虚拟化无线接入网的优化控制研究

发布时间：2018-11-20 06:57

【摘要】：无线局域网(WLAN)以自身成本低廉、安装简单等特性在日常生活中得到了广泛普及,近年来无线数据业务量更是呈现出迅猛增长的趋势,毫无疑问WLAN存在着巨大的发展潜力,但与此同时WLAN也暴露出一些问题。一是传统网络中分布式架构不能完成大型环境组网,而集中式架构组建大型网络时设备受制约严重;二是现有WLAN网络对用户QoE考虑不够,也不能进行细化到特定用户的管控;三是用户接入AP的默认算法很容易造成网络的不平衡。对于上述出现在当前WLAN的问题,本文认真分析研究后,在同一个逻辑集中管控架构下,设计并实现了一些优化控制策略。首先,本文在该架构下研究了虚拟化无线接入网的问题。设计并实现了一个针对虚拟接入点(VAP)的用户接入管理子系统,包括portal前端页面、后台验证逻辑及流程控制、数据库存储、后台与控制器的交互,它能完成的功能主要包括如下几个部分:一是用户入网的portal认证,区分用户身份进行不同认证流程,验证其合法性后存储相关信息,并与控制器交互以协同完成专属虚拟接入点(PVAP)的操作;二是系统用户的信息维护,允许对个人账户及设备信息进行查看或修改;三是WLAN网络状态的可视化,结合STA和AP的位置信息,在百度地图上向网络管理员提供全网的AP和STA连接状态等信息。然后,本文在该架构下,研究了STA关联的优化控制算法。本文以平衡各STA获得的网络吞吐量,并尽力提高整个网络的吞吐量为目标,先设计了一个全局接入控制算法(GACA),该算法以最大化网络总吞吐量为目标函数建立起一个混合整数非线性规划问题,然后用混合自适应遗传算法来完成求解,得到STA关联AP的优化方案,该算法适合周期性运行来对网络进行调整;接着设计了一个增量式接入控制算法(IACA),此算法综合考虑STA接入不同AP对整体网络的影响,为STA挑选最合适的AP让其关联,该算法适合当有新STA想要连接到网络时运行。通过在NS-3上进行大量仿真实验,证明了本文设计的算法是有效的。
[Abstract]:WLAN (WLAN) has been widely used in daily life because of its low cost and simple installation. In recent years, wireless data traffic has been increasing rapidly. There is no doubt that WLAN has great development potential. But at the same time WLAN also exposed some problems. One is that the distributed architecture in the traditional network can not complete the large-scale environment networking, but the equipment is severely restricted when the centralized architecture builds the large-scale network, the other is that the existing WLAN network does not consider the QoE of the user enough, nor can it be refined to the control of the specific user. Third, the default algorithm of user access to AP is very easy to cause network imbalance. For the above problems which appear in the current WLAN, after careful analysis and research, this paper designs and implements some optimal control strategies under the same logical centralized control framework. Firstly, this paper studies the problem of virtualized wireless access network under this architecture. A user access management subsystem for virtual access point (VAP) is designed and implemented, including portal front-end page, background verification logic and flow control, database storage, background interaction with controller. The functions it can accomplish mainly include the following parts: first, the portal authentication of users entering the network, distinguishing the identity of users to carry out different authentication processes, verifying its legitimacy and storing relevant information. And interacts with the controller to cooperate to complete the operation of the exclusive virtual access point (PVAP); The second is the information maintenance of the system users, allowing the individual account and equipment information to be viewed or modified; The third is the visualization of WLAN network state, combined with the location information of STA and AP, to provide the network administrator with the information of AP and STA connection status of the whole network on the map of Baidu. Then, the optimal control algorithm of STA association is studied in this paper. In order to balance the throughput of each STA and improve the throughput of the whole network, a global access control algorithm, (GACA), is designed in this paper. In this algorithm, a hybrid integer nonlinear programming problem is established with the objective function of maximizing the total throughput of the network. Then the hybrid adaptive genetic algorithm is used to solve the problem, and the optimization scheme of STA associated AP is obtained. The algorithm is suitable for periodic operation to adjust the network. Then an incremental access control algorithm (IACA),) is designed which considers the influence of STA access to different AP on the overall network and selects the most appropriate AP for STA to associate. The algorithm is suitable for running when a new STA wants to connect to the network. Through a lot of simulation experiments on NS-3, it is proved that the algorithm designed in this paper is effective.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN92

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