Mobile web services for peer-to-peer applications

The role of the Service Oriented Architecture (SOA) is going to be more and more popular in the software design for distributed systems. This middleware framework tries to simplify as much as possible the software architecture of distributed applications. In infrastructure based networks like the Internet the SOA is successfully implemented by XML Web Services in a client-server manner. in ad-hoc systems without any infrastructure, the Peer-to-Peer (P2P) paradigm is attractive. Thus, a Web Service realization using the P2P paradigm is promising, since a uniform middle-ware can be achieved without any constraints of the underlying network and communication paradigm. In this article, we look at a heterogenous environment being composed of mobile nodes with computing and communication capabilities. Each (peer) node equally acts as both, server and client. These nodes provide their services to other nodes in the distributed environment, and they are able to use remote services. We distinguish and discuss different SOA realizations enabling P2P computing and introduce a common software architecture for P2P Web Services. On this basis, we introduce an implementation of P2P Web Services on Java enabled mobile devices. We focus on the server implementation, enabling mobile devices (phones and PDAs) to provide and publish their services.