无线自组织网络TDMA多址接入和分组转发设计实现

发布时间：2018-08-28 14:07

【摘要】：无线自组网作为一种无中心的分布式网络现在应用越来越广泛,传输的业务也由原来的低速率短消息业务逐渐向多媒体应用方向发展。因特网中原有的QoS(Quality of Service,服务质量)保障机制在无线自组织网环境中并不适用,无线自组织网的特点决定了相应的网络协议和算法应该按照特定的场景进行设计。TDMA多址接入协议因在网络负载较重的环境下依然有较好的吞吐量表现而成为目前多址接入协议研究的热点。此外,无线自组网在多跳传输时如何减少多媒体业务的传输时延也是一项非常关键的研究内容。本文基于ARM+FPGA+nRF24L01为核心的硬件平台,旨在设计能支持多跳环境下多媒体业务传输的无线自组网演示平台。首先,本文简要介绍了无线自组网中多址接入协议的研究现状和多媒体业务通信的QoS需求并介绍了常用的分组调度算法,分析各自的优缺点。然后,根据我们面临的实际问题提出了TDMA协议的设计方案和基于FPGA的实现方案,包括帧结构设计、开环同步、闭环同步、拓扑自适应和程序设计等。同时,为了进一步提高网络QoS保障能力,论文设计并实现了快速分组转发(AAF)算法策略,大大减少了节点分组转发时延。为了增强语音等多媒体业务的服务质量,本文采用了基于区分业务类型的QoS保障技术,介绍了分组调度中最关注的几种指标,采用了基于WRR调度算法,能够保证在多种业务同时传输的情况下依然有良好的多跳语音传输效果。基于RED的队列管理策略能避免网络中的全局同步问题,结合TCP传输控制协议,真正意义上做到了拥塞避免。最后,进行了硬件平台的介绍和详细的测试分析。包括硬件平台的基本指标测试(通信距离,传输速率,功耗性能)、语音的传输性能测试(主观评价的传输质量,客观评价的传输质量)和组网测试(丢包率,吞吐量等)。通过多种情况下的测试数据验证了设计的完备性和算法的可行性。
[Abstract]:As a distributed network without center, wireless ad hoc network is more and more widely used, and the traffic of wireless ad hoc network is gradually developing from low rate short message service to multimedia application. The original QoS (Quality of Service, quality of Service (QoS) guarantee mechanism in the Internet is not applicable in the wireless ad hoc network environment. The characteristics of the wireless ad hoc network determine that the corresponding network protocols and algorithms should be designed according to specific scenarios. TDMA multiple access protocol has become the present because of its better throughput performance under the heavy network load environment. The research focus of multiple access protocols. In addition, how to reduce the transmission delay of multimedia services in wireless ad hoc networks is also a key research topic. Based on the hardware platform of ARM FPGA nRF24L01, the purpose of this paper is to design a demonstration platform of wireless ad hoc network which can support multimedia service transmission in multi-hop environment. Firstly, this paper briefly introduces the research status of multiple access protocols in wireless ad hoc networks and the QoS requirements of multimedia traffic communication, and introduces some commonly used packet scheduling algorithms, and analyzes their advantages and disadvantages. Then, according to the practical problems we face, the design scheme of TDMA protocol and the implementation scheme based on FPGA are proposed, including frame structure design, open-loop synchronization, closed-loop synchronization, topology adaptation and program design. At the same time, in order to further improve the network QoS support ability, this paper designs and implements a fast packet forwarding (AAF) algorithm, which greatly reduces the node packet forwarding delay. In order to enhance the quality of service (QoS) of multimedia services such as voice, this paper adopts the QoS support technology based on differentiated service types, introduces several indexes that are most concerned in packet scheduling, and adopts the scheduling algorithm based on WRR. It can ensure that the multi-hop voice transmission effect is still good in the case of multi-service simultaneous transmission. The queue management strategy based on RED can avoid the global synchronization problem in the network. Combined with the TCP transport control protocol, congestion avoidance is achieved in real sense. Finally, the hardware platform is introduced and analyzed in detail. It includes the basic index test of hardware platform (communication distance, transmission rate, power performance), voice transmission performance test (subjective evaluation of transmission quality, objective evaluation of transmission quality) and networking test (packet loss rate, throughput, etc.). The completeness of the design and the feasibility of the algorithm are verified by testing data in various cases.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.532

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