Research On Mobile Vehicle-Ground Communication Technology Based On Wireless Mesh Network

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.