Fundamental challenges in mobile computing

This paper is an answer to the question "What is unique and conceptuntly different about mobile computing?" The paper begins by describing a set of constraints intrinsic to mobile computing, and examining the impact of these constraints on the design of distributed systems. Next, it summarizes the key results of the Coda and Odyssey systems. Finally, it describes the research opportunities in five important topics relevant to mobile computing: caching metrics, semantic callbacks and validators, resource revocation, analysis of adaptation, and global estimation from local observations.