Journal of Xidian University ›› 2016, Vol. 43 ›› Issue (4): 128-134.doi: 10.3969/j.issn.1001-2400.2016.04.023

• Article • Previous Articles     Next Articles

Airtime fairness scheduling algorithm for multi-rate WLANs

PAN Zhipeng;WU Bin;YE Tianchun   

  1. (Institute of Microelectronics, Chinese Academy of Sciences, Beijing  100029, China)
  • Received:2015-03-31 Online:2016-08-20 Published:2016-10-12

Abstract:

The DCF (Distributed Coordination Function) used in the IEEE 802.11 protocol provides equal transmission opportunities to each station, which will lead to the performance anomaly in the multi-rate wireless local area network (WLAN). In this paper, we propose a round-robin queue scheduler based on linear scaling of airtime fairness after a detailed theoretical analysis of throughput fairness and airtime fairness. It counts the accurate channel occupancy time of each station, then adopts round-robin to ensure the airtime fairness, and finally improves the system throughput. According to the quality of service (QoS) of data flows, the proposed algorithm can achieve a compromise between transmission efficiency and delay performance by dynamically updating the polling cycle. Simulation by NS-3 and verification by the hardware system show that the proposed algorithm can effectively improve the system uplink and downlink throughput performance while ensuring per-station airtime fairness.

Key words: WLAN, throughput fairness, airtime fairness, queue scheduler, NS-3 simulation