基于SDN的WLAN接入技术研究

发布时间：2018-12-25 15:36

【摘要】：随着无线数据的迅猛增长和无线终端数量的快速增加,现有的网络架构和接入点(AP)选择机制已经不能满足用户日益增长的需求。由于传统网络架构的限制,在现有的网络架构上改进也不够灵活,因此需要突破现有网络架构的束缚,重新创建一个新型网络架构,从而满足网络规模日益增长的需要。软件定义网络(SDN)由于其控制与转发分离、可编程性、高创新性的特点成为当前网络新架构的研究热点。SDN新型网络架构以其集中控制、可编程性、虚拟化等特性和WLAN技术的移动性和灵活性的特点,可以较好的解决当前无线网络的问题。而基于SDN提出新型AP选择机制,不仅是对SDN新型网络架构的进一步研究,也是对现有AP选择机制的一种改革和创新。本文通过对传统WLAN网络架构的分析,针对它们存在的问题,调研了现有多种基于SDN的无线架构,提出了新的基于SDN的WLAN组网架构,重点描述了新型架构的业务流程、虚拟AP的设计和控制器的设计。本文结合多路径的场景对该架构进行仿真,仿真表明,由于虚拟AP设计和网络资源虚拟化的特性,新型组网架构在网络吞吐量和平均传输时延方面相比传统CAPWAP架构有一定的改善。此外,本文还提出了基于SDN的WLAN新型AP选择机制-SNBE机制。该机制使用多种参数来表征AP所提供服务的性能,使用合适的度量函数来选择最佳的AP供用户接入。相比传统机制的仅参考单一参数,多参数能够更准确的评估AP可提供的传输性能,所以SNBE机制可以选择负载更小且传输性能更优的AP,改善了整个网络的吞吐量和平均传输时延。通过仿真,对比SNBE机制、传统AP选择机制、基于探测响应帧平均延迟的MPD机制,本文验证了SNBE机制具有良好的性能。
[Abstract]:With the rapid growth of wireless data and the rapid increase in the number of wireless terminals, the existing network architecture and access point (AP) selection mechanism can no longer meet the growing needs of users. Because of the limitation of the traditional network architecture, the improvement of the existing network architecture is not flexible enough, so it is necessary to break the shackles of the existing network architecture and re-create a new network architecture to meet the increasing needs of the network scale. The software defined network (SDN) has become the research hotspot of the new network architecture because of its separation of control and forwarding, programmability and high innovation. The new network architecture of SDN has its centralized control and programmability. Virtualization and the mobility and flexibility of WLAN technology can solve the current wireless network problems. The proposed new AP selection mechanism based on SDN is not only a further study of the new SDN network architecture, but also a reform and innovation of the existing AP selection mechanism. Based on the analysis of the traditional WLAN network architecture and their existing problems, this paper investigates the existing wireless architecture based on SDN, proposes a new WLAN network architecture based on SDN, and describes the business process of the new architecture. Virtual AP design and controller design. This paper simulates the architecture with multi-path scenarios. The simulation results show that, because of the characteristics of virtual AP design and network resource virtualization, Compared with the traditional CAPWAP architecture, the network throughput and average transmission delay of the new network architecture are improved. In addition, this paper also proposes a new AP selection mechanism of WLAN based on SDN-SNBE mechanism. The mechanism uses a variety of parameters to characterize the performance of the services provided by AP, and uses appropriate metrics to select the best AP for users to access. Compared with the traditional mechanism which only refers to a single parameter, the multi-parameter can more accurately evaluate the transport performance that AP can provide, so the SNBE mechanism can choose the AP, with less load and better transport performance. The throughput and average transmission delay of the whole network are improved. By comparing the SNBE mechanism with the traditional AP selection mechanism, and based on the MPD mechanism which detects the average delay of response frames, this paper verifies the good performance of the SNBE mechanism.
【学位授予单位】：北京邮电大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN925.93

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