Abstract: Aiming at the problems of high transmission delay, low channel utilization and throughput of the binary exponential backoff algorithm, we proposed an adaptive backoff algorithm based on MAC layer protocol. Firstly, the size of the backoff factor was obtained by comparing the system delay median and packet transmission time, so that the backoff window changed dynamically. Secondly, the multiconflict Ethernet communication network model was established based on the maximum number of backoff time slots. The simulation results show that compared with the binary exponential backoff algorithm, the algorithm has lower transmission delay, higher throughput and channel utilization in the multiconflict Ethernet scenario, thus improving the transmission realtime performance.

Key words: MAC layer, Ethernet, backoff algorithm, delay