A framework to support QoS in burst switched broadband convergence networks

Abstract

Optical Burst Switching (OBS) has been proposed as an alternative switching technology for the next optical backbone network based on the current technology. OBS separates the control channel for the Burst Control Packet (BCP) and the data channel for data burst. BCP is transmitted ahead of data burst as the defined offset time in order to configure the switches along the route of burst. When the offered load increases to the OBS network, data bursts can be dropped due to limitation of optical buffers. Also, the burst loss can occur due to the congestion in the control channel. When the load increases in the control channel, the congestion occurs by heavily loaded traffic. The congestion makes the offset time variation and it incurs burst loss. There have been many researches about a contention resolution issue, however no clear solution have been appeared due to the intrinsic limitation of OBS network. Thus, we propose a new architecture - Burst Switched Broadband Convergence Network (BS-BcN) which provides a basic framework to solve the basic limitation of OBS network. New data channel scheduling algorithm and new control channel algorithm for (BS-BcN) are proposed to reduce the burst loss in OBS network. Also, new reservation scheme is proposed to configure core-contention free OBS network. All of our proposed algorithms can operate on the BS-BcN environment. First contribution is to propose a new Broadband Convergence Network (BcN) architecture based on ITU-T’s NGN architecture with Optical Burst Switching (OBS) technology. With the centralized resource manager of the NGN, we can improve QoS in terms of burst loss rate. Ideally, no burst blocking occurs and no capacity is wasted in the core optical network on bursts that are doomed to be eventually lost. It is important that OBS has a way to survival solution in the future network. Our proposed algorithm solves main problem and provides basic architecture to be deployed as NGN solution. Second contr...