Supporting adaptive video applications in future IP networks

Certain video applications may be able to tolerate a degree of fluctuation in quality. Therefore it would be useful for the network to offer a class of service that could meet the requirements of adaptive video sources. As part a general study into the problems of providing multiservice in future packet switched networks we have been investigating the requirements for network support of adaptive video applications. We propose that this class of traffic should be provided with explicit congestion feedback from the network nodes, and that the feedback mechanism should be optimised to the needs and characteristics of adaptive video. Whilst certain aspects of feedback control developed for computer data may offer some benefits to adaptive video, we believe that they may be insufficiently responsive, particularly in cases where the round trip time (RTT) is high. The paper outlines the basic components of a reactive congestion control system, and discusses how we propose to optimise a reactive congestion control scheme to the needs of adaptive video applications