Control algorithms of SONET integrated self-healing networks

As the deployment of high-speed fiber transmission systems has been accelerated, they are widely recognized as a firm infrastructure of the information society. In SONET, the self-healing networks have been highlighted as one of the most advanced mechanisms used to realize SONET survivable networks. Several schemes have been proposed and studied due to the rapid progress in the development of highly intelligent network elements (NEs). A DCS based distributed self-healing network is discussed from the viewpoint of its control algorithms. The self-healing algorithm, called TRANS, is explained in detail. It possesses such desirable features as providing fast and flexible restoration with line and path level restoration applied to an individual STS-1 channel, the capability of handling multiple and even node failures, and so on. Both software simulation and hardware experiment verify that TRANS works properly in a real distributed environment, the result of which is shown in the paper. In addition, the combined use of TRANS and ring restoration control is proposed taking into account a practical SONET application