As the most important cornerstone of the network, the optical fibre cable technology is also accelerating the pace of development in the context of the continuous evolution and upgrading of the optical transmission network. At present, in order to meet the need for the deployment of the over 100G network, such as the 400G network, the optical fibre is evolving towards the large effective area and ultra-low loss. Furthermore, with the implementation of the "Broadband China" strategy, the construction of the optical network city is carried out fully, and more FTTx deployment need-oriented optical fibers/cables emerge. The in-depth coverage of the 4G network and the vigorous development of the data center also bring new opportunities to the optical fibre/cable industry. We can see that China's optical fibre/cable industry is facing a new round of development under the impetus of the market and technology, and the innovation of the optical fibre/cable technology also lays the foundation for accelerating the application of the ICT technology to all walks of life.

The rapid surge of the data flow promotes the continuous upgrading of the optical transmission network from the previous 40g a few years ago to the currently deployed 100g on a large scale, and to the future-oriented 400g and 1T WDM network, and the continuous improvement of the optical transmission network performance is promoting the industry to break through the performance bottleneck of the existing optical fibre technology and research and develop the new optical fibre technology that is suitable for the super 100G era. ITU-T will issue the G.654.E optical fibre standard in September, 2016, which will pave the way for the large-scale development of the 400G network with large effective area and low/ultra-low loss in future.

At present, China Unicom launches the pilot demonstration of the existing 400G network based on the G.654.E optical fibre, to assess its transmission performance and environmental adaptability, which lays the foundation for the introduction of the G.654.E optical fibre over the high-speed backbone transmission network in future. At this point, the reporter of the People's Posts and Telecommunications newspaper interviews Wang Guangquan, the director of Network Technology Research Department, China Unicom Network Technology Institute and Zhou Qinmin, the Strategy & Marketing Manager of YOFC.

Consensus on Application of G.654.E Optical Fibre

Wang Guangquan simply and directly clarifies the context of the G.654.E optical fibre that the existing G.652 optical fibre network cannot meet the requirement of the future optical transport network for the ultra-high speed, ultra-large capacity and ultra-long distance transmission, and the industry expects to introduce the new optical fibre technology to support the implementation of the over 100G network technologies, such as the 400G and 1T network technologies. He states that the G.654 optical fibre was applied in the submarine cable previously, and its standard is composed of part A, B, C and D. At present, the industry reaches a consensus on the land application of the G.654 optical fibre to adapt to the deployment of over 100G system, and ITU-T is formulating the G.654.E standard, which will be issued in September, 2016.

Zhou Qinmin states that a large number of validation data demonstrates that the existing modulation/demodulation and signal processing technology (even the G.652 optical fibre with the ultra-low loss) cannot effectively meet the requirements for the ultra-long distance transmission without the relay at the 400G or higher rate. Hence, it is essential to the new optical fibre. YOFC began to conduct the R&D work of relevant technology in 2010, cooperated with relevant institutes to complete the first single wavelength T-bit real time transmission test worldwide by the “Yuanbei” single mode optical fibre with the low loss and large effective area in 2013, and delivered the international paper in 2014. Subsequently, YOFC together Chinese Unicom Network Institute completes the transmission test of the single wavelength 100G network. A large number of theoretical and experimental data demonstrates that this type of optical fibers can provide the powerful transmission performance over the high speed transmission system compared to other communication optical fibre. YOFC released the “Super Yuanbei” single mode optical fibre with the ultra-low loss and large effective area whose performance is improved greatly, during the OFC conference, USA in April, 2015. Hence, YOFC became the first domestic and the third international manufacturer of the optical fibre products with the large effective area and ultra-low loss and the unique domestic enterprise which masters the optical fibre technology with the ultra-low loss, which fills the domestic gap.

Wang Guangquan thinks that the key issues on the deployment of the 400G network is mainly to balance the spectrum efficiency, transmission distance, system capacity and cost under the Shannon limit. At present, three are major trends for the development of the optical fibre technology. Of which, the first one is the optical fibre with the low/ultra-low loss, the second one is the optical fibre with the large effective area, and the third one is the optical fibre with the large effective area and low/ultra-low loss. The domestic manufacturers basically select the development path of the optical fibre with the large effective area and low/ultra-low loss, namely, the new optical fibre - G.654.E.

Zhou Qinmin thinks that the optical fibre with the large effective area and low/ultra-low loss is one-step process. The G.654.E optical fibre with the large effective area and low/ultra-low loss is the best choice of the 400G/1T system for it can provide excellent macro bending and micro bending properties under certain conditions, to meet the requirements for the deployment in the complex environment.

Orderly Development of China Unicom 400G Network Demonstration

Wang Guangquan states that China Unicom upholds the cautious and scientific attitude to introduce the G.654.E optical fibre and conducts the laboratory and the pilot demonstration of existing network step by step for the construction period and service life is long and the investment is large for the optical fibre cable. China Unicom demonstrated the transmission performance of the G.654.E optical fibre based on the 100G commercial platform in 2014. The test result indicates that the G.654.E optical fibre can extend the optical transmission distance by 70% - 100% compared to the traditional G.652 optical fibre. In order to assess the transmission performance and environmental adaptability of the G.654.E optical fibre, China Unicom conducted the pilot demonstration of existing network in the east and west respectively in 2015 and carried out the further test over the 400G system recently. He states the facts proved that it is the most suitable time to promote the pilot demonstration of the existing G.654.E optical fibre over the 400G system at the present time node for the whole optical fibre/cable industry chain has accumulated relevant technologies, and China Unicom will share the test result of the pilot demonstration of existing network with its industry counterparts, to promote the innovative development of the whole optical communication industry.

At present, several manufacturers participate in the existing network pilot demonstration of the China Unicom G.654.E, including YOFC. Zhou Qinmin expresses that YOFC actively participated in the pilot demonstration of the existing G.654.E network of China Unicom and provided both the single mode optical fibre with the low loss and large effective area and the single mode optical fibre with the ultra-low loss and large effective area exclusively since 2015. Furthermore, it sets up a special technical team according to the need of the pilot demonstration of existing network, to follow up the whole process, and actively cooperate with China Unicom to promote the land use of the G.654.E optical fibre worldwide for the first time. YOFC also participates in the establishment of the G.654.E international standard and submits relevant manuscripts to ITU. China Unicom leads to promote the establishment of the CCSA G.654.E industry standards at the end of 2015, and YOFC actively submits manuscripts and makes it contribution as the leader of fibre optic enterprise leaders.

The emergence of new optical fibre is both the opportunity and the challenge for the industry. From the perspective of Wang Guangquan, the introduction of the G.654.E optical fibre is expected to provide strong support for the 400G, 1T and higher rate optical transmission in future, to promote the rapid upgrading of optical backbone network. However, this is also a challenge for operators, and the construction of the optical fibre network cannot start from scratch for the service life of the laid optical fibre is usually 20 – 30 years. Hence, the G.654.E optical fibre shall be introduced on the basis of the scientific, rigorous, repeated demonstration. He reveals that China Unicom will collect the test data of the 400G system continuously, and compare with the performance difference between the G.654 optical fibre and the G.652 optical fibre, to demonstrate the best incidence optical power of the optical fibre, so as to demonstrate the transmission performance improvement of the G.654 optical fibre.

In addition to the optical fibre/cable manufacturer, various major mainstream system equipment manufacturers also participate in the pilot demonstration of existing 400G network of China Unicom. Wang Guangquan sums up that the technical development needs to be supported by the entire industry, and it can implement the technical breakthrough and bring the scale application only when various links of the industrial chain join hands at the end of the interview. He expresses that China Unicom will uphold the open and win-win attitude and share its test result of the existing network demonstration with its industry counterparts, and expect more manufacturers to participate in it, to lay a solid foundation for the advent of the 400G era. Zhou Qinmin states that YOFC will increase the R&D efforts of the G.654.E optical fibre continuously and share its latest technologies and products with its industry counterparts, to provide the power support for the pilot demonstration of the existing 400G network and the large-scale deployment in future.