Study Of Service Discovery In Ubiquitous Computing

The computing paradigm is coming to the ubiquitous computing era with the rise of internet applications. The new computing paradigm focuses on taking computer into human being's life and working environment, and forms a computing environment with the objective of providing computations everywhere at any time. In this environment, computing is not limited to desktop, users can enjoy themselves with computing ability and information provided by pocket equipments, wearable computers, context-sensitive equipments and etc. The mechanism of discovery and management of resources is one of the most important technologies of ubiquitous computing.This thesis introduces the research status of ubiquitous computing, analyzes some of system prototypes, and compares the schemes they have discovered and managed for services. Based on those mentioned above, this thesis discusses a service discovery and management framework build on JXTA protocol, and describes the whole structure of this framework and specification of the important parts. By giving some examples, this thesis goes deep into details with advantage of the discovery schemes of JXTA. By giving examples which combine JXTA with other technologies, the flow of service management is analyzed.JXTA is a Peer to Peer project, which defines a set of public protocols, and every protocol is easy to implement and be integrated into the existing systems. JXTA Searcher provides a "Hub" searching service for both JXTA nodes and the web which allows consumer applications to efficiently find providers that can answer their requests. This thesis discusses the key protocols which have been implemented in the service management framework, especially in peers discovering, services searching and services loading. The process is shown as following: the peers provide modules which can be discovered by the rendezvous peers, and the system provides the links of these modules for services providers. Then the requesters download these modules which would be assembled toservices by script language, and release these services to all peers.A method of service discovery is implemented in the service management framework. It doesn't rely on center peers, and it is independent of network protocol. The performance is not reduced at all when more peers join the network and it is easy to extend to portable equipments. This thesis is worthy for further research in ubiquitous computing.