Quasi-FIFO collision resolution scheme for wireless access networks

Binary Exponential Back-off (BEB) scheme is widely adopted in both wire and wireless networks for collision resolution. Since the back-off windows among competing users are not synchronized, BEB algorithm results in "capture effect" and, in the limit as the number of users approaches infinity, BEB is unstable for every arrival rate greater than 0. In wireless networks, a common backoff window size can be broadcast by the base-station or access point. Maximum throughput can be achieved when the back-off window size is equal to the number of competing users. A novel Quasi-FIFO back-off scheme is proposed not only to improve the bandwidth usage, but also to maximize the throughput. In Quasi-FIFO, packets generated in a given cycle period are guaranteed to be serviced in the next cycle. Newly arrived packets can not Join the contention until the current cycle has completed and all the packets generated in the previous cycle are transmitted successfully.