Fundamental Challenges in Mobile Computing

This paper is an answer to the question: "What is unique and conceptually 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. A Wall Street stockbroker is more likely to beWhat is really different about mobile computing? The mugged on the streets of Manhattan and have his computers are smaller and bits travel by wireless rather laptop stolen than to have his workstation in a than Ethernet. How can this possibly make any difference? locked office be physically subverted. In addition to Isn’t a mobile system merely a special case of a distributed security concerns, portable computers are mor