Efficient Photo Crowdsourcing in Delay-Tolerant Networks with Evolving POIs

In a disaster or battlefield zone, the rescue workers, soldiers and other survivors (referred to as nodes) may need to survey the damages and send images to the command and control center (the server) in a hop by hop fashion in the absence of any communication infrastructure. The server considers some area/landmark as the point of interest (POI), and distributes the request to the nodes to collect more information about them. Nodes take photos of POIs and share them among each other using store and forward paradigm, called Delay-tolerant Networks (DTNs) to send them to the server. Due to highly intermittent contact characteristics of nodes in a DTN network, and bandwidth and storage limitations, redundant photos need to be omitted in this forwarding technique whereas photos that cover different angles and views of the targets need to be shared. Another challenge is that, over time, some server-listed POIs may not be of importance whereas some new POIs might be of interest. In this work, we propose a scheme that is able to dynamically update the list of POIs based on the current photo metadata, with reduced consumption of the bandwidth, energy and the storage at nodes by sending only important photos of POIs. We compare our proposed schemes with a related well-known scheme [21] to show the scalability of our approaches which provide the same level of photo coverage, but consumes much less energy and bandwidth