在传统的互联网体系结构中,IP地址既作为节点的位置标志又作为节点的身份标志,难以适应列车通信。针对这一问题,提出身份与位置分离体系结构,并设计一种列车通信方案。在基于身份与位置分离体系结构的列车通信方案中,IP地址只作为节点的位置标志,引入端点标志符作为节点的身份标志,使得节点移动时也不会中断连接。列车中的节点通过移动网关接入互联网,对于MANET节点发送给互联网节点的数据报文,移动网关在转发之前需要对该数据报文重新封装;当节点移动时,利用路由更新选项和路由确认选项进行路由更新,并且这些选项都封装在IPv6逐跳选项报头中,不需要额外的信令开销。性能仿真及分析表明,与基于MIPv6的通信方式相比,该方案具有更高的报文递交率以及更低的报文开销。
In the traditional Internet architecture, the IP address functions as the locator as well as the identifier. This dual nature makes it difficult to enable mobility in train communication. In this paper, a new Internet architecture based on identifier-locator split is proposed. In the proposed architecture, the IP address functions only as the locator while the endpoint identifier is introduced to function as the transport identifier. The train communication scheme based on this architecture is proposed. The nodes in the train communicate with the nodes within the Internet through the mobile gateway. The mobile gateway re-encapsulates the packets before forwarding them for the MANET nodes. The scheme introduces route updating option and route acknowledgement option to update the routes. These options are encapsulated in the IPv6 hop-by-hop options header. The performance simulation results show that the new scheme has the higher packet delivery ratio and lower packet overhead than the traditional communication scheme based on MIPv6.