Redundancy-Based Semi-Reliable Packet Transmission in Wireless Visual Sensor Networks Exploiting the Sensing Relevancies of Source Nodes

Visual data monitoring in wireless sensor networks can significantly enrich a large set of surveillance and general purpose monitoring applications. However, transmission of image snapshots or video streams can rapidly deplete the energy resources of the deployed nodes, turning energy efficiency into a major optimization issue. During wireless transmissions, packets can be corrupted directly affecting the monitoring quality of the applications. One reasonable way to reduce quality loss is the transmission of redundant packets for higher error resilience, but additional packet transmissions may incur in undesirable energy consumption. Frequently, some monitoring quality loss may be tolerated since visual information retrieved from source nodes may have different relevance for the applications, according to the monitoring requirements and the current sensors’ poses and fields of view. In such way, we propose that only high-relevant source nodes will transmit redundant packets, assuring error resilience only for the most relevant visual data for the monitoring application. Doing so, energy is saved over the network when fewer packets are transmitted in average, potentially enlarging the network lifetime with reduced impact to the overall monitoring quality. Key-Words: packet-level redundancy; wireless visual sensor networks; semi-reliable transmission; sensing relevance of source nodes.