Spectrum Allocation Technique for Traffic Grooming in Flexgrid Optical Network

摘要

The massive growth of Internet and communication modes has made the networking technology a promising solution that provides services in a cost effective manner and with better scalability. The traffic in backbone networks is ever increasing. Future networks must be stuffed with advanced resources to meet the increasing traffic demands, the evolution of bandwidth hungry services, like video on demand, e-learning and grid computing applications. Optical networking provides an efficient solution to satisfy the requirements of today's communication revolution, since it provides massive advantages in terms of bandwidth, which could be exploited to meet the performance requirements. Optical networks based on Wavelength Division Multiplexing provide wavelengths firmly allocated throughout the optical spectrum which is parted by 50 or 100 GHz. The Elastic Optical Network helps to improve the overall performance of the network by allotting multiple sub channels to future connection requests with smaller bandwidth granularity (hence the term elastic) by the use of a flexible spectrum grid. We compare three cases, including traditional coarse ITU-T wavelength grid and spacing, mini-grid and grid-less. Though grid-less is the most flexible of all, it is also equally important to evaluate the mini-grid case that lies between the cases of coarse grid and grid-less. This is because today most of optical components cannot really achieve fully grid-less tunability. The working of flexible-grid EONs to that of fixed-grid WDM networks under dynamic traffic, with and without grooming capability, in cases of blocking probability and overall spectrum occupation is compared, thus determining quantitatively the benefits of EON in comparison to grooming based WDM networks.