Global originality: Successful development of underwater cableless telephone technology

According to the website of the Ministry of Industry and Information Technology, recently, the scientific research team of Professor Qiao Gang of the School of Hydroacoustics of Harbin Engineering University successfully completed the national "863" plan project of "remote, vector, full-duplex hydroacoustic communication technology", invented the underwater multi-user, full-duplex acoustic communication method, and developed the world's first underwater acoustic communication machine with full-duplex communication capability and networking ability, which solved the problem that the transmission and reception could not work at the same time in the past underwater acoustic communication, and was a major technological progress in the field of underwater acoustic communication
。

Recently, researchers successfully realized two-way synchronous data transmission
with a distance of 5 kilometers in the experiment of the prototype.
This major technological breakthrough in the field of underwater acoustic communication means that in the future, underwater communication is expected to bid farewell to the "walkie-talkie" era and achieve the same experience
as making a phone call on land.

Because seawater has a strong absorption effect on radio waves, radio waves generally do not travel more than 100 meters underwater, while sound waves can travel thousands of kilometers
at a speed of 1.
5 kilometers per second underwater.
However, due to the limitations of the complex underwater environment and underwater acoustic channels, underwater acoustic communication lags far behind the current rapid development of radio communication in terms of quality, efficiency and networking capacity, and it is difficult to meet people's needs
for exploring the ocean and expanding underwater space.
At present, the equipment widely used in the field of underwater communication is divided into two types
: cableless and cabled.
The cableless communication equipment adopts half-duplex communication mode, and the call effect is similar to that of a walkie-talkie, and the two-way communication efficiency is low
.
Cabled devices enable full-duplex communication and can speak in both directions like a phone call, but the movement of the device is limited
by the cable.

The underwater acoustic communication technology conquered by Professor Qiao Gang's scientific research team can overcome the weaknesses of current underwater cable communication, greatly improve the flexibility and timeliness of obtaining data, and reduce risks and costs
.
At the same time, it is also an innovation and improvement
of the current cable-free half-duplex underwater communication equipment.
For the first time in the world, single-sensor underwater directional communication and dual-user communication are realized, which greatly improves network efficiency and information throughput, overcomes the problem of non-uniform Doppler compensation in ultra-wideband communication, and improves the stability of
underwater acoustic communication system.

Underwater acoustic communication is the only form of communication that can carry out remote information transmission underwater, and its own technical characteristics and unique advantages make it one of the important technologies in marine resources development and marine environment stereoscopic monitoring system, and has important application value
in marine technology and marine engineering, disaster prevention and environmental protection, navigation and other fields.

Underwater acoustic communication technology is one of the most cutting-edge technologies in the field of marine high-tech today, but due to the sensitivity and great application value of underwater acoustic communication technology, foreign countries have long listed it as a high-tech product prohibited from exporting to China, and it is still strictly controlled
.
In the early 90s of last century, China's 863 Project delegation visited France, and once when Chinese experts talked about underwater acoustic communication technology, the French claimed that "everything can be discussed, but underwater acoustic communication cannot be discussed
.
" ”

The Institute of Acoustics of the Chinese Academy of Sciences has previously developed a hydroacoustic communication system
for the "Jiaolong" deep submersible.
The scientific research achievements of the Kazakhstan project have undoubtedly made China make leaps and bounds in
the field of hydroacoustic communication.