Overview

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Quality of Service (QoS) is considered an important user demand, receiving wide attention in real-time multimedia research. However, in most systems, users do not have any real influence over the QoS they can obtain, since service characteristics are fixed when the systems are initiated. Furthermore, multimedia applications (and their users) can differ enormously in their service requirements as well as in the resources which need to be available to them. These applications present increasingly complex demands on quality of service, reflected in multiple attributes over multiple quality dimensions.

At the same time, the use of laptop computers coupled with wireless network interfaces is growing rapidly. Recent technological development lead to the fusion of wireless ad-hoc networks, peer-to-peer computing and multimedia content. As devices move within the range of each others a local ad-hoc network forms spontaneously, creating a new, highly dynamic and decentralized environment for multimedia applications.

Such an environment is expected to be heterogeneous, consisting of nodes with several resource capabilities. For some of those there may be a constraint on the type and size of applications they can execute with user's acceptable quality of service. For example, video conferencing systems often use compression schemes that are effective, but computationally intensive, trading CPU time for limited network bandwidth. A mobile client with limited CPU and memory capacity, but sufficient link speed, with nearby more powerful (or less congested) devices, can divide the computational intensive processing into tasks and spread it among different neighbours.

It is obvious that these requirements for more flexible QoS-aware applications impact on the available support from the underlying environment (language, middleware, operating system and networks).

This work considers a system where wireless/mobile nodes may dynamically enter the range of each other, and of wired infrastructures (even clusters of nodes), opportunistically taking advantage of resource availability, distributed across neighbour nodes, forming temporary coalitions for service execution, considering QoS-aware applications.

It is clear that such coalition formation presents very significant challenges, especially at the architectural level. Major developments are required in the fields of communications protocols, data processing and application support. Our goal is to develop an architecture which enables the creation of a new generation of nodes that can effectively network together, providing a flexible platform for the support of distinct network applications.

In this context, we have been considering different, related, [Topics|Research Topics]: {BR}
→ '''Anytime Algorithms for QoS Systems'''{BR}
→ '''Dynamic QoS Adaptation '''{BR}
→ '''Dynamic Server-based Scheduling'''{BR}
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