Green Protection With Transmission Impairment Consideration In WDM Optical Networks

Optical networks with Wavelength Division Multiplexing (WDM) technology are widely used recently owing to the high transmission speed, huge bandwidth capacity and high flexibility. With the increase of energy consumption, how to reduce the energy consumption in a WDM network has become one of the urgent problems to be solved. In this dissertation, we mainly investigate energy-saving protection schemes for WDM optical networks with transmission impairment consideration, introduce the sleeping mechanism into dedicated and shared segment protection schemes in WDM networks, and propose several effective power-aware algorithms. Extensive simulations have been used to evaluate the performance of our proposed algorithms.Firstly, we analyze the development situation and key technologies of WDM optical networks, mainly focusing on transmission impairments, green technology and protection strategy. Secondly, based on wavelength layered graph model, we propose an Impairment-based Power-saving Dedicated Segment Protection Algorithm, called IPDSP. With different optimal objectives, i.e., energy-saving or performance trade-off between energy-saving and blocking probability, IPDSP can be further divided as IPDSP-Dif and IPDSP-Mix. IPDSP-Dif encourages packing working and protection paths into different optical fibers, and establishes connections by active resources as far as possible, which is beneficial to put more equipment into sleeping state to reduce the total energy consumption of the networks. Although PDGSP-Dif has low energy consumption, it has a higher blocking probability. IPDSP-Mix also encourages to use activate resources to create connections. However, it allows working and protection paths to be in the same fiber, which is helpful to shorten path length and to save wavelength resources. It can also make a trade-off between energy saving and blocking probability.Finally, with a consideration that more resources have been occupied by dedicated protection schemes and its resource utilization is low. We propose an Impairment-based Power-saving Shared Segment Protection Algorithm, called IPSSP. With two different optimized aims of energy saving and balance between energy saving and blocking probability, IPSSP can be specified as IPSSP-Dif algorithm and IPSSP-Mix algorithm. Both of them can increase the sharing rate of protection resources, save the wavelength resources and make more links to be free. Therefore, compared with IPDSP-Dif and IPDSP-Mix, IPSSP-Dif and IPSSP-Mix have relatively low value of blocking probability. Compared with IPSSP-Dif, IPSSP-Mix can achieve a better trade-off between energy consumption and blocking probability.