Cross-Layer Framework for QoS Support in Wireless Multimedia Sensor Networks

The emergence of wireless multimedia sensor networks (WMSNs) has made it possible to realize multimedia delivery on tiny sensing devices. The volume and characteristics of multimedia data is quite different from the data generated in WSNs that has raised the need to explore communication protocols for multimedia delivery in WMSNs. The existing studies focus on providing quality-of-service (QoS) to each individual source but they are not adaptive to create room for maximizing the number of sources. In this paper, we propose a novel cross-layer framework for QoS support in WMSNs. The objective of the proposed framework is to maximize the capacity of the deployed network to enhance the number of video sources given that the QoS constraint of each individual source is also preserved. This is achieved by implementing Wyner-Ziv lossy distributed source coding at the sensor node with variable group of pictures (GOP) size, exploiting multipath routing for real-time delivery and link adaptation to enhance the bandwidth under the given bit error rate. Hence, application requirements are mapped on joint operations of application, network, link and MAC layers to achieve the desired QoS. Simulation results reveal that the framework admits larger number of video sources under the satisfied distortion constraint.