基于AP可替代性模型的密集无线网络节能机制研究  

Energy Saving Mechanism Based on AP Substitutability Model in Dense-deployed WLANs

作　　者：范云涛[1,2] 李贺武[1,2] 孙文琦[1,2] 

机构地区：[1]清华大学信息化技术中心无线与移动网络技术研究室,北京100084 [2]清华大学信息科学与技术国家实验室,北京100084

出　　处：《小型微型计算机系统》2015年第5期897-902,共6页Journal of Chinese Computer Systems

基　　金：国家"八六三"项目-5G无线密集网络构架与关键技术研发项目(2014AA01A701)资助;清华大学自主科研计划项目(20131089339)资助;国家自然科学基金项目-下一代互联网项目(61161140454)(PIRSES-GA-2013-610524)资助

摘　　要：在无线网络中为了节能,主流做法是将AP(Access Point,无线接入点)进行聚簇,在网络闲时关掉一些AP而让剩下的AP来支持用户.聚簇的关键在于合理的聚簇依据.相关研究中通常利用AP之间相互监听到的RSSI(Received Signal Strength Indication,接收信号强度指示)进行聚簇.AP之间的RSSI并不是一个合理的依据,因为AP之间是否可以相互替代应从用户的角度出发,而不应从AP角度来衡量.此外,相关研究中还缺乏覆盖损失的量化描述,以及应对用户数目震荡性变化的措施.本文利用AP监听到的用户的RSSI构建了AP可替代性的数学模型,以期为AP聚簇提供合理的依据,并基于AP可替代性设计了节能机制.分析表明AP可替代性模型是有效、稳定的.利用AP可替代性模型可以量化描述AP可替代性与覆盖损失之间的关系,从而可以根据实际需求来确定聚簇的粒度,实现了节能与保持覆盖的两相兼顾,体现了本文机制的灵活性.此外,本文还设计了应对用户数目震荡性变化的双阈值策略,有效的避免了聚簇算法被反复无意义的执行.实验结果表明,相比于同类研究,本文的节能机制在损失很小的节能效果的同时,显著地减小了覆盖损失.For supporting peak usage,APs （Access Points） are always placed densely in today＇s WLAN,which leads to excessive energy consumption at the same time. Clustering APs of the same area and switching off some APs for normal network access is the main solution to saving energy. How to cluster APs and find the substitutability of APs is the key. RSSI between APs used to cluster APs in related research is not good enough for clustering APs, since the substitutability of APs is from not AP side but user side. Besides, there lack the quantified description of coverage loss and the mechanism to handle the continuous change of user number. This paper introduces a model of the AP＇s substitutability using RSSI that APs hear from users to support clustering. Experiment results show that the model of AP substitutability is valid and stable. Moreover, the relationship of coverage loss and substitutability can be quantified through the model, so that the clustering scale can be decided according to real requirement to make a compromise between energy conservation and coverage. A double threshold strategy is also proposed to handle the continuous change of user number to avoid the repeatedly running of algorithm. In comparison with related works,our work sacrifices only a little energy conservation to achieve a remarkable low coverage loss.

关 键 词：无线网络 AP可替代性 节能 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]