A Cross-Layer QoE-Based Approach for Event-Based Multi-Tier Wireless Multimedia Sensor Networks

Abstract

Wireless Multimedia Sensor Networks (WMSNs) are attracting attention from both academic and industrial environments due to the rapid development of low-cost multimedia sensors. With the enhancement of the multimedia content captured by multimedia devices, WMSNs play an important role in pervasive and ubiquitous systems. The multimedia content in these networks has the potential to enhance the level of collected information, by enlarging the range of coverage, and enabling multi-view support. In the case of WMSN applications, the multi-tier network architecture has proved to be more beneficial than single-tier architecture in terms of energy-efficiency, scalability, functionality and reliability. In this context, a multimedia event detection application is a promising application for multi-tier WMSNs, where the lower-tier nodes detect an event occurrence by means of scalar measurements, and the higher-tier nodes will be woken up to send real-time video flows from the event area. The transmission of multimedia content requires a certain quality level from the user's perspective, while energy consumption and network overhead should be minimized. Among the existing mechanisms for improving video transmissions, application-level Forward Error Correction (FEC) is regarded as a suitable solution to improve video quality level from the user´s standpoint. In this work, the authors propose an adaptive cross-layer approach, which includes a Quality of Experience (QoE)-aware FEC mechanism for WMSNs by generating redundant packets, based on frame importance from user's experience. Additionally, the aothors introduce a multi-tier routing protocol to select the best route to transmit multimedia data. According to the simulation results, the proposed cross-layer approach achieved high video quality level with reduced transmission of redundant packets, which will bring many benefits to a resource-constrained system.