(A) framework for secure and error-resilient video transmission over wireless networks

Abstract

The recent increase in Internet traffic over wireless networks has primarily resulted from the increase in mul-timedia service traffic. For example, video services such as YouTube, private broadcasts, and video surveillance have become a key medium through which personal and business videos can be disseminated to the public, and it also promotes the creation of videos. In addition, Internet protocol television (IPTV) like Netflix is becoming a popular service and its service area extends from wired devices to wireless devices with the support of network bandwidth increases. Therefore, multimedia service traffic over IEEE 802.11 wireless networks is continually increasing and will continue to increase. In order to provide enhanced quality of experiences (QoE) to mobile users, two major issues should be care-fully addressed. First, video quality degradations during wireless transmission should be minimized to provide enhanced quality of video services. Due to various types of interference (e.g., channel interference, hidden ter-minal problems, congestion, etc.), the wireless transmission of multimedia service traffic is error-prone. Fur-thermore, mobile users can experience various service quality degradations even if the wireless network band-width is sufficient to support the transmission. For example, mobile users experience various video quality deg-radations when they use multimedia services including buffering delays, connection losses, and freeze frames. In order to solve this video quality degradation issue, an error-resilient video transmission schemes should be further studied. Second, the secure transmission of multimedia service traffic should be provided to prevent threats on privacy and social security, and the illegal use of commercial video contents. The eavesdropping by cyber-attackers can be a serious problem as a wireless transmission technique becomes a general medium for transmitting recorded video. For example, Iraqi militants intercepted transmitted surveillance video from a military unmanned air vehicle (UAV), called Predator, with simple data-leeching software that costs only $26. In addition, privacy protection can also be significantly threatened when video surveillance devices are eavesdropped. In the case of the kindergarten CCTV operated by Hong Kong Society in 2015, CCTV was installed inside a children’s toilet. In order to solve this secure transmission issue, multimedia service traffic should be transmitted with appropriate encryption schemes. Therefore, this dissertation presents a secure and error-resilient video transmission framework that can provide an adaptive video encryption with battery-conservation and an error-resilient transmission of recorded video on a per-packet over wireless networks. In order to provide the secure and error-resilient video transmission of recorded video, the significant subset of H.264/AVC recorded video over MPEG-2 transport stream (TS) that has critical impact on decoding, called critical video data, is identified and reallocated on a per MPEG-2 TS packet basis within the unit of inter-frame dependency. The reallocated critical video data can be transmitted with different transmission priorities on a per IP packet basis to achieve error-resilient transmission of recorded video. Furthermore, the reallocated critical video data can also be adaptively encrypted by considering currently available computing power. The evaluation results on IEEE 802.11 testbed with standard definition and high definition videos demonstrate that the proposed scheme has significant performance enhancements over the conventional video frame prioritization scheme in terms of transmission overhead, transmitted video data utilization, peak signal-to-noise ratio, and subject quality test. In addition, further evaluation results on testbed with Raspberry Pi and AR.drone demonstrate that the proposed framework provides an enhanced video transmission security with less than half of the battery power consumptions that would be required by the fully-encrypted transmission scheme.