Audio Quality: Dstar vs. P25 vs. DMR

I have no experience with D-STAR but I've heard complaints from other hams about D* audio quality. You are not alone. I do have experience with Kenwood NEXEDGE, iCom iDAS, P25 (phase 1), and DMR/MOTOTRBO.

From my experiences, Kenwood's NEXEDGE (NXDN) and Icom's iDAS (also NXDN) sound very much like P25. The differences are subtle and it's hard to tell which sounds better or more natural sounding compared to the other. OTOH, DMR totally blows away P25 and NXDN, still sounding a little nasily but much more natural and less robotic than P25 or NXDN. It follows that DMR would also blow away D* in overall audio quality.

My vote for best digital 2-way communications audio is DMR.

Lately I've been selling off my Kenwood NEXEDGE (NXDN) digital radios and going with DMR all the way.

http://forums.radioreference.com/digital-voice-amateur-use/259366-audio-quality-dstar-vs-p25-vs-dmr.html

From what I have experienced with D-Star you'll have to be next to the repeater if you have a handheld or if you have a mobile d star capable radio you'll have a better chance accessing the system. The audio is some what garble or R2/D2 robot voice when someone isn't close enough.

NXDN is popular in my area but when I try to talk to the locals on NXDN it's like talking to the dead silent but when someone else is talking everyone responds. Audio is nice.

Now for MotoTRBO aka DMR as it better known as for the past 5 months now I am happy that I made the switch to this digital mode. I currently own MotorolaXPR 5550 mobile & XPR 655o both 440mhz radios. I like the sound of DMR sounds good.

Haven't tried p25 as of yet.

Making Private Calls

There are actually four types of calls on DMR: "Private", group, All-Call, and Data calls (Text Messaging).

The general feeling of most network operators in the Amateur networks is to discourage "Private" calls because they tie up time slots and other users will not know why.  If you really feel you want a "Private" call use your cellphone. The use of All-CALL is also discouraged except for emergency type use. Data calls (Text messaging) uses very little bandwidth and works fine locally but may not work across the bridges unless they are configured for it.

A repeater operator can also implement RAS (Restricted Access to System) with Key Authentication and keep all the Non-Mototrbo radios from using the system (as they do not support this technology), this will also keep non-authenicated radios from listening to group calls on the RAS enabled repeaters. RAS also allows the repeater operator to lock out individual user IDs, or only allow access to authorized user IDs.

In Canada, encryption is allowed in amateur radio unlike the US.

"Private" calls are not really private, my radio has the option of allowing me to hear ALL calls on a time-slot.

Dstar vs Dmr rx only

You can make your own minds up from this, my icom 5100 is rx via raspi the dp3600 is rx via gb7mb both work great , I would have done fusion also but not a sausage on it up here ..a dead mode

Toronto on the DMR network of 130+ repeaters

It's great to have Toronto on the network of 130+ repeaters now. Our growth has been very strong over the last 3 years. We are in 11 countries now with over 2200 users. We expect Italy to be online very soon. We're offering something that is very new and innovative at http://dmr-marc.net. If you want to join us, we're a tech savvy crew and we have some real neat tools to make sure our network is very reliable and efficient. We only require the MOTOTRBO repeaters since we want to commonize the architecture to a compatible top level and achieve the highest reliability so that our volunteer staff doesn't have to spend hours troubleshooting issues. However, Since DMR is an international standard, you can use several mobiles and portables from Motorola, Vertex Standard, Tait, Kirisun, Hytera, Simoco, the Harris radios that are made by Hytera, and other smaller Chinese startup DMR manufacturers. Do some digging as Dave suggested and you will find the radios are sold by tiers. Some radios lack features and are dirt cheap. Some have all the bells and whistles and cost more. I've seen DMR radios go for as low as $200 new and as high as $625 new, depending on what features you get and from what distributor. XPR8400 Repeaters are less than $2000 USD and contain all you need to get on the network aside from a duplexer and antenna Do your homework and talk to someone who has a TRBO system on the air and ask them what they think. Don't just take our word for it. 73.

DMR just my opinion

DMR is great. I can drive across the state of Michigan and be in coverage of the 12 linked 

DMR repeaters, the radio will 'roam' from site to site without changing channel!
comparing prices d-star is NOT cheap either

DSTAR HT's : id51a $640, IC91 $540, IC92AD $555, ID31 (monoband) $300
DSTAR Mobiles: IC-2820H $944, ID1 $950 ID880H $500
compare that to the price of motorolas DMR's
DMR HT's: XPR7550 $700, XPR6550 $629, SL7550 $700
DMR Mobiles: XPR4550: $550 XPR5550 $600
Also motorolas xpr3500 series is a cheaper DMR radio line with less features then the 6550/7550's

Its true moto makes you Buy CPS, Hytera i think is FREE.

My Opinion

INHO DMR is an answer to a question nobody asked. It's very, very expensive, it's radios are only available in single band configuration at a time when a majority of new radios sold are at least dual banders and they have no amateur radio embellishments that are built in like D-Star. Both technologies use the AMBE vocoder and thus have to pay license fees to Digital Voice Systems, Inc., who holds the patent, and that's what keeps the cost high. The D-Star protocol was developed as an open standard by the Japan Amateur Radio League (JARL) and as such, is much more in tune to what hams want in a radio system. Because DMR systems are marketed solely as commercial systems, they have almost nothing of such embellishments and such things are add-ons and modifications designed by various amateur groups that must be added to TDMA radios. D-Star has most of such things already, for about the same cost as the single band DMR radios. So why spend about the same amount for a radio that only does a small portion of what D-Star already does? With D-Star you can talk to hams in Nigeria. You can't do that with DMR.

Canadian DMR C-Bridge Launches

On February 23rd, Canada took it’s first step toward the creation of a national amateur radio DMR network with the launch of the first inter-provincial DMR networking server. This server, known commonly as a “c-Bridge”, which is manufactured by Rayfield Communications, will serve as a network hub for Canadian amateur radio DMR repeaters, allowing them to reliably link to one another and to the larger DMR-MARC global network using the Internet. The Canadian c-Bridge is located in Montreal and is currently supporting several DMR repeaters in Ontario and Quebec, including the VA3XPR digital DMR repeater located in downtown Toronto.