Implementation Issues on Market-Based QoS Control

In this paper, we discuss two major tradeoffs, spatial and temporal tradeoffs, that appear when applying marketbased computing to multimedia network applications. The former appears between computation and communication cost, depending on how agents are distributed over network. The latter appears between reactiveness and correctness of result, depending on how the network environment dynamically changes. By implementing a market-based resource allocation mechanism to a desktop conferencing system, we clarified that (1) as for spatial tradeoff, the centralized computation becomes profitable in proportion to the number of clients, and that (2) as for temporal tradeoff, the merit to respond quickly to the change of the environment by prematurely terminating the computation supersedes the merit to improve the accuracy of the resource allocation by performing the calculation until the market perfectly clears. It has also been proved that the market-based mechanism can achieve efficient allocation in an actual network environment.