Resource type specific Resource Handlers are provided for the reservation of resources for an application session, along with a Resource Allocation Manager for bookkeeping and analysis of a resource allocation situation, Application Session Management and Scheduling means for selecting a next application session and Activity Block at least on the basis of the resource allocation situation, and executing means for executing the Activity Block in the course of the selected application session. A system is provided with a protocol connecting said Resource Handlers, Resource Allocation Manager, Application Session Management and Scheduling means, and executing means to control the execution order and to implement the transfer of information between the resource reservation means, Resource Allocation Manager, Application Session Management and Scheduling means, and executing means. Also provided is a method for the execution of application sessions in an electronic device, as well as to an electronic device.