Power efficient resource allocation algorithms for provisioning in SDH networks

Synchronous Digital Hierarchy (SDH) is a widely used technology in access and core networks for carrying different types of traffic. It defines a hierarchy for multiplexing lower rate traffic containers into higher rate traffic containers. Provisioning refers to the process of allocation of resources to carry a given traffic demand. Due to the continued expansion of the networks employing SDH technology, the power consumption of the network increases becoming a bottleneck for further expansion. Allocation of resources to traffic demands in power-efficient ways will therefore help in minimizing the capital and operational costs in running the network. In this work, the power consumed by a switch matrix having the capability to switch different traffic containers in different amounts is considered. The objective is to minimize the number of network elements deployed in the network by allocating resources to traffic demands in power-efficient ways. A formulation based on Integer Linear Programming (ILP) is presented; three different heuristic approaches, based on how higher order trails are used and the use of grooming, are proposed. It is found that the grooming-based heuristic performs better in terms of the total power consumption relative to the weighted number of requests accepted. It is also found that, for small networks, the grooming heuristic performs identical to the optimal solution found by an LP solver when the problem is feasible. It can be noted that the power-efficient design is also a cost-efficient design since the capacity of the switch matrix determines the number of network elements that are required for deployment in the network.