Connection Provisioning in QoT-Guaranteed Distributed All-Optical Networks

As an optical signal propagates along a lightpath to its destination in wavelength-routed optical networks (WRONs), the quality of transmission (QoT) is degraded by transmission impairments such as crosstalk and amplified spontaneous emission noise. Consequently, the signal’s bit error rate at the destination’s receiver can become unacceptably high. Recently, many BER-aware connection provisioning algorithms have been proposed that incorporate physical layer impairments in terms of increased blocking rate from the BER constraint. However, they have a high computational complexity compared to traditional connection provisioning schemes because of the complexity of BER estimation. The delay involved in the computation greatly affects the performance in distributed networks because the latency worsens the contention and makes instantaneous network status impossible to obtain. In this paper, distributed connection provisioning schemes are compared using two BER estimation procedures and several wavelength assignment algorithms. Simulation results show the effects of delay in connection provisioning and measure the performance in terms of blocking probability.