A Data Scheduling Method for Video-on-Demand Systems on Radio Broadcasting Environments

Due to the increase in the speed of wireless communication in recent years, video-on-demand (VoD) systems has got great attention. In conventional VoD systems, when the number of clients receiving video data increases, the problems of longer playback interruptions or longer buffering times occur. Accordingly, several research focus on the VoD systems that adopt broadcast-type distribution (B-VoD). In B-VoD systems, video files are divided into several parts and distribution servers broadcast them in the sequences of predetermined broadcast schedules to reduce interruption time. However, conventional broadcasting methods do not consider the issues that occur in actual B-VoD systems, such as initial buffering delay and the increases of data sizes caused by video file division. Interruption time can be further reduced by considering them. Hence, in this research, we propose a data segment scheduling method for B-VoD systems. We measure the performance of our proposed method on an actual B-VoD system utilizing radio broadcasting (VHF-band) to achieve a broadcast-type distribution. The results of the experiments confirmed that, under the condition of an uninterrupted playback, the waiting time until the start of a playback can be reduced by up to 85% under our proposed method by dividing the requested video data into 6 parts and broadcasting the parts in parallel.