Hi! Now i know tinyos has mechanism to handle the duplicate packet,thank you very much!
All the best! 2009/4/28 Razvan Musaloiu-E. <[email protected]> > Hi! > > On Tue, 28 Apr 2009, 林枫 wrote: > > Hi,Razvan ME: >> Thank you for you reply.I have read the file CC2420PacketC.nc, but i >> can not find any code that handles this problem.In 802.15.4-2006,there is >> no >> content to >> handle this problem too.I have read some implementation of 15.4 written in >> c,they just ingore this problem and let the upper layer to handle the >> duplicate frame(maybe process it once more ).I wonder why they do not >> handle >> this problem in the mac layer.I mean i can keep a table in the mac layer >> to >> record the sequence number of different source node , if the sequence >> number >> of the incoming frame is the same as the sequence number of last frame >> from >> the source node,we discard it.Maybe it costs too much,but if we do not do >> anything there will be errors. >> > > One more place to look at is this one: > tinyos-2.x/tos/chips/cc2420/unique > > The table that keeps track of the sequence numbers is in UniqueReceiveP.nc. > :-) > > -- > Razvan ME > > > 2009/4/28, Razvan Musaloiu-E. <[email protected]>: >> >>> >>> Hi! >>> >>> On Tue, 28 Apr 2009, 6lowpan wrote: >>> >>> Hi everyone. >>> >>>> >>>> In 802.15.4,when a receiver receives a frame from a sender ,it will send >>>> back an ack.If the sender fails to receiver the ack,it will send the >>>> frame >>>> with the same sequence number again. >>>> >>>> >>> The retransmission happens only if the PACKET_LINK is enabled. >>> >>> I can not find how the receiver handles this frame in the document.Does >>> it >>> >>>> discard it or process it once more? >>>> >>>> >>> The code is in tinyos-2.x/tos/chips/cc2420/packet. >>> >>> All the best! >>> Razvan ME >>> >>>
_______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
