At 02:35 AM 8/12/2010, you wrote:
>One of the shortcomings of the linking arrangement - the near >station has no idea whether the far end station is linked or not >unless the near station has internet access. The near station >cannot interfere with a contact on the far end or transmit over the >far end station. If the far end is Callsign routing has similar limitations, even more so, because it's a stateless system. Before DPlus came to Melbourne, it was not uncommon to have a routed conversation taking place, and someone else from an entirely different part of the world put out a call, because they just happened to slip in between transmissions. The status reporting via the radio is all well and good, but my experience over the last 10 years (IRLP has a similar mechanism that attempts to avoid intruding on local QSOs before making a link) is that it's actually quite common for the timing to be such that the query about remote end status occurs in between transmissions. On IRLP, the answer is to listen before transmitting, just in case. With callsign routing, this is not possible (because it's one way stateless and doesn't setup a link), and you're operating totally blind. On IRLP, it's also possible to set a time after the last transmission where the node will report itself as "busy" to incoming connections. This prevents connections sneaking in between local transmissions. Just pointing out that callsign routing is not immune to intruding in on remote conversations and in some cases can be even worse. At least with DPlus, you can wait a few minutes after linking and eventually hear the remote conversation, or not. We need to be aware of the limitations of whatever technology we're using. DPlus and callsign routing both have their respective limitations. 73 de VK3JED / VK3IRL http://vkradio.com
