Services composition model for home-automation peer-to-peer pervasive computing

Collaborative mechanisms between services are a crucial aspect in the recent development of pervasive computing systems based on the paradigm of service-oriented architecture. Currently, trends in development of services computing are taking into account new high-level interaction models founded on services composition. These services make up their functionalities with the objective of creating smart spaces in which services with different purposes can collaborate to offer new and more complex functionalities to the user transparently. This leads to the creation of collaborative spaces with value-added services derived from the composition of existing ones. However, there are many aspects to consider during the development of this type of systems in pervasive spaces, in which the extensive use of embedded devices with limited characteristics of mobility, computing resources and memory, is a large handicap. This paper describes a model of services composition based on a directed acyclic graph used in a services middleware for home-automation, in which we work with loosely coupled services-oriented systems over the peer-to-peer technology JXTA. The presented composition model guarantee the acyclicity of the composition map between services as well as favours the building of collaborative light services using peers as proactive entities, which could be executed on embedded devices. These ones are capable of establishing dynamic intercommunications, synchronizing with others and form coalitions to cooperate between theirs for a common purpose.