基于竞争窗口递减因子自适应调整退避算法

计算机工程与科学

基于竞争窗口递减因子自适应调整退避算法

张长森，陈鹏鹏

（河南理工大学计算机科学与技术学院，河南焦作 454000）

收稿日期:2015-06-15 修回日期:2015-09-30 出版日期:2016-12-25 发布日期:2016-12-25
基金资助:
国家自然科学基金(51174263)；教育部博士点基金（20124116120004）；河南省基础与前沿技术研究(142300410144)

A selfadaptive adjusting backoff algorithm based

on contention window diminishment factor

ZHANG Changsen,CHEN Pengpeng

(College of Computer Science and Technology,Henan Polytechnic University,Jiaozuo 454000,China)

Received:2015-06-15 Revised:2015-09-30 Online:2016-12-25 Published:2016-12-25

摘要/Abstract

摘要：

包括IEEE802.11、802.15.4标准在内的许多无线网络协议都采用二进制指数退避机制管理数据的重发。在动态分布式的网络环境中，二进制指数退避算法固定的竞争窗口递减方式难以适应动态变化的网络规模。针对这一问题，提出了一种改进的回退机制，该机制通过引入竞争窗口递减因子，自适应地调整无线节点的等待时间，以实现网络吞吐量的最大化。同时，在算法实现上提出一种启发式算法以跟踪网络中竞争节点数量的改变。在IEEE 802.11 DCF协议中以相同的物理层参数进行仿真，结果表明改进算法提高了网络吞吐量，降低了分组平均接入时延。

关键词: 退避算法, 竞争窗口, IEEE 802.11 DCF, 归一化饱和吞吐量, 递减因子

Abstract:

Numerous wireless network protocols, including IEEE802.11 and 802.15.4, manage the retransmission of data frames with the binary exponential backoff (BEB) mechanism. In a dynamic distributed environment, the fixed way the BEB adjusts contention window cannot adapt to the ever changing network size. To solve this problem, we propose an improved selfadaptive adjusting backoff algorithm based on contention window diminishment factor. By introducing the concept of contention window diminishment factor, the algorithm adaptively adjusts the waiting time of wireless nodes to realize the network throughput maximization. In addition, in order to track the changing number of competition nodes, we propose a heuristic algorithm when implementing our new backoff scheme. Simulations on the same physical layer parameters of the IEEE 802.11 DCF protocol show that the proposed algorithm can improve the throughput and decrease the frame delay.

Key words: backoff algorithm, contention window, IEEE802.11 DCF, normalized maximum throughput, diminishment factor

张长森，陈鹏鹏. 基于竞争窗口递减因子自适应调整退避算法[J]. 计算机工程与科学.

ZHANG Changsen,CHEN Pengpeng.

A selfadaptive adjusting backoff algorithm based

on contention window diminishment factor

[J]. Computer Engineering & Science.

参考文献［15］

［1］	Part 11:Wireless LAN medium access control (MAC) and physical layer (PHY) specifications:IEEE Std 802.11［S］.New York:IEEE Press,2007.
［2］	Liu Yunlu,Pu Juhua,Fang Weiwei,et al.A MAC layer optimization algorithm in wireless sensor network［J］.Chinese Journal of Computer,2012,35(3):529539.(in Chinese)
［3］	Sun X H,Lin D.Backoff design for IEEE 802.11 DCF networks:Fundamental tradeoff and design criterion ［J］.IEEE/ACM Transactions on Networking,2015,23(1):300316.
［4］	Guang L,Assi C M,Benslimane A.Enhancing IEEE 802.11 random backoff in selfish environments［J］.IEEE Transactions on Vehicular Technology,2008,57(3):18061822.
［5］	Kwak B J,Song N O,Miller L E.Performance analysis of exponential backoff［J］.IEEE/ACM Transactions on Networking,2005,13(2):343355.
［6］	Cali F,Conti M,Gregori E.Dynamic tuning of the IEEE 802.11 protocol to achieve a theoretical throughput limit ［J］.IEEE/ACM Transactions on Networking,2000,8(6):785799.
［7］	Shurman M,AlShua’b B,Alsaedeen M,et al.NBEB:New backoff algorithm for IEEE 802.11 MAC protocol［C］∥Proc of 2014 37th MIPRO,2014:540544.
［8］	Mao Jianbing, Mao Yuming, Leng Supeng,et al.Performance analysis of multichannel MAC schemes based on 802.11［J］.Journal of Computer Research and Development,2009,46 (10):16511659.(in Chinese)
［9］	Shi Chun,Dai Xianhua,Liang Pingyuan.Adaptive backoff algorithm based on node number estimation with multiple thresholds［J］.Chinese Journal of Electronic,2012,40(6):11081114.(in Chinese)
［10］	Gou H,Yoo Y.An energy efficient MAC protocol based on IEEE 802.11 DCF for wireless sensor networks in port logistics［C］∥Proc of the 14th HPCCICESS,2012:728733.
［11］	Ni Q,Aad I,Turletti T,et al.Modeling and analysis of slow CW decrease IEEE 802.11 WLAN［C］∥Proc of the 14th PIMRC,2003:17171721.
［12］	NahOak S, ByungJae K, Jabin S, et al.Enhancement of IEEE 802.11 distributed coordination function with exponential increase exponential decrease backoff algorithm［C］∥Proc of the 57th VTC,2003:27752778.
［13］	Wu H T,Cheng S D,Peng Y,et al.IEEE 802.11 distributed
	coordination function (DCF):Analysis and enhancement［C］∥Proc of ICC,2002:605609.
［14］	Bianchi G.Performance analysis of the IEEE 802.11 distributed coordination function［J］.IEEE Journal on Selected Areas in Communications,2000,18(3):535547.
［15］	Cheng Yanhong,Li Zhishu,Chen Liangyin.An adaptive MAC protocol for wireless LANs under errorprone environment［J］.Journal of Computer Research and Development,2012,49(1):174182.(in Chinese)
	附中文参考文献：
［2］	刘云璐,蒲菊华,方维维,等.一种无线传感器网络MAC协议优化算法［J］.计算机学报,2012,35(3):529539.
［8］	毛建兵,毛玉明,冷甦鹏,等.基于802.11的多信道MAC协议性能分析［J］.计算机研究与发展，2009,46(10):16511659.
［9］	石春,戴宪华,梁平元.基于多门限估计节点个数的自适应退避算法［J］.电子学报,2012,40(6):11081114.
［15］	程艳红，李志蜀，陈良银.差错信道下无线局域网的自适应MAC协议［J］.计算机研究与发，2012,49(1):174182.