Icom/Kenwood NXDN

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rdunajewski
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Icom/Kenwood NXDN

Post by rdunajewski »

I'm putting together a site with information about the new NXDN digital voice/data format developed by Icom and Kenwood. While it's designed for business and industrial sectors, it may be of use on the Ham bands for some people or just as general interest. I don't have Kenwood stuff so I can't review or post information about them.

I have the Icom FR6000 repeater, F6061 mobile radio, and the F4161 portable radio. I must say the digital works quite well and the hardware is SO cheap compared to P25 non-sense. I mean, P25 is great if you need it for a government purpose, or if you can afford to play with it, but I don't have such luxuries. The repeater only cost me $1500! What's a P25 repeater going for these days?

Anyone else have info to share?

Here's the site:
http://nxdn.mygmrs.com
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Re: Icom/Kenwood NXDN

Post by Mong »

Don't listen to rayray, he just needs to have interoperability with his local swat team when they need his technical assistance....
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Re: Icom/Kenwood NXDN

Post by rdunajewski »

Used equipment, but we're talking new here. $1400 for a new analog/digital repeater that will support digital trunking and IP networking in Q4 2008 is a bargain. My mobile only cost $500 with digital, and the portable can be had for $400 with digital (F4061). True, it's not easy to find used Icom stuff on eBay. But when you do, you can find some great deals. NXDN is really too new to find a lot of used equipment online now, but give it a couple years.

Being strictly a personal user, NXDN works better for me than D-Star or P25 could. While NXDN and D-Star cost roughly the same, D-Star can't be used outside of the Ham bands. I can use my radios to monitor businesses who may use NXDN in the near future. I'd also like to see digital allowed on GMRS, which can really benefit from the lower cost of NXDN equipment. The PMR446 radio service in Europe now allows digital (dPMR), which uses NXDN. So it's already proven useful for a personal radio service similar to GMRS. D-Star will likely never be adapted for anything but Ham.
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Re: Icom/Kenwood NXDN

Post by Mong »

RayRay wrote:I thought DStar was used in China or thereabouts for their local Government services


You thought that because shawn thought that.
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Re: Icom/Kenwood NXDN

Post by rdunajewski »

They say D-Star is used in Japan's public safety, but can anyone confirm that? NXDN could be what they're using in Japan as it is.. who knows. The two are said to be similar. D-Star itself was developed by JARL, Japan Amateur Radio League, not a public safety group. So I doubt the D-Star we use here is used in public safety over there.
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Re: Icom/Kenwood NXDN

Post by rdunajewski »

RayRay wrote:And for those who will ask, the video is here

http://www.arvidnews.com/dv/index.html
I guess it'll cost $22 to find the definitive answer, huh? :baby:
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Re: Icom/Kenwood NXDN

Post by Mong »

rdunajewski wrote:
RayRay wrote:And for those who will ask, the video is here

http://www.arvidnews.com/dv/index.html
I guess it'll cost $22 to find the definitive answer, huh? :baby:

I bet you can contact the JARL for free and ask them :baby:


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Re: Icom/Kenwood NXDN

Post by motorola_otaku »

(warning: tl/dr rant ahead)

Fucking great, now we have another digital mode to deal with. :ve4uo:

Big M has TRBO, Kenwood has NEXEDGE, iCom has D-STAR, Alinco has their backward-ass mode that only they make radios for, there's that AOR mode for HF, and, of course, we have P25. Seriously, this shit is getting out of hand. There needs to be more pressure from the market/user community to pick a mode and stick with it.

Yes, I have P25 toys, but that's all they are to me: toys. I cringe at the thought of safety-of-life-critical users relying on it. Yes, it may work well when the infrastructure side is built out to sufficient coverage density, but when you look at the cost versus analog coverage of equal density, where's the benefit? Increased spectral efficiency? If we (the FCC) had managed the 30-956 spectrum better over the last 40 years, we wouldn't need 6.25kHz channel bandwidth.

Here's a revolutionary idea: instead of opening up LMR spectrum at 700 MHz, where land-mobile propagation sucks massive donkey balls, why the fuck didn't the FCC move DTV up the spectrum and open up 470-512 to public safety nationwide instead of just in select user markets? That's 42 MHz of prime, usable UHF real estate, with equipment already on the market to support it. And for that matter, why is public safety even on 800 MHz in the first place? Shit sucks, as anyone who has ever used an 800 radio in simplex mode can attest to. Allowing safety-of-life-critical comms there was arguably the biggest mistake the FCC ever made. Put fucking business and SMR/eSMR there, and let their market forces deal with the shitty propagation. But I digress...

I would rather see analog reign supreme, but if we absolutely have to have digital voice then I vote P25 be the de-facto standard for everyone:
Established user base: The P25 standard is 12 years old. Public safety and government have been using it for years. There is motivation and pressure of both the financial and political variety to continue improving on it. Who's going to put pressure on iCom to make improvements to D-STAR? The ham community?
Wide availability of surplus commercial gear: How did FM in the 30 MHz+ bands get its start? *drumroll* Converted commercial gear, that's how! The Japanese manufacturers began making Ham-marketed FM radios long, loooong after the fact. We have a leg up in this regard in that the big 3 Japanese manufacturers are already licensed for the IMBE vocoder; all they need is sufficient demand to port it over to the Ham market. Remember, the dollar always speaks last and loudest.
It makes logical sense to have public safety and Ham on the same page: This is probably the stickiest of all the worms out of the can, but relevant nonetheless. Imagine how a legitimate volunteer emergency comms group, be it RACES, ARES, MARS, or anyone else, might improve their sales pitch to potential served agencies by saying "we already have P25 capability on VHF/UHF bands, and use it daily." You and I know that might not mean shit in the greater scheme of things, but bureaucrats would eat it up.

And before any of you guys throw the "too expensive" flag, keep in mind that right now the only market for P25 is public safety and government. Save greed, there's no barrier stopping Yaecommwood from pricing hammy P25 gear on the same level as D-STAR or analog FM.

And finally, as a licensed GMRS user (WQAP701, look it up) and owner of 2 repeaters, if I put anything digital on the air it's going to be P25. Several of my guys already have the capability, and I can cheaply hook up the rest if the need arises.
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Re: Icom/Kenwood NXDN

Post by k3who »

motorola_otaku wrote:(warning: tl/dr rant ahead)

Fucking great, now we have another digital mode to deal with. :ve4uo:

Big M has TRBO, Kenwood has NEXEDGE, iCom has D-STAR, Alinco has their backward-ass mode that only they make radios for, there's that AOR mode for HF, and, of course, we have P25. Seriously, this shit is getting out of hand. There needs to be more pressure from the market/user community to pick a mode and stick with it.
I'll second that, if they want to sell more radios they all need to agree on a standard mode. That's one reason I've not bought a digital capable radio. Others would be I don't know anyone around here that uses anything digital and I can't bring myself to pay the price for anything digital capable. This is still pretty new so I'm waiting to see what sticks and for the price to come down. I'm not like you Mototards who always have to have the best and latest :baby: :baby: :baby: =P I do more listening than talking anyway, there aren't many hams around here I want to talk to.
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Re: Icom/Kenwood NXDN

Post by rdunajewski »

Kenwood's NEXEDGE is NXDN. NXDN is the name of the CAI (Common Air Interface). Kenwood calls the system Nexedge, Icom calls it IDAS. Both use NXDN, and both are interoperable with each other. That's why I commend the move to get two of the major manufacturers together, develop a low-cost digital format that allows smaller businesses and Part 90 users to comply with future 6.25 kHz mandates by the FCC. 25 kHz and 12.5 kHz analog won't be around forever, eventually everyone will have to go digital in Part 90. Not everyone can afford P25, so MotoTRBO and NXDN are the digital formats of choice for businesses that have no need or desire for P25.

D-Star is not a commercial Part 90 format in the US, and I doubt it will ever be. NXDN is meant to take some of the benefits of D-Star and adapt them to North American needs. D-Star and NXDN were never meant to coexist in the Part 90 radio services.

The mom and pop nursery or lawn mowing business does NOT need an encrypted, trunked, networked P25 system. Once analog is gone for Part 90, those small-time radio users either have to use cell phones (or Nexthell), or nothing at all. The non-P25 digital formats fill the void. NXDN was never meant to take over P25. The only thing NXDN is competing with is MotoTRBO, which is showing lots of bugs in firmware and security holes (hijacked repeaters). My point is that NXDN's cost allows it to be used on Ham whereas P25 is too expensive. Sure, P25 repeaters will always be out there for those who have the money, but Ham should NEVER be forced into one digital format. That's how P25 became such a money-hungry monster. Competition between the different formats keeps things a little cheaper.
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Re: Icom/Kenwood NXDN

Post by Mong »

motorola_otaku wrote:
Fucking great, now we have another digital mode to deal with. :ve4uo:

Actually, only those who want to use it have to "deal with it". As has been point out, this is meant for businesses, just like the motoblo-oh crap.

I agree with you on the entire 470-512 VS 700/800 crap, but I'm not sure what they could have done differently in the areas where they are already using the T-band. I admit I do not know just how effectively they actually utilitize that portion of the spectrum where it is used.

rdunajewski wrote: eventually everyone will have to go digital in Part 90
Not saying it won't happen at some point, but has anyone seen any mandate (or serious proposal) to do so?


We're not even moved to 12.5, sure don't see analog going away for business/public safety use anytime soon. As an example, I saw two deputies yesterday where I used to live, one had a GP300 and the other had a HT600. Hell, if 6ch is all they need, I'd not have an issue using a HT600 either.
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Re: Icom/Kenwood NXDN

Post by rdunajewski »

I agree that analog is not going to disappear tomorrow, but it's on it's way out. Hell, even P25 Phase I (what we're all used to now) isn't 6.25 kHz compatible, that's why Phase II is being hashed out (I believe they settled on a TDMA system like MotoTRBO). So, everyone who spent the cash on P25 systems will now have to cash it in for Phase II stuff when the mandate rolls around. It will happen, it's just not known when. I heard rumors (facts?) that 6.25 kHz would be mandated a few years after 12.5 kHz.

Here is the FCC Report and Order that addressed the migration to 6.25 kHz. It's dated March 22, 2007, which is before NXDN equipment started rolling out. They declined to set a fixed date for 6.25 kHz migration, but urge licensees to consider going right to 6.25 kHz from 25 kHz, rather than having to go from 25, to 12.5, to 6.25, within only about 10 years. This report lit the fire under everyone's ass to start expediting 6.25 kHz development and to get it out soon. This is why MotoTRBO, NXDN, and P25 Phase II seems to be coming out all within a year of each other. Had equipment been available sooner, the FCC may have set a date in stone. All radios must have 6.25 kHz capability by 2011 (used to be 2005, but no one was even thinking of 6.25 kHz before that deadline, so it was extended).

http://hraunfoss.fcc.gov/edocs_public/a ... 1692A1.pdf

The 470-512 MHz band is heavily utilized here now, and is growing daily. Seems like every town around here moved on up to the T-band and businesses are doing the same thing. I'd say 75% of the action around here is on UHF (including businesses, not just public safety). Public Safety is the major user of VHF around here, save for the low-power business channels. Lots of trunking in the T-band, too.
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Re: Icom/Kenwood NXDN

Post by motorola_otaku »

Mong wrote:I agree with you on the entire 470-512 VS 700/800 crap, but I'm not sure what they could have done differently in the areas where they are already using the T-band. I admit I do not know just how effectively they actually utilitize that portion of the spectrum where it is used.
They'd have the entire 42 MHz range available to use, as opposed to just the measly 6 MHz increments allocated piecemeal here and there.

Correct me if I'm wrong, but doesn't NEXEDGE work like TRBO in that it uses 2 TDMA slots per 12.5 channel to achieve "virtual" 6.25 spacing? Isn't that, like, cheating? :baby:
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Re: Icom/Kenwood NXDN

Post by rdunajewski »

motorola_otaku wrote:
Mong wrote:I agree with you on the entire 470-512 VS 700/800 crap, but I'm not sure what they could have done differently in the areas where they are already using the T-band. I admit I do not know just how effectively they actually utilitize that portion of the spectrum where it is used.
They'd have the entire 42 MHz range available to use, as opposed to just the measly 6 MHz increments allocated piecemeal here and there.

Correct me if I'm wrong, but doesn't NEXEDGE work like TRBO in that it uses 2 TDMA slots per 12.5 channel to achieve "virtual" 6.25 spacing? Isn't that, like, cheating? :baby:
No, NXDN (NEXEDGE) is FDMA, each channel is a true 6.25 kHz channel. MotoTRBO is a 12.5 kHz TDMA channel, with the capability to optionally support a second voice or data path (the second time slot). MotoTRBO, when used in simplex mode, loses the second voice/data path and becomes a single-channel 12.5 kHz single-slot system. The reason for that is, two radios in simplex mode can't accurately time the slots properly so they don't interfere unless there's a repeater coordinating things. THAT'S cheating in my book.

On NXDN, if you want to add a second channel, it can be anywhere within the 70 MHz bandwidth of the radio. You can have a 6.25 kHz channel in 450 MHz, and the second channel at 480 MHz. MotoTRBO requires you to license a full 12.5 kHz channel, whereas NXDN can be licensed on the mostly vacant 6.25 kHz channels allocated years ago by the FCC. Areas like NYC are nearly impossible to locate frequencies for, but the 6.25 channels are mostly free even in such a busy area.

I'm not a fan of TDMA for the above reasons. The FCC considers TDMA to be "6.25 kHz equivalent" and so it's legit as far as they're concerned. FDMA is the only proper way to get 6.25 kHz channels.
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Re: Icom/Kenwood NXDN

Post by escomm »

NXDN is a nice toy.

Too bad the audio sounds like one has a sock in one's mouth. Like all digital modulation schemes.

6.25KHz is a pipe dream. Unless Motorola throws R&D at it I doubt we'll ever see a commercially viable solution.
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Re: Icom/Kenwood NXDN

Post by rdunajewski »

escomm wrote:NXDN is a nice toy.

Too bad the audio sounds like one has a sock in one's mouth. Like all digital modulation schemes.

6.25KHz is a pipe dream. Unless Motorola throws R&D at it I doubt we'll ever see a commercially viable solution.
True that is sounds nasally like any digital format, but I will say that it works very well. It's easy to understand the other user despite the less-than-crystal-clear audio. My town's analog patch to the P25 TRS sounds so much worse when the mobile FD units have "full quieting". They have hardcore P25 garble 90% of the time.

I will say that repeater desense really does kill the digital signal. In analog mode you hear the noise on the signal, but switch to digital and you'll just get bits and pieces of garble. Only when going through a desensed repeater, though. Simplex mode works great in weak signal conditions and going through a properly tuned repeater works great too. I honestly can't complain yet. Other than the fact that I only know one other person with NXDN equipment nearby at this time.
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