【作者】 张彤；

【导师】 李红艳；

【作者基本信息】 西安电子科技大学 ， 控制理论与控制工程， 2007， 硕士

【摘要】 随着人们对语音、视频、数据等各种需求的不断增长,核心网已具有相当规模。用户终端与核心网间的“最后一英里”接入成为了当前研究的焦点。宽带无线城域网IEEE 802.16协议的提出,为宽带无线接入提供了一个全球统一的标准。尽管IEEE 802.16协议的MAC(Medium Access Control)层定义了较为完备的信令体系、基于服务质量(QoS)的调度业务类型及相应的带宽请求/分配机制等机制,但是却把具体的准入控制机制、分组调度算法等机制的设计细节留给了开发者去实现。在对IEEE 802.16的MAC层技术深入理解的基础上,根据对IEEE 802.16系统中目前的QoS架构和一些最新文献提出的QoS架构解决方案的总结,综合其中存在的优缺点,完善了QoS架构,对基站(BS)和用户站(SS)上QoS模块的功能进行了描述,对一些重要模块的实现方法给出了建议,并描述了数据在BS与SS间传输的过程。针对现有的IEEE 802.16的准入控制机制中带宽分配方案存在的问题,我们提出一种基于IEEE 802.16的联合动态带宽分配的准入控制机制。提出的准入控制机制综合考虑了对固定用户和移动用户的支持,采用动态带宽分配的方式,通过带宽借用的方法,在保证公平的对固定用户和移动用户提供服务的条件下,提高系统的带宽利用率。最后通过仿真对提出的准入控制机制的性能进行了验证。更多还原

【Abstract】 With the people’s rapid demand for voice、video、data,Backbone network has considerable size. The“last mile”access between users and backbone network becomes the focus of the current study. A new Broadband Wireless Metropolitan Area Network protocol named IEEE 802.16 is proposed, which provides a unified global standard for Broad Wireless Access. Although IEEE 802.16 protocol’s MAC Layer defines the QoS signaling mechanism、service types and corresponding bandwidth request/allocation mechanism and so on . However, some mechanisms’specific design details in IEEE 802.16 are left to the developers to realize, such as admission control mechanism、packet scheduling algorithm, etc.Based on a detailed technical analysis for IEEE 802.16 MAC layer, in view of the deficiencies existing in the IEEE 802.16’s QoS framework and the relevant literatures’QoS framework, this thesis improved a QoS framework. In the framework we describe the function modules on BS and SS, propose the realized methods for some related modules, and summarize the process of data transmission between BS and SS.Subsequently we propose an admission control mechanism combined with dynamic bandwidth allocation based on IEEE 802.16.The proposed admission control mechanism considers the support for both fixed users and mobile users, and adopts the method of dynamic bandwidth allocation and bandwidth borrowing. The mechanism’s target is to ensure fairness in the provision of services for fixed and mobile users, and at the same time to improve the system bandwidth utilization. Finally, we test our admission control mechanism’s performance through simulation.更多还原