一种针对无线环境下临时断接的快速重连机制

A Fast Reconnect Mechanism for Temporary Disconnection in Wireless Environments

传统的中间件不能很好地适应无线环境带宽小、延迟大、抖动强的特点,如何扩展传统的中间件,使之适应无线环境的特点成为研究的热点。本文首先对无线环境下的断接情况进行了分析,提出临时断接和持久断接的概念;其次,提出了针对无线环境中临时断接情况的一种快速重连机制—FRTD机制,它通过为客户方赋予唯一的连接标识,同时在服务方缓存请求应答,从而实现了快速重连的目的;最后,在GIOP协议的服务上下文中对应用层透明地添加了连接标识,对GIOP协议进行了扩展,并以CORBA中间件为实验平台在ORB内核中实现了FRTD机制。实现结果和应用表明了FRTD机制的有效性。该机制同样适用于其它的通信中间件。

Traditional middleware cannot satisfy the requirements of applications in wireless environments. Researches on the mechanisms of extending traditional middleware and making it usable in wireless environments become hot. First, we analyze the disconnection in wireless environments and present two different disconnection concepts： disconnection and temporary disconnection. Second, we present a FRTD （Fast Reconnect for Temporary Disconnection） mechanism in wireless environments. FRTD implements fast reconnection through giving every client a unique ID and caching the results on the server side. Finally, we extend the GIOP protocol through adding a session ID in the service context of the GIOP protocol, and implement FRTD in the ORB kernel. The results and the application prove the efficiency of FRTD. FRTD also applies to the other communication middleware.