Energy-Efficient Mobile Cache Invalidation

Caching data in a wireless mobile computer can significantly reduce the bandwidth requirement. However, due to battery power limitation, a wireless mobile computer may often be forced to operate in a doze or even totally disconnected mode. As a result, the mobile computer may miss some cache invalidation reports. In this paper, we present an energy-efficient cache invalidation method for a wireless mobile computer. The new cache invalidation scheme is called grouping with cold update-set retention (GCORE). Upon waking up, a mobile computer checks its cache validity with the server. To reduce the bandwidth requirement for validity checking, data objects are partitioned into groups. However, instead of simply invalidating a group if any of the objects in the group has been updated, GCORE retains the cold update set of objects in a group if possible. We present an efficient implementation of GCORE and conduct simulations to evaluate its caching effectiveness. The results show that GCORE can substantially improve mobile caching by reducing the communication bandwidth (thus energy consumption) for query processing.

[1]  Tomasz Imielinski,et al.  Mobile wireless computing: challenges in data management , 1994, CACM.

[2]  Rafael Alonso,et al.  Database system issues in nomadic computing , 1993, SIGMOD Conference.

[3]  A. Prasad Sistla,et al.  Data replication for mobile computers , 1994, SIGMOD '94.

[4]  Ouri Wolfson,et al.  Object allocation in distributed databases and mobile computers , 1994, Proceedings of 1994 IEEE 10th International Conference on Data Engineering.

[5]  Tomasz Imielinski,et al.  Replication and mobility , 1992, [1992 Proceedings] Second Workshop on the Management of Replicated Data.

[6]  B. R. Badrinath,et al.  Checkpointing distributed applications on mobile computers , 1994, Proceedings of 3rd International Conference on Parallel and Distributed Information Systems.

[7]  Dhiraj K. Pradhan,et al.  Location management in distributed mobile environments , 1994, Proceedings of 3rd International Conference on Parallel and Distributed Information Systems.

[8]  Tomasz Imielinski,et al.  Mobile wireless computing , 1994 .

[9]  Randy H. Katz,et al.  Adaptation and mobility in wireless information systems , 2002, IEEE Communications Magazine.

[10]  Tomasz Imielinski,et al.  Energy efficient indexing on air , 1994, SIGMOD '94.

[11]  Tomasz Imielinski,et al.  Sleepers and workaholics: caching strategies in mobile environments , 1994, SIGMOD '94.

[12]  Tomasz Imielinski,et al.  Querying in Highly Mobile Distributed Environments , 1992, VLDB.