Cross-layer video transmission over IEEE 802.11e multihop networks

With the development of electronics and computer industry, powerful wireless terminals came to facilitate human life. In the last decade, both customers and researchers paid attention to wireless video applications because they contain abundant and visual information. To ensure wireless video transmission, many cross-layer schemes which combined routing and scheduling mechanisms have been proposed. However, characteristics of wireless networks such as limited resource and fluctuated link quality degrade video transmission quality. In this paper, several mechanisms are designed to improve wireless video transmission performance: (1) an integrated routing metric is proposed to evaluate path quality, taking hop count, congestion bottleneck and other parameters of a path into account; (2) traffic assignment and traffic adjustment modules are designed to make routing scheme be flexible to the changing environments; (3) an enhanced link layer scheduling algorithm based on our previous work is proposed. Simulation results show that compared to commonly used schemes, the proposed network layer scheme always provides better performance with various traffic modes. Combined with link layer scheduling algorithm, the performance could be further improved.