The shared medium and multihop nature of wireless multimedia sensor networks (WMSNs) involving scalar and camera sensor (CS) nodes poses fundamental challenges to the design of an effective scheme, which can offer, reliable packet delivery, and resource allocation across different network flows. These flows are incurred by multiple events occurring concurrently in the monitored region in presence of shadow-fading environment. In this article, we propose a conjunctive cooperative communication and resource allocation scheme, named cooperative communication and optimal resource allocation (CORA), for Quality of Service (QoS) support in WMSNs. To exploit cooperative communication, we propose coalition formation framework (CFF) along with shortest path routing framework. The shortest path routing framework increases the lifetime of the CS nodes by decreasing hop-by-hop energy consumption. CFF partitions the links (consisting of CS nodes) into disjoint coalitions, which help in concurrent hop-by-hop packet transmission by reducing interference between concurrently scheduled links. This, in turn, increases packet delivery ratio (PDR) and throughput with maximum rate allocations to the competing links. We demonstrate the performance of CORA over the benchmark scheme network flow interaction chart (NFIC), with regard to PDR, throughput, and the lifetime of the CS nodes.

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.

A distributed topology management scheme in wireless multimedia sensor networks (WMSNs) ensures coverage of an event, prolongs network lifetime, and maintains connectivity between camera sensor (CS) nodes. However, the deployment of WMSNs in unattended environments makes the nodes vulnerable to security attacks. Hence, security issues should be considered, along with topology management, in WMSNs. In this work, we propose a trust-based distributed topology management scheme, named TRAST, for use in WMSNs. TRASTexploits the received signal strength of the control packets, which are then used to construct the distributed topology. In a non-secure distributed topology, the use of trust helps in providing coverage of an event, and maintaining connectivity, even in the presence of malicious attacks. The proposed topology management scheme achieves higher average coverage ratio and average packet delivery ratio than those corresponding to the LDTS and T-Must schemes, in the presence of malicious attacks.