使用发布订阅中间件支持移动计算

提出了一个扩展发布订阅中间件以支持移动计算的新协议．该协议针对移动计算的需求，由老的事件代理暂存客户移动期间到达的消息，客户在连接到新的事件代理后，消息被自动有序发送给客户，保证了移动透明性．此外协议采用同步算法和消息合并操作防止了消息丢失和重复．移动客户可以在不同的地域与不同的事件代理节点连接和可靠接收消息．实验表明谈协议完全满足移动应用的要求，保证了应用的透明性、消息完整性和有序性．

Using Publish/Subscribe Middleware to Support Mobile Computing

Publish/subscribe middleware dynamically route and deliver message from publishers to subscribers and its communication is anonymous, inherently asynchronous and multicasting in nature, which is touted to facilitate mobility. A novel protocol to support mobile computing with puhlish/subscribe middleware is presented. In this protocol, the old event broker acts as a proxy to store messages in its cache while the mobile client is moving. When the client connects another event broker, messages stored in the old event broker will be fetched and dispatched to the client in order. In addition, a synchronization algorithm and a message merge operation are adopted, which prevent message loss and duplication. Thus, mobile clients can reliably receive messages in different areas and event brokers. The experiment shows that our protocol can effectively address the challenges raised by emerging mobile applications.