RWA problem for designing DWDM networks - delay against capacity optimisation

Adaptation of QoS in DWDM optical networks routing and the wavelength assignment (RWA) problem, known as an NP-hard problem, are addressed. The QoS constraint based routing RWA computes lightpaths for the original-destination node pair, (O, D), to meet the QoS propagation delay requirements. A heuristic algorithm based on a genetic algorithm (GA) is then developed to solve this problem. A simulation program is developed to demonstrate the efficiency of the GA for the COST 239 network. The trade-off between the capacity and the propagation delay has been analysed. Results show that the trade-off is 8.7% of the average capacity, increasing to 10.6% decrease for the average delay.