Communication Cost of Content-Aware Mobile Database with Different Caching Approaches for M-Commerce Applications

Abstract In recent years, mobile computing technology has advanced so that users can carry the portable computers to access information from the network even when they are moving. In such a mobile environment, a personal communication service (PCS) network must keep track of the location of each mobile user in order to correctly deliver calls. Thus, the cache patterns for the M-Commerce applications are with the characteristics of Location-Awareness and Content-Awareness. A basic scheme used in the standard protocols is to update the location of a mobile user whenever the mobile user moves to a new location. Thus, the communication cost of location update operations increases rapidly as the mobility of the devices arises. In recent years, some caching approaches and management strategies for location updates have been proposed. However, the communication cost of the proposed approaches is an important issue needed to be investigated. Though data replication could reduce the communication cost for accessing information, the communication cost for maintenance/operation would increase. Thus, in this paper, three caching approaches, i.e., index caching, judicious caching, and pre-fetch caching, are studied and the communication cost for a content-aware mobile database with the caching approaches is evaluated by using analytical method and simulation study. The results of this study show that the communication cost of the pre-fetch caching is less than those of judicious caching and index caching with the penalty of some communication cost of database maintenance and update operations.