Fujitsu applies Discrete Multi-Tone for 100G optical transmission with 10G components

Fujitsu Laboratories Ltd. and Fujitsu Research and Development Center Co., Ltd. of China will present at OFC/NFOEC next week results from their work with applying Discrete Multi-Tone (DMT) – a common modulation/demodulation format in DSL networks – to optical transmission. The labs say use of DMT enables 100-Gbps transmission via optical components designed for 10-Gbps fiber-optic networks. The work provides a direction toward low-cost 400 Gigabit Ethernet devices, they say.

The technology will be demonstrated at the Fujitsu Optical Components Ltd. booth on the show floor.

DMT divides the data to be transmitted into multiple subcarriers (carrier waves). Multi-level modulation is used for each subcarrier to achieve high transmission speeds. To optimize each subcarrier's power and number of multiple values, Fujitsu engineers developed an algorithm that checks receiving conditions between optical transceivers at the time the system is started up and optimizes power and the number of multiple values to suit the transceivers and line conditions.

The approach enables module designers to use conventional 10-Gbps components to transmit 100-Gbps signals, the laboratories assert. If some components can’t maintain sufficient linearity, these components can be profiled in advance and compensated for, the labs explain.

Applying the technology to four channels would enable creation of a 400-Gbps Ethernet transceiver, the Fujitsu researchers add. An integrated DMT modem is “under consideration,” according to the Fujitsu team. Meanwhile, additional improvements for using existing technologies are underway.

For more information on optical transceivers and suppliers, visit the Lightwave Buyer’s Guide.