Since 1990, the world has invested a cumulative total of more than $50 billion in laying submarine cables. The total length has reached more than 1.4 million kilometers, which could circle the globe 35 times. In addition, bandwidth usage has increased by 40 percent annually over the past five years.
In an era of rapid global information development, submarine Internet cables carry 98% of international bandwidth.
The number of Internet users is currently growing at a compound annual growth rate of over 22%. At the same time, bandwidth usage per user is growing at a compound annual growth rate of 20%. And total bandwidth usage is growing at a CAGR of more than 50%.
With the rise of 5G commercialization, 4K/8K video, data centers, cloud services, IoT and Big Data, the world is in the midst of a wave of digital transformation and bandwidth demand will continue to grow.
Submarine Internet cables show three main development trends.
Submarine cable system
1. The greatest demand for submarine cables (cables transoceánicos con fibras) in the last decade has been for higher capacity. Therefore, the pursuit of higher single-wave rate and higher single-fiber pair capacity is the trend of development. The current single-wave rate can reach more than 200G, and the single-fiber pair capacity can reach 25.6T. while the future single-wave rate will develop towards 400G and 1T.
2. As the demand for bandwidth increases, the number of fiber pairs in the submarine cable system has grown from 2 pairs to the current 16 pairs. In the future, it will move toward 32 pairs of fibers and 64 pairs of fibers under development.
3. Submarine cables must accommodate longer transmission distances. Trans-Pacific submarine cables, for example, can now cover transmission distances of up to 16,000 kilometers.
4. Submarine network connectivity will evolve toward greater flexibility. From the early days of point-to-point transmission, submarine Internet cable systems have evolved to today's wavelength-tunable OADM bifurcation based on WSS equipment.
Manufacturing of submarine cable
1. With the increase in the number of fiber pairs, it is necessary to improve the cable formation process and, at the same time, increase the number of fiber pairs in the original cable structure. This is the only way to guarantee the quality of the transmission signal.
2. Since the voltage of the rely submarine cable will increase from 15kV to 20kV, which poses new requirements for insulation reliability. Therefore, it is necessary to innovate in insulation materials, extrusion processes and insulation layer thicknesses.
3. The cost and manufacturing capacity of submarine cables must be further optimized. On the one hand, process changes can be made on the basis of existing processes. On the other hand, changes in the overall process can be achieved through technological innovation.
Fiber optic cable
In the past, fiber optic submarine cables used hybrid fiber links that required dispersion management and dispersion slope. With the advent of coherent transmission technology, single-mode fiber (fibra de monomodo) is increasingly used in submarine fiber optic cable networks.
The demand for single-mode fiber in submarine fiber optic cables is lower attenuation and larger effective area. The future trend of submarine fiber optic cable will be multimode to singlemode, including multicore fiber and few-mode fiber.