Exploiting super peers for large-scale peer-to-peer Wi-Fi roaming

With the low installation and maintenance cost of IEEE 802.11-based equipment, dense Wi-Fi deployments are a reality, especially in today's urban areas. This vast number of WLANs can be exploited to achieve low-cost ubiquitous wireless Internet access, which is also demostrated by the emergence of community-based wireless access schemes. In our prior work we have developed a reciprocity-based peer-to-peer architecture for Wi-Fi sharing, where peers provide free Wi-Fi access to others in order to enjoy the same benefit when they are away from their own Wi-Fi network. Our system tries to match peer consumption with contribution and we have shown it to work well for city-scale Wi-Fi sharing communities. However, when attempting to roam outside the city boundaries, the statistics are such that there is typically a lack of consumption-contribution information between consuming and providing members, which hinders the system's scalability. In this work, we extend our architecture with global-scale roaming capabilities by relaxing the requirement for full decentralization. In particular, we exploit special trusted super-peers which act as representatives of different Wi-Fi sharing communities (e.g., communities of different geographical regions) and which mediate transactions when there is insufficient information about peer contribution history. Extensive simulations show that this super-peer-assisted approach can significantly enhance the system's performance in terms of roaming coverage.