Error-resilient techniques for video transmission over wireless channels

Video communications over wireless networks have always been a challenging issue. When a video stream is conveyed through a wireless communications channel to the receiver end, it is exposed to high levels of burst and random bit errors. These channel errors severely degrade the service quality of video communications, in particular for carrying out two-way communications, due to the propagation and accumulation of errors throughout the transmitted video stream. There are several procedures used to reduce these deteriorating effects, including the use of forward error correction techniques, feedback algorithms, error concealment methods, and error resilience schemes. This paper presents these remedial solutions and describes popular error control and resilience algorithms, namely Turbo codes, error-resilient entropy codes, and two-way decoding with reversible codewords. The improvement in perceptual quality offered by these schemes is demonstrated. This paper also shows that the combination of these three error control and resilience methods gives a better performance than conventional forward error correction techniques when compressed video is subjected to error-prone environments.