“Just-enough” resource allocation for heterogeneous 10/40-gb/s services in dispersion-limited transparent optical networks

Transparent optical networks offer a common transport platform for services with different bit-rates, transmission formats and technologies. In such a heterogeneous scenario, it is an inefficient use of network resource to provision end-to-end lightpaths without considering the different optical performance requirements of the different service interfaces. This paper proposes an efficient routing and wavelength assignment algorithm, based on service interface tolerance to optical noise and chromatic dispersion that allocates a lightpath with just enough end-to-end optical signal integrity for the connecting service. We investigate its performance in transparent optical networks with heterogeneous services at 10 and 40-Gb/s. For 40-Gb/s services, optical duobinary (ODB) and RZ-DQPSK modulation formats are assumed. We demonstrate that network blocking can significantly be reduced by the proposed algorithm.