Resource adaptive hierarchical organization in pervasive environments

Pervasive computing environments are characterized with an array of heterogeneous devices. Within such environments, it is necessary to accommodate devices with restrictions on available resources through cooperation of devices that have greater resource availability. Traditionally, such cooperation is achieved based on information available prior to operation, resulting in a rigid structure that cannot change during runtime. In this paper, we present a generic framework aimed at achieving a dynamic, hierarchical overlay of devices based on their resource availability. We consider the processing power, memory and battery power, on each device as the dynamically changing resources. Based on the proposed Availability metric, a hierarchical overlay structure is developed among the available devices. Devices in the lower layers of the hierarchy seek operational support from those in the higher layers which are relatively more resourceful. The resulting hierarchical organization is utilized to provide support for service composition and management. The proposed adaptive mechanism allows dynamic restructuring of the hierarchy based on changes in the availability of resources. In addition, the adaptive hierarchical organization results in enhanced longevity of resources and increased availability of services to applications. The performance improvements achieved through the dynamic resource organization are demonstrated through experimental results.