A design for file access in a mobile environment

Reducing communication cost is important in a mobile environment, because transmission of data over the radio link is slow, expensive, and unreliable. Providing data consistency is crucial because many mobile applications are database applications which rely on consistent data. We propose a design for a file access mechanism specific to a mobile environment. Our two main design goals are to reduce communication cost and to provide data consistency. We reduce the amount of communication by extensive use of caching, profile information (files the user accesses), a proxy process, delayed writes, and availability of loose-reads. We provide data consistency by using the proxy services, a centralized data manager with callbacks, and strict-reads. Our design is general enough to suit the needs of both mobile database and office applications