microwave
Member
Has anyone compared all three digital voice modes? I'm unhappy with the Dstar quality. P25 sounds good with a new DSP and I haven't tried DMR. What are your experiences with voice quality?
Audio Quality: Dstar vs. P25 vs. DMR
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n1das
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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.
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.
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N1XDS
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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 Motorola XPR 5550 mobile & XPR 655o both 440mhz radios. I like the sound of DMR sounds good.
Haven't tried p25 as of yet.
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 Motorola XPR 5550 mobile & XPR 655o both 440mhz radios. I like the sound of DMR sounds good.
Haven't tried p25 as of yet.
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"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."
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You have identified a fundamental problem with D-Star.
The format is inferior in that it doesn't re-sync immediately when the signal drops out. You can demonstrate this issue easily - while listening to a D-Star transmission, simulate a drop-out by disconnecting your antenna and then quickly reconnecting it. The audio will be gibberish for three to five seconds until re-sync finally occurs.
The commercial formats re-sync almost immediately. In the case of P25, that is a part of the standard and a required conformance test.
This issue makes D-Star hugely inferior to the commercial digital modes for mobile and portable operation where fading and drop-outs are inherent. The second rate performance of D-Star compared to the commercial formats is part of the reason for the growing amateur interest in DMR and NXDN. They just flat-out work better.
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You have identified a fundamental problem with D-Star.
The format is inferior in that it doesn't re-sync immediately when the signal drops out. You can demonstrate this issue easily - while listening to a D-Star transmission, simulate a drop-out by disconnecting your antenna and then quickly reconnecting it. The audio will be gibberish for three to five seconds until re-sync finally occurs.
The commercial formats re-sync almost immediately. In the case of P25, that is a part of the standard and a required conformance test.
This issue makes D-Star hugely inferior to the commercial digital modes for mobile and portable operation where fading and drop-outs are inherent. The second rate performance of D-Star compared to the commercial formats is part of the reason for the growing amateur interest in DMR and NXDN. They just flat-out work better.
shmget
Member
I just starting doing stuff with NXDN. If you are able to get on the WW network, I'm usually listening later at night after 9pm. I've been on around commuting times, too. I've found to make contacts I have to be persistent.
N1XDS
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I sold off my NXDN radio I just didn't like how the locals wouldn't speak to me but they would speak to someone else. It's clicklish on some of the repeaters around here. :roll:
Part of the reason that D-Star doesn't resync properly is that it's not being used as designed by the JARL. The actual protocol has absolutely no concept of "reflectors" anywhere in the documents that I have seen on it. Another part is that it is quite likely that the use of UDP for data transfer between gateways allows those resync frames to get "misplaced", resulting in "R2D2". A third factor is that there are issues within the Icom D-Star repeaters that quite likely contribute to the problem.
Having said the above, there have been efforts by hams to improve D-Star; several of the above points are fixed in the software based controllers and gateways that I know of. The only thing we cannot do without breaking compatibility with Icoms systems is change to full time use of TCP for the home-brew networks.
N8OHU
N8OHU: "Part of the reason that D-Star doesn't resync properly is..."
You observations may have merit, but if so, they constitute additional D-Star weaknesses beyond the flawed "air interface".
The lack of re-sync on signal drop-outs affects even simplex radio-to radio transmissions, and thus has nothing to do with reflectors, other than the fact that they will "reflect" the incoming data errors from signal issues on the initiating user's transmissions.
As you note, hams are adding innovations to D-Star. Reflectors are an example of this - which illustrates the fact that, as conceived by JARL, D-Star doesn't fit US amateur operations very well.
It's sad that we didn't have domestic leadership participating in the development of a digital voice format with enough versatility to meet everyone's needs worldwide and based on the highest technical standards.
It's also unfortunate that so many innovations are being developed for D-Star when that effort could have been invested in a format with a real future. It's kind of like building a beautiful new house on former marshland. Sooner or later folks are going to see the that the foundation is settling and notice the cracks in the walls.
You observations may have merit, but if so, they constitute additional D-Star weaknesses beyond the flawed "air interface".
The lack of re-sync on signal drop-outs affects even simplex radio-to radio transmissions, and thus has nothing to do with reflectors, other than the fact that they will "reflect" the incoming data errors from signal issues on the initiating user's transmissions.
As you note, hams are adding innovations to D-Star. Reflectors are an example of this - which illustrates the fact that, as conceived by JARL, D-Star doesn't fit US amateur operations very well.
It's sad that we didn't have domestic leadership participating in the development of a digital voice format with enough versatility to meet everyone's needs worldwide and based on the highest technical standards.
It's also unfortunate that so many innovations are being developed for D-Star when that effort could have been invested in a format with a real future. It's kind of like building a beautiful new house on former marshland. Sooner or later folks are going to see the that the foundation is settling and notice the cracks in the walls.
JRayfield
Member
We did have "domestic leadership participating in the development of a digital voice format with enough versatility to meet everyone's needs worldwide and based on the highest technical standards".
It's called DMR. Motorola was heavily involved in the development of DMR, even though it was presented to ETSI for setting it up as a standard. In fact, Motorola owns some of the intellectual property used in DMR (in other words, they invented it). With some possible slight changes/additions to how DMR is implemented in mobiles and portables, it might easily be made very much 'amateur radio friendly' (such as sending callsigns over the air, just as D-Star does), without having to change the actual 'standard'.
John Rayfield, Jr. CETma
W0PM
It's called DMR. Motorola was heavily involved in the development of DMR, even though it was presented to ETSI for setting it up as a standard. In fact, Motorola owns some of the intellectual property used in DMR (in other words, they invented it). With some possible slight changes/additions to how DMR is implemented in mobiles and portables, it might easily be made very much 'amateur radio friendly' (such as sending callsigns over the air, just as D-Star does), without having to change the actual 'standard'.
John Rayfield, Jr. CETma
W0PM
MTS2000des
5B2_BEE00 Czar
The biggest stumbling block for many hams with TRBO is the price of the programming software, and now the entitlement key requirement if you wish to program wideband, even in the ham bands- other manufacturers like Kenwood allow current radios to be programmed for wideband only in the HAM portions of the VHF and UHF bands (this is the case on my TK-2312). Programming software is also cheap and widely available from Kenwood, Icom and Vertex for their DMR and analog radios. This is why NXDN/iDAS has taken off at quicker pace, it's more ham friendly to the wallet.
That being said, there is no question that DMR has the best audio quality compared to NXDN and D-star. D-star is to venerable to QRM as has been discussed. I wonder how much gas there is left on the D-star bus?
It's too bad the Vertex eVerge DMR radios do not support IP connect. They would be a perfect way for hams to get into DMR for less than many D-star radios cost, and they use the same programming cables (portables at least) as the Yaesu ham rigs. Dealers are pretty liberal with "helping" buyers get software as well.
That being said, there is no question that DMR has the best audio quality compared to NXDN and D-star. D-star is to venerable to QRM as has been discussed. I wonder how much gas there is left on the D-star bus?
It's too bad the Vertex eVerge DMR radios do not support IP connect. They would be a perfect way for hams to get into DMR for less than many D-star radios cost, and they use the same programming cables (portables at least) as the Yaesu ham rigs. Dealers are pretty liberal with "helping" buyers get software as well.
JRayfield: "We did have "domestic leadership participating in the development of a digital voice format with enough versatility to meet everyone's needs worldwide and based on the highest technical standards".
It's called DMR...."
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I guess I thought I was clear enough since the format being discussed was D-Star.
Apparently not, so it should have read:
It's sad that we didn't have domestic leadership participating in the development of an amateur radio digital voice format with enough versatility to meet everyone's needs worldwide and based on the highest technical standards.
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The point is that amateur radio in the US is stuck with a digital voice format developed elsewhere, one which not only needed extensions to fit US ham's operational desires but one which is technically deficient - it just doesn't work very well at the basic air interface level.
This has driven knowledgeable hams to adopt commercial formats such as DMR and NXDN along with P25. DMR appears to be the winner in this so far and had Yaesu chosen DMR for their new digital ham radio they would have become a serious threat to the future of D-Star.
Sadly, they did not, thus earning the scorn of countless US hams who have no need whatsoever for yet another incompatible digital voice format.
It's called DMR...."
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I guess I thought I was clear enough since the format being discussed was D-Star.
Apparently not, so it should have read:
It's sad that we didn't have domestic leadership participating in the development of an amateur radio digital voice format with enough versatility to meet everyone's needs worldwide and based on the highest technical standards.
--------------
The point is that amateur radio in the US is stuck with a digital voice format developed elsewhere, one which not only needed extensions to fit US ham's operational desires but one which is technically deficient - it just doesn't work very well at the basic air interface level.
This has driven knowledgeable hams to adopt commercial formats such as DMR and NXDN along with P25. DMR appears to be the winner in this so far and had Yaesu chosen DMR for their new digital ham radio they would have become a serious threat to the future of D-Star.
Sadly, they did not, thus earning the scorn of countless US hams who have no need whatsoever for yet another incompatible digital voice format.
microwave
Member
I understadn
I dealt with the same thing on a P25 repeater. It's hardly used now because two of the people in the group moved away.
I dealt with the same thing on a P25 repeater. It's hardly used now because two of the people in the group moved away.
The software is a big stumbling block, as you say. But a dual band radio is what I consider a necessity in the ham world. Unless you want to walk around with your pockets stuffed full of radios, analog compatibility is a definite must. Whatever the good and bad points of all the digital formats, there is only one company that fits those two criteria. That would be Icom. D-Star may have its problems, but no other company is interested in our (hams) digital dreams.
Just one opinion,
Dave
K9DPM
That may be, but need I point out that, to many of those that use D-Star on a daily basis, the fact that it "needed extensions to fit US ham's operational desires" isn't an issue; many of us wanted something that we could tailor to our needs and neither DMR nor NXDN can do that as easily. Alan W7QO couldn't have done what he's done with the NXDN World Wide network if Scott KI4LKF hadn't developed DExtra; DPlus is nice, but the ability to link reflectors, as Scott's DExtra implementation can do, makes creating small friendly experimentation clusters possible. DMR might be technically superior in some ways, but I really don't see anything in it that hasn't been made possible by the efforts of dedicated hams, and it doesn't feature some things that are often overlooked in the D-Star Specification documentation.
As for your comments about Yaesu and it's apparent ignoring of the desires of DMR enthusiasts by releasing several FDMA radios, go back and read their Digital Roadmap; the short form of it is that this has always been the plan, and if they do release a TDMA radio, they will let us know at any time after the release of the mobile one.
N8OHU
JRayfield
Member
Ok, I understand what you meant now. And you sure did further explain your thoughts nicely. I can't agree more. I'm still hoping that Yaesu will come up with a flash update for their new digital portable, for DMR, after the FCC puts their 'official ok' on DMR.
John Rayfield, Jr. CETma
W0PM
John Rayfield, Jr. CETma
W0PM
kayn1n32008
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While I would love to see yaesus TDMA ham radio be DMR compliant, sadly I do not think that this will be the case.
I am slowly starting to plant the seeds in my club for putting up Albertas first Uhf DMR repeater. First though, I have to bring a much better broadband connection to our flagship repeater site. Currently we have D-Star and echo/IRLP and it is taxing our DSL (max 750kbps upload) connection. With the competion in the DMR segment, I believe this format is the way to go.
Sadly I believe the Yaesu FDMA digital will go the way of the Alinco digital line.
As amateurs, I believe we need to 'force' amateur manufacturers, by way of our pocket books, to start producing formats that will bring the hobby into the 21st century.
While it is great that JARL took on the challange off writing a protocol, it is limited, and has not been adopted by any other companies aside from Icom. I believe D-Star is going to plateau, where DMR is goint to continue to gain popularity and user density for the longterm.
While I would love to see yaesus TDMA ham radio be DMR compliant, sadly I do not think that this will be the case.
I am slowly starting to plant the seeds in my club for putting up Albertas first Uhf DMR repeater. First though, I have to bring a much better broadband connection to our flagship repeater site. Currently we have D-Star and echo/IRLP and it is taxing our DSL (max 750kbps upload) connection. With the competion in the DMR segment, I believe this format is the way to go.
Sadly I believe the Yaesu FDMA digital will go the way of the Alinco digital line.
As amateurs, I believe we need to 'force' amateur manufacturers, by way of our pocket books, to start producing formats that will bring the hobby into the 21st century.
While it is great that JARL took on the challange off writing a protocol, it is limited, and has not been adopted by any other companies aside from Icom. I believe D-Star is going to plateau, where DMR is goint to continue to gain popularity and user density for the longterm.
kayn1n32008
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I truly hope that Yaesu takes notice of this and takes it to heart.
I really would like to see a decent amateur radio that uses an already in use commercial market protocol. Sadly it will probably have to be a non modifiable radio to keep the morons from modding it to use OOB rather than buying proper commercial gear.
xmo said:
I truly hope that Yaesu takes notice of this and takes it to heart.
I really would like to see a decent amateur radio that uses an already in use commercial market protocol. Sadly it will probably have to be a non modifiable radio to keep the morons from modding it to use OOB rather than buying proper commercial gear.
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Boatanchor
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Lots of people 'invested' (wasted) large sums of money on D-Star and P25 radios, only to later end up selling the gear for a third the price they paid, to some other sucker.
It was/is all hype IMHO.
+-5Khz FM gives better audio quality (under most signal conditions), cheaper repeater setup & running costs, universal access to cheap equipment and really, I don't see any compelling reason to go down the public safety path and be royally screwed over at every turn.
It was/is all hype IMHO.
+-5Khz FM gives better audio quality (under most signal conditions), cheaper repeater setup & running costs, universal access to cheap equipment and really, I don't see any compelling reason to go down the public safety path and be royally screwed over at every turn.
kayn1n32008
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I see it quite differently. At one time amateur radio lead the curve. Wether it was adopting AM, SSB, FM or Data transfer. Sadly that is not the case any more. I agree 5KHz FM does sound good... Under some conditions IF you have adequate signal strength and flat land with zero picket fencing, digital modes have much more to offer IMO, like zero picket fencing, better fringe coverage, and better voice quality through out the whole coverage area.
I am not sure what you mean by hams getting 'roally screwed' like PS though. When my club puts up a repeater we have already evaluated a site, the site owner, do RF surveys, and used Radio Mobile to see what kind of coverage we can expect. We do not willy nilly put up repeaters and 'hope for the best' because that is a waste of time and energy.
While it IS cheaper to put up an analog repeater, my club is financially stable and are looking for ways to spend lottery money. Money that if we do not spend we will lose.
While digital equipment is more expensive to get into, I feel the ROI is much higher with DMR then P25(b*tch to link) or D-Star(Icom only).
Boatanchor said:
I see it quite differently. At one time amateur radio lead the curve. Wether it was adopting AM, SSB, FM or Data transfer. Sadly that is not the case any more. I agree 5KHz FM does sound good... Under some conditions IF you have adequate signal strength and flat land with zero picket fencing, digital modes have much more to offer IMO, like zero picket fencing, better fringe coverage, and better voice quality through out the whole coverage area.
I am not sure what you mean by hams getting 'roally screwed' like PS though. When my club puts up a repeater we have already evaluated a site, the site owner, do RF surveys, and used Radio Mobile to see what kind of coverage we can expect. We do not willy nilly put up repeaters and 'hope for the best' because that is a waste of time and energy.
While it IS cheaper to put up an analog repeater, my club is financially stable and are looking for ways to spend lottery money. Money that if we do not spend we will lose.
While digital equipment is more expensive to get into, I feel the ROI is much higher with DMR then P25(b*tch to link) or D-Star(Icom only).
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