DESIGN AND DEVELOPMENT OF ADAPTIVE ROUTING ALGORITHM TO REDUCE DISTORTION DURING VIDEO TRANSMISSION

Now days a video application i.e. video clip transmission has become part of life, since the development of video compression techniques and advent of smart phones. With increase in video clip transmission, video traffic is playing a major role in the wireless networks. Unlike the new generation cellular mobile networks, the traditional network is restricted for low-rate audio communication. New generations of cellular mobile networks are capable of transferring the data traffic at much higher bit rate than traditional networks. In our project we tried to improve the quality of the video by considering the requirements of the application, particularly we addressed for the distortion of video which is experienced during transmission from source to destination. The encoding scheme of the video clip will cause the loss of some packets per frame, these lost packets per frame should be within the certain threshold otherwise we cannot decode the frames correctly. The frame loss will lead to certain amount of distortion in video. In GOP, the positions of the not decodable frames will give the distortion value for that link in the path from the source to destination. So we are trying to construct model which will provide details of the losses of frames in GOP when video is transferred from source to destination. This shows us how the transmitted path will be impacting on the performance of a quality of video. So our objective is to choose the path which has minimum distortion from source to destination. In the formulation we will consider the history of a frame loss in GOP for all the paths. Our solution to the problem is to first capture the process of evolution of frame loss then selects the path which has less distortion. In GOP, the fine grained information is carried by the I-frames if such longer I-frames we lose then it will impact more on the distortion metric. So our approach will take care of such frames and are transmitted via less congested path. The path of transmission is calculated using dijistra's algorithm. The the percentage reduction in distortion of video is higher when there are higher number of nodes for transmission. The PSNR value of the transmissited data increases as the bit error rate and frames distortion increases. PSNR is lower when the bit error rate and packet distortion is low.When the data is being transmitted, the route of transmission changes at the node where the PSNR of the route is higher than the specified threshold valueThe threshold value is calculated after observing the PSNR value during the first time of transmission. The threshold value is set a 0.9 times the maximum PSNR value during first transmission.