QoS-based dynamic allocation in embedded systems: A methodology and a framework

This paper focuses on a methodology for the dynamic allocation of embedded resources apt to satisfy requests of service with constraints of Quality of Service (QoS). Given a set of services provided by an embedded system, this methodology suggests how to determine the best match between a requested service and the set of Embedded subSystems (EsSs) able to provide that service. The selection of EsSs is carried out on the basis of the results of an a priori evaluation of the performances of service execution and of the availability of the single embedded resources. Moreover, the proposed methodology defines some guidelines to dynamically schedule and thus to assign the execution of the services to the chosen EsSs. With regard to the selection process this methodology benefits from both the content- and the collaborative-based filtering methods. To evaluate its consistency it has been implemented in a testing framework, named BIOS, that includes a repository of services, of service providers (i.e. of EsSs), of evaluation outcomes of the performances of each EsS in carrying out its own services, of an engine for the dynamic selection of the EsSs able to satisfy the requirements of a given service and of a container of Real-Time Operating Systems (RTOSs) able to efficiently schedule and to assign the execution of the requested services to the chosen EsSs. Considering state-of-the-art services provided by Body Sensor Network (BSN) subsystems, the hybrid solution proposed for the selection process has been tested and it has shown better results in comparison to the content-based filtering technique.