2023-12-01 — AMSAT-CA Formed, Amateur Radio Will Soon Lose Use of Most of the 1240 - 1300 MHz Band, Digital Voice or Data - Not an Either Or Choice, More Thoughts on IPv6 - No “44Net” within IPv6
We in Philadelphia ARES whose served agency is the Southeastern PA Chapter of the American Red Cross (SEPA-ARC) have run into the problem of magmount failure as many SEPA-ARC vehicles have fiberglass bodies. Bill W3AOK has designed and built a suction cup mount which has stood up to 60MPH travel and performs well with a half-wave antenna (thus not requiring a ground plane) such as a Diamond SR-777. I'll send you a photo in email. 73 de K3FZT / Steve
23cm: This shows how important political representation of ham radio is! Finnish hams lost the 23cm band completely last year. In Scandinavia (SM, OZ, LA, OH) the 70cm band has been only 6 MHz wide for a long time, including the ISM band. The Scandinavian hams must operate their relays with 1.6 MHz offset, partly up and partly down. Many relay input frequencies are in the ISM band :-(
Integrated voice and data: One feature makes or breaks digital voice for me: Any delay of more than perhaps 200 ms. I want do do my QSO, especially group QSOs, with a minimum of delay. You know the effect: You start to talk and after a word or two you release the PTT to check whether you are alone. Some time ago I bought a DMR handylalkie. These days, I only use it in FM mode. On the other side: Try to spell an URL over voice...
@AF7SJ: I did not talk about standard VoIP acros the Internet. I did talk about radio services like DMR, linked through massive digital networks over the Internet. In this environment, delays during a hand-over easily add up to several seconds.
The delays start with the codecs that need a certain number of samples before they can start to compress speech. The RF transmission uses time-domain multiplex (TDM), adding another few ms. This all happens in front of the VoIP transmission. Then we need the hand-over procedure that needs to flush all buffers. Then follows another TDM RF transmission. At the receiver you need a buffer to mask Internet and RF delays - this buffer must be filled before its output can be used.. Finally another codec delay.
It looks like the IARU were successful in keeping this as a recommendation - meaning its still up to individual countries to decide whether to implement it (assuming my reading of this is correct)
I expect CEPT will make it mandatory as it is future commercial GALILEO usage which has driven this. As GPS is not affected, I suspect the FCC couldn't care less unless some commercial or political pressure is brought.
Well done to the IARU representative though. Tough negotiations - only two instances of interference documented, but a lot of commercial and political pressure in the negotiations. I'm glad it got sorted by this conference - it threatened to go on longer, or become instituted in a worse manner.
There's a talk on this on YouTube from the RSGB by one of the IARU representatives - it sounds very frustrating.