A Multichain Backoff Mechanism for IEEE 802.11 WLANs

The distributed coordination function (DCF) of IEEE 802.11 standard adopts the binary exponential backoff (BEB) for collision avoidance. In DCF, the contention window is reset to an initial value, i.e., CWmin, after each successful transmission. Much research has shown that this dramatic change of window size may degrade the network performance. Therefore, backoff algorithms, such as gentle DCF (GDCF), multiplicative increase-linear decrease (MILD), exponential increase-exponential decrease (EIED), etc., have been proposed that try to keep the memory of congestion level by not resetting the contention window after each successful transmission. This paper proposes a multichain backoff (MCB) algorithm, which allows stations to adapt to different congestion levels by using more than one backoff chain together with collision events caused by stations themselves as well as other stations as indications for choosing the next backoff chain. The performance of MCB is analyzed and compared with those of 802.11 DCF, GDCF, MILD, and EIED backoff algorithms. Simulation results show that, with multiple backoff chains and collision events as reference for chain transition, MCB can offer a higher throughput while still maintaining fair channel access than the existing backoff algorithms

[1]  Raj Jain,et al.  A Quantitative Measure Of Fairness And Discrimination For Resource Allocation In Shared Computer Systems , 1998, ArXiv.

[2]  Luigi Fratta,et al.  Performance evaluation and enhancement of the CSMA/CA MAC protocol for 802.11 wireless LANs , 1996, Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications.

[3]  Marco Conti,et al.  Dynamic tuning of the IEEE 802.11 protocol to achieve a theoretical throughput limit , 2000, TNET.

[4]  L. Kleinrock,et al.  Packet Switching in Radio Channels: Part I - Carrier Sense Multiple-Access Modes and Their Throughput-Delay Characteristics , 1975, IEEE Transactions on Communications.

[5]  Yuguang Fang,et al.  Design of MAC protocols with fast collision resolution for wireless local area networks , 2004, IEEE Transactions on Wireless Communications.

[6]  Norman Abramson,et al.  The ALOHA System-Another Alternative for Computer Communications , 1899 .

[7]  Bo Li,et al.  A new collision resolution mechanism to enhance the performance of IEEE 802.11 DCF , 2004, IEEE Trans. Veh. Technol..

[8]  Ilenia Tinnirello,et al.  Kalman filter estimation of the number of competing terminals in an IEEE 802.11 network , 2003, IEEE INFOCOM 2003. Twenty-second Annual Joint Conference of the IEEE Computer and Communications Societies (IEEE Cat. No.03CH37428).

[9]  V. Vitsas.  Throughput analysis of linear backoff scheme in wireless LANs , 2003 .

[10]  Marco Conti,et al.  IEEE 802.11 protocol: design and performance evaluation of an adaptive backoff mechanism , 2000, IEEE Journal on Selected Areas in Communications.

[11]  Jing Deng,et al.  On optimizing the backoff interval for random access schemes , 2003, IEEE Trans. Commun..

[12]  A. Girotra,et al.  Performance Analysis of the IEEE 802 . 11 Distributed Coordination Function , 2005 .

[13]  Ananthanarayanan Chockalingam,et al.  Analysis of link-layer backoff schemes on point-to-point Markov fading links , 2003, IEEE Trans. Commun..

[14]  Byung-Jae Kwak,et al.  Analysis of the stability and performance of exponential backoff , 2003, 2003 IEEE Wireless Communications and Networking, 2003. WCNC 2003..

[15]  Marek Natkaniec,et al.  An analysis of the backoff mechanism used in IEEE 802.11 networks , 2000, Proceedings ISCC 2000. Fifth IEEE Symposium on Computers and Communications.

[16]  Nah-Oak Song,et al.  Enhancement of IEEE 802.11 distributed coordination function with exponential increase exponential decrease backoff algorithm , 2003, The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring..

[17]  V. Bharghavan,et al.  MACAW: A media access protocol for wireless LANs , 1994 .

[18]  Brahim Bensaou,et al.  Achieving fairness in IEEE 802.11 DFWMAC with variable packet lengths , 2001, GLOBECOM'01. IEEE Global Telecommunications Conference (Cat. No.01CH37270).