S Savory

Adaptive Transceivers in Nonlinear Flexible Networks

The authors thank the UK EPSRC for their support through the UK EPSRC programme grant UNLOC, EP/J017582/1.

Throughput Gains From Adaptive Transceivers in Nonlinear Elastic Optical Networks

In this paper, we link the throughput gains, due to transceiver adaptation, in a point-to-point transmission link to the expected gains in a mesh network. We calculate the maximum network throughput for a given topology as we vary the length scale. We show that the expected gain in the network throughput due to transceiver adaptation is equivalent to the gain in a point-to-point link with a length equal to the mean length of the optical paths across the minimum network cut. We also consider upper and lower bounds on the variation of the gain in the network throughput due to transceiver adaptation, where integer-constrained channel bandwidth assignment and quantized adaptations are considered. This bounds the variability of results that can be expected and indicates why some networks can give apparently optimistic or pessimistic results. We confirm the results of previous authors that show finer quantization steps in the adaptive control lead to an increase in the throughput since the mean loss of throughput per transceiver is reduced. Finally, we consider the likely network advantage of digital nonlinear mitigation and show that a significant tradeoff occurs between the increase in the signal-to-noise ratio for larger mitigation bandwidths and the loss of throughput when routing fewer large-bandwidth superchannels.

Using 25 GbE client rates to access the gains of adaptive bit- and code-rate networking

For transmission within optical mesh networks, different signal routes acquire different impairments and are received with different signal-to-noise ratios (SNRs). The SNR can be utilized through adaptive bit- and code-rate modulation, which leads to data rates that are not multiples of the preferred 100 GbE client rate. This paper considers the use of slower 25 GbE lanes both with inverse multiplexed 100 GbE client rates and with native 25 GbE client rates and compares network blocking performance. The use of inverse multiplexed 100 GbE client data on four 25 GbE lanes accesses the lions share of stranded capacity within the network.