Discovering Resources in Tuple-Based Pervasive Systems using Resource-Aware Routing

One of the main challenges in pervasive systems is the efficient discovery of and access to resources in the dynamic environments of such systems. Existing resource discovery mechanisms are proved inefficient because they use broadcasting to communicate request messages for resources to peers. In this paper we present a more efficient mechanism for tuple-based pervasive systems by restricting such communications to a restricted number of social peers. Human behavioral patterns in social interactions to find their required resources known as peer to peer social networks are used instead. This is achieved by deploying a resource-aware routing mechanism. Each peer uses a special data structure to cache in locally the results of its previous searches for resources in the form of tuples. If it finds information on the peer holding its newly required resource in its local data structure, it only sends its request direct to that peer. Otherwise, it sends its request to its immediate peers, and so on to peers next to immediate peers if unsuccessful, until it finds the peer holding the resource. The resource discovery mechanism actually uses a globally accessible tuple space to store findings about all requests for resources in the form of tuples. This resolves the problem of keeping consistent the information cached locally by each peer. We ran exemplar scenarios on a prototyped implementation of our proposed mechanism in the Linda In a Mobile Environment (LIME) environment running on different hardware and under different operating systems.