Opportunistic interaction in P2P ubiquitous environments

In this paper we present the design and implementation of an ubiquitous system that supports the opportunistic collaborative edition of shared documents. Our system is based on the instant messaging metaphor in the sense that it uses concepts and interfaces similar to those used in instant messaging systems. We employ the concept of group to define a cluster of users that work on a particular shared document and use awareness to convey the state of users with respect to the shared documents (editing, reading, not using it). The system is implemented using a peer-to-peer (P2P) architecture and can be accessed by means of mobile devices such as handheld computers or cellular phones as well as from desktop computers. The P2P architecture provides the system with useful properties such as fault tolerance, the possibility of using public key infrastructures to implement secure transactions, scalability, a P2P repository to store shared documents and a distributed awareness service.