MAWA:基于移动Agent的一种高效可靠无线Web访问机制

MAWA:An Efficient and Reliable Web Access Scheme in Mobile Wireless Environments Based on Mobile Agents

在无线移动环境中进行Web访问承受着更多的技术挑战,移动设备在此环境中进行无线Web访问时需有一种高效且可靠的机制给予支持,以克服由于移动设备自身硬件能力的有限,移动设备自身的物理移动及无线网络的不可靠性而带来的困难.提出一种基于移动Agent的无线Web访问机制MAWA.该机制利用移动Agent作为移动设备与Web服务器之间交互的中介,有效避免移动设备不必要的Web页面更新提交操作,从而节省了其无线网络连接开销,与其他协议相比有着较高的执行效率;同时该机制还可有效支持移动设备进行无线Web访问时在基站间的切换,及运行期间发生故障后的状态恢复,从而确保了移动设备运行过程的可靠性.最后通过实验分析了MAWA机制的可靠性与高效性.

Web access in mobile wireless environments suffers more challenge because of mobile device＇s limited storage, the mobility of mobile device, and the unreliable wireless network environments. It requires some facilities between the wired network and the terminals to help overcome the difficulties of unreliable wireless link, mobility and mobile device capability limitation. Presented in this paper is a new Web access scheme named MAWA, which uses mobile agents to facilitate seamless logging of mobile unit＇s access activities, thus avoiding unnecessary wireless communication cost. There are three classes of agents in MAWA： Terminal agent, base station agent, and MU agent. Terminal agent runs in the mobile unit, and requests for Web pages from browsers performed by users are transferred to this agent. Base station agent resides on base station with responsibility for creating, storing, sending and receiving an instance of MuAg according to the request from MU or other BsAg. It also maintains the local MuAg queue, and transfers the message or data between MU and its MuAg respectively. MU agent is responsible for a certain MU. This scheme can also help MU handoff among base stations and recover when mobile client suffers a failure. Compared with other schemes by simulation tests, this scheme shows its efficiency and reliability.