The POR Protocol: Tying Data To Geographic Locations In Mobile Disconnected Networks

We propos e an efficient Position-based Opportunistic Routing (POR) protocol which takes advantage of the stateless property of geographic routing and the broadcast nature of wireless medium. When a data packet is sent out, some of the neighbor nodes that have overheard the transmission will serve as forwarding candidates, and take turn to forward the packet if it is not relayed by the specific best forwarder within a certain period of time. By utilizing such in-the-air backup, communication is maintained without being interrupted. The additional latency incurred by local route recovery is greatly reduced and the duplicate relaying caus ed by packet reroute is also decreased. In the case of communication hole, a Virtual Destination-based Void Handling (VDVH) scheme is further proposed to work together with POR. we take inspiration from real life solutions. Suppose if we lost/found an item, a common practice is to post a note around the area where it was lost/ found, and later we refer back to the same location to check for further updates. Similarly, in the anytime-anywhere mobile sensing era, information is commonly tagged with location, thus encouraging location-based queries. To facilitate such queries, we advocate building “directories” around locations of interest by having nearby mobiles carry the data generated around these locations.