On Backoff in Fading Wireless Channels

The authors consider the impact of transmission errors on the backoff algorithm behavior in the IEEE 802.11 protocol. Specifically, since the backoff algorithm assumes that all packet losses are due to collisions, it unnecessarily backs off when a packet is lost due to a transmission error. Two performance problems arise as a result: Low throughput, due to unnecessary loss of transmission time; and unfairness when two competing links have different transmission error rates. In this paper, the authors characterize this problem and propose three solutions to it. The solutions aim to provide discrimination between transmission errors and collisions such that the sender can back off appropriately.