JPS61255134A - Two-way repeater - Google Patents

Abstract

PURPOSE:To decrease cost of a repeater by providing a switch circuit to input/ output terminals of two parallel amplifiers, selecting a normal amplifier when either of the amplifiers is faulty and changing over the switch circuit in time division to send PCM signal in two-ways. CONSTITUTION:The switch circuit 1 is arranged respectively to the input/output terminals of the amplifier 2 amplifying the PCM signal S1, the switch circuit 1 is arranged to the input/output terminals of the amplifier 2 amplifying the PCM signal S2 to constitute a repeater 5. If either of the amplifiers 2 is faulty, a terminal station sends a switching signal to the normal amplifier 2 to change over the switch circuit 1. Since the switch circuit 1 is switched alternately at each time interval (t), the PCM signals S1, S2 are sent in the direction of arrow by the amplifier 2 in time division.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a bidirectional repeater for transmitting PCM signals.

[Conventional technology]

In the conventional bidirectional repeater, as shown in FIG. 4, amplifiers 2 for repeating and amplifying PCM signals 81 and 82 are disposed on each of the forward and return paths to form one repeater 4. 3 is a communication cable.

[Problem that the invention seeks to solve]

The above-mentioned conventional repeater consists of one system with two amplifiers, so the repeater is expensive.
If an amplifier on either the outbound or return route becomes a failure, there is a drawback that the system will no longer function in communications that require simultaneous transmission and reception, such as in telephone communications.

[Means for Solving the Problems] The bidirectional repeater of the present invention selects a first amplifier and either an input end or an output end of the first amplifier and connects it to a first communication cable. a second switch circuit that selects either the input end or the output end of the first amplifier and connects it to a second communication cable; a second amplifier; a third switch circuit that selects either the input end or the output end of the amplifier and connects it to the third communication cable; and a fourth switch circuit that selects either the input end or the output end of the second amplifier and connects it to the third communication cable and a fourth switch circuit connected to the communication cable of 1ζ during normal operation, the PCM signal from the first communication cable is transmitted through the first switch circuit, the first amplifier, and the second switch circuit. PCM transmitted to the second communication cable and from the fourth communication cable.
A signal is transmitted to the third communication cable via the fourth switch circuit, a second amplifier, and a third switch circuit, and when any of the amplifiers fails, the first switch circuit.

The PCM signal is transmitted by switching the switch circuit connected to the normal one of the amplifiers in a time-sharing manner by a switching signal from a terminal station connected to any one of the second, third, and fourth communication cables. It is characterized in that the information is transmitted in both directions.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which switch circuits 1t-
A switch circuit 1 is also arranged at the input and output terminals of an amplifier 20 for amplifying the PCM signal S2, thereby forming a repeater 5. Reference number i3 is a communication cable. Normally, the switch circuits 1 are all connected as shown and have exactly the same function as a conventional bidirectional repeater, but if any of the amplifiers 2 becomes a failure, Normal amplifier 2
A switching signal is sent from the terminal station to the switch circuit l.
is switched as described below.

The circuit at this time is as shown in FIG. Since the switch circuit l is alternately switched every time interval t, the PC
The M signals 81 and 82 are time-divisionally transmitted by one amplifier 2 in the directions shown by solid and broken arrows in FIG. 1, respectively. Figure 4 shows the PCM on communication cable 3 in this case.
T indicates the time axis, and τ indicates the transmission speed of the PCM signal.

At this time, the transmission capacity is reduced by less than half tζ of the normal state, but it is possible to avoid disconnection of all of the transmission capacity of the system, and about half of the transmission capacity can be restored immediately.

[Effects of the invention] ・Go to 1 As explained above in 1, the present invention has the following features:
``r''・``a) Prices of repeaters and communication cables・
It has the effect of being able to immediately recover from a system failure in the event of an amplifier failure on either the outbound or return trip. In addition, during multi-system transmission, there are also effects such as division of transmission capacity, branching in the middle of a relay section, etc., increasing Vζ versatility.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a block diagram of an embodiment of the present invention. FIG. 813 is a block diagram and timing diagram showing the operation of FIG. 1, and FIG. 4 is a block diagram of a conventional example. 1... Switch circuit, 2... Mountain... amplifier, 3...
...Communication cable, 4.5...Repeater,
81.82...PCM signal, T...time axis. Mostly one person and two people

Claims (1)

[Claims] a first amplifier; a first switch circuit that selects either an input end or an output end of the first amplifier and connects it to a first communication cable; and an input end or an output end of the first amplifier; A second switch circuit which selects one of the ends and connects to the second communication cable, a second amplifier, and a third switch circuit which selects either the input end or the output end of the second amplifier. and a fourth switch circuit that selects either the input end or the output end of the second amplifier and connects it to the fourth communication cable, During normal operation, the PCM signal from the first communication cable is transmitted to the second communication cable via the first switch circuit, the first amplifier, and the second switch circuit, and from the fourth communication cable. transmits the PCM signal to the third communication cable via the fourth switch circuit, the second amplifier, and the third switch circuit, and when any of the amplifiers fails, the first, second, Transmitting the PCM signal in both directions by switching the switch circuit connected to the normal one of the amplifiers in a time-sharing manner by a switching signal from a terminal station connected to either the third or fourth communication cable. A two-way repeater characterized by: