A dynamic and adaptive cache retrieval scheme for mobile computing systems

Abstract

Recent advances in wireless technologies have made the mobile computing a reality. In order to provide services of good quality to mobile users and improve the system performance, the mobile computing system is usually of a distributed server architecture. As users move to a new service area, the new server is expected to take over the execution of running programs for mobile users so as to reduce the communication overhead of the mobile system. This procedure is referred to as service handoff. Note that when service handoff occurs, the cache of the new sewer does not contain any data entry that was accessed by prior transactions and the new server will thus lose its advantages for cache access. To remedy this, the authors examine several cache retrieval schemes to improve the efficiency of cache retrieval. In particular they analyze the impact of using a coordinator buffer to improve the overall performance of cache retrieval. Moreover, in light of the properties of transactions (i.e., temporal locality of data access among transactions), they devise a dynamic and adaptive cache retrieval scheme (DAR) that can adopt proper cache methods based on some specific criteria devised to deal with the service handoff situation in a mobile computing environment. The performance of these cache retrieval schemes is analyzed and a system simulator is developed to validate the results.