A wavelength retuning scheme with no service interruption in survivable optical networks

This paper proposes a new wavelength retuning scheme in a survivable all optical WDM network. Compared with the existing wavelength retuning schemes developed for all-optical networks, which can alleviate the wavelength continuity constraint but may not avoid service interruption or data loss, the proposed scheme is able to alleviate the wavelength continuity constraint and reduce the connection blocking probability with no service interruption to the on-going traffic. This is achieved by allocating two link-disjoint routes, one for active path and one for backup path, to each incoming connection request and conducting wavelength retuning only on the backup path. An optimal backup path wavelength retuning scheme and a heuristic algorithm are developed and the performance evaluation on the proposed schemes is presented.