Scalable Service Composition in Mobile Ad hoc Networks using Hierarchical Task Graphs
Prithwish Basu · 2005
Abstract – Service discovery is an essential component of application development in dynamic environments such as mobile ad hoc networks (MANETs). This is because the service providing devices are themselves mobile in MANETs and hence, the service–device binding cannot be tightly coupled over the lifetime of an application. Therefore, during the progress of a distributed application, a user should be capable of discovering and utilizing several different instances of a particular service in the network, if necessary. A common goal of all service discovery protocols is to discover the required services in a timely and scalable fashion, so that the application can run smoothly. In this paper, we investigate a related dimension of the service discovery problem, namely, service composition. In general terms, service composition refers to the process of combination of multiple simple services in order to form a larger, more complex distributed service. This offers users a great degree of transparency in discovery and selection of required services, instead of having to be cognizant of all the details about the simpler services that constitute the complex ones. Also, this can reduce discovery latency at the time of executing distributed applications. Owing to the hierarchical nature of the service composition framework, we represent a