Here's a suggestion, I don't know if it meets your requirements. What if you not use CTP and just make your own app to check if nodes are alive or not. Create two types of packets (three if you want to send actual data). One packet should have a data field that has certain bytes (lets say decimal 3). This packet is used to send acknowledgement requests and this packet at a certain time interval. So, if a node wants to know which other nodes in its neighborhood are alive, it sends this acknowledgment request. A node receiving this packet checks this request using some sort of simple if statement, and sends an acknowledgment, which tells the node that sent the initial acknowledgment request that it is still alive. Then, you could do some sort of averaging to figure out that if an acknowledgment was not received after a certain number of intervals, then the node is probably dead.
Let me know if that makes sense. Cheers, On Tue, Sep 22, 2009 at 7:35 PM, Varun Jain <[email protected]> wrote: > I need to tell the ROOT/BaseStation node in the network about a > particular node being turned off. As the neighboring nodes have information > about a particular node and they receive constant beacons from each other, I > am wondering that if I can work out that a beacon has not been received then > one of the neighboring nodes should be able to send a message to the Root > node telling that a node in its routing table is not there anymore. But then > due to changes in ETX values Nodes might be changing their Routing tables, > so a change in the Routing table entry in one of the neighboring nodes is > not a sure shot way to find out the status of nodes. If my reasoning is > correct, then how can we achieve this??? > > > > Cheers, > > Varun Jain > > > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Mohammed > Billoo > *Sent:* Wednesday, 23 September 2009 6:21 AM > *To:* [email protected] > *Subject:* [Tinyos-help] Using CTP to detect Node Status?? > > > > Hi, > > > > Do you want to tell the same node that it has been turned off or do you > want to tell another node in the network that a particular node has been > turned off ? I read the TEP on CTP and didn't see any form of Acks being > used so that you could determine whether a node is turned on or off based on > these Acks. Maybe you could integrate an Ack method with CTP to figure out > if a node is on or off. > > > > Regards, > > -- > Mohammed Billoo > > > > Hi, > > If I want to know that a node has been turned off in the network, is > there a way that the neighbor nodes can inform it?? I know there is an > application called "Antitheft" which uses sensors to do that but I do > not want to use sensors, I want to use the routing information available > with the neighboring nodes to inform this. I was thinking if it can be > done from within the CtpRoutingEngine???? > > > > To understand better about the CTP protocol, could someone explain what > can be possible effects of the "etx" bug fixed recently (Sep 21,2009) in > CtpRoutingEngine and CtpRoutingPacket if we do not commit the fix in our > code. I just want to understand the misbehavior that the bug can cause > (if not fixed) in the network?? > > > > Thanks, > > Varun Jain > -- Mohammed Billoo
_______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
