Optical Networking, Redefined.
March 7, 2016

OFDM Powers Next Gen Ethernet Speeds

Orthogonal Frequency-Division Multiplexing (OFDM) has long been a fixture in the wireless communications world. Now, with the unrelenting, explosive growth in demand for data capacity, OFDM is poised to take the stage to usher in the next generation of optical transmission speeds. Recently, researchers conducted a study where, for the first time, 560G was successfully transmitted over single-mode fiber at two kilometers. To reach that speed, 128-QAM modulation was used in a four-channel coarse wavelength division multiplexing (CWDM) configuration, each channel carrying 140G for a total of 560G. This is a significant development for the optical networking industry because it has the potential to help drive the impetus for 400G certification by the IEEE 802.3 400G Ethernet task force. Additionally, it could further boost the growth of the optical transceiver market, reported to grow to $9 billion according to MarketersMEDIA.com. It’s no wonder that OFDM would be the technology of choice, because unlike older, single-carrier technologies, its multi-carrier architecture allows for many data streams to be carried over a single fiber optic cable. This, in turn, provides for higher data transmission rates and greater data capacity; two capabilities that will a boon to data centers and Internet backbone connectivity. In the case of data centers, where server connectivity speed is key, OFDM does present a challenge. While its ability to carry multiple data streams does boost speed and capacity, this capability can cause poor inter-connectivity performance due to its high peak-to-average power ratio (PAPR). This is remedied by implementing Discrete Fourier Transform (DFT), coupled with pre-equalization, greatly reducing the PAPR. Want to know more? Contact us for expert advice on your current and future optical equipment needs.