A Study on the Energy Saving Characteristics of OSPF Routing Based on the Energy Profiles in IP Networks

Nowadays the research of energy saving on the IP networks have been studied the various methods in many research institutes. In this paper, we present a two-step routing in an IP network having a different energy profiles, and analysis of the characteristics in detail.
The routing of 1-phase is the OSPF routing method considering the energy cost in addition to existing costs for energy savings. And weighting the energy consumption of an existing OSPF routing when the metric system and network element. To achieve maximum energy savings, it is analyzed for a wide range of cases. The results show that the energy saving efficiency can get about 67% at in ingress input load by using random energy profiles in IP networks. Although the number of hops is a slight increased due to routing the paths for the minimum energy consumption in the algorithm of this method, the increment hop number is limited the mean 1.4 hops. This paper confirms that the energy profile of core router has the large effects of energy saving than the energy profile of edge router, and the proposed method has the excellent energy saving characteristics in IP networks.
2-phase After creating the core nodes to sleep as much as possible, but the path is affected by sleep nodes applies the method of re-routing. At this time, we confirm that the characteristics of mean delay and energy efficiency can be satisfied by limiting an allowable hop number in the reroute paths, and utilization rate of nodes and links for assuring energy saving and network-level QoS. Since the efficiency of energy saving and delay characteristics differ according to selection methods of core nodes to go into sleep state, it is that the a method of core node selection based on MP(minimum_path) is more excellent than others in terms of network-level QoS and energy saving in IP networks.