A spatially aware policy conflict resolution for information services

A pervasive computing environment is characterized by computing capabilities and effective use of smart spaces. Many critical elements of pervasive computing, such as wireless networks are now viably commercial products. Ambient services are known as one of the main types of pervasive information services in which suitable information is presented to the users based on their surrounding geographical environments. Increase in the use of such services may cause service domain overlapping in which many of the users are located in several domains simultaneously. The aim of this paper is to present the best information service composition to such users by considering spatio-temporal contexts and analyses. User’s location, direction and speed were regarded as the most effective spatial contexts. Spatio-temporal topological relationships as well as influenceability relation were used to model the topological context. The proposed methodology was implemented in three nested service domains. Based on the results, composition of the proposed services and the period for service update were described as “good” by 75 and 80 percent of the users, respectively.