ITR: Exploiting Remote Infrastructure for Mobile Information Access

Carnegie Mellon University, Pittsburgh PA

Investigators

Abstract

The researchers propose to design, implement, analyze and evaluate mechanisms that will enable mobile clients to opportunistically exploit computing, data and communication resources in the fixed infrastructure to facilitate information access. A mobile client typically faces many resource challenges. These include unpredictable variation in wireless network quality; wide disparity in the availability of remote services; limitations imposed by weight and size constraints on CPU power, memory size and disk capacity; and concern for battery power consumption. The goal is to exploit remote infrastructure, such as transient caching sites or compute servers, to overcome these challenges. When such infrastructure is unavailable or would be too expensive or slow to access in terms of battery power or bandwidth, the researchers wish to be able to continue operation relying solely on local resources. The challenge is to come up with the adaptive mechanisms, algorithms and policies that can be effectively implemented on a resource-limited mobile client, yet function smoothly and seamlessly from a user's viewpoint. The research will span both experimentation and analysis. On the one hand, the researchers plan to design, implement, and evaluate mobile computing systems embodying innovative solutions to the challenges described above. This will give the researchers the hands-on experience and insights needed to elucidate sound design principles for this domain. In parallel, the researchers plan to conduct an analytical and modelling effort to obtain a deeper understanding of fundamental tradeoffs in adaptation, and to explore a much broader region of the design space than feasible experimentally. This effort will be organized into three major thrusts: 1.Efficient file cache management for mobile clients 2.Offloading computation for energy and bandwidth savings 3.Modelling and analysis of adaptation tradeoffs In the first thrust, the researchers plan to explore the use of intermediate caching sites in the infrastructure to improve the efficiency of cache management in mobile file systems. The importance of caching for mobile information access is widely acknowledged, but what specific form it should take in the mobile systems of the future remains an open question. In the second thrust, the researchers will explore techniques for mobile clients to adaptatively offload computation on servers in the infrastructure. Such offloading may be useful for improved performance as well as enhanced battery life. In the third thrust, the researchers will analytically investigate a wide range of policies for the mechanisms developed in the other thrusts. The mobile computing systems of the future are likely to encounter considerable variability in environmental conditions, user preferences, and application characteristics. Characterizing this large multi-dimensional space analytically, and understanding its implications for alternative policies will be critical to the development of successful systems. If successful, the research will bring mobile computing one step closer to reality. Although commercial deployment of mobile computing systems is an enormous potential market for industry, many difficult technical problems remain to be solved. Incremental efforts by industry to extend today's widely-deployed commercial off-the-shelf systems to mobile environments will not solve these problems. The researchers proposed effort, combining experimentation and analysis on a key set of challenging problems, thus represents a high-risk, high-payoff venture.