Multiple Access with Collision Avoidance for Wireless: Difference between revisions

Revision as of 17:46, 7 December 2014

Revision as of 08:46, 9 December 2014

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=== Unsolved problems ===

MACAW does not generally solve the [[exposed terminal problem]]. Assume that node G has data to send to node F in our example. Node G has no information about the ongoing data transfer from A to B. It initiates the process by sending an RTS signal to node F. Node F is not in the transmission range of node A and cannot hear the RTS from node G, since it is exposed to [[co-channel interference]]. Node G assumes that its RTS was not successful because of collision and hence backs off before it tries again. In this case, the solution provided by the RRTS mechanism will not improve the situation much since the DATA frames sent from B are rather long compared to the other frames. The probability that F is exposed to transmission from A is rather high. Node F has no idea about any node interested in initiating data transfer to it, until G happens to transmit an RTS in between transmissions from A.

Furthermore, MACAW might not behave normally in [[multicasting]].