ISSN 1000-1239 CN 11-1777/TP

计算机研究与发展 ›› 2016, Vol. 53 ›› Issue (1): 193-205.doi: 10.7544/issn1000-1239.2016.20148143

• 网络技术 • 上一篇    下一篇

无线局域网的动态切分与重构

许士博,刘晓兰,任丰原   

  1. (清华大学计算机科学与技术系 北京 100084) (xshbo@csnet1.cs.tsinghua.edu.cn)
  • 出版日期: 2016-01-01
  • 基金资助: 
    国家自然科学基金项目(61225011);国家“九七三”重点基础研究发展计划基金项目(2012CB315803)

Splitting and Restructuring a WLAN Dynamically

Xu Shibo, Liu Xiaolan, Ren Fengyuan   

  1. (Department of Computer Science and Technology, Tsinghua University, Beijing 100084)
  • Online: 2016-01-01

摘要: 因用户的游移和喜好集会活动,用户在无线局域网(wireless local area network, WLAN)中的分布是非常不均匀的且是动态变化的.当1个WLAN的用户数量很大时,整个网络和每个用户的吞吐量都会大幅下降.对于1个WLAN范围内的间歇拥塞问题,已有的性能改进方法存在一些不足.因此,提出了1套WLAN动态切分与重构的方案SRD(splitting and restructuring dynamically),引入了影子AP(shadow access point, SAP)和终端映射2个概念,并对终端映射和方案的整体性能进行了形式化分析,设计了最优映射的计算方法.该方案能根据网络负载及状态的变化,动态地将1个拥挤的WLAN切分成若干子网,并重构成1个微型的集中式架构的WLAN,从而对各子网中的终端分布进行监控.因此,该方案能大幅减少1个子网中的终端数量,提高用户吞吐量,缓解冲突和异构速率的影响.仿真结果表明,该方案能成倍地提高网络及每个用户的吞吐量,此外,该方案的部署不需要用户终端设备作任何的更改.

关键词: 无线局域网, 接入点, 间歇拥塞, 影子AP, 终端映射

Abstract: Due to user mobility and favorite of collective activities, the distribution of users in WLANs is seriously uneven and changeable. When a lot of users congest in a WLAN, the WLAN performance degrades and the user experience becomes worse. To address dynamical congestion in a WLAN, existing solutions are unpractical. In this paper, through introducing shadow access point (SAP) and station mapping, a solution called splitting and restructuring dynamically (SRD) is proposed, and formal analysis of station mapping and performance is conducted, and an algorithm for the optimal mapping is devised. According to the change of WLAN status, SRD can dynamically split an overcrowded WLAN to multiple sub-WLANs and restructure them into a centralized WLAN. So, the distribution of stations in all sub-WLANs can be monitored and controlled centralizedly. SRD can reduce the number of stations in each sub-WLAN, and improve user throughput and alleviate the impact of both collisions and multi-rate. The simulation results show that SRD can improve the WLAN throughput a lot. Besides, SRD requires no modifications on user devices.

Key words: wireless local area network (WLAN), access point (AP), occasionally crowded, shadow AP (SAP), station mapping

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