CARPOOL: Connectivity Plan Routing Protocol

Basic Internet access is considered a human right, however geographical, technological and socio-economic reasons set barriers to universal Internet access. To address this challenge, we have proposed an access method based on message ferrying that enables free delay-tolerant Internet access to all, and developed Connectivity plAn Routing PrOtOcOL (CARPOOL), a reference routing protocol for the proposed access method. In this paper, we describe CARPOOL in depth and evaluate its performance for increasing traffic load. Focusing on an urban scenario, where means of public transport, such as buses, follow predefined routes and schedules, CARPOOL utilises a priori knowledge about their current location to extend Internet access provided by hotspots to users and areas that are not typically covered. Our simulation results show that CARPOOL effectively exploits the existing connectivity plan of public transportation, achieving high delivery ratio with minimum overhead. This paper also discusses possible enhancements of the proposed routing protocol.