Energy-saving Routing Algorithms In Mixed Line Rate Optical Networks

Mixed Line Rate(MLR)optical network has become a hot topic in recent years due to its high transmission rate,low-cost and more suitable for heterogeneous trafficrequests.In recent years,low-carbon,energy-saving and green has become the trend of social development.Consequently,how to design effective energy-saving routing algorithms that guarantee network performance while reducing energy consumption at the same time is one of the key issues of MLR optical networks.In this paper,we focus on the research of energy-saving routing algorithm for MLR optical networks,and propose three energy-saving routing algorithms that consider the factors of physical impairment,energy consumption and traffic grooming.And extensive simulations are used to evaluate the effectiveness of the algorithms.In this paper,we firstly analyze the development situation and research status of MLR optical networks,mainly focusing on survavibility and energy-saving technology.And we investigate the routing algorithms that are based on physical impairment,survivability,energy-saving and supporting traffic grooming in MLR optical networks,respectively.Based on wavelength layered graph model,we propose an Physical Impairment aware and Energy-saving Shared Path Protection,called PIE-SPP and its improved algorithm,called PIE-SPP1.When the two algorithms establish connections for traffic requests,the factors such as link and node status,physical impairments,spectral distance between optical channels of different modulation models and so on are considered.PIE-SPP and PIE-SPP1 algorithm allow working and protection paths are aggregated into different fiber links,and encourage to utilize activated devices to establish working paths.They make use of resources in sleeping mode to establish protection paths as much as possible,which is beneficial to put more equipments in sleeping mode to reduce energy consumption.PIE-SPP algorithm firstly choose lightpaths having lowest physical impairments,but PIE-SPP1 algorithm always encourage to choose lightpaths having lowest energy consumption.Therefore,the energy-saving performance of PIE-SPP 1 is more superior than PIE-SPP algorithm.Secondly,we focus on MLR optical network supporting traffic grooming,and propose a Holding-Time aware and Energy-saving Grooming,called HTEG.With the consideration of the number of idle wavelengths and matching degree of holding-time of traffic and remaining holding-time of the existing path in activation state,this algorithm encourages to choose the path with the least additional energy consumption during the holding-time of traffic,which can reduce the energy consumption and carbon dioxide emissions.Finally,based on VC++ 6.0 software,a MLR optical network simulation platform is developed to evaluate the performance of PIE-SPP,PIE-SPP1 and HTEG,and compare them with the existed algorithms proposed in the previous literatures to verify the effectiveness of the proposed algorithms.