Opportunistic Geographical Information Dissemination via Public Transportation Networks

Geographical opportunistic dissemination scheme in an urban setting has a lot of potential applications range from daily services like advertising and local weather forecast to safety-related services such as fire/accident warning. These applications share several unique characteristics such as location-based address of nodes and maintaining in an area for a specific time. However, all existing solutions fail to take into account these characteristics.In this paper, we propose a novel opportunistic information dissemination scheme via metropolitan bus networks. The scheme firstly makes use of geographical information like street map and bus route to convert information dissemination within a specific area to opportunistic multicast to non-overlapped road segments. A probabilistic routing protocol based on closest distance predictability is presented to multicast the message to its multiple destination road segments and then disseminate to roadside users. We use dissemination ratio and number of replicas as metrics to evaluate the performance of the scheme. And the simulation results show that the proposed dissemination scheme achieves high dissemination ratio when the number of buses is enough with an acceptable number of replicas (network overhead).