MAHADEV SATYANARAYANAN
Carnegie Group Professor, Computer Science
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As an experimental computer scientist, I love to design, implement andevaluate computing systems that provide new capabilities whilepreserving conceptual simplicity.  I am especially interested in thequestion: “How can we provide mobile users with reliable, efficient,safe and easy access to shared information?”

Internet Suspend/Resume. I am excited about a new vision of mobile computing called InternetSuspend/Resume (ISR).  The term “mobile computing” typically evokesimages of a laptop, handheld, or wearable computer.  However, theplummeting cost of hardware suggests that pervasive computinginfrastructure could minimize the need to carry such devices in thenear future. In such a world, personal computing will be availableanywhere on demand, like light at the flip of a switch. A user couldtravel hands-free, yet be confident of making productive use ofslivers of free time anywhere.  The essence of ISR is rapidpersonalization and depersonalization of anonymous hardware fortransient use.  As its name implies, ISR mimics the closing andopening of a laptop. A user can suspend work on an ISR machine at onelocation, travel to another location, and resume work there on anyother ISR machine.  Hardware virtualization and file caching are thekeys to ISR's precise customization and simple administration.

Coda and AFS. ISR builds on my long-standing interest in distributed file systems.As a principal architect and implementor of the Andrew File System(AFS), I witnessed first-hand the power of a scalable distributed filesystem to serve as the read-write information-sharing backbone of alarge user community.  The Coda File System is a descendant of AFSthat supports disconnected and weakly-connected operation as well asread-write server replication. Coda's design provides high availabilityand allows users who are temporarily isolated from servers to continuework uninterrupted.  Coda serves as the data caching and updatepropagation layer of ISR.

Odyssey, Chroma and Aura. Odyssey explores a different aspect of mobile computing.Here, applications collaborate with the operating system in adaptingto the changes induced by mobility. These changes include variation innetwork bandwidth, battery level, cache state and other systemresources.  Chroma is a descendant of Odyssey that supports theconcept of “cyber foraging,” or the opportunistic use of remoteexecution and data staging servers to enhance the power ofresource-poor mobile hardware.  Chroma is a key component of the Auraproject, a collaborative effort with Professors Dan Siewiorek, PeterSteenkiste and David Garlan to explore the theme of distraction-free ubiquitous computing.