EBvN: efficient BvN in multi-fiber/multi-wavelength overlaid-star optical networks

Overlaid-star networks with reservation-based scheduling could be appropriate networks for metro areas. The Birkhoff–von Neumann (BvN) scheduling could be used at the core nodes of an overlaid network to schedule lossless traffic transmission among edge nodes. The common method is to schedule traffic separately for each wavelength channel, called separated BvN (SBvN) scheduling in this paper. However, SBvN cannot schedule all traffic demands, especially at high-traffic loads. In this paper, the BvN scheduling procedure is modified to efficiently schedule traffic in overlaid-star networks with multi-fiber/multi-wavelength architecture, called efficient BvN (EBvN). Instead of using one processor to schedule traffic on one wavelength channel in each core node, the proposed EBvN technique uses only one processor to schedule all traffic demands on all fibers/wavelength channels at the same time. Performance evaluation results under both uniform and non-uniform traffic distributions show that more traffic demands can be scheduled under EBvN compared with SBvN. In addition, the scheduling speed of EBvN is mostly faster than SBvN. Finally, EBvN can provide bound on the maximum scheduling time of EBvN. As a trade-off between scheduling time and residual traffic, EBvN with filling empty cells (EBvN_FEC) is proposed that can reduce residual traffic, but at the expense of slightly increasing scheduling time. EBvN_FEC is more effective than EBvN under non-uniform traffic distribution.