Evaluating the ability of SDH to transport broadcast quality video

SDH networks have been developed to provide a common transport infrastructure which is capable of delivering not only today's voice and data services, but future broadband ATM applications. There is also an increasing demand to support broadcast television services at contribution-quality levels. Video services demand a more stringent level of timing and synchronisation performance than other services. Without care, using SDH networks to transport video will visibly degrade the quality of video service. This places new requirements on the performance, specification and evaluation of the SDH network, SDH terminal equipment and video codec equipment. This paper reviews the benefits and consequences of transporting video on SDH and the current specifications used to specify the timing performance of equipment and networks. Missing specifications are identified, which allow degradations to exist-unseen by conventional measurements. A new video wander tolerance template is presented that can be used to specify the timing performance. Finally, new methods for the evaluation of video transport performance on SDH are presented, describing the requirements for new specifications and the new metrics available.