The use of MulTCP for the delivery of equitable quality video

Instead of constant bit rate encoding and delivery with the known problems of variable quality, not fully using the network at all times, and session rejection, we describe a system in which independent video servers, by using a set of fixed quality encodings and analyzing the statistics of the encoded video they are about to deliver, vary the aggressiveness of TCP rate control so as to obtain unequal shares of the contended network, in such a way that more complex video sequences get a bigger share. Compared to an equal share of bit rate, there is much less variation in quality between video streams delivered at the same time. This paper reports on the use of MulTCP, a server side modification to TCP, to apportion bandwidth more appropriate to the demands of the content being streamed. We present results of NS-2 simulations of our autonomous rate adaptive streaming server using MulTCP as the transport and show how similar qualities across content types are maintained when streaming over a contended network.