REAL TIME ISOCHRONOUS FILE TRANSFERS FOR ENABLING GLOBALLY SCALABLE P2P VIDEO-ON-DEMAND

摘要

A method for real-time content transfers between two devices ensuring that the network or the end devices do not get choked. Real-time requirements are stringent for allowing audio-video/multimedia files to be played immediately. The method involves sending the files isochronously using uniformly spaced UDP packets. The overall rate of transfer, can be higher than that required for real-time playing, allowing faster downloads of the file. Since, the method ensures that the network or the devices do not get chocked, it is good for all kind of file transfers – even those where real time play is not applicable. The method ensures that a device can transfer multiple files simultaneously to different devices, limited only by network bandwidth and the processing power. This method empowers even lightweight devices such as STB with Hard-disk to functions as Servers for Peer-to-Peer file video transfers. Unlike UDP protocol, this methodology ensures reliable file transfers. Unlike, TCP protocol, this methodology ensures real-time file transfers, which are not affected by distance. Unlike both UDP and TCP protocols, this method doesn’t choke the network or devices. Unlike RTSP protocol, this method uses only UDP packets for data as well as control purposes. The Real-time Isochronous File Transfer methodology also ensures that ongoing file transfers are not affected by any new Isochronous file transfers. This prevents congestion in the network. This is achieved by testing out the efficacy of a new file transfer, at a lower QOS level, before it is continued at a higher QOS level. If insufficient bandwidth is present the new file transfer is not initiated. For real-time playing, the downloading is always ahead of the playing point. This facilitates the user to Fast Forward from the current playing point, till the downloading point. Other VCR functions are provided from the local storage itself. Unlike RTSP protocol, this method does not require the VCR controls to be sent to the server side, and the sever side sending different streams in response. Unlike RTSP, this methodology ensures that the entire video file is transferred continuously, irrespective of VCR controls (including Pause) being used by the user.