D Star
Well yesterday Hannah and myself saw a presentation of D Star radio. I have to say at first I was quite impressed. The routing systems were weird, and the system seemed to be fairly open. And both Kenwood and Icom were using it (though as it seems all that Kenwood does is rebadge icom dstar radios for the japanese market.)
The data modes on 23 centemetres (1.2GHz) were amazing, 128kbps while slow to us with our fast broadband connections, was very fast for radio based data modes.
But upon looking into it further is that the codec used for the audio modes is the AMBE codec. This is the bad part, while the whole dstar standard is open, the codec used for audio is propriatory and the licensing fees for the codec are insane.
It just doesn’t feel like amateur radio when the main part of the radio system that being the voice mode, is not open. Amateurs have gone from AM voice to SSB to various digital modes like psk31 all of which are open protocols, where the AMBE codec is closed.
I am highly skeptical of D-Star and the motives of the commercial organisations (principally one radio manufacturing concern) pushing it. The radios are profoundly expensive, have NO DX advantage over analogue (especially sideband), in spite of claims to the contrary – refer the Utah Amateur Radio Group’s findings at the url below. As one with a background in broadcasting and high-quality a.m. transmission on 160 metres, I find the audio far from “crystal clear” as some have described it. To me, it sounds like typical highly compressed digital audio – swishy, mechanical, and peppered with compression artifacts of all kinds.
On this basis, one starts to think “is this ‘the Emperor’s New Clothes’”, or perhaps just a sales pitch for the gullible and uninformed?
Ivy, this website does a great deal to reinforce your misgivings about the audio codec, specifically where people try to apply it to emergency operation with lots of background noise at the transmitting end:
http://utahvhfs.org/dstar_codec_behavior.html
In America, manufacturers of these radios are offering huge subsidies to amateur radio organisations for the setting up of emergency repeaters, the catch being that they have to use the D-Star system. That is giving many hams, and emergency service people, the jitters. And although the system is nominally an innovation of the JARL, in practice the chips to use it are unavailable, except in the communications transceivers of ONE manufacturer and its associates.
The whole thing stinks too much of commercial manipulation to me. I frankly think that anyone who would put over Aust $1000 into buying such a radio – given that inevitable codec and connectivity improvements will quickly render these radios, and possibly the D-Star system obsolete – needs a reality check and possibly a psychiatric examination!!!!
All the best,
Chris Long VK3AML.