On Thu, Apr 29, 2010 at 1:35 PM, Lynn W. Deffenbaugh (Mr) <[email protected]> wrote:
> An excellent analysis for your home QTH, but decided impractical for a > multi-day, over-the-road trip. Just to move it from theoretical into the real world... here's a quick peek into Curt's neighborhood. I was going to layer all the images one on top of the other, but after starting to compile a list of digipeaters I got tired, and realized that I don't have the time to find all digipeaters within 3 hops of Curt let alone capture and composite all the coverage areas. I gave up after just 2 hops. Also note that this is only a list of digipeaters using a green star icon, and does not include any other digipeating hardware that might be using a different icon. Stations that most likely can hear Curt from his last reported location based on the area these stations are reporting being able to hear: N8PVL-2 W8FSM-3 VE3WRC-1 VA3SWO-1 W8OAK-13 K1DE-5 N8PVL-2 can communicate with: K8TIH K8UI-1 K1DE-5 W8FSM-3 W8FSM-5 VE3KCR W8FSM-3 can communicate with: VE3KSR W8FSM-5 N8TJG-10 VA3DVR K8TIH K8UI-1 K1DE-5 WF5X-13 WB8NLS AB8XL KB8SWR-5 KF8YK-1 W8LBZ-1 N8PVL-2 VA3SW0-1 WD8EJC-10 W8FSM-5 K8TIH N3EOY-11 W8OAK-13 W8FSM-4 VE3KCR W8XR W8LBZ-1 N8PVL-2 VE3WRC-1 can communicate with: K8TIH VA3SWO-1 W8OAK-13 W8LBZ-1 VA3SWO-1 can communicate with: VA3ROG W8FSM-5 VA3DVR K8UI-6 K8UI-1 VE3WRC-1 VA3KMS VE3KCR W8FSM-3 W8WE-1 KB8SWR-5 K8DAC-7 W8OAK-13 can communicate with: W8FSM-5 K1DE-5 WF5X-13 AB8XL VE3WRC-1 W8FSM-3 N8ZSA-1 WB8NLS WD8DX-9 WC8EMA K1DE-5 can communicate with: VE3KSR W8FSM-5 N8TJG-10 K8TIH NK8X-10 K8UI-1 WF5X-13 WB8NLS AB8XL W8FSM-4 W8FSM-3 KB8SWR-5 W8DF-5 N8PVL-2 WD8EJC-10 VA3DVR N8OBU-5 WF5X-13 W8OAK-13 VA3KMS VE3KCR KB8UIH-2 KB8VEE-1 W8XR KB8ZGL-7 W8LBZ-1 K8DAC-7 You'll notice that many callsigns are included in a number of lists. this is because the digipeaters create a web of interconnections with each other. Because we are using the new-Paradigm setttings, each station will only fire off once, and this reduces congestion from what it used to be, but you can still see that there are an awful lot of stations out there that will get fired off. Remember as well, I gave up after just 2 hops. I didn't extend out to the third layer, where there will be many more digipeaters activated. In my desktop example, I only used 3 digipeaters on the first hop, where in Curt's world, it's probably 5 digipeaters that could hear him direct. On the second hop, every one of those digipeaters could communicate with more than three neighbors, with some able to communicate with over 20 neighboring digipeaters. In the real world, collisions and other propagation anomalies will kill a number of the packets being pushed around, but due to the interwoven nature of the APRS network, each of the listed digipeaters will probably end up handling the packet sooner or later. I have always said that it would be interesting to be able to defeat the anti-dupe filter on the APRS-IS to see how many different copies of the packet you can see, and all the different routes that the packet traversed. At the very least it would be neat to get a tally of the number of duplicates that have been discarded per packet. I know that I can fire off a packet from here with a no hop path, and get gated to the internet 3 times. Add in a single named digipeater, and now there will be 6 copies gated to the APRS-IS. Make it a 2 hop path, with 2 digipeaters, and now there are a total of 9 copies gated. A 2 hop path with 3 digipeaters makes it 12 copies. How many i-gates are within 2 hops of Curt and all those digipeaters? How many copies do each of those i-gates hear? It boggles the mind! James VE6SRV
