Akiya Suzuki

First system demonstration of hitless λ-tuning sequence for dynamic wavelength allocation in WDM/TDM-PON

We propose hitless wavelength-tuning sequence for dynamic wavelength allocation in WDM/TDM-PONs and demonstrate highly frequent wavelength-tunings in 100-ms intervals without data-frame loss using MAC boards. Pay-as-you-grow operation based on the proposed sequence is also shown.

Demonstration of Load-Balancing Operation Based on Hitless Dynamic Wavelength Allocation on Symmetric 40-Gbit/s λ-Tunable WDM/TDM-PON

This paper reports the world-first system-level demonstration of dynamic wavelength allocation (DWA) on a wavelength-tunable (λ-tunable) wavelength division multiplexing/time division multiplexing-passive optical network (WDM/TDM-PON). To achieve DWA, a DWA calculation is necessary that determines new optical network unit assignments to the optical line terminal ports according to the bandwidth demand. In addition, a wavelength-tuning (λ-tuning) sequence that induces no data-frame loss, i.e., a hitless λ-tuning sequence, is essential. First, we propose a bidirectional hitless λ-tuning sequence and investigate its feasibility using media access control boards that we developed for symmetric 40-Gbit/s λ-tunable WDM/TDM-PONs, which are also the worlds first. Then, with a DWA calculation according to the downstream traffic loads, we show automatic dynamic load-balancing operation.

Scalability of a hitless λ-tuning sequence to upstream transmission at dynamic wavelength allocation in WDM/TDM-PON [invited]

This paper clarifies the scalability of the hitless wavelength-tuning (λ-tuning) sequence for dynamic wavelength allocation (DWA) on a λ-tunable wavelength-division-multiplexing/time-division-multiplexing passive optical network (WDM/TDM-PON). The λ-tuning that induces no data-frame loss, i.e., hitless λ-tuning, is essential in DWA. We derive requirements to prevent two types of upstream data-frame loss that the λ-tuning causes. To clarify the scalability of the hitless λ-tuning sequence against system parameters, we theoretically analyze the maximum input data rate to the optical network units (ONUs) to achieve λ-tuning without upstream data-frame loss while varying values for buffer size and λ-tuning time of the transceivers in ONUs and the DWA cycle. Then, using media access control boards that we developed for symmetric 40 Gbit/s λ-tunable WDM/TDM-PONs, we demonstrate hitless λ-tuning and confirm the validity of the theoretical analysis.