【作者】 许超；

【导师】 张朝阳；

【作者基本信息】 浙江大学 ， 通信与信息系统， 2006， 硕士

【摘要】 近年我国有线接入的宽带用户数量增长迅猛,用户对宽带数据业务的需求迫切。国内的电信运营商普遍存在着由于覆盖、装备和环境限制等众多因素造成的网络部署问题,无法满足用户不断增长的电信业务的需求,此时宽带无线接入技术具有了特别的的现实意义。无线局域网(WLAN)技术已经得到了广泛的应用,但是人们对于宽带无线通信的探索并未停止,人们期待更大的覆盖范围、更高的信息速率、更好的服务质量。因此,IEEE802.16技术应运而生,它是一种全新的无线城域网(WMAN,Wireless Metropolis Area Network)技术,峰值数据率达75Mbps,单基站覆盖半径最大达48千米,解决了宽带接入的“最后一公里”问题。 基于固定宽带无线接入空中接口标准IEEE802.16d,详细分析了媒体接入控制(Media Access Control,MAC)层协议;通过软件设计实现了整个MAC层协议过程;在Wi-MAX演示平台上完成了整个MAC协议的验证。 详细分析了IEEE802.16d MAC层的协议过程,包括网络拓扑结构,协议栈分层结构,帧结构和接入方式。详细设计并实现了MAC层最关键的公共部分子层(Common Part Sublayer)的协议过程,将MAC协议从功能上划分为控制面和数据面两部分,控制面主要负责MAC层本身的管理,包括建立下行同步、获取下行上行参数、初始化测距、协商基本功能、注册、传输操作参数、建立预连接、周期性测距、连接维护和冲突解析等等;数据面负责在对等实体间传输音频或视频文件,包括上层SDU、MAC层PDU和物理层SDU等数据格式间的相互转换,以及为保证数据可靠传输所采用的ARQ过程。整个软件设计均包括基台(Base Station,BS)和用户台(Subscriber Station,SS)两部分,给出了详细的软件设计方案,包括软件流程图和程序结构图等。 介绍了IEEE802.16d MAC协议的平台实现方案,设计了MAC层与物理层的服务访问接口模块,通过一系列握手原语完成了MAC层与物理层的并行开发和联合调试,最终成功实现了音频文件从基台经过本项目的Wi-MAX演示系统准确传递到用户台的整个过程,并达到了较好的系统性能。更多还原

【Abstract】 Recently, the quantity of cable broadband access subscriber has been growing fast, and the data services requirements from the users are hugeness. However, the services capacity of the telecom operators is limited because of the restricted coverage, equipments and environment. Broadband wireless access can be used to remedy the deficiency of cable network. WLAN technologies have been employed widely. People need larger coverage, higher data rate and better quality of service, so IEEE802.16 technologies arises at the historic moment. It belongs to Wireless Metropolis Area Network technologies. Its peak data rate could be 75 Mbps, and the radius of the coverage could be 48 km. It is the solution for the "last mile" problem in broadband access.Based upon the air interface standard for fix broadband wireless access system IEEE802.16d, Media Access Control (MAC) layer protocol is analyzed in detail; the whole MAC protocol process is implemented by software design; the testing and verifying of the whole MAC protocol is performed on the Wi-MAX demo system.The IEEE802.16d MAC protocol process is analyzed in detail, including network topology, protocol stack hierarchical model, frame structure and access mode. The MAC protocol can be divided into control panel and data panel in functions, the key common part sublayer protocol process is designed and implemented, such as system initializing, periodic ranging, bandwidth allocation, connection building and maintaining, data transmission and ARQ process. The whole software design contains Base Station(BS) part and Subscriber Station(SS) part and very detailed design plan is given, such as detailed software flow chart and program structural drawing.The platform implementation plan of IEEE802.16d MAC protocol is given, the interface between MAC layer and physical layer is designed. The parallel development and combined debugging between MAC layer and PHY layer are completed. Finally, the whole process that a audio file can be transmitted from the base station to the subscriber station though our Wi-MAX demo system is implemented successfully.更多还原