On Wed, Jul 1, 2009 at 7:59 PM, Varun Jain<[email protected]> wrote: > Hi, > > I am currently using TinyOS-2.0.2 and Micaz-type of motes to implement a > security APPLICATION in a building. We are using a door sensor (Reed Switch) > and Motion Sensor(PIR Sensor) to sense if people are present in a certain > ROOMS and doors are closed when they should be closed. We have also added a > small 8-segment DISPLAY to send some messages to the nodes in case of an > emergency. In total, we have about 20 ROOMS each with its own ROOM ID and > > > > To send a particular message to a particular node, I am using ‘drip’ and in > the message I send the node id. At the NODE END, I read the message and if > the source field matches with the TOS_NODE_ID then we process the packet (I > tried implementing TYMO but ending up using drip to do my application). Now, > we have some group of nodes which form a group so that if an EMERGENCY > message is sent, it goes to all these group of nodes. For this purpose, I > have GIVEN them the same TOS_NODE_ID. Now, if I send a FIRE message through > DRIP, it displays correctly on these group of nodes. > > > > I know dissemination was not designed for this purpose but all the > dissemination actions work correctly but I am observing something weird WITH > CTP (using ‘link estimator’. A particular message from a particular node > seems to be receievd multiple times at the Root Node. My question is that > could it be possible that the group of nodes with the same id is forwarding > the same packet again. There are about 10 nodes with the same id. I would > believe that it should not happen like that because each node in the > ctp_data_header carries a unique originSeqno. If the frame sent on the > serial port at the Root Node is the following, should there not be only one > instance of this packet?? DOES THE ROOT NODE REJECT any packet which is > recieved TWICE with the same originSeqNo????????
Your application should filter the duplicates - CTP's duplicate suppression is not guaranteed to suppress all the duplicates. If you have duplicate node id's in the network, unique originSeqno will not help because you can get duplicate <nodeid,originSeqno> from different nodes with the same nodeid. > My application is similar to Antitheft where I am interested in sending only > the status of the node, so I do not send items like parent, hopcount, seqno, > etc like in TestNetworkmsg. Should I be sending the parent in each packet??? You can just send your payload. - om_p _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
