Efficient Execution of Service Composition for Content Adaptation in Pervasive Computing

Abstract

Multimedia content adaptation has been proved to be an effective mechanism to mitigate the problem of devices and networks heterogeneity and constraints in pervasive computing environments. Moreover, it enables to deliver data taking into consideration the user's preferences and the context of his/her environment. In this paper, we present an algorithm for service composition and protocols for executing service composition plan. Both the algorithm and the protocols are implemented in our distributed content adaptation framework (DCAF) which provides a service-based content adaptation architecture. Finally, a performance evaluation of the algorithm and the protocols is presented.

Multi-criteria Content Adaptation Service Selection Broker

“…In the reference system architecture (i.e., Figure 1), there are multiple adaptation service providers with different QoS. As an adaptation task can be achieved by more than one adaptation service providers, choosing appropriate adaptation service providers is an obvious requirement [1]. The multi-criteria content adaptation service selection (CASS) problem of interest can be formulated as follow:…”

“…To address the adaptation path construction, a directed acyclic graph (DAG) is discussed in [1], [4]. The transformation prescript graph for DAG is organized in serial manner and bounded by the media format.…”

“…The transformation prescript graph for DAG is organized in serial manner and bounded by the media format. A static path determination criteria (SPDC) policy that suffers from a number of shortcomings is discussed in [1], [4]. In this paper, we propose an algorithm that consists of a greedy and single objective assignment function that is constructed on top of an adaptation path tree.…”

“…Electronic documents are becoming increasingly rich in content and varied in format and style while at the same time client devices are getting increasingly varied in their capabilities. Moreover, the original content is normally developed for desktop computers and is naturally made-up of media objects of different types with complicated structure and layout [1]. Thus, direct content delivery to handheld devices without layout adjustment and content adaptation often leads to disorganization of information [2].…”

“…Although many content adaptation approaches exist [2], [4], [5], [6], [7], most of them tend to be fully or partially centralized suffering from scalability and single-point failures. Recently, a service-oriented content adaptation (SOCA) framework has been proposed to address the contentdevice mismatch problem [1], [4], [7]. A service, in service-based content adaptation, abstracts a set of functionalities offered by the content adaptation service providers.…”