Multimedia documents scheduling using proxies in a distributed environment

Husni Fahmi, Purdue University

Abstract

With the rapid proliferation of the Internet, deployment of large-scale proxy servers is imperative for managing quality of service (QoS) requirements in distributed multimedia applications. A key challenge is to allow dynamic mapping of QoS connections to network resources, including link capacities and buffering capabilities of the proxy servers. A resource management framework is presented for a proxy-based networking infrastructure. This framework can be treated as a multiobjective integer optimization problem of minimizing the cost of transmission while maintaining load balance among proxies. A heuristic method using Lagrangian relaxation and a rounding algorithm to achieve near-optimal solutions in real-time is proposed. Although this approach is centralized, the resulting routing information can be propagated to individual nodes for QoS path updates. Extensive simulations reveal that the heuristic consistently yields near-optimal solutions, is scalable to a large-scale proxy-based networking infrastructure, and has computation time within the time scale of network state updates of existing network services. A proxy-based framework that provides QoS support to mobile users is also proposed. Admission control is exercised to ensure long-term availability of resources to mobile clients. Bandwidth allocation is implemented using a Linux Traffic Control that employs Stochastic Fairness Queueing and Token Bucket Filter disciplines. An adaptive technique is used to synchronize multiple streams prior to their transmission to the clients for presentation. A number of quality adaptation strategies that accommodate the diverse requirements and capabilities of clients are described.

Degree

Ph.D.

Advisors

Ghafoor, Purdue University.

Subject Area

Electrical engineering|Computer science

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