现有位置服务(LBS)应用平台都采用基于中间件或组件对象的分布式计算模式,要求LBS用户必须与系统特续稳定连接,而在带宽有限的移动网络环境中,无法确保用户在使用过程中能够达到持续稳定的网络连接。为此,提出利用移动Agent来构建LBS应用平台,以便能够实时有效地为LBS移动用户提供各种信息服务。平台采用两层业务结构为基础来设计基于知识库管理的移动Agent;利用启发式动态路径串行迁移策略来实现Agent的移动;采用基于Home Agent的消息特发方式来实现Agent之间的相互通信;采用XML和GML来实现LBS各种数据的集成;并结合Applet采实现LBS信息的SVG或XML数据客户端显示。系统原型的实现验证了该方案的可行性。
The LBS (Location Based Service) platform in existence are based on the mid-lets intermediates or components. They require the users to keep in touch with the LBS servers to maintain stabilized link in getting information. But it is difficult to make the connection persistent in the mobile network with limited bandwidth. The mobile agent based LBS platform is built in order to overcome these disadvantages. It can provide the LBS mobile users with information services effectively in real time. The design of mobile agent is based on two-layer operation structure and knowledge base management in the platform. And the transfer of mobile agent makes use of strategy with serial transfer and heuristic dynamic router. The communications between different agents are an improved message whose transmission is realized via home agent. The integration of data uses the XML and GML format. The clients display the LBS services information with SVG or XML data. The implement of a prototype shows that this method is feasible.