A mobility-aware dynamic database caching scheme for wireless mobile computing and communications

This paper describes a mobility-aware dynamic database caching scheme for wireless mobile computing and communications. A mobile-floating agent scheme is proposed, in which:caching techniques are cognizant of the mobile nature of mobile users and the location-sensitive nature of mobile systems. The mobile-floating agent maintains a second class cache in the fixed network and employs Barbara's ''invalidation reports broadcasting'' cache consistency strategies to maintain a dynamic cache consistent with the first class cache in the mobile client. The ''invalidation reports broadcasting'' scheme is combined with knowledge of the mobility behavior of each individual mobile user and broadcasts of invalidation reports only occur within the user's mobility area The evaluation results show that, for a large system (200 cells), this scheme can reduce the system cost by more than 87%, for even highly mobile users, compared with a fully replicated database system.