Wavelength retuning in a WDM mesh network with survivable traffic grooming

This paper proposes a new survivable traffic grooming wavelength retuning (STGWR) scheme in an all-optical wavelength division multiplexing (WDM) network. In a dynamic WDM network, a connection may require bandwidth less than a wavelength capacity. Also, a connection should be protected against any network failures. Survivable traffic grooming (STG) can protect connections at subwavelength granularities. Wavelength retuning is a promising approach in an all-optical WDM network, where a signal must remain on the same wavelength from its source to the destination, to alleviate the wavelength continuity constraint and reduce the connection blocking probability. While both STG and wavelength retuning have attracted extensive research attentions nowadays, no effort has been made to combine these two promising approaches in one network. In this paper, we propose a wavelength retuning scheme with no service interruption in an all-optical network with survivable traffic grooming capability. The scheme allocates two routes, one for active path and one for backup path, in a shared mesh restoration way to each incoming connection request and conducts wavelength retuning only on the backup path. Both wavelength retuning and mesh protection are done at the connection level instead of at the lightpath level. The simulation results of the proposed schemes are also presented