Link State Information Approximation for Hierarchical QoS Routing

In this paper, Service Boundary Line approximation method is proposed to improve the accuracy of aggregated link state information in transport networks that conduct hierarchical QoS routing. This method selects the main link state information in the network and transports the data to the external networks together with the aggregation information, reducing information distortion caused from the loss of some link state information during link aggregation process. The proposed method is especially useful for aggregating links that have both delay and bandwidth as their QoS parameters. Simulation results show that our approximation method requires a storage space that is 1.5-2 times larger than those in other known techniques, depending on the main line state information selection method, but that information accuracy is 2-5 times higher.