QoE-based Bandwidth Allocation In FTTH Networks

Currently, there are three services on the FTTH network, High SpeedInternet service, IPTV services and VoIP services. There exists mutual isolationbetween the three services. However, in the High Speed Internet service, theuser’s applications, such as online video, file downloads, video chat, arecompeting for the bandwidth of each other, resulting in network congestion,leading to poor user experience. And then the user wants to improve the userexperience of certain applications, but the network scheduler has no idea whatthe user is thinking about. Here a problem comes up: the network schedulercannot apply a dynamic bandwidth adjustment of the application according tothe user’s QoE on the specific application. It is the QoE-based bandwidthallocation problem in this paper.A bandwidth allocation method is proposed based on the “sweet point”.“Sweet point” is the specific bandwidth value. The QoE gets worse quicklywhen the bandwidth is smaller than the “sweet point”, and keeps the sameapproximately when the bandwidth is larger than the “sweet point”.Requirement of the "sweet point" based bandwidth allocation method is thatthe network scheduler should guarantee the bandwidth of the specificapplication greater than the “sweet point”according to a user’s request, as wellto improve the user experience on a specific application.In this paper, we utilize software-defined network (SDN) to realize the"sweet point" bandwidth allocation method in FTTH networks. This papermainly includes two aspects, one is the realization ofa user’s request workflow,and the other is the use of SDN technology to realize the user-specificapplication’s bandwidth capabilities. Why we used SDN technology is that thebroadband remote access server (BRAS) which is in charge of the bandwidth access management and control cannot guarantee the bandwidth to a specificapplication. However, SDN technology provides us with a tool that candistinguish between different user application flows, and can dynamicallyprovide bandwidth guarantees for each application flow, so that the applicationbandwidth can be kept greater than "sweet point" value, in order to protectusers of the experience of the application. Therefore, we can use SDNtechnology to ensure the application bandwidth greater than "sweet point".