Adaptive QoS and Security for Video Transmission over Wireless Networks: A Cognitive-Based Approach

Transmitting video streams while ensuring security is a challenging issue in wireless networks. Due to the openness of the wireless medium, encryption techniques should be used in many critical applications to secure video stream transmission. However, this may impact the quality of service required to efficiently reconstruct video data caused by the processing overhead and delays generated by the encryption procedure. In addition, a degradation of the transmission performance in terms of signal to noise ratio (SNR) and bit error rate can occur due to the varying characteristics of the wireless environment, which affect the available bandwidth on the channel. Thus, adaptable approach that can make a trade-off between security enforcement and transmission performance is required. In this work, we investigate the design of a video stream transmission scheme over wireless networks that can ensure security and efficiency. Our proposal is cognitive-based in the sens that security policy is selected according to the risk level evaluated by the receiver. This is done using real-time assessment of the network security state, intrusion detection, access history, and resource availability in the mobile device. The main goal is to satisfy the real-time constraints of the video stream and guarantee clear reconstitution of specific part of the scene qualified as the region of interest (ROI) by adapting the compressing parameter, qualified as the delivery ratio, according to the selected security policy and the transmission characteristics of the wireless channel.