The use of light for information transmission can be said to have a long history, the "beacon tower" of the ancient times has let people experience the convenience of transmitting information through light. However, this primitive optical communication method is relatively backward; limited by the transmission distance visible to the naked eye, the reliability is not high. With the development of social information transmission, it further promotes the birth of modern optical communication.
In 1800, Alexander Graham Bell invented the "light telephone".
In 1966, a British-Chinese Charles Kao proposed the theory of optical fiber transmission, but the loss of optical fiber was as high as 1000dB/km.
In 1970, the research and development of quartz fiber and semiconductor laser technology reduced the fiber loss to 20dB/km with high laser intensity and high reliability.
In 1976, the continuous development of optical fiber technology reduced the loss to 0.47 dB/km, which meant the loss problem of transmission medium was solved, and promoted the vigorous development of optical transmission technology.
Enabling industry-wide innovative applications
China has been leading the world in the development of all-optical networks and continues to lead the development direction of the light industry. This leads to two generations of all-optical network development: all-optical network 1.0 era characterized by all-optical network and all-optical network 2.0 era characterized by all-optical automatic scheduling. With the opening of the commercial deployment of ROADM/OXC, 200G / 400G and optical network automatic control system by the three domestic operators, China has entered the all-optical network 2.0 era comprehensively, thus creating more possibilities for the incubation of innovative applications in the industry.
All-optical network is based on optical fiber medium transmission, with natural hard isolation attribute, is the highest security information transmission technology, not only can provide a guaranteed bandwidth rate, with ASON technology, support up to 99.999% security; Based on end-to-end all-optical network, one-hop direct wavelength can provide deterministic low delay guarantee, transmission delay up to microseconds; Based on optical network automatic control system, it supports minute-level business opening and realizes online self-management of business.
With the emergence of NG OTN (next generation OTN, the fifth generation) technology, it will lay a solid foundation for all-optical network to move towards thousands of lines. In December 2019, complete the next generation OTN technology industry standard approval project in China Communication Standardization Association (CCSA); In February 2020, China Mobile completed the industry's first NG OTN pilot network in Qingdao, Shandong Province; In May 2020, China Telecom took the lead in completing the m-SERVICE OTN prototype test, marking a milestone in the next generation OF OTN technology. This technology supports more business connections and higher network resource utilization, which can flexibly adapt to the on-demand carrying requirements of various emerging businesses.
As the cornerstone of the digital economy, the new infrastructure construction represented by all-Optical Network 2.0 will promote OTN to play a more important role in the new era and help the sustained and high-quality development of China's digital economy.
