【作者】 程谦云；

【导师】 方旭明；

【作者基本信息】 西南交通大学 ， 通信与信息系统， 2009， 硕士

【摘要】 随着信息技术和互联网络的快速发展,人们越来越希望无线网络信号能够覆盖生活的每个角落,甚至是铁路列车。旅客希望能够在列车上高速率地、快捷地接入公共互联网,从而享受网络提供的各种服务。这种铁路列车上的信息服务要求对车地通信技术提出了严峻的挑战,而现有的车地通信技术已经难以满足上述业务需求,因此有必要研究并设计一种更有效的车地通信技术来满足上述业务需求。为满足新的业务需求,本文提出一种基于无线Mesh网络的车地通信技术实现方案:由车载终端无线节点移动接入沿路布置的无线Mesh网络,从而通过无线Mesh网络连接地面的公共互联网络。同时,车载终端作为网关节点在车厢内部搭建局域网为旅客提供公共互联网络服务。无线Mesh网络在第一、二层采用IEEE802.11b/g协议,在第三层采用TCP/IP协议族中的IP协议。而在无线Mesh网络的二、三层之间,本文增加了无线Mesh层,该层被用实现无线Mesh网络中的车载终端移动接入以及无线Mesh网络路由、代理、快速切换等功能。本文在分析利用基于无线Mesh网络的车地通信技术解决车地通信问题的可行性后,设计并实现了车地通信所需无线Mesh网络设备的软硬件。之后,对车地通信无线Mesh网络设备性能进行了测试,并搭建了基于无线Mesh网络的车地通信测试环境进行了仿真测试。最后,本文指出了基于无线Mesh网络的接入方案在车地通信应用中的特点。更多还原

【Abstract】 With the fast development of information technology and Internet, people are expecting that every corner can be covered by wireless network, and even in train. Passengers hope that they can rapidly access to Internet in the train to get various services with high data rate. The passenger’s access demand to the public information network on the railway is an austere challenge for vehicle-ground communication technology, and the existing mobile access technology is still difficult to meet the above need. Therefore, it is necessary to research and develop a sort of more effective vehicle-ground communication technology to meet the service demand.In order to meet the new service demand, this thesis proposes the vehicle-ground communication technology based on wireless mesh network scheme: the vehicle can connect with ground schedule center and ground public Internet network via the wireless node of vehicle-carried terminal accessing to the wireless mesh network which is disposed in roadside in mobile way. The vehicle schedule station communicates with the ground control center through the vehicle-carried terminal; simultaneously the vehicle-carried terminal can do as the gateway node inside the train to build local area network in the compartment interior to provide the public Internet service for the passenger. The wireless mesh network adopts IEEE802.11b/g protocol on layer 1 (L1) and layer 2 (L2), and IP protocol of TCP/IP protocol on layer 3 (L3). And between L2 and L3 in the wireless mesh network, a new layer, named wireless mesh network layer, which is used to implement the mobile access of vehicle-carried terminal, routing, network management and fast handoff function in wireless mesh network.After analyzing the feasibility to utilize the vehicle-ground communication technology based on wireless mesh network to solve the problem of vehicle communication, this thesis designs and implements the software and hardware of the wireless mesh network equipment which is needed by the vehicle-ground communication. And then, the thesis introduces the test of the wireless mesh network equipment performance, and the simulated environment of the vehicle-ground communication technology based on wireless mesh network. Finally, this thesis conclusion points out the merits and shortcomings of the vehicle-ground communication technology based on wireless mesh network access scheme in vehicle-ground communication application.更多还原