JPH04104530A - Terminal station equipment for optical submarine cable system - Google Patents

Abstract

PURPOSE:To protect a line signal from overload trouble and to facilitate handling in the field by interposing optical fibers having a large loss characteristic between an optical fiber cable and an optical submarine cable. CONSTITUTION:Optical fibers 9 for connection which has a loss characteristic to attenuate an optical signal are interposed between an optical fiber cable 7 and an optical submarine cable 4. In this case, fibers 9 of large loss are arranged in a terminating device 3 which performs interface between the optical fiber cable 7 for intra-office wiring and the optical submarine cable 4 through a transmission terminal station equipment 2 which converts electrooptic signals of a lower-order group to a multiple signal, and the input level of a submarine repeater 6 is adjusted and set in consideration of the loss of the optical submarine cable 4, thereby preventing overload to the submarine repeater 6. Thus, the terminating device adjusts the level of the optical signal by optical fibers for connection whose large loss characteristic is several or more times as large as that of the normal optical fiber cable, and thereby, it is sufficient if optical fibers for connection are cut to a length corresponding to the required loss in a narrow storage space.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a terminal station device for an optical submarine cable system, and more particularly to a terminal station device for a submarine cable system that adjusts the level of an optical signal to be transmitted.

[Conventional technology]

Conventional terminal equipment for optical submarine cable systems consists of transmission terminal equipment that multiplexes, separates, and converts low-order optical and electrical signals, and cable termination equipment that terminates and distributes optical submarine cables. It transmits and receives optical signals to and from submarine repeaters via optical submarine cables. The maximum length of the optical cable is determined by the allowable optical transmission/reception signal level between the transmission terminal equipment and the submarine repeater. On the other hand, if this cable length is selected to have less than the specified loss, overload will occur at the input point of the submarine relay, the line side input point of the transmission terminal equipment, and the line side input point of the transmission terminal equipment. A fixed optical signal attenuator was inserted to prevent system failure due to overload.

[Problem to be solved by the invention]

In this conventional terminal equipment for optical submarine cable systems, the introduction of a fixed optical attenuator is difficult in terms of physical accommodation space and implementation due to its shape, and it is difficult to set the attenuation amount arbitrarily. In this case, it is necessary to prepare various types of fixed optical attenuators that are expected in advance, and even if a variable optical attenuator is used, the shape becomes thicker, which causes problems in terms of accommodation space and mounting.

[Means to solve the problem]

The terminal equipment for an optical cable system of the present invention includes a transmission terminal equipment that converts optical signals of a lower group into multiplexed signals, an optical fiber cable for intra-office wiring from the transmission terminal equipment, and an optical submarine cable from a submarine repeater. and a termination device for connecting the optical fiber cable and the optical submarine cable, and an optical fiber having a high loss characteristic is interposed between the optical fiber cable and the optical submarine cable.

〔Example〕

Next, FIG. 1, which describes the present invention with reference to the drawings, shows
FIG. 1 is a block diagram showing an embodiment of the present invention.

This embodiment includes a transmission terminal device 2 that converts optical signals of a lower group into multiplexed signals, an optical fiber cable 7 for intra-office wiring from the transmission terminal device 2, and an optical submarine cable 5 from a submarine repeater 6.
In the termination device 3 for connecting the optical fiber cable 7 and the optical submarine cable 5, a connecting optical fiber 9 having a loss characteristic that attenuates the optical signal as shown in FIG. 2 is interposed between the optical fiber cable 7 and the optical submarine cable 5.

In this way, the terminal bag W3 that interfaces the optical fiber cable 7 for intra-office wiring and the optical submarine cable 4 is connected to the terminal bag W3, which interfaces the optical fiber cable 7 for intra-office wiring and the optical submarine cable 4, through the transmission terminal equipment 2 that converts the electrical and optical signals of the lower group into multiplexed signals, as shown in FIG. By arranging the high-loss fiber 9 and adjusting and setting the input level of the submarine repeater 6 in consideration of the loss of the optical submarine cable 4, overload to the submarine repeater 6 can be prevented. In addition, the line signal regenerated by the submarine repeater 6 is transmitted via the submarine cable 4, interfaced with the optical fiber cable for intra-office wiring at the termination device 3, and connected to the transmission terminal device 2 having a signal conversion and separation function. , distributed to lower-level terminal equipment. In this case, the line signal can be protected from overload failure by adjusting and setting the high loss fiber 9 shown in FIG. 2 so that the light receiving level of the termination device 3 and the transmission terminal device 2 will not be overloaded.

〔Effect of the invention〕

As explained above, the present invention enables a termination device to adjust the level of an optical signal using a connecting optical fiber that has a high loss characteristic several times higher than that of a normal optical fiber cable. The effect is that it is convenient to handle on-site by simply cutting the connecting optical fiber to a length corresponding to the loss and connecting it.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a connecting optical fiber of this embodiment. ]... Terminal device, 2... Transmission terminal device, 3... Termination device, 4... Optical submarine cable, 5... Optical submarine cable, 6... Submarine repeater, 7... ... Optical fiber cable, 8... Optical fiber for connection.

Claims (1)

[Claims] a transmission terminal device that converts the optical signals of the lower group into multiplexed signals;
A termination device is provided for connecting an optical fiber cable for intra-office wiring from the transmission terminal device and an optical submarine cable from a submarine repeater, and an optical fiber with high loss characteristics is provided between the optical fiber cable and the optical submarine cable. An end station device for an optical submarine cable system characterized by intervening fiber.