Opportunistic vehicular routing

In a wireless ad hoc network, an opportunistic routing strategy is a strategy where there is no predefined rule for choosing the next node to destination (as it is the case in conventional schemes such as OLSR, DSR or even Geo-Routing). Rather, an intermediate node en route acts in an impromptu fashion and takes a decision that is based solely on current circumstances. A popular example of opportunistic routing is the “delay tolerant” forwarding to “data mules” when a direct path to destination does not exist. Conventional routing in this case would just “drop” the packet. With opportunistic routing, a node acts upon the available information: it seeks the neighbor best qualified to “carry” the packet to destination. If none is available, it will await the right opportunity. This procedure is also known as “data muling” or Delay Tolerant Network (DTN) routing. The Vehicular Ad Hoc Networks (VANET), because of its intrinsic intermittent connectivity (during off peak hours and at night) is an ideal “playground” for opportunistic routing/multicast. In this paper we will examine two examples of VANET opportunistic routing: Delay Tolerant geo-inspired routing and real time video stream multicast of emergency/accident multimedia reports to vehicles in disconnected platoons using network coding.