Spectrum and waveband assignment in elastic optical waveband networks

Elastic optical networks can increase spectral efficiency by assigning a variable amount of spectral resources to satisfy a traffic request, instead of the fixed amount of spectrum as allocated by current fixed grid optical networks. Waveband networks reduce the number of optical switch ports by aggregating lightpaths into a waveband, and switching them with a single waveband port. We formulate the waveband selection, spectrum allocation, and waveband assignment problem in an elastic optical waveband network that supports a fixed number of waveband sizes. We propose heuristics to select waveband sizes and study the effect of the number of waveband sizes on the number of optical switch ports. We also address the spectrum allocation and the waveband assignment problem in elastic waveband networks with no restrictions on the number of waveband sizes. We propose an auxiliary graph based heuristic and study the trade-offs between spectral usage and the number of optical switch ports. Additionally, we propose traffic ordering strategies and study their efficacy in reducing the number of optical ports and efficiently utilize the optical spectrum in a waveband network.