Design and implementation of a mobile application support system

A high-performance mobile application support system is developed and set up at the Computer Science Department of HKUST. The system provides both transparent mobility support over cellular wireless computer networks and mobile application programming interface with which a mobile application can identify its current network location. The system incorporates a number of substantial enhancements beyond the mobile-IP protocol. A mobile host always monitors signal qualities from all reachable base stations and uses these information to decide when and to which base station it should hand off. This allows a mobile client application always maintaining the highest possible data transfer rate with servers on the wired network. Moreover, the system automatically caches data packets in nearby base stations in an attempt to avoid packet losses during hand-off and to reduce hand-off latency. Early experience showed that the system supports mobility very well and most often data caching in nearby base stations is not necessary.