Energy-minimized Design For IP Over WDM Network

With the fast expansion of the Information and Communication Technology(ICT) section,its energy consumption has become an important issue. The energy consumption of all the network equipment deployed may eventually become the obstacle for the sustainable development of the Internet. Core optical networks are important parts of the Internet. Thus, how to make it energy-efficient has attracted extensive attention from both academia and industry.In this study, we focused on reducing the energy consumption of IP routers, which is the most energy hungry equipment in the core IP over WDM network. Firstly, we propose an adaptive clock frequency strategy for router cards to minimize the total energy consumption of IP over WDM networks. Rather than always running at a full speed, the clock frequency of a router card is adaptively adjusted according to its actual carried traffic demand. Through combining the lightpath bypass strategy, the proposed adaptive clock frequency strategy can effectively reduce the energy consumption of the IP over WDM network up to more than 40% compared to the case without such an adaptive capability. Moreover, the study also indicates that a router card supporting a small number of discrete clock frequencies can perform close to a card with continuously changed clock frequencies.Secondly, the core network carries a high bandwidth. Thus, any network attack can lead to the loss of a huge amount of data. Network security and survivability is of paramount importance. This study looks into an energy-minimized IP over WDM network based on a mixture of sleep-enabled and non-sleep-enabled router cards where a certain percentage of the network bandwidth must be carried by non-sleep-enabled router cards. Through combining the lightpath bypass strategy, we can design an IP over WDM network that can ensure more than 50% traffic demand carried by non-sleep-enabled router cards, and owing to the energy saving capability by sleep-enabled router cards, the proposed scheme can save up to 34% energy consumption compared to the case where all the router cards are non-sleep-enabled.