Collision-free bandwidth-variable optical burst switching ring network

Recently, flexible bandwidth allocation has been proposed in an orthogonal frequency division multiplexing based elastic optical network, which is a promising technology for 100G and beyond optical networks. In this paper, for the first time we introduce flexible bandwidth to an optical burst switching (OBS) ring network and propose a novel bandwidth-variable OBS (BV-OBS) ring network. In the proposed BV-OBS ring network, the durations of bursts are fixed to one timeslot in the time domain, while the bandwidths are variable in the frequency domain according to the burst size. With fixed burst duration and variable bandwidth, the BV-OBS ring can achieve the state of being collision free with high bandwidth efficiency. Simulation results show that a BV-OBS ring network outperforms previous OBS rings proposed in wavelength division multiplexing networks in both network throughput and end-to-end delay.