The growing demand for cloud-based applications and the use of new technologies like AI, machine learning, and AR/VR drive the need for upgrades to high-capacity, fast, and efficient 100G networks and place higher requirements on the optical transmission system. Solutions with high performance and reliability are required to realize the upgrade of the optical transmission network. Driven by powerful demand, 100G coherent DWDM has gradually developed and matured, providing an effective solution for 100G long-distance optical transmission.
Coherent DWDM Technologies for 100G Optical Transmission
The combination of coherent key technologies, including advanced modulation (QPSK/QAM), coherent detection, and digital signal processing (DSP), represents the state of the art in efficient DWDM transmission. The coherent DWDM technology enables DWDM networks to transform from 10G per DWDM channel to 100G per DWDM channel, which helps upgrade existing 10G/40G networks to 100G Ethernet for higher bandwidth and spectrum utilization.
In addition to increasing optical channel capacity, 100G coherent DWDM technologies can be used to deliver cost-effective and highly reliable 100G optical transport. The higher-order modulation can provide higher data rates within a given transmission bandwidth, which represents higher bandwidth utilization. Coherent detection offers the advantages of high sensitivity, great tolerance toward optical impairments, and high spectral efficiency. Digital signal processing allows coherent transceivers to compensate for signal distortion caused by fiber dispersion, polarization mode dispersion, and carrier phase noise at little cost. Besides, 100G DWDM technology provides a cost-effective solution for long-distance backbone networks, which can transport 100G data rate capacity over a single wavelength across long distances with high optical performance.
In short, coherent DWDM technologies can create a more advanced and sophisticated optical transmission system for high-speed and high-capacity 100G transmission.
100G Coherent DWDM Solution
With leading-edge coherent DWDM technologies, the 100G coherent DWDM solution has gradually matured, including 100G coherent optical modules and OTN transport equipment. As shown in the figure below, coherent modules connected with a transponder/muxponder enable 100G transmission over ultra-long distances, supported by Mux/Demux, EDFA, and other devices.
Mux/Demux connects seamlessly with transponder, muxponder, and amplifier, forming a cost-effective and high-capacity DWDM tailored solution.
Transponder/Muxponder enables a smooth transition from 10G/40G to 100G client interfaces and allows flexibility and scalability for fiber optic connectivity in WDM networks.
EDFA and Raman amplifiers are used for optical signal amplification and fiber loss compensation, allowing for regional and long-distance point-to-point connectivity.
The 100G coherent DWDM solution is mainly used in line-side optical transmission of 100G WDM system and is suitable for metro, regional and long-haul applications.
Benefits of 100G Coherent DWDM Solution
The 100G coherent DWDM solution has become a preferred choice for many application scenarios because of its obvious advantages, as follows.
Long Haul: Support 100G optical transmission even over distances up to 1000km.
High Bandwidth: The combination of coherent detection and DSP technique can compensate for various fiber transmission impairments and simplify link transmission, thus enabling larger bandwidth.
Seamless Upgrade: Enable seamless upgrade of long-haul optical transmission systems from 10G/40G networks to 100G Ethernet without changing the original infrastructure.
Cost-effectiveness: Provide better OSNR performance and sensitivity, as well as better DGD and dispersion tolerance than other line-side optical modules.
The Closing Thought
The 100G coherent DWDM solution is a cost-effective solution to accommodate the current and future needs of bandwidth-demanding cloud-based applications. This solution is widely recognized by industry and has been massively deployed.
