QoS and Context Awareness for Mobile Computing

Systems must provide for mobile applications to be aware of the context in which they are being used. This is necessary to permit adaptation to heterogeneity of hosts and networks and variations in the user’s environment, and so enable applications to be effective in a wide range of devices and situations. While we acknowledge that deterministic QoS management may be unrealistic in these circumstances, we also believe that management of resources provides the most reliable basis for managing the problems giving rise to this non-determinism, especially where overprovisioning to ensure QoS is not possible. We provide an overview of a system model for context and QoS-aware application support, and the work being undertaken to address the issues this model raises. We then describe an example application to illustrate the need for the integration of the elements in the model.