A Novel Adaptive P-Persistent MAC Scheme for WLAN Providing Low Delay Variance

The paper proposes and analyzes a novel adaptive p-persistent-based (APP) medium access control (MAC) scheme to provide low delay variance for IEEE 802.11 WLAN. The APP MAC scheme can differentiate permission probabilities of transmission for stations being incurred with different packet delays, and the permission probability is designed as a function of the numbers of retransmissions and re-backoffs so that stations being with larger packet delay can attain higher permission probability. Additionally, the scheme is modeled by a Markov-chain and successfully analyzed, where the system throughput and delay are derived. Results show that the proposed APP MAC scheme can achieve lower delay variance than conventional algorithms; it can effectively reduce the collision probability and the mean delay, therefore, the mean throughput is enhanced, as well.