JPH04266226A - Data transmission system - Google Patents

Abstract

PURPOSE:To recognize a signal path in a terminal-section duplicated transmission line and to facilitate the maintenance by inserting an index signal representing the signal path to a transmission signal. CONSTITUTION:Each of terminal equipments A, B is provided with a 1st index insertion circuit 301 inserting an index signal representing a signal via an active line to a transmission signal sent to the active line, a 2nd index insertion circuit 302 inserting an index signal representing a signal via a standby line to a transmission signal sent to the standby line and a detection means detecting the index signal from a reception signal, and also a deciding circuit 501 deciding the index signal detected by the detection means 401 is whether the index signal representing a signal via the active line or the index signal representing a signal via the standby line. That is, the index signal representing a terminal section with the signal passed therethrough is inserted to a transmission signal from the terminal equipment and the reception side extracts the index signal to recognize the path through which is received signal passes.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operating system detection system for a duplex terminal section transmission line.

0002

[Prior Art] A method of duplicating terminal sections is known as one of the methods of improving the reliability of a transmission path. In particular, when the terminal side and the network side monitor each received signal and detect a failure, , a method is known in which the operating systems are switched independently. FIG. 2 is a block diagram of a conventional configuration example, and shows, as an example, a configuration in which the terminal section on the terminal device A side and the terminal section on the terminal device B side are duplicated. In the figure, a basic line interface circuit 101 is a means for sending a transmission signal to a basic line and passing a received signal received from the basic line to a selection circuit 202. The protection line interface circuit 102 is a means for sending a transmission signal to the protection line and passing the received signal received from the protection line to the selection circuit 202. Selection circuit 20
2 is means for selecting either the received signal received from the basic line interface circuit 101 or the received signal received from the protection line interface circuit 102. On the other hand, a selection circuit 201 in the network is a means for selecting either the transmission signal via the basic line in the terminal section or the transmission signal via the protection line and passing it to the relay section. In the figure, when transmitting data DA from terminal device A to terminal device B, data DA is first input to the basic line interface circuit 101 and protection line interface circuit 102 of terminal device A, and is transmitted to the basic line and protection line, respectively. Sent out. Next, the selection circuit 201 in the network selects either the data DA via the basic line in the terminal section or the data DA via the protection line and passes it to the relay section. The relay section passes the data DA to both the basic line and the protection line of the terminal section on the terminal device B side. In terminal device B, data DA via the basic line is sent to the basic line interface circuit 101.
and passes the data DA via the protection line to the selection circuit 202 and the protection line interface circuit 102.
and passes it to the selection circuit 202. Selection circuit 202
selects either the data DA received from the basic line interface circuit 101 or the data DA received from the protection line interface circuit 102. The case where the data DB is transmitted from the terminal device B to the terminal device A is also similar to the above.

0003

However, in this conventional method, the selection circuit 202 in the terminal device and the selection circuit 201 in the network perform switching operations independently, so the transmission signal and the reception signal are separated from each other. It may go through a line,
The disadvantage is that the terminal cannot recognize this.

SUMMARY OF THE INVENTION The present invention aims to eliminate such drawbacks, and aims to provide a data transmission system that allows a receiving terminal device to recognize the route taken by a received signal.

[0005]

[Means for Solving the Problems] The present invention provides a first interface circuit connected to a basic line, a second interface circuit connected to a protection line, and a an opposing terminal device equipped with a first selection circuit that selects one of the received signals; a first section connected to the first interface circuit and the second interface circuit of the own terminal device; a second selection circuit that selects one of the transmission signals passing through the two interface circuits; and a second selection circuit that selects one of the transmission signals passing through the second interface circuit; In a data transmission system configured with a terminal section duplex transmission line having two sections, the terminal device inserts an indicator signal indicating that the signal is transmitted via the basic line into the transmission signal sent to the basic line. a second index insertion circuit that inserts an index signal indicating that the signal is transmitted via the backup line into the transmission signal sent to the protection line; a detection means that detects the indicator signal from the received signal; A determination circuit that determines whether the index signal detected by the detection means is an index signal indicating that the signal is transmitted via the basic line or an index signal indicating that the signal is routed via the protection line. shall be.

[0006]

[Operation] An index signal indicating the terminal section through which the signal passes is inserted into the transmission signal from the terminal device, and the receiving side extracts this index signal to recognize the route through which the received signal has passed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of this embodiment,
As an example, a configuration is shown in which the terminal section on the terminal device A side and the terminal section on the terminal device B side are duplicated. As shown in FIG. 1, this embodiment includes a basic line index insertion circuit 301 which is a means for inserting an indicator signal Sn indicating that the signal is transmitted via the basic line into the transmission signal and passing it to the basic line interface circuit 101; A protection line index insertion circuit 3 is a means for inserting an index signal Se indicating that the signal is via a protection line into the signal and passing it to the protection line interface circuit 102.
02, the basic line interface circuit 101 which is a means for sending the transmission signal received from the basic line index insertion circuit 301 to the basic line and passing the received signal received from the basic line to the selection circuit 202, and the preliminary line index insertion circuit 302. sends the transmission signal received from to the backup line,
a protection line interface circuit 102 which is a means for passing the received signal received from the protection line to the selection circuit 202;
A selection circuit 202 is a means for selecting either the received signal received from the basic line interface circuit 101 or the received signal received from the protection line interface circuit 102, and an index signal Sx is generated from the received signal selected by the selection circuit 202. A detection circuit 401 serving as a detection means and an index signal S detected by the detection circuit 401
Indicator signal Sn indicating that x is a signal via the basic line
A determination circuit 50 is a means for determining whether the signal is a signal sent via a backup line or an indicator signal Se indicating that the signal is transmitted via a protection line.
1.

That is, as shown in FIG. 1, this embodiment includes a basic line interface circuit 101 connected to the basic line, a protection line interface circuit 102 connected to the protection line, and this basic line interface circuit 101 or this Protection line interface circuit 10
A selection circuit 20 that selects one of the received signals passing through
2, and a first section connected to the basic line interface circuit 101 and the protection line interface circuit 102 of the terminal device A (B), respectively, and this basic line interface circuit 10.
1 or a selection circuit 201 that selects one of the transmission signals passing through the backup line interface circuit 102;
and a terminal section duplex transmission line having a second section between the terminal through which the transmission signal selected by this selection circuit 201 passes and the first section related to the other party's terminal device B (A). In the data transmission method, terminal devices A and B have a basic line indicator insertion circuit 301 that inserts an indicator signal indicating that the signal is sent via the basic line into the transmission signal sent to the basic line, and a basic line indicator insertion circuit 301 that sends the signal to the protection line. A protection line indicator insertion circuit 302 that inserts an indicator signal indicating that the signal is transmitted via a protection line into a transmitted signal, a detection means 401 that detects an indicator signal from a received signal, and this detection means 40.
Determination circuit 501 that determines whether the index signal detected in step 1 is an index signal indicating that the signal is transmitted via the basic line or an index signal indicating that the signal is routed via the protection line.
Equipped with.

Next, the operation of this embodiment will be explained. When transmitting data DA from terminal device A to terminal device B, data DA is first input to basic line index insertion circuit 301 and protection line index insertion circuit 302 . The data DA input to the basic line index insertion circuit 301 has an index signal Sn indicating that the signal is transmitted via the basic line inserted therein, and is sent to the basic line via the basic line interface circuit 101. Data DA input to backup line index insertion circuit 302
An index signal Se indicating that the signal is transmitted via the protection line is inserted, and the signal is sent to the protection line via the protection line interface circuit 102. Next, the selection circuit 201 in the network selects either the transmission signal DA+Sn via the basic line in the terminal section or the transmission signal DA+Se via the protection line and passes the transmission signal DA+Sx to the relay section. The relay section passes the transmission signal DA+Sx to both the basic line and protection line of the terminal section on the terminal device B side. In terminal device B, the received signal DA+Sx via the basic line is received by the basic line interface circuit 101 and passed to the selection circuit 202 , and the received signal DA+Sx via the protection line is received by the protection line interface circuit 102 and passed to the selection circuit 202 .
pass it on to The selection circuit 202 selects either the received signal DA+Sx received from the basic line interface circuit 101 or the received signal DA+Sx received from the protection line interface circuit 102. The detection circuit 401 detects the index signal Sx from the received signal DA+Sx selected by the selection circuit 202, and the determination circuit 5
01, it is determined whether this indicator Sx is an indicator signal Sn indicating that the signal is via the basic line or an indicator signal indicating that the signal is via the protection line. This makes it possible to determine whether the terminal section on the terminal device A side is operating on either the basic line or the protection line. The case where the data DB is transmitted from the terminal device B to the terminal device A is also similar to the above.

0010

As described above, the present invention has the advantage of being able to access devices outside the route that can determine whether the selection circuit within the network is selecting the basic line or the protection line.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a block configuration diagram showing the configuration of a conventional example.

[Explanation of symbols]

101 Basic line interface circuit 102
Protection line interface circuits 201, 202 Selection circuit 301 Basic line index insertion circuit 302 Protection line index insertion circuit 401 Detection circuit 501 Judgment circuit

Claims (1)

[Claims] Claim 1: A first interface circuit connected to the basic line, a second interface circuit connected to the protection line, and a second interface circuit for selecting one of the received signals via the first interface circuit or the second interface circuit. An opposing terminal device equipped with a selection circuit, a first section connected to the first interface circuit and the second interface circuit of the own terminal device, and a transmission signal passing through the first interface circuit or the second interface circuit. and a second section between the terminal through which the transmission signal selected by the second selection circuit passes and the first section related to the terminal device of the other party. In the data transmission method, the terminal device includes a first indicator insertion circuit that inserts an indicator signal indicating that the signal is transmitted via the basic line into the transmission signal sent to the basic line, and a first indicator insertion circuit that inserts an indicator signal indicating that the signal is transmitted via the basic line; a second indicator insertion circuit that inserts an indicator signal indicating that the signal is transmitted via the backup line into the transmission signal sent to the line; a detection unit that detects the indicator signal from the received signal; and an indicator signal detected by the detection unit. 1. A data transmission system comprising: a determination circuit for determining whether the signal is an index signal indicating that the signal is transmitted via a basic line or an index signal indicating that the signal is transmitted via a protection line.