针对旅客列车车-地宽带互联的AP(Access Point,接入点)间切换不仅要求切换执行快速、而且要求切换判决迅速的特点,研究如何实现车载通信网关自主快速的AP间切换.为此首先提出狭义和广义AP间切换的概念,以描述车载通信网关自主地从一个AP切换到下一个AP的完整过程,并根据旅客列车宽带Internet应用的需求与特点建立车-地宽带互联的广义切换模型.为实现该模型的AP间切换性能,进一步设计基于RSM的切换判决模型和基于多无线模块的快速AP间切换算法TTBC.研究表明,基于车-地宽带互联的广义切换模型及其切换判决模型,结合快速AP间切换算法TTBC,不仅可将网络中断时间减少至毫秒级,并且可保证切换前后的通信质量,从而实现车载通信网关随旅客列车在不同AP间快速移动时自主快速的AP间切换.%This paper is to study how to realize the autonomous and rapid inter-AP handoff for broadband trainground internetworking,namely, not only to execute the handoff process rapidly but also to make the handoff decision quickly. Hence,the special and general inter-AP handoff concepts are presented to describe the complete process that the mobile node switchovers from one AP to another,and the general inter-AP handoff model for broadband train-ground internetworking is built up. On the basis of this model, the RSM based handoff decision model and the multi-radio based fast handoff algorithm TTBC are designed. The network interrupt latency is shortened to several milliseconds and the link quality is maintained during the pre-and-post handoff process while the mobile node is moving along the serial APs with the passenger train.
展开▼
