RU2445733C2 - Submarine digital fibre-optic cable communication system - Google Patents

Abstract

FIELD: information technology.

SUBSTANCE: system comprises coastal stations and branching stations fitted with mutichannel communication equipment connected to each other by a main cable. The line channel of the system uses submarine optical amplifiers and couplers with low-power hydroacoustic stations inside housings, and hydroacoustic transceivers of submarine objects and vessels allow enable to lower the amplifiers or couplers on a conducting rope to the required depth over a point lying at the sea bottom, and transmitting an identification code signal to begin communication.

EFFECT: design of a network communication structure with lower electrical energy consumption and power supply, while increasing reliability and longevity of the communication system.

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Description

The invention relates to the field of electrical engineering, namely to wire communication technology and can be used to organize communication between underwater objects (PO) at great depths, as well as ships and coastal control points.

It is known that, along with the subsystems of energy, navigation, etc., on each software and vessel there are subsystems for communication of the collection and exchange of information.

All subsystems of software and vessels are connected with their communication subsystems, which are the main links connecting ship captains with superior officers and play a crucial role in ensuring coherence of actions.

Successful completion of the task to a large extent depends on the availability of timely and sufficient information. This software information, as a rule, is obtained from coastal control points via radio channels of radio communications SDV and ELF, KB, SV and DV ranges.

Analogue (Soloviev V.I., Novak L.I., Morozov I.D. Communication at sea. - L.: Shipbuilding, 1978, Communication system with software, pp. 144, 204).

To communicate with the software in the underwater position, heavy-duty (up to 2000 kW) coastal SDV and VLF transmitting radio centers (MPCs) are used. The main element of these MPAPs are antenna complexes containing tens of kilometers of antenna-feeder lines. The power supply of the MPC is provided by diesel power plants with a capacity of up to 12,000 kW. The cost of each such center is about $ 70 million.

The disadvantages of the analogue are the low reliability and survivability of the coastal antenna-feeder lines SDV, ELF PDRTS, as well as their high cost.

The prototype of the claimed system is a "System of underwater cable deep-sea communication with software." Katanovich A.A. et al. Patent RU 2260249 C2 of July 14, 2003, class. HB04 10/16, 13/02.

The submarine cable communication system contains two coastal endpoints, between which an underwater trunk cable is laid along the seabed, optical repeaters are connected through certain lengths, from them on short cable sections, at the ends, floating underwater sonar stations are fixed. Optical transceiver stations are installed on the coastal terminals of the system, with the help of which information signals are transmitted through the optical fibers of the cable. Remote supply of underwater optical repeaters and underwater sonar stations is carried out from coastal terminals through a copper tube, which is an element of the design of an underwater optical cable.

The disadvantages of the prototype are that the types of gas emitters emit high power signals, up to several thousand watts, into the region of the sphere by 360 °.

The operation of such gas-powered generators requires the consumption of significant power supply, complicates the equipment, and increases the size of the gas-stove.

The aim of the invention is to expand the functionality of underwater cable communication systems by creating two-way sonar communication channels, with reduced signal radiation power.

This goal is achieved by the fact that in a system containing coastal terminals, between which an underwater trunk cable is laid along the seabed, optical repeaters are connected through certain lengths, from them floating underwater sonar stations are fixed on short cable ends at the ends, while on the coastal terminals points of the system are installed transceiver stations of the optical range, with which information signals are transmitted via an optical cable, and remote power e underwater optical repeaters and underwater sonar stations are carried out from coastal terminals through a copper tube, which is an element of the design of the underwater optical cable, the system additionally has underwater line amplifiers and couplers, and the sonar stations are located inside the cases of underwater amplifiers and couplers, for communication ships are equipped with small-sized low-noise sonar stations, lowered from the board into the water on a cable-cable with using the winch to the desired depth.

This principle of building the system allows you to get away from the phenomenon when the boundaries of the underwater layers of water with sharp changes in temperature or density difference prevent the sonar signal from passing in the right direction, which can disrupt communication between individual vessels and make it impossible.

The position with the range of the transmission level has significant difficulties. It is necessary to take into account the differences in the transmission capacities of hydroacoustic signals and the dependence on the communication range. Up to several thousand watts of power may be required for the transmission of gas.

As you know, when receiving a hydroacoustic signal at different distances from the emitter, the signal intensity changes in accordance with the ratio:

where R is the distance, km;

I _o - the intensity of acoustic vibrations at the point of their occurrence, W;

β = 0,036 f ^3/2 - sound absorption in water, dB / km;

f is the frequency, kHz.

The limiting values of the intensities of the received signals can be considered intensities at distances of 0.1 and 50 km. From relation (1) we have the ratio of the intensities of the received signals for f = 2 kHz (worst case) J _{c, 01} / J _{s, 50} ≈75 · 10 ⁴ , which corresponds to 59 dB.

If we add to this value the dynamic range of the emitted signal (of the order of 10–20 dB), then it becomes clear that the amplifier must be included in the receiving path of hydroacoustic signals with automatic gain control to a depth of about 60–80 dB.

In the proposed system, the distance between the transmitting HAS and the receiving HAS

can be reduced from 0 to several meters or less, which eliminates the problems described above.

Figure 1 shows a functional diagram of a submarine cable digital optical fiber communication system and the general principle of implementing communication options between it, software, surface vessels and coastal points (PS), where:

1 - cable of the main optical communication line;

2 - underwater object (ON) - underwater vehicle, submarine, etc .;

3 - surface ship;

4 - linear underwater amplifier (LPU) with a hydroacoustic station (GAS);

5 - linear underwater coupler (LPO) with sonar station (GAS);

6 - branch cable from the main highway to an intermediate coastal point;

7 - sonar transceiver (GLP);

8 - cable cable;

9 - radiation beams from the gas and gas compressor;

Figure 2 shows a block diagram of the passage of optical information signals between the software, the vessel and coastal launchers, where:

10 - coastal points (BP) A, B, C, D with complexes of channel-forming equipment;

11 is a block connecting optical fibers (OV) and remote power supplied through a copper tube of a linear cable;

12 - converter digital signal to the GAS for transmission;

13 - amplifier GAS signal transmission;

14 - converter GAS to a digital signal at the reception;

15 - amplifier of the received digital signal;

16 - reflector (emitter / receiver) of GAS signals;

17 - equipment for remote supply of medical facilities and gas;

18 - equipment for monitoring the status of the cable line;

19 - equipment for monitoring the quality of communication channels;

20 - transmission equipment;

21 - receiving equipment;

22 - equipment for digital grouping of communication channels;

23 - a hardware complex for displaying the status of communication channels and the state of the cable line;

Blocks 11-15 are the hardware parts of MPI 4 and LPO5, which perform the tasks of transmitting and receiving information on the optical fibers of the cable line.

The transmitting part (blocks 11, 12, 13, 16) removes the digital transmission signals from a specific optical fiber (OB), converts them into a GAS-shape, which is amplified and supplied to the reflector 16 and then into the water by a narrow beam 9 up.

The receiving part (blocks 16, 14, 15, 11) removes the GAS signal from the reflector, converts it to digital form, amplifies and feeds it into the optical signal, determined for receiving information signals of the cable line, which are received on BP10, PO2 or vessel 3.

Low-power sonar stations lowered from the board of PO2 or vessel 3 on a cable cable 8 are similar in principle to their construction and operation.

The system operates as follows.

To get in touch, the software 2 or surface vessel 3 approaches the location point of the nearest medical facility 4 or medical facility 5, becomes above it, and is held in automatic positioning mode. From aboard software 2 using a winch on a cable cable 8 lower the sonar transceiver (GLP) 7 to the desired depth and signal a password. After identifying a friend / foe signal at the main coastal transceiver station 10, a specific channel is allocated for communication and a connection is established with the calling vessel and, if necessary, between the required vessels.

The main BP 10 has data on the location of PO 2 and ships 3 in the region where the submarine cable communication system is located and has the ability and technical means to organize ship-to-ship, ship-PO, PO-ship communications.

The coordinates of the location points on the seabed of the cable communication line, LPU4 and LPO5 are known with an accuracy of ± 2 meters, they are recorded using navigation systems during the laying of the cable of the communication line.

In constant mode, the communication system operates on reception, listening to the underwater environment. Information signals generated at the BP10, PO2 or ship 3 transceiver stations on the coast are converted from digital to GAS or vice versa, transmitted and received through the optical cores of a linear trunk cable, mutually processed in the hardware of LPU4, LPO 5 and optionally converted to telegraph or telephone view.

Each PSU has a complex of channel-forming equipment 17-23, with the help of which remote power supply is provided to medical facilities and medical facilities 17, digitalization of signals from analog or telegraphic form of communication channels 22, exchange of information for transmission 20 and reception 21, monitoring of cable operability, its optical and electrical parameters 18-19, which are displayed on the screen of monitors 23.

In the information transfer path, an analog (voice) or telegraph signal is converted into a digital form, which is transmitted in the OB of the cable of the linear path.

In the receiving path, the signal received via the OB of the linear cable is digitally amplified to the desired level, converted into analog form and sent to the desired telephone or telegraph communication channel. The number of OBs in the cable can be different, from 4 or more.

The effectiveness of the proposed system lies in the fact that the system provides the ability to create two-way hydroacoustic communication with a low signal radiation power, while significantly reducing the power consumption and power supply of the HAS, reducing the likelihood of damage during construction and increasing the reliability and durability of the system as a whole.

Claims (1)

An underwater cable digital fiber-optic communication system containing coastal end points, between which an underwater trunk cable is laid along the seabed, optical repeaters are connected through certain lengths, from them floating underwater sonar stations are fixed on short cable ends at the ends, while on the coast end points of the system are installed transceiver stations of the optical range, with which information signals are transmitted via an optical cable, and Underwater optical transponders and underwater sonar stations are supplied with power from coastal terminals through a copper tube, which is an element of the construction of the underwater optical cable, characterized in that the system additionally has underwater linear couplers containing each transducer of a digital signal to a sonar signal for transmission with an amplifier this signal, as well as the signal converter of the hydroacoustic station into a digital signal received from the amplifier m this signal, the sonar station located inside housings submarine amplifiers and couplers, while for small-sized vessels are equipped with low-power communication hydroacoustic stations are omitted from the board in the water-in cable via winch cable to the desired depth.

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