Protecting real-time traffic service in a 3-LIHON hybrid node

Recently a new hybrid optical network, integrating circuit and packet transport services has been proposed. This network, called 3-Level Integrated Hybrid Optical Network (3-LIHON), provides different transport services for guaranteed, real-time, and best-effort traffic. This article proposes a protection mechanism for the real-time traffic in the 3-LIHON network. Indeed real-time traffic carries a small but important portion of the traffic, i.e. control traffic. The proposed scheme exploits the redundancy provided by 3-LIHON nodes, thus not requiring additional hardware, representing a cost-efficient solution. The availability achieved by this protection scheme is assessed by means of structural models, and a sensitivity analysis is performed. Simulation results measuring the real-time and best-effort traffic delays, obtained with the protection method, are presented and evaluated. The effectiveness of the mechanism is demonstrated, since the delay experienced by real-time traffic is below required limits. Also the delay for best-effort traffic is not really affected by the application of the protection mechanism.