Transmission of video with caching mechanism and retransmission of I-frames

Real-time digital video transmission over Internet is a challenging issue because it leads to packet loss and storage capacity problems. The performance of a cache depends on the implemented mechanisms that are responsible for the maintenance of the stored data. Mechanisms that support caching of streaming video include PLFU (Partial Least Frequently Used). The PLFU caching server is compelled to cache the entire video stream even though some segments may never be viewed and therefore inevitably run out of storage space. The PLFU mechanism excessively reserves space for all kinds of frame losses and monitors and recovers from all types of losses. This research enhances the caching ability of PLFU mechanism by selectively storing parts of the video stream on the caching server instead of the entire stream. In addition, enables the cache proxy server to recover from the more critical I-frame losses that can take care of the rest of frame losses without excessive monitoring and reservation of storage space. Caching the selective part of video by the proposed algorithm increases the number of on demand files in cache proxy server and reduces the number of trips between the cache proxy server and the origin server. The proposed mechanism loss recovery algorithm sends a TCP/IP repair request to the origin server for retransmission of I-frame. The playing quality is much better due to this retransmission of I-frame. The performance of proposed caching mechanism and retransmission of I-frames is evaluated through a simulation.