A Proposal of QoS-aware Power Saving Scheme for SDN-based Networks

The amount of Internet traffic is increasing rapidly day by day due to increase in Internet users and communication devices such as smart phones. In order to handle network traffic, network devices such as routers and switches are being added steadily causing significant power consumption by the network. Internet traffic at a particular place/country fluctuates in different time of a day and different day of a week. However, network devices are configured to operate fully whether they are idle or fully utilized. Many researchers have proposed schemes to reduce power consumption by network devices by putting their links or devices themselves to sleep when their utilization is less than a certain threshold. However, the schemes do not consider the types and QoS of traffic when putting the devices or links to sleep. It has been noted that lower the rate of a link, the lesser it consumes energy. In this paper, instead of putting devices or links to sleep, we reduce the rate of links in order to save energy as well as satisfy the QoS of the traffic. We distinguish two types of traffic Real-Time and non-Real-Time. We maintain the shortest path delivery (QoS) for Real-Time traffic and reroute non-Real-Time traffic if needed to reduce the rate of a link. The simulation results have shown that we can reduce the power consumption by network devices and at the same time maintain the QoS of the traffic.