Routing Concurrent Video Signals over SDH Networks

Synchronous Digital Hierarchy (SDH) is a standard for data transmission over telecommunication networks which is often used for framing and synchronization at the physical layer. SDH networks can carry large payloads, but, at the same time, accommodate lower speed signals packed into elementary transport units. The price of this flexibility consists of a potential waste of capacity, due to the complexity of simultaneously determining an efficient signal packing and routing. We address the problem of maximizing the number of communication requests of a given set which can be routed so as to fulfill capacity restrictions (on links and encoders/decoders) and additional constraints imposed by the signal packing mechanism. Despite the technological complexity, we show that a flow formulation can still be provided including signal packing. This formulation shows a nice experimental behavior when tested on the video network of one major Italian broadcasting company.