A Virtual Networked Appliance using Automatic Service Composition Ch. Namman*, A. Mingkhwan** *Department of Information Technology, Faculty of Information Technology, **Department of Information Technology, Faculty of Industrial and Technology Management, King Mongkut's Institute of Technology North Bangkok, Thailand Email: chnamman@gmail, anirach@ieee.com Abstract – Nowadays, developments in information technology and networking are rapidly driving the enhancement of networked appliances in the home environment. Networked appliances can be represented by the functionality that they offer to the network in terms of services. The user can then request their services via the home network framework. Such representation makes it possible to provide new concomitant capability by creating a virtual appliance. However, due to the vast number of home networked appliances and their complicated services, such composition can prove challenging for the non- technical home user. In this paper, we propose our framework for providing automatic service composition capabilities in networked appliances. It uses both centralized and decentralized approaches. The framework is based on a knowledge transfer mechanism whereby each device would have its own composition knowledge and is able to transfer to other devices in the network. Keywords – automatic service composition, heterogeneous environment, networked appliance, service discovery I. INTRODUCTION Nowadays, the development of networked appliances in the home environment has become hugely supported by the great advances in information technology and broadband networks [1-3]. A networked appliance [4] is a dedicated function consumer equipment containing a networked processor (in addition to computer devices such as PC, PDA) which can be connected with other devices over a network. They describe the functionality they can offer to the network in terms of services which the user and other networked devices would become possible to access. The devices can therefore offer the possibility of providing new synergetic capability by creating a virtual appliance. For example, a virtual TV is created by the cooperation of the PC’s visual service, the Hi-Fi’s audio service and the set-top box’s receiver service. Due to the variety of networked appliances and their complex services, it has not proved easy for an ordinary home user to configure those services to provide a new virtual appliance. Our paper is addressing this issue by proposing a framework for automatic service composition that can easily and effectively be operated by a normal home user. The Service Oriented Computing (SOC) [5] paradigm defines mechanisms to publish, find and bind service. Those features make it particularly applicable for a heterogeneous environment where interoperability is essential. Service composition is the functionality in SOC that can be defined as the process of discovering, integrating, and executing a set of related services in order to fulfill either user or device requirement. “Service” can be as either a functionality of hardware device or a software function, which accept a proper input and generate some output according to its functionality. Service composition enables the user to obtain resources and services from the environment to perform required tasks. Many researches and projects in service composition focus on Web Service Composition [6-8]. Some researches use a centralized approach for service discovery and service integration. The centralized approach may not be efficient and suitable for some situations. For example, it may incur a large overhead or a bottleneck when network services access and use the system frequently. Also, a centralized server can suffer from problems such as high operational and maintenance costs, single point of failure, and scalability. Other researches addressed a de-centralized approach. With this approach each node can be both client and server where they can advertise their need or/and aid each other very directly. The downsides of the approach are the higher bandwidth used, increased security issues, and the difficulties of maintaining the network. Our framework proposes a hybrid approach for automatic service composition that use both centralized and decentralized approaches. Any networked device has its own composition knowledge which can be transferred to other devices. We call this process Knowledge Transfers. The devices use a centralized approach by default to perform the composition process. However, when the central server is unavailable they have ability to use a decentralized approach. The paper is organized as follows: Section 2 provides a survey or the related work; we illustrate a scenario of automatic service composition in our framework in Section 3; then present a framework for automatic service composition in Section 4. Section 5 presents the current implementation; and ISBN: 1-9025-6016-7 © 2007 PGNet