OS service update for an online adaptive embedded multimedia system

The increasing popularity of nomad multimedia systems put new challenges for their design: increasing functionalities, limited energy and computation resources. These systems must provide a maximum application quality of service (QoS) in the presence of a dynamically varying environment (e.g. video streaming and multimedia conferencing) and multiple resources constraints. To respond to the changing resource availability and application demands, a new class of adaptation method is emerged. It combines the adaptation simultaneously upon the different layers related to the target system: hardware, application and OS. This paper presents an overview of a multilayer. The global manager (GM) is uses to handle large and long-term variations whereas the local manager (LM) is used to guarantee the real time constraint. This paper focuses on the LM that intervenes only in the application layer and OS layer.