China's submarine fiber optic cable starts here
Author/ IT Times reporter Qian Lifu
Editor/ Qian Lifu Sun Yan
On April 20, 1994, China opened the 64K international dedicated line, which was in line with the international Internet, and since then China has been officially recognized in the international community as a country with a full function of the Internet.
In the past 30 years, the Internet has rewritten almost everything, whether it is the pulse of the economy or social life. The prosperity and development of the Internet is inseparable from a "hero behind the scenes", which is the optical fiber cable hidden in the depths of the seabed, carrying about 99% of the world's intercontinental communication data traffic, making transoceanic communication instantaneous. Without submarine fiber optic cables, the Internet is just a local area network, and people around the world cannot be tightly connected.
On December 15, 1993, the China-Japan submarine optical fiber cable was officially opened and put into use, which was the first large-capacity submarine communication optical cable leading to the world in the mainland, providing a channel for the mainland to access the international Internet in the future. In contrast to the vigorous development of the Internet in the mainland, in the past 30 years, the communication capacity and construction capacity of the mainland's submarine optical fiber cable have made a huge leap, and at the same time, it is also witnessing the rapid development of China.
From the "sheep intestine trail" to the world
The China-Japan submarine optical fiber cable from Nanhui in Shanghai, China to Miyazaki, Kyushu, Japan, with a distance of 1,252 kilometers, is an international communication project signed by the General Administration of Telecommunications of the Ministry of Posts and Telecommunications of the mainland, KDD of Japan and AT&T of the United States in 1990. After two years and eight months of construction, it was officially completed and put into operation on December 15, 1993.
China's submarine fiber optic cable road started from here.
The China-Japan submarine fiber optic cable is an extremely important international communication line, which not only connects the communication between China and Japan, but also communicates with the world directly through the Pacific fiber optic cable system, and is mainly used for international long-distance telephone services and digital circuit services between China, Japan and the United States.
The total capacity of the China-Japan submarine fiber optic cable was 7,560 call lines (about 560 Mbps), which was more than 15 times that of the China-Japan submarine coaxial cable (with a capacity of 480 lines) opened in October 1976. The opening of the China-Japan submarine optical fiber cable increased China's international communication capacity by more than 80% at that time, creating good conditions for promoting Shanghai's economic revitalization and accelerating the development and opening up of Pudong.
Just as mobile communications have undergone iterative upgrades from 2G and 3G to 4G and 5G, the communication capabilities of submarine fiber optic cables have also improved rapidly over the past 30 years. The China-Japan submarine fiber optic cable, which opened in 1993, has a transmission capacity of only 560 Mbps, while the new trans-Pacific submarine cable NCP, which was completed and put into operation in 2018, has a design transmission capacity of more than 60 Tbps, which is 110,000 times that of the former.
The evolution of communication technology is never-ending, and the same is true for submarine cable systems. Chen Liang, deputy general manager and senior engineer of China Submarine Cable Construction Co., Ltd., said that with the development of wavelength division multiplexing and space division multiplexing technology, the single-wavelength rate of submarine cable transmission system is constantly improving. "Now, the submarine cable transmission capacity has reached the level of hundreds of Tbps. If the number of voice calls is still used as a reference, 100Tbps capacity can provide about 2.8 billion people to talk at the same time, compared to about 15,000 people at the same time. He said. From 15,000 to 2.8 billion or even higher, it can be seen that the communication capacity of submarine optical cables has improved rapidly.
While the communication capacity has been greatly improved, the number of submarine optical cables on the mainland is also increasing. By the end of 2023, the mainland has participated in the construction of 24 international submarine cable systems, invested in the construction of 17 active international, Hong Kong, Macao and Taiwan communication submarine cables, purchased or leased more than 30 international submarine cables, and built more than 230 overseas communication network nodes.
From "hand-in-hand" to underwater robots
To this day, an old photo published in the 1000th issue of Shanghai Telecom is still moving.
The photo truly records the scene of the construction of the Sino-Japanese submarine fiber optic cable 31 years ago: hundreds of people stood in the silt of the coastal tidal flats, with the scorching sun on their heads, holding hands and shoulders, pulling the submarine cable to the shore joint point little by little.
During the construction of the submarine fiber optic cable between China and Japan 31 years ago, there was a lack of advanced construction equipment, so hundreds of people could only carry the submarine cable hand in hand and shoulder and stand in the silt to pull the submarine cable to the shore joint point
At that time, because the tidal flats were full of silt, the cable laying boat ran aground 3 kilometers away from the shore joint, and at the same time, due to the lack of advanced construction machinery and equipment, it could only adopt the "soil method" and rely on the tactics of the sea of people to drag the submarine cable back to the shore, and finally succeeded after 20 hours of hard fighting. At that time, the report of the "Shanghai Telecom" newspaper recorded: "In order to help, they shouted the trumpet, and in this team, there are leaders with gray sideburns, thin cadres of organs, and even crew members and members of the engineering team......
The spirit of hard work has always inspired submarine cable builders, but the scene of hand-in-hand shoulders is a thing of the past. Nowadays, the mainland's submarine cable construction capacity and level have been greatly improved, and mechanization, automation and even intelligent operation have become the mainstream.
"Now when the fiber optic cable lands on the shore beach, it will no longer be 'hand-in-hand', but will be carried out by mechanized traction, and sometimes even by underwater directional drilling." Chen Liang said.
The navigator underwater robot displayed in China Submarine Cable Construction Co., Ltd. is the epitome of the rapid improvement of the level of submarine cable construction in mainland China in recent years. The Navigator underwater robot is a cutting-edge equipment for submarine cable construction independently developed and put into use in recent years, which has been assembled on the "Tianyi Marine" submarine cable construction ship, solving the problem of "stuck neck" in this field. After reaching the bottom of the sea, the navigator underwater robot can automatically search for the submarine cable, and then put down the burial knife to dig trenches, it is also equipped with manipulators, hydraulic tongs, etc., which can complete fine operations such as wet plugging and unplugging, and can also cut the submarine cable underwater for submarine cable repair.
Today, the Navigator underwater robot has been put into use, which is a cutting-edge equipment for submarine cable construction independently developed by China Telecom, which solves the problem of "stuck neck".
While the hard equipment and hard power are improving, the combat effectiveness of the construction team is also constantly improving, promoting the overall leap in the level of submarine cable communication construction in the mainland. "At the earliest, submarine cable construction basically relied on foreign submarine cable general contractors. At present, domestic basic telecommunications companies have carried out the whole process of international submarine cable construction as the leading party in the Asia-Pacific region. Domestic communication manufacturers have also made great progress in the production and manufacturing of optical fiber transmission equipment, submarine cable special equipment, and optical fiber and cable, and participated in the competition and implementation of international projects. Chen Liang said. At the same time, he said that it is still necessary to continuously increase the research of independent key core technologies in the field of submarine cables, strengthen the deployment of submarine cable ships, improve the level of submarine cable maintenance and support, and ensure the security of national marine information communication and data.
From envy to pride
China Telecom is the founder of the submarine cable industry in mainland China, and China Submarine Cable Construction Co., Ltd. is a wholly-owned subsidiary of China Telecom, which is a leading position in submarine cable construction, maintenance and design consulting in China. As an "old submarine cable man" who has been engaged in submarine cable construction for nearly 30 years, Chen Liang has the most personal experience of improving the communication capacity and construction level of submarine cables in mainland China.
In 1999, Chen Liang participated in the offshore construction of the Shanghai section of the first Io-Europe No. 3 international submarine fiber optic cable to Southeast Asia, the Middle East and Europe. At that time, the British large submarine cable construction ship completed more than 700 kilometers of offshore construction from Shanghai to Okinawa, Japan in 45 days. Looking at the advanced equipment on foreign construction ships and the advanced technology and management processes shown, Chen Liang was both envious and emotional.
Twenty years later, when the new Transpacific (NCP) international submarine fiber optic cable project was being built, he and his colleagues stood on their own construction boats and used their own advanced equipment to lay submarine cables. Now, the capacity of operating equipment and construction vessels has been greatly improved, and the operation area has moved from offshore to deep sea, and the fourth generation of deep-sea construction ships is also about to be built.
In the past 30 years, the mainland has built more and more submarine cables to reach the world and realize the interconnection of the world. For users, it is becoming more and more "insensitive", even if some submarine cables are interrupted due to earthquakes and other reasons, it will not affect users' use of the Internet. With the increase in the number of submarine cables, different submarine cables are backed up to each other, and the corresponding services can be switched instantaneously.
Submarine fiber optic cables have become the lifeblood of the global information economy, and as an "old submarine cable man", Chen Liang called on the public to protect the safety of submarine cables and ensure the provision of high-quality international communications and Internet services when carrying out marine development and production operations.