Absolutely true about occasional breaking stations in between 'overs' during a conversation. I try and leave a few seconds pause between PTTs just to accommodate breaking stations (who have no clue about the conversation in progress). Also I / the station I am in contact with have the option to ignore the breaking station. I do agree that it can be a bit disrupting. On the other hand the breaking station knows what repeater or ham call he is trying to reach with call sign routing. (and if by a pc on the internet looking at dstarusers.org know who is occupying what repeater).
I have never played with IRLP or Echolink but in 30 years of PMR / Land Mobile service I have seen some of the very best and also some of the very worst amateur linked systems in terms of audio levels, quality, noise and distortion. Dstar seems to be consistent in that stations are all pretty much equal in loudness and there is no white noise / crackle, etc. Instead we have loss of sync beyond forward error correction's ability to fill in the blanks. R2D2, so to speak. For me, a hybrid of linking and callsign routing works best. One size doesn't fit all. I am sure each system has it's pluses and minuses - as said "different horses for different courses." steve On Wed, Aug 11, 2010 at 3:23 PM, Tony Langdon <vk3...@gmail.com> wrote: > At 02:35 AM 8/12/2010, you wrote: > > > 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 > > -- NU5D - Nickel Under Five Dollars
