Improving Quality of Service and Assuring Fairness in WLAN Access Networks

As public deployment of wireless local area networks (WLANs) has increased and various applications with different service requirements have emerged, fairness and quality of service (QoS) are two imperative issues in allocating wireless channels. This study proposes a fair QoS agent (FQA) to simultaneously provide per-class QoS enhancement and per-station fair channel sharing in WLAN access networks. FQA implements two additional components above the 802.11 MAC: a dual service differentiator and a service level manager. The former is intended to improve QoS for different service classes by differentiating service with appropriate scheduling and queue management algorithms, while the latter is to assure fair channel sharing by estimating the fair share for each station and dynamically adjusting the service levels of packets. FQA assures (weighted) fairness among stations in terms of channel access time without decreasing channel utilization. Furthermore, it can provide quantitative service assurance in terms of queuing delay and packet loss rate. FQA neither resorts to any complex fair scheduling algorithm nor requires maintaining per-station queues. Since the FQA algorithm is an add-on scheme above the 802.11 MAC, it does not require any modification of the standard MAC protocol. Extensive ns-2 simulations confirm the effectiveness of the FQA algorithm with respect to the per class QoS enhancement and per-station fair channel sharing

[1]  Scott Shenker,et al.  Analysis and simulation of a fair queueing algorithm , 1989, SIGCOMM '89.

[2]  Abhay Parekh,et al.  A generalized processor sharing approach to flow control in integrated services networks: the single-node case , 1993, TNET.

[3]  Ruay-Shiung Chang,et al.  A Priority Scheme for IEEE 802. 11 DCF Access Method , 1999 .

[4]  Kang G. Shin,et al.  Achieving efficient channel utilization and weighted fairness for data communications in IEEE 802.11 WLAN under the DCF , 2002, IEEE 2002 Tenth IEEE International Workshop on Quality of Service (Cat. No.02EX564).

[5]  Vaduvur Bharghavan,et al.  Achieving MAC layer fairness in wireless packet networks , 2000, MobiCom '00.

[6]  Sunghyun Choi,et al.  Collaborative QoS architecture between DiffServ and 802.11e wireless LAN , 2003, The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring..

[7]  Claude Castelluccia,et al.  Differentiation mechanisms for IEEE 802.11 , 2001, Proceedings IEEE INFOCOM 2001. Conference on Computer Communications. Twentieth Annual Joint Conference of the IEEE Computer and Communications Society (Cat. No.01CH37213).

[8]  Thierry Turletti,et al.  Adaptive EDCF: enhanced service differentiation for IEEE 802.11 wireless ad-hoc networks , 2003, 2003 IEEE Wireless Communications and Networking, 2003. WCNC 2003..

[9]  Martin Heusse,et al.  Performance anomaly of 802.11b , 2003, IEEE INFOCOM 2003. Twenty-second Annual Joint Conference of the IEEE Computer and Communications Societies (IEEE Cat. No.03CH37428).

[10]  Raj Jain,et al.  Analysis of the Increase and Decrease Algorithms for Congestion Avoidance in Computer Networks , 1989, Comput. Networks.

[11]  Hyuk Lim,et al.  Analysis and design of the virtual rate control algorithm for stabilizing queues in TCP networks , 2004, Comput. Networks.

[12]  Ieee . Wg.  Part 11 : Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specification , 2003 .

[13]  K. K. Ramakrishnan,et al.  A Proposal to add Explicit Congestion Notification (ECN) to IP , 1999, RFC.

[14]  Abhay Parekh,et al.  A generalized processor sharing approach to flow control in integrated services networks-the single node case , 1992, [Proceedings] IEEE INFOCOM '92: The Conference on Computer Communications.

[15]  Paramvir Bahl,et al.  Distributed fair scheduling in a wireless LAN , 2000, IEEE Transactions on Mobile Computing.

[16]  John V. Guttag,et al.  Time-based Fairness Improves Performance in Multi-Rate WLANs , 2004, USENIX Annual Technical Conference, General Track.