Comments for Zigbee Mesh routing - Interactive Tutorial at http://freaklabs.org , comment 1 to 9 out of 9 comments http://freaklabs.org Sat, 31 Jul 2010 02:56:11 +0100 FeedCreator 1.7.2 http://freaklabs.org/index.php/Blog/Zigbee/zigbee-mesh-routing-interactive-tutorial.html#comment-233 I assume you want to write a simulator in C# for AODV. I think the only way to do it is to translate an existing implementation to C# or write one from scratch. I had to write a small sim in C using the Zigbee spec to test out the algorithm before I implemented it. - Akiba Tue, 24 Mar 2009 18:24:45 +0100 http://freaklabs.org/index.php/Blog/Zigbee/zigbee-mesh-routing-interactive-tutorial.html#comment-232 sir can u give me idea how we implement it in C# - upasna Tue, 24 Mar 2009 16:30:48 +0100 http://freaklabs.org/index.php/Blog/Zigbee/zigbee-mesh-routing-interactive-tutorial.html#comment-231 hello sir i want to implement this AODV algo in C#.NET. Sir, PLZ help me. - upasna Tue, 24 Mar 2009 16:29:09 +0100 http://freaklabs.org/index.php/Blog/Zigbee/zigbee-mesh-routing-interactive-tutorial.html#comment-210 sorry. temporary brain freeze. it should be "more than", which would trigger the frame to get dropped and the old entry to be kept. - Akiba Thu, 12 Mar 2009 10:08:06 +0100 http://freaklabs.org/index.php/Blog/Zigbee/zigbee-mesh-routing-interactive-tutorial.html#comment-209 "if the route discovery frame has a path cost less than the old discovery entry with the same RREQ ID" Hey is this supposed to be less than or more than? - Geoff Thu, 12 Mar 2009 09:07:44 +0100 http://freaklabs.org/index.php/Blog/Zigbee/zigbee-mesh-routing-interactive-tutorial.html#comment-207 The src/dest seq numbers aren't being shown. Actually, the Zigbee version of AODV uses what's called route request IDs (RREQ ID) that are stored in the route discovery tables when you are looking for a new route. Those entries are purged after a certain amount of time, which I believe is to handle the issue of stale discovery entries that you mentioned. As for an explanation of how a stale entry can mess things up, in AODV, when you are discovering the route, you need to send a route discovery frame (route request). These get broadcast to the network and are tagged with an identifier (RREQ ID). If you don't purge these, then it's possible that some time later, a route request from a different node with the same ID comes through. Needless to say that this is not a good situation. Here's the gory details of what can happen: if the route discovery frame has a path cost less than the old discovery entry with the same RREQ ID, then the new discovery frame will be dropped and the old one will be kept. The old entry however is irrelevant to the current route discovery process that is going on so it can seriously screw up the algorithm. - Akiba Wed, 11 Mar 2009 09:29:10 +0100 http://freaklabs.org/index.php/Blog/Zigbee/zigbee-mesh-routing-interactive-tutorial.html#comment-205 By the way, are the source and destination sequence numbers being shown in the animation? Did you remove them because they aren't really required for understanding? Just wondering how important they are. Wikipedia's article on AODV mentions a few issues with AODV concerning intermediate nodes holding recent but not up to date DestSeqNum's. They mention that it can cause intermediate nodes to hold inconsistent routes. I'm not quite sure if I fully understand how the sequence numbers can cause inconsistent routes to be created, do you reckon you could add some explanation about it to this article? Wikipedia touches on that issue very briefly but doesn't explain it properly. Sorry to be such a nagging grandma! :D - Geoff Wed, 11 Mar 2009 07:29:13 +0100 http://freaklabs.org/index.php/Blog/Zigbee/zigbee-mesh-routing-interactive-tutorial.html#comment-183 cheers for this overview, very helpful! :) - geoff Tue, 24 Feb 2009 11:00:24 +0100 http://freaklabs.org/index.php/Blog/Zigbee/zigbee-mesh-routing-interactive-tutorial.html#comment-130 very clear, thanks ! - ward Sun, 07 Dec 2008 18:57:01 +0100