Community-centric mobile peer-to-peer services: performance evaluation and user studies

The popularity of social networking services emphasises the importance of user communities. As the next evolutionary step, social networking will evolve towards user communities that are dynamically established according to contextual aspects such as the shared location and/or activities of people. In this vision, distributed peer-to-peer (P2P) technologies provide a respectable alternative to the centralised client-server technologies for implementing the upcoming community-centric mobile services. This thesis focuses on the development of enabling techniques and methods for a communitycentric mobile service environment and on the evaluation of users’ perceptions and user acceptance of novel community-centric mobile services. The research was carried out by first examining the applicability of different P2P system architectures for implementing the management of user communities. Next, an experimental prototype of a community-centric mobile service environment was implemented. The experimental prototype was used for evaluating the performance of the community-centric mobile service environment and for conducting the user studies of novel community-centric mobile services. The evaluation was conducted in a real deployment environment with test users. The main results are the following: (1) a conceptual analysis of the advantages and disadvantages of P2P group management systems that are implemented using architecturally distinct P2P system architectures; (2) a performance evaluation of a P2P community management system, in which each community is implemented as an independent structured P2P overlay network; (3) a novel community-centric mobile service environment and its core component, a mobile middleware, which enables the use of P2P technologies and context information as part of Web-based applications running on a Web browser; (4) an evaluation of users’ perceptions and user acceptance of novel community-centric mobile services that are related to making a selection of an entertainment premise based on its music style and voting for music in a user community.