Required bandwidth must be considered also. You will be one of many users of the spectrum.
Originally Posted by WX1DX
GMSK works for about $300 - no ICOM gear required. $300 covers HF/VHF/UHF with
a single analogue radio. No intermediating hardware required for freq. or time division. Radio to radio. Clear audio synced and/or data.
Be careful who you call "ignorant" - my background is in RF & computer systems engineering going back over 40 years.
I'm sorry if I just slew your sacred cow, but D-Star is like DSB AM in the 60s - yeh, it works, but it ISN'T the future.
I'll admit that both Yaesu and the NXDN folks may have an axe to grind in some of their conclusions, but their engineering analysis of the faults & limitations of D-Star are right on the mark.
None of the existing digital voice/data formats are ideal - if one of them was, everyone would embrace it and we could shut down all the research labs. Too much of what is deployed now days in the commercial area is deployed due to political or nationalistic reasons, combined with marketing muscle and crony capitalistic inside dealing (yes, I "DID" say Motorola) and NOT with technical merit. Unfortunately, hams have to deal with such sideshows if we want to piggyback on some of the "economies of scale" in manufacturing the hardware required to deploy digital systems. As time goes on and DSP hardware and other programmable components become more powerful & less expensive some of these constraints may well ease.
I stand by my statement regarding D-Star: yes, for amateur use presently it is by far the most widely deployed digital system, but so was DSB AM in the mid-50s. Just like DSB AM, D-Star won't disappear anytime soon, but I truly believe it will be but a "bit player" (no pun intended) in the future of amateur digital systems.
Originally Posted by KB8O
The chip is $20. Buy the chip and build a radio or dongle/dvap etc.
Originally Posted by K8WHB
I wouldn't consider one portable a "system". Maybe they have plans for a repeater, maybe not, but they have a LONG road ahead of them since they are on their digital format.
Originally Posted by K8WHB
I'm a Prisoner (FH#1125), Locked up in Hellschreiber.
30 Meter Digital Group #1076 - JT65-HF Addict (currently in treatment)
If there really is a digital audio future for ham radio anytime in the foreseeable future??? My suspicion is those attracted to digital on VHF/UHF have already made the move and on HF its likely decades away. And it will remain that way until there is developed and accepted a single digital standard that all hams embrace for all bands from DC to light. According to the ham industry, 2 meter FM HT's are still the biggest selling product in the marketplace and thats not going to change until there are like-priced digital radios to a single universally accepted standard. And I'm not holding my breath for that to happen soon -- unless it is government mandated -- which is not likely.
Originally Posted by K8WHB
Reminds me of the DVD Blu Ray Battles a few years ago. May the bet mode win.
Originally Posted by N0SSC
I just have to dive in this abyss ..
I have 2 NXDN repeaters up and functional today with 2 more in the works. Let's be clear about some things.
a) there is no patent costs or should I say royalty costs. The cost of the codec from DVSI is down to the low double digits if not single digits in volume, so while you can call that a patent cost, it's really not much in the grand scheme of things (cost of all the parts of a radio).
b) there is simple no comparison between NXDN and D-Star. Icom did *everything* wrong with D-Star (not their problem they didn't know better just jumped on the JARL spec). And yet they did most everything right with NXDN (probably thanks to the joint development with Kenwood). D-Star suffers from 3 major issues. A religious group called the USTRUST that seems to thing they can *control* the network and callsign routing, the later is what turns most off after the initial "Oh gee, this is cool" factor is gone. Lastly, why on earth didn't Icom implement the FEC that could have been done to resolve this R2D2 issue... instead they elected to use the bandwidth to do low speed data, and yet that's really only available on the upper frequency implementations.
NXDN on the other hand, has NO callsign routing, is fully IP enabled from the factory, supports FEC so no more R2D2, and probably the best part the price. Repeaters are as easy as putting up an IC-FR5000/6000 (or if you want to save about $500, just get an UR-FR5000/6000, that's all that in the 19" rack chassis anyway. They can be had for around $700 complete with controller... Just add duplexer and PS and you are on the air with NXDN. The mobile radios from at least Icom are way cheaper than than a D-Star mobile, the HT's are a little more money, and I honestly don't know why they are that much higher.
To add IP linking, you simply get the UC-FR5000 linux board and plug it in, you'll need a $40 compact flash from Icom with some software on it, but that's it. Poof, you can link 16 repeaters together. I have mine linked currently to FLA and OH with TX and Seattle working to come online.
The repeaters as just brain dead easy to get on the air and quite flexible. You can support *both* 25kzh wide/5khz deviation FM or 6.25khz digital on the same box in either mixed digital or mixed analog modes. This allows for easy transition among any user base
The largest advantage for me is the 20-30% extension in coverage area with digital. For a weak signal on analog, with lots of background noise, that same signal is perfect in digital. The one thing you will notice is that you are either in the repeater or you aren't, there is no gray area .
If in Atlanta, 443.025+ PL 127.3/RAN 1 or 442.025+ PL 127.3/RAN 1 are both on the air. What we in the ham NXDN side are working on now is a more robust IP linked network... Thanks to the NXDN forum for releasing the specs, while it documents all the CAI, it also has allowed us to discover some things in the IP side.
If you think D-star is good, you have got to hear NXDN, it's simply amazing to hear Tampa or Cleveland exactly as if there were next to you on simplex...
And out of the box, there is interoperability with other NXDN devices....
If you have any questions, feel free to contact me directly... but I read through this thread and felt compelled to correct some miss-truths, specifically around the cost of the codec, etc. Would it be nice if it were free, or open hardware, sure, but it also has some advantages at being built by a commercial company and put in silicon, and that isn't cheap to do...
Alan - W7QO
we don't want your halfway chips and specs without code; we want FULL SOURCE CODE. GO CODEC2!!!!!!!
Rick Muething has already showed how to force a paradigm shift with WINMOR in the Winlink system. I'm not sure that the source is released yet, but it's FREE, and Pactor III and above cost thousands of dollars per modem.
Free good, Source better, Free + source best.
Proprietary = doomed to fail
Last edited by KE7VZW; 09-17-2012 at 01:49 PM.