Towards QoS-Aware Load Balancing for High Density Software Defined Wi-Fi Networks
Towards QoS-Aware Load Balancing for High Density Software Defined Wi-Fi Networks
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DOI：
10.1109/access.2020.3004772
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发表时间：
2020-06
期刊：
影响因子：
3.9
通讯作者：
Sohaib Manzoor;Ze Chen;Yayu Gao;Xiaojun Hei;W. Cheng
中科院分区：
文献类型：
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作者：
Sohaib Manzoor;Ze Chen;Yayu Gao;Xiaojun Hei;W. Cheng
高密度Wi-Fi网络需要负载均衡以确保服务质量(Qos)。在传统的Wi-Fi网络中，无线站点自己学习接入点(AP)的负载并做出关联决策，导致AP之间的负载分配不均匀。新的范式软件定义网络(SDN)具有集中式架构，允许轻松管理、测量和控制高密度Wi-Fi网络。本文针对软件定义的Wi-Fi网络(SD-Wi-Fi)提出了一种支持服务质量的负载均衡策略(QALB)，以解决OpenFlow使能AP(OAP)之间的Wi-Fi拥塞问题。SDN控制器选择OAP在不咨询控制器的情况下做出关联决定的负载级别。通过考虑诸如分组丢失率、接收信号强度指示符(RSSI)和吞吐量等多个度量，来自过载OAP的无线站被移交给欠载OAP。搭建了仿真平台和具有相同设置的大规模低成本实验平台，对负载均衡策略的性能进行了评估。结果表明，与基于信道测量的接入选择方案(CMAS)、下行信干噪比AP选择方案(DASA)、平均探测时延方案(MPD)和RSSI方案等4种非静态方案相比，在高密度SD-Wi-Fi中，QALB的吞吐量优化高达16%，平均帧时延降低19%，重传次数减少49%，切换次数减少15%，负载均衡度提高22%，重关联次数减少38%。
High density Wi-Fi networks require load balancing in order to ensure quality of service (QoS). In the traditional Wi-Fi networks, the wireless stations learn the access points (APs) load and make the association decisions themselves leading to uneven load distribution among the APs. The new paradigm, software defined networking (SDN), has a centralized architecture, which allows to manage, measure and control high density Wi-Fi networks easily. In this paper we propose a QoS-aware load balancing strategy (QALB) for software defined Wi-Fi networks (SD-Wi-Fi), as a solution to address the problem of Wi-Fi congestion among the OpenFlow enabled APs (OAPs). The SDN controller selects a load level up to which the association decisions are made by the OAPs without consulting the controller. The wireless stations from an overloaded OAP are handed to an underloaded OAP by considering multi-metrics such as the packet loss rate, received signal strength indicator (RSSI) and throughput. An emulation platform and a large-scale-low-cost testbed with the same settings are constructed to evaluate the performance of our load balancing strategy. The results show that in comparison to four non-static schemes such as, channel measurement based access selection scheme (CMAS), (DL-SINR) downlink-signal to interference plus noise ratio AP selection scheme (DASA), mean probe delay scheme (MPD) and RSSI scheme, the proposed QALB, optimizes the throughput up to 16%, reduces the average frame delay up to 19%, minimizes the number of re-transmissions by 49%, reduces the number of handoffs by 15%, improves the degree of load balancing by 22% and minimizes the re-association times by 38%, in high density SD-Wi-Fi.