Hi, On Thu, 15 Apr 2010, Nabeel Ahmed wrote: > Thanks for your fast response. I did disable virtual carrier sense as > well. But, I still see these unpredictable delays. Can you think of what > possibly the hardware may be doing during these transmission periods > that could introduce such delays?
yes. a)some other node is transmitting a packet on the air. This other node may be in your network, or someone elses network. The ath5k hardware is refusing to transmit at the same time as someone else is transmitting. b)it is the beacon transmit time when you send your request to transmit. Every 100ms, (the default value for time between beacons), a beacon is sent. There is a period of time reserved for the sending of a beacon, and no data packets are sent. Question: you note the transmission delays are up to 3ms in size. What is the distribution of these delays - or how frequently do they occur? If we know how frequently they occur, or if they are timed to the beacon sent slot, then we can get a clue as to the cause of the delay. Question. After 10 minutes (or any other long period) of operation, what is the average transmission delay. - So for 10 thousand packets, what is the average delay? If you remove the antenna of your card, wind the receive gain down to the minimum possible value, your card card will receive the minimum of packets from other boxes. Does this make a difference to average delay period? If it does make a difference using lower gain, then you know that other boxes are at fault. Derek. -- Derek Smithies Ph.D. IndraNet Technologies Ltd. ph +64 3 365 6485 Web: http://www.indranet-technologies.com/ "How did you make it work??" "Oh, the usual, get everything right". _______________________________________________ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel
