In underwater communications research, significant advances have been made through testing of a new technology developed by Huawei. These innovations could redefine the standards for data transmission in the deep sea, while highlighting the strategic importance of these discoveries for China.
China has reportedly tested a polar code device from Huawei Technologies, which facilitates underwater communications.
In tests in the South China Sea, the People’s Liberation Army (PLA) transmitted a message 30 kilometers (18.6 miles) underwater using the communications equipment, according to Chinese media.
Scientists submerged a small hydrophone to a depth of 1,000 meters (3,280 feet) and successfully received signals from a ship, achieving a data transmission rate of 4,000 bits per second (bps).
The PLA conducted the experiments in collaboration with Xiamen University, which recently tested the new underwater data transmission system at an undisclosed location in the South China Sea.
Huawei’s Data Progress
Although extremely low frequency (ELF) radio waves can travel underwater, they transmit only a few characters of data per minute. Sound waves, on the other hand, travel faster, but transmitting data over long distances is complicated by intrusions from the sea floor, sea surface, and ocean currents.
In 2008, Turkish academic Erdal Arıkan introduced the polar code, an error correction technology. This allows for more reliable and accurate data transmission, especially when the signal quality is good.
Implementing this technology is proving to be complex. Huawei is among the few telecom companies that have advanced their networks using this method. A Chinese media outlet claims that the technology recently tested by Huawei sets new records for underwater acoustic communication devices.
According to the South China Morning Post (SCMP), China has already set a record for underwater data transmission in March 2022. Zhejiang University and the China State Shipbuilding Corporation conducted a test at 14 km (8.7 miles) with a rate of 3,000 bps.
Polar codes are widely used in 5G and consumer electronics, revolutionizing data transmission. Huawei’s wireless earphones using this technology achieve six times the data speed of the latest Bluetooth devices, with one-thirtieth lower latency, double the range, and 40% lower power consumption.
Advanced data transmission
NATO has designated China as a strategic focal point and is increasing its influence in Asia, raising concerns in Beijing. NATO’s current underwater communications protocol for submarines, JANUS, launched in 2017, allows communications up to 28 km (17.4 miles).
However, at this distance, the frequency of sound waves drops to 900Hz, limiting data transmission. JANUS uses Orthogonal Frequency Division Multiplexing (OFDM), which distributes data streams across multiple sound waves for fast short-distance transmission.
According to the SCMP, in China, OFDM is seen as obsolete due to its high power requirements, complexity, and limited performance over long distances. To overcome these limitations, a Chinese team has designed a new underwater communication system using High-Order Polarization Weight (HPW) coding, a method introduced by Huawei in 2017.
Unlike OFDM, HPW does not require data fragmentation and can encode information on a single carrier wave, reducing power consumption and device complexity. APL Unit 92150, based in Quanzhou, Fujian, collaborated with Professor Tong Feng’s team from the College of Marine and Earth Sciences at Xiamen University to develop this advanced system.
In tests, they achieved error-free data transmission over 30 km (18.6 miles) with frequencies ranging from 4,000Hz to 8,000Hz. The SCMP reports that the breakthrough, rooted in number theory, was published in the Chinese Journal of Acoustics in July and is part of a larger family of polar codes developed by Huawei.
