more dstar
KD7BWB says:
I must tell you, after talking to a Icom rep (at ICOM America) about D-Star, and getting few good answers to my questions, I must tell you this is going to be an enourmous boondoggle. For one thing, there is no question of D-Stars' increased cost, for zero voice communications gain.
For one thing, while performance for digital radio is quite good, at normal signal levels, poor signal levels begin to show real problems. Digital voice either works or it doesn't, and the drop out generally occurs sooner than analog total unintelligability. Marginal signal for Digital, is normally quite readible at the same level on analog (if you allow the same amount of noise to be present that might be present in a SSB shortwave signal). This is not an exageration, it is simple fact.
On average, D-Star voice over 2-meters (the cheapest of the bands for performance/dollar) is more than 100% more expensive to install than a good quality analog 2-meter repeater. This is no joke, for the average repeater club. I can read a price list from any retailer for D-Star. Just for a 2-meter repeater requires at least three(3) basic components, totaling more than $4000, and we haven't even gotten to power supplies, duplexers and antennas.
A good Hamtronics repeater is less than $1600 for the basic chassis. And they've got hardware in orbit. Trying to do D-Star in space will require much more cabinet space, power and weight.
The other major problem is the vocoder codec is proprietary, requiring (some time in the future, you know, when JARL figures there's real money in it) a use license for each radio maker/user. Like P-25 (a competing vocoder) the license is beyond the price range of even the largest Ham club. What this means to the average user is that there is no way a Ham can design/build his own D-Star hardware. Some people are still building their own repeater hardware (Hamtronics still supplies receiver/transmitter kits for repeaters, and they are the best analog repeater RF equipment available [don't get me wrong, I don't own any Hamtronics]). This kind of hands-on experience will be impossible via D-Star. After all, people are still building transcievers for VHF, and Ten-Tec still produces the T-Kit 1220 2-meter transceiver. I built one of these and it works quite well, into all of the most popular repeaters in my area.
I like toys, I even like expensive toys. But D-Star is a STUPID expensive toy, that will tend to destroy more of VHF ham radio, because of its' proprietary nature. Ham Radio is about radio communications, not sending voice by any means possible.
IRLP and like systems are NOT Ham Radio expanded by Internet, it is Internet with a radio gateway. And D-Star is not radio expanded by digital, it is contract digital transcievers/repeaters paid for by Amatuers. Commercial Radio would love to have such a technological diversion.
D-Star is a long way from a good idea.
_________________
Paul Pollock
KD7BWB
D-Star is an expensive joke!
HAM RADIO STUFFING SAYS:
Paul, you have made the point quite well. It is cheaper to get a used hand me down VHF anaolg repeater from the public service agency then it is buy a DSTAR reapeter.
How many clubs have the budget to buy a DSTAR system. Secondly who wants wants to obsolete there current working anolog equipment and throw it away.
KD7BWB SAYS:
It is cheaper to buy a BRAND NEW analog repeater, than a D-Star product. And that's the point. I haven't seen a single NEW repeater that even gets close to the cost of a D-Star repeater (althoug some can approach $3000).
Don't get me wrong, Digital audio radio is coming. I am especially excited by the notion of digital voice radios for shortwave ham bands. This doesn't work very well when you operate digital audio with an analog radio; but a specialized digital radio would work quite well.
Alinco already has a protocol that works and is built into some of their VHF/UHF radios, it also works fine through the analog repeaters as long as you still send the PL-Tones properly. But these radios really shine between radios simplex.
D-Star is mutually exclusive. It requires its' own repeaters, and analog radios cannot travel via D-Star repeaters, while D-Star radios cannot use an Analog repeater. That's how picky they are. I think there is room for digital audio, but making them inoperative with analog repeaters makes the whole proposition very expensive and time consuming. It also means there will be multiple effort expended (one an already present system of analog repeaters, and the other will be the growth of a D-Star system; fighting over the same spectrum). This is NOT going to be a pretty picture.
I live in Arizona, and there is already over 100 repeaters in this state. This means there is two problems, frequency spectrum AND places to put repeaters. Many Amatuer repeaters in Arizona have to share physical space with public services, which brings into play jurisdiction problems with access to facilities that are also shared with government. Government facilities managers are going to have very little sympathy for Amatuers wanted to install another system of repeaters for the same radio spectrum with zero voice advantage.
In my view, the digital data advantages require an enourmous commitment of resources that have absolutely nothing to do with Amatuer Radio. Facility conveniences are a nice idea, but cellphone already supplies them already, and none are required for emergency situations. They are all fun stuff that requires a lot of Human hand-holding. Cellphone companies already has commercial and manpower resources to provide these services. Re-inventing this wheel misses the point of Amatuer Radio. We are precluded from commercial investment or profit. And carrying out these features on a day-to-day basis is going to make Amatuer Radio look more and more like something that needs FCC commercial service supervision.
What Price Glory?
Thanks for your input, it was a great post <grin>!
_________________
Paul Pollock
KD7BWB
D-Star is an expensive joke!
KG7HQ SAYS:
The D-Star system is a nice arrangement. Unfortunately it's out of bounds price wise for most in the area allowing it's implimentation to stagnate. It's also a proprietary format which closes out others from developing further to reduce the over all cost.
Maybe Icom will re-evalute this in the future and provide a better cost effective means for digital communications.
73's de KG7HQ
_________________
Thank You,
Michael
ARS - KG7HQ
Assistant Director/Technical Specilist
Northwest Division
ARRL
kg7hq@arrl.net
http://www.wetnet.net/~kg7hq
KG7HQ SAY MORE:
It's too bad that Icom tried to monopolize the market in this area instead of making it open source. I recently saw where they upgraded the firmware for addtional and improved features. But since the price is still up there, most hams will just thumb their nose at it and maintain normal FM communications with the continuious experimentation using sound card interfaced systems for digital support.
I'm seeing the Terminal Node Controller (TNC) communities take a hit as more look for a less expensive means of facilitating digital comms.
Open source software defined systems are the new rage... I hope the big "3" amateur radio companies pay attention and get invovled soon.
73's
_________________
Thank You,
Michael
ARS - KG7HQ
Assistant Director/Technical Specilist
Northwest Division
ARRL
kg7hq@arrl.net
http://www.wetnet.net/~kg7hq
