At 05:34 PM 6/7/2010, you wrote:
>And that D-STAR protocol definition is defined by the JARL... > >How much of a prospect is it the JARL would be willing to update the >DSTAR protocol with an open source vocoder if it were competitive to AMBE? Assuming the JARL were open (pun not intended!) to the idea. The rest of this message deals with the case where the JARL to decide to amend the D-STAR protocol (if they don't, then we would be dealing with a fork instead). The biggest challenge will be not breaking gear that's in the field. The DV Dongle is the easiest case, because the new (open) codec can simply be added to DVTool, and run entirely in software when needed, with the dongle only being used to encode/decode an AMBE stream. The Icom radios would require a series of replacement boards for their existing DV boards, to use the new codec, otherwise you're going to have a bunch of users who will find D-STAR suddenly becomes hit and miss. Also, the spec would need to be updated to include notifying the remote end which codec is in use, somewhere in the protocol, since this can no longer be assumed. There could be an opportunity in the new add-on board to have field programmable components on board, so any further enhancements to the codec/DSP can be downloaded and installed. The above is the minimum that would have to be done. There might be other unintended consequences that need to be dealt with (I can see the possibility for all sorts of "corner cases"). >--------------- >Codec2 is in at least partial code form so far: ><http://www.rowetel.com/ucasterisk/codec2.html>http://www.rowetel.com/ucasterisk/codec2.html Looks promising. Where I see this gaining traction first is in HF digital voice experimentation, which hit a major speed bump when patent issues became apparent. However, codec2 will need to get into the 1200bps and below range to be really effective in this application. >It seems to be competitive in the current market, a third-party >daughter board similar to UT-118 would have to be developed that had >dual AMBE/Codec2 capability, and sold at-cost to undercut the >current UT-118 cost. Assuming (warning - monster assumption!) the >SMT design was donated by hams and it was sold at cost, and it had >automatic codec detection and switching capability, it would be a >competitive way to bring an open source codec to "DSTAR". And be able to be fitted without too much hassle/expense to existing equipment in the field (like my 91AD). 73 de VK3JED / VK3IRL http://vkradio.com
