Topology Management-Based Distributed Camera Actuation in Wireless Multimedia Sensor Networks

Wireless Multimedia Sensor Networks (WMSNs) involving camera and Scalar Sensor (SS) nodes provide precise information of events occurring in the monitored region by transmitting video packets. In WMSNs, it is necessary to provide coverage of events occurring in the monitored region for longer durations of time. The Camera Sensor (CS) nodes provide the coverage of an event and transmit the video data to the Base Station (BS), when these nodes are actuated by the associated SS nodes on occurring of an event. Therefore, in the existing pieces of work, distributed actuation focuses on the coverage of an event and prolongation of the lifetime of the CS nodes. However, for distributed actuation of the CS nodes, the SS nodes play a vital role. When the data sent by the associated SS nodes in an event area exceed the preconfigured threshold, the CS nodes start sensing the event and send the video data to the BS. Therefore, in addition to the lifetime of the CS nodes, the lifetime of the SS nodes and their data reporting latencies are important aspects for distributed actuation of the CS nodes, while sending both the video and scalar data to the BS. In this work, we propose a topology management-based distributed camera actuation scheme, named TADA, to prolong the lifetime of SS nodes, and decrease the data reporting latency in event area only. The increased lifetime of the SS nodes, in turn, increases the event coverage and packet delivery ratio. To increase the lifetime of the SS nodes in an event area, the SS nodes with the most residual energies are selected as the packet aggregators. In addition, the transmission range of these nodes is decreased, and in-network packet aggregation is performed, while reporting the happening of an event to the associated CS nodes. The aggregator selection mechanism helps in balancing energy consumption of the SS nodes. Similarly, the decrease in transmission range and aggregation mechanism help in decreasing energy consumption of these nodes. The transmission range of the SS nodes is decreased using social network analysis and Coalition Formation Game (CFG). CFG also helps in decreasing the data reporting latency of an event by the SS nodes to their associated CS nodes. Performance evaluation results show that the proposed scheme, TADA, which is based on the distributed topology management protocol named T-Must, achieves high performance in terms of the lifetime of the SS nodes, data reporting latency, coverage ratio of the event, event reporting credibility index, and packet delivery ratio in an environment affected by shadow fading.