Every diver has felt the urge to speak underwater, but generations of divers have had to settle for a safety line connecting them to other divers. By tugging on the line they conveyed messages.
Will divers ever be able to speak to each other while engaging in underwater activity?
Two new Israeli developments are designed to enable underwater communication – by vocal means or by transferring written messages.
UTC can take credit for making one of the breakthroughs.
UTC has developed a two-way radio that is the basis for applications such as underwater speaking, underwater locating (by transmitting warning signals), and underwater transfer of written messages by beeper.
The applications employ a special software component. According to the company’s physicist CEO, Dr. Elazar Sonnenschein, the radio’s innovation is its ability to convey sound waves in an underwater medium (where sound wave dispersal is difficult) and decipher them. According to Dr. Sonnenschein, the device is intended for both military units and civilian divers. One of the communications systems allows the transfer of written texts from a ship to several divers simultaneously. Five thousand UTC diving kits were recently sold to civilian markets in China and the United States. In Israel the device underwent testing in commando units and was deemed operational.
Dr. Sonnenschein points out that the two-way radio’s new applications, which supply information on what’s happening underwater, can also be used to maintain offshore drilling rigs especially in view of the large-scale development expected in the coming years, given the recent discovery of vast gas reserves off the Israeli coastline.
The navy’s tests also include an underwater communications system called DeepLink that will enable the transfer of messages – especially written texts. DeepLink is a Low Probability of Intercept (LPI) acoustic communication network suitable for the Underwater Acoustic Channel (UWAC). According to Rafael, DeepLink’s dimensions enable it to be carried by divers or small underwater vehicles.
Using CDMA (Code Division Multiple Access) communication with MIMO (Multi-Input, Multi- Output) techniques, DeepLink overcomes the multi-path interferences of the UWAC, ensuring high reliability in various environments such as deep water, shallow water, and harbors. DeepLink is designed as an ad-hoc network and includes a multi-hop mechanism.
Its unique capabilities are the built-in message distribution protection and multihop mechanisms, which increase network reliability and connectivity between nodes, thus providing a solution for non-line-ofsight scenarios.
DeepLink supports both SMS and navigational control messages, allowing the user to create his own mission status. Each node contains a user interface which includes a virtual keyboard (for SMS writing), a navigation system, and network display