Train Mobile Network Quality Of Service To Key Technologies

With the rapid development of data services, how to effectively apply the Networks Mobility (NEMO) technology to satisfy passengers' needs of access to Internet has become a challenging task in the railway environment. Due to the high-speed mobility of the train, the diversification of wireless network services, and tremendous increase in the number of wireless network users, the existing Quality of Service (QoS) solutions for a single mobile terminal have been difficult to guarantee real-time and reliable data transmission in the high-speed passenger line.Firstly, a multiple mobile routers configured model for train-based mobile network is established. Aiming at the problem of path selection in nested train-based mobile network with multiple access technologies, a best default Mobile Router (MR) selection mechanism using policies is presented. An option of the Router Advertisement message is optimized to include the information about the nested level and root-MR connectivity, so that the users of the train-based mobile network can use the information and policies to select a best default MR to connect to the Internet.Secondly, a handover scheme based on multiple mobile routers is proposed. Two or more mobile routers are configured on the train, which enables different mobile routers to access different subnets during a handover and cooperatively receive packets destined for each other. The overlapped reception of packets from deferent subnets makes the packet loss independent of the handover latency.Finally, a new resource reservation protocol based on Next Step in Signaling (NSIS) for mobile networks is studied. On this basis, an adaptive resource reservation scheme based on the line information is presented. Before the train handoff to a new subnet, the next visit subnet of the train, the subnet resident time and the current available network bandwidth are considered to make advance resource reservation to support real-time and reliable services.The schemes are proved effective through mathematic analysis and simulation experiments. The results show that the proposed schemes respectively have good performance in terms of throughput, packets losses and resource utilization efficiency.