or DSQ in the system does not make it need repair... APCO P25 and Smartnet P25 ( as well as EDACS AEGIS ) for the last 10+ years uses a codec/vocoder that is inferior to D-Star (IMBE vs AMBE)... does that make it broken??? No .. just not perfect :-) We still use it. We just live with it and work around it.. It DOES mean try and do better in the next generation.. IE P25 Phase II... If that is the greatest failing we have in a totally amateur digital system... it does not seem to be a big issue to meWith 6k25 emissions we can carve up the band pretty tight on adjacents to keep overlap contours to a minimum from adjacent service areas. Sounds like a coordination issue.. not a technological failing... we do it on 12k5's now.. we can do it on 6k25's next... Yes... Icom oversold it.. but 6k25 does quite well as long as you use reasonable dbu contours to protect adjacents from each other or on channel.. Same in commercial when you get to 6k25... Line them up and they do not play nice end to endThe IF filters are what they are and DSP has limits... I had no intention of comparing D-Star to Smartnet or EDACS if that is how you took it... I was saying that the repeaters used in those trunking systems inherently have the modulator and discriminators capable of extracting GMSK ( D-Star) modulation for external processing...no more... I have spent a lot of internet study time, testing etc.. but still less than $500.00 ( of that $350.00 was for the nice little 1U rackmount PC ) converting my Mastr III station... it seems like I am still about $6000.00 in the black compared to converting it to P25... for example... which would sort of be a rational ... albeit expensive comparison :-) I am not trying to push anything on anyone... it is another repeater technology.. and you no longer need to buy the repeater from a sole source.. hopefully that growth might trigger other vendors to offer terminals.. if the market were bigger.. they would be in the game... ignoring it does not help to that end :-) Doug KD8B Kris Kirby wrote: On Fri, 2 Apr 2010, Doug Bade wrote: I would be glad to elaborate about D-Star Repeater conversions as there are multiple ways to do it now and Any EDACS capable or Smartnet Capable repeater would do D-Star as both fundamentally have the parts to transmit and receive GMSK type waveforms There is one issue that needs to be handled. When a D-Star repeater hears another user on the input for a callsign not it's own, the modem is captured, and any input packet that starts or is received in the middle of that transmission is discarded. This, of course, would not be permitted in the Motorola world; something would have to be done with the received information, even if a band-opening allowed a remote digital user to interfere with a digital trunking system's input channel(s). Practically speaking, I think that the earlier data should be thrown out, and the packet decode restarted with the new signal. Of course, short of doing SDR and de/re-coding on the fly, this is not a trivial problem to fix. When your RSSI is measured as BER, it's a different world. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
At 4/2/2010 09:49, you wrote: There's also a substantial base of users who like D-STAR because there isn't a scanner that can decode it. Funny you should mention that. A pair of bootleggers using D-STAR showed up on the input to a friend's 2 meter analog repeater. After a couple of months he decided to buy a D-STAR HT so he could listen in eventually make contact. As soon as they heard another voice they were gone haven't been back. Bob NO6B
