JPS6247232A - Line switching system - Google Patents

Abstract

PURPOSE:To control various high switchings by modulating a subcarrier by a code signal in the transmission side to transmit switching control information and discriminating normality of a line with the code signal detected by demodulation of said information in the reception side to perform required switching control. CONSTITUTION:A pattern detector DETP (205-P) checks whether the received code signal has a prescribed pattern or not, and it judges that a stand-by system is normal if the code signal has the prescribed pattern. If a trouble occurs in a current system No.1 and a pattern detector DET1 (205-1) does not detect the prescribed code signal to detect this trouble, the trouble of the system No.1 is reported from the reception side through another route. Then, a changeover switch SW1A (105-1) is switched in the transmission side. In the reception side, a changeover switch SW1B (203-1) is switched because the pattern detector DETP (205-P) receives a pattern of a pattern generator PGP (106-P), and a changeover switch SW1C (204-2) is switched to a stand-by line. Thus, switching from the current system to the stand-by system is completed.

Description

[Detailed Description of the Invention] [Table of Contents] Overview Industrial Application Fields Conventional Technology Problems to be Solved by the Invention Example of a One-Step Action to Solve the Problems First Example (Fig. 2) - Fig. 11) Second embodiment (Fig. 12 - Fig. 14) Third embodiment (Fig. 15 - Fig. 18) Fourth embodiment (Fig. 19) Fifth embodiment (Fig. 19) (Figures 20 to 23) Sixth embodiment (Figure 24) Effects of the invention C Company Summary: In a communication system using a route backup method, the subcarrier is modulated with a code signal and transmitted from the transmission example of each line. At the same time, the modulated signal received on the receiving side of each line is modulated by iM to detect the code signal, and by detecting this signal, it is determined whether the line is normal and the necessary control is performed. Since it has been made possible to perform various kinds of high-level switching control, it becomes possible to perform various types of switching control.

C. Industrial Application Field] The present invention relates to a method for switching lines, and in particular to a system for switching lines, and in particular to a method for switching between an N-channel working line, one to one, and two to an M-channel prefacility line. In the Ko1 method,
t) relates to a line switching system that can perform advanced IJJ switching control by exchanging a lino switching control signal obtained by modulating the sub-1ull transmission wave with a two-to-one signal.

In the route reservation method 18 and 2, a large number of lines, for example, N
(N is an integer) A protection line of 1 or M channels is provided for each working line of the channel, and the line is ensured by switching to the protection line in the event of a failure of the working line.

In such a route reserve formula, the working line and child (I
There is a demand for a company that can perform line switching with the N line as high as possible (311).

((Technology from ID) Conventionally, as a line switching system that is different from the route backup system, for example, Predetermined lap/!!
! By transmitting the number ``ll1lL,'' it detects that the protection line is vacant and switches to the protection line.

[Problem that the invention seeks to solve]

However, with this method, although it is possible to switch to the protection system by detecting a pilot signal, the difference between the bi-four-1- signal sent to the protection line and the pie-1]tsu-1- signal sent to the working line. Since both use the same signal, there is a problem in that it is not possible to detect whether or not the active system J2 has been successfully replaced by the backup system J2 based on the received pilot signal.

Furthermore, when a television signal is temporarily transmitted using a protection line (occasional old TV), it becomes impossible to monitor the status of the protection line.

rMeans to solve the problem〕 FIG. 1 shows the basic configuration of the present invention.

Fig. 1 fa number 1, I shows the first invention, 100 is a code signal transmitting means which modulates the sub Ill transmission wave with the yaw signal, combines it with the main signal and sends it out, It will be established in

200 is a signal receiving means which performs IM modulation on the received subcarrier modulated wave and detects the signal, and is provided in the reception/!11 of each line.

2) - By detecting the code signal, it is determined whether the line is normal (that is, the signal assigned to each active line is correctly received by the receiving system corresponding to the transmitting side, and there is no error). Perform IJ change control as required.

FIG. 1tb) shows the second invention, and 100 is a code signal transmitting means which modifies the subcarrier with a code signal, combines it with the main signal and sends it out, and transmits the signal on each line. installed on the side.

200 is a code signal receiving means, which performs iM modulation on the received subcarrier modulated wave to detect a two-to-one signal; 300 is a bit error rate measuring means, which measures the pip error rate of the received signal; These numbers are assigned to the receiving side of each line.

Based on the detection of this code signal, the total A111 error rate, and the error rate, it is determined whether the line is normal or not, and necessary connection/J change control is performed.

[For production]

Sub-Il! by the 2-1 signal on the sending side! Modulate the transmitted wave and switch all HilJ information, the receiving side transmits this to ij2 #l
) Detection 1 to Tool 1: Since the normality of the line is determined based on the signal and necessary switching control is performed, it is possible to perform various advanced switching controls. At this time, by measuring the hit error rate of the received signal and determining it simultaneously with the code signal, it is possible to more reliably determine whether the line is normal.

〔Example〕

[First Embodiment] FIG. 2 is a diagram showing the configuration of an embodiment of the line switching system of the present invention. In the same figure, TP]A, TP2A, -
, TPNA each have a multiplexed Hesbun[-signal input terminal<Iot-1,]]ot-2. -101-N
), each connected to a multiplexer (not shown), for example. TPIB, TP2B, -, TPN
B are multiplexed base-hough 1-signal output terminals (201-1, 201-2, -, 201-N), each of which is connected to, for example, a demultiplexer (not shown). Terminal TPI 8 (101-1) and terminal TPI
B (20L] ), terminal TP28 (101-2)
and terminal TP2B (201-2) lIN, -, terminal TIIN8 (101-N) and terminal TPNB (20
+-N) are positive 1 system, No, 2 system, ~, II, respectively.
k1. An N-system working voice multiplex line is formed, and each group has the same configuration. For example, in the Ml system, the terminal TPIA
The multiplexed audio input from (101-1) is sent to a synthesis circuit 111A (102-1).

Transmitter TXT via branch circuit 111B (103-1>
(104-1) and is converted into, for example, a microwave signal and transmitted.
) receives this, demodulates it and plays the multiplexed audio,
Switching switch-f-5hlc (2 (M-1) t [Te end PTP] Send from R (20+-1). Other active system 1
'i, 2. The same applies to −, positive, and N. Also, the synthesis circuit 11P (102-P), the transmitter TKP
(xo4-p > , receiving unit RXr' (202-P)
constitutes a standby system, and selector switch 5WIA (105-
1) and 5WIB(203-] ), 5W2A (
105-2) and 5W2B (203-2>).

-, 5WNA (105-N) and swNB (203-N)
By switching the current system NO, l,
tt, 2. -, &, N in parallel, so that in the event of a failure in each working system, the baseband signal of that working system can be transmitted via the protection system.

Each active system Na, '1, depression 2, -, tooth N is a pattern generator PCI (]]06-]), PG, respectively.
2 (106-2'), -, PGN (106-N
>, and each generates a code signal (system code signal) with a different pattern.

These code signals are respectively modulated by the modulator MODI (10
7-1), MO+11 (107-2), -,
MODN (107-N) is added to modulate the secondary IRQ transmitter, modulated by the respective code? ! I
! Generates modulated waves. These signals are respectively synthesized by circuit] 118 (102-1), ++2^ (102-2)
, -, IN8 (102-N), and is added to the base band signal of each system and sent out.

On the receiving side, each receiving unit RXI (202-
1> , llX2 (202-2> , -, RXN'
Demodulate the (202-N > ] output, extract the code signal, and send it to the pattern detector + [TI (2o5-+ >
, IIET2 <2a5-2'> , -, DETN(
205-N) and also checks whether it has a defined pattern for the system. As a result, each receiving section RXI (202-1'), RX2 (202
-2>.

-., RXN (202-N) determines that the system is normal only when receiving a normal pattern, and outputs the respective base band signals to the output terminals. Similarly, in the backup system, the pattern generator PGP (+06-P
>, a code signal having a unique pattern is generated, and a modulator MODP (107-P) modulates the subcarrier to generate a modulated wave. This signal is synthesized by the synthesis circuit I
P (102-P) to the transmitter TXP (104-P
) on the receiving side. XP(
202-P) to extract the two-node signal. Pattern detector D [! TP (205-P
) checks whether the received code signal has a predetermined pattern or not, and when the pattern is normal, it is determined that the backup system is normal.

For example, if the working tooth 1 has a fault and the pattern detector DET+ (205-1) detects this by not detecting a predetermined code signal, the receiving side will notify the tooth 1 fault through another route. As a result, the changeover switch s old^(]'05-1) is switched on the transmitting side. On the receiving side, a pattern detector I'IETP (2
05-P) Cover 7 Generator PGP (106-
P ) (7) Upon receiving the pattern, the changeover switch 5WIB (203-1) is changed over, and then the changeover switch SC (204-2) is changed over to the backup line. This completes the switching operation from active to standby.

In the previous explanation, the system codes of the current groups are all different, but in special cases they may all be the same.

FIG. 3 shows each pattern generator PCI (10
6-1), PG2 (106-2), -, l"
GN (106-N), PGP (+06-P)
This shows an example of the configuration. In the figure, a general code section 1 is set with a code consisting of a fixed pattern by operating a switch, for example. The latch section 2 reads out this pattern frame by frame in accordance with the frame timing signal from the frame timing generation section 3 and holds it as a parallel signal. Output as . The clock generating section 5 is necessary for the operation of the frame timing generating section 3 and the parallel/serial converting section 4 and supplies a lock.

Note that pattern generation is not limited to the method shown in Figure 3.
For example, a predetermined pattern may be registered in a read-only memory (ROM) and then read out to generate the pattern.

Further, in the configuration example shown in FIG. 3, a clock generator is provided for each pattern generator, but as shown in FIG. 4, each pattern generator PG1 (106-1), PG2
(+06-2), ---, PGN (106
-N), a juicing section 6 may be provided at the same time.

Furthermore, even when a clock generation section is provided in common for each pattern generator as shown in FIG. The pattern generators may be operated by their respective built-in clock sources in the event of a link source failure.

Further, instead of generating the code signal alone, modulation may be performed by combining other data and a code-signal pattern.

5 to 7 show each modulator 1 old (
107-1), MO+12 (107-2), -
j MOnN (107-N), gate ODP (1
07-P) is shown. FIG. 5 illustrates a case where FSK modulation is performed. The code signal from the pattern generator passes through a low-pass filter 11, removes noise, is amplified as required by an amplifier 2, and is applied to a modulator 13 to generate, for example, a binary FSK signal. arise. This signal further passes through a bandpass filter 14 to extract a signal in a predetermined band to generate a modulated wave output.

FIG. 6 shows a case where P and SK modulation is performed.

The code signal from the pattern generator is passed through a low pass filter 1.
1 to remove noise, the amplifier 12 performs the necessary amplification, and the signal is added to the balanced modulator 15 to generate the sub! By modulating the AI1 transmission, a binary FSK signal is generated, for example. This signal further passes through a bandpass filter 14 to extract a signal in a predetermined band to generate a modulated wave output.

FIG. 7 shows a case where ASK modulation is performed. The code signal from the pattern generator is passed through a low pass filter 11
After noise is removed through the amplifier 12, the signal is amplified as required, and is applied to the switching section 17 to switch the subcarrier from the subcarrier generator 16, thereby generating an ASK signal. This signal further passes through a bandpass filter 14 to extract a signal in a predetermined band to generate a modulated wave output.

FIGS. 8 to 10 show each receiving section RXI (2) in FIG.
02-1), RX2 (202-2)'+ -, RXN
(202-N) and RXP (202-P). FIG. 8 illustrates a case where a binary FSK signal is demodulated. The modulated wave input passes through a bandpass filter 21 to be band-limited, and after being subjected to amplitude limitation in a limiter 22, FM detection is performed in a discriminator 23 to generate a demodulated signal, which is passed through a low-pass filter 24 to an identification reproducing circuit 25. added to. In the clock regeneration circuit 26, the demodulated signal is differentiated in a differentiating circuit 27, and after passing through a bandpass filter for 2 days to limit the band, a predetermined amplification is performed through an amplifier 29 to regenerate the clock of the input signal. This clock identifies the demodulated signal and recovers the original code to produce data output.

FIG. 9 shows a case where a binary PSK signal is demodulated. The modulated wave input is band-limited through a bandpass filter 31 and input to a phase detector 32 . On the other hand, the output of the bandpass filter 31 is 2i! It is multiplied by 2 in the ai multiplier 33, passed through a bandpass filter 34, limited to 411 bands, and then output to the amplifier 3.
After passing through a frequency divider 36 and receiving a predetermined amplification, the subcarrier component is re-divided by 2. In the phase detector 32, the modulated wave is A demodulated signal is generated by phase detection.

After unnecessary components are removed from the tM tone signal in a low-pass filter 37, the discriminator 38 identifies it by a constant darkness value and outputs a binary signal 1-7, and this signal is used for code regeneration M
Added to 39. On the other hand, the clock regeneration circuit 40 regenerates the clock of the code signal using the output signal of the discriminator 38, and the three code regeneration circuits 41z regenerate the original code using this clock and the output signal of the discriminator 38, and output the data. occurs.

FIG. 10 shows a case where an ASK signal is demodulated. The modulated wave is band-limited through a bandpass filter 41 and applied to a detector 42 where it is envelope-detected to produce a demodulated signal. The demodulated signal passes through a low-pass filter 43 to remove unnecessary components, and then is applied to an identification and reproducing circuit 44. The clock regeneration circuit 45 regenerates the input signal from the clock signal, identifies the tM tone signal, regenerates the original code, and outputs the data. Live.

FIG. 1I shows the pattern detector D [MiT+ (205-1
), DVT2 (205-2), -, DP, T
N (205,, N'), nIjTP (20
5-P) shows a configuration example. The data output generated in the demodulator is passed through the serial/parallel converter 48 for synchronization detection 1nl l? Each synchronization signal from 849 is converted to a jiff string signal, and -7f! It is added to the I detection cycle 1185o. A predetermined code signal 1 is preset in the code setting section 51, and the coincidence detection circuit 50 compares the code set for each synchronization signal with the input parallel signal, and generates an output signal when they match. do. At this time, the four synchronization detection circuits perform synchronization detection from data input and clock input,
A synchronization signal is output for each frame J.

The protection circuit 52 performs a predetermined protection operation based on the output signal of the coincidence detection circuit 50 and the peer signal, and generates a line monitoring output η indicating that the line is normal. The protective operation in the protection circuit 52 prevents the reception from occurring due to a slight hit error.
- This is to prevent a failure from being immediately determined even if a discrepancy occurs between the front and back, and forward protection and rear protection are performed respectively.

In the embodiment described above, only the configuration and operation when switching from active to standby were explained, but it is possible to perform the switch in the same way when switching from standby to active. It has become.

[Second Embodiment] FIG. 12 shows the configuration of a second embodiment of the line J length system of the present invention. In the same figure, the same parts as in FIG. 2 are indicated by the same symbols, and Ill: PI
(30+-1) ,)it! 172 (30j-2)
,-,BERN (301-N), BEIiP
(301-P) is an error rate detector.

In the embodiment shown in FIG. 12, in addition to the operation that is superior to the embodiment shown in FIG. It is equipped with a secondary
As in the embodiment shown in the figure, at the same time as the code signal is detected, the pick error rate of the received signal is checked, and switching and restoration are performed only when the line quality of the system to which switching is to be made is good. I set it to 1 δ.

FIG. 13 shows an example of the configuration of an error rate detection circuit, and shows a case where a parity check method is used. In the figure, ta+ indicates the configuration of the transmitting side, and a counter 55 counts the number of bits in the data input and creates a parity hit to be inserted at the end of the frame. Figure 13(b) shows an example of a frame structure, and shows that a parity bit A is inserted at the end of a frame consisting of multiple bits of data. In addition, in FIG. 13 (C1 shows the configuration of the receiving side, the counter 57 counts the data input for each frame according to the frame signal, the parity signal G, The parity check circuit 58 outputs a parity check signal by checking the corresponding bit of the data input when there is an output signal of the counter 57, and calculates the error rate from this and performs the above-mentioned process. Performs J change control.

FIG. 14 shows a case where the error rate is detected by error detection of the code signal.

The code 1- of the system is preset in the code setting section 59, and is outputted in parallel. On the other hand, the synchronization detection circuit 60 detects and outputs a frame synchronization signal from the data input and clock input. ! In response to the frame synchronization signal, the 1-to-serial conversion circuit 61 converts the code signal into a serial signal and outputs it, and the -number output circuit 62 detects a match between this signal and the data input, and when they match, The counter 63 counts the output of the coincidence detection circuit for each frame synchronization signal to determine the bit error rate, and performs the above-mentioned switching control based on this.

[Third Embodiment] FIG. 15 shows the configuration of a third embodiment of the present invention, and the same parts as in the embodiment of FIG. 2 are designated by the same symbols. , CG (+08-1, 108-2
CD (206) is a pattern detector IIFTP <205' ) is a channel code detector having a similar configuration.

In FIG. 15, channel code generator CG (206
) generates different channel codes depending on the Qi tunnel to be transmitted. For example, when the No. 1 system is switched to the protection line, this channel code F is multiplexed and synthesized with the system code ' generated by the pattern generator PCI (106-1>) of the active line No. 1, and is modulated. It is added to the receiver MOIII (107-1) and sent out as a modulated wave, and is sent to the receiver MOIII (202-P) of the protection line.
) and demodulated. pattern detector ii
The ETP (205-P) detects the system T1-1ξ, switches between active and standby, and controls the system T1-1ξ (Natsu 111), but the output CD (20
6) detects the channel code, and changes the circuit configuration by switching the circuit constants in the pre-m line.

When performing multi-channel transmission, for example, the emphasis characteristics, frequency characteristics, or levels may differ depending on the channel, so it is necessary to change the de-emphasis characteristics for each channel in the reception example. However, according to this embodiment, when switching from the working line to the protection line, the By specifying changes in circuit constants on the transmitting side using channel codes, the circuit configuration can be changed according to the characteristics of the line.

FIG. 16 shows an example of the configuration of the de-emphasis circuit in the protection line. 60 is a (M modulator, which demodulates the input of the protection line and generates a demodulated signal. 61,
62 is a switching circuit, which is a channel code detector CD.
can be switched synchronously according to the channel code output. 63-1 to 63-4 are de-emphasis circuits (DRMP) for 600 channels, 960 channels, television, and 1800 channels, respectively.

FIG. 17 shows an example of the configuration of the channel code 1 and the detection section. In the figure, 65 is a synchronization detection circuit 111, which generates a frame synchronization signal from data input and clock input. The serial/parallel conversion circuit 66 receives data input.
When the frame synchronization signal is generated, it is converted into a parallel signal and output. A code command circuit 67 detects various codes from this output and outputs them as a thousand-tunnel switching signal.

FIG. 18 shows an example of a channel code. By combining the 3-bit signals as shown in the figure, for TV, for 600 channels, for 960 channels,
It is shown that the de-emphasis circuits for 1200 channels and 1800 channels are selected.

[Fourth Embodiment] FIG. 19 shows the configuration of a fourth embodiment of the present invention. In the same figure, the same parts as in FIG. The code generator CD (206) is a channel code detector having a similar configuration to the pattern detector DETP ('205-P).

In FIG. 19, channel code generator CGP (1
08-P) generates a channel code 1'', which is passed through the pattern generator pGP (106-P).
It is combined with the system code 1- generated by P), applied to the modulator MOIIP (107-P), sent out as a modulated wave, and received by the receiver RXP (202-P).

The pattern detector IIHTP (205-P) detects the system code and switches between active and standby as described above.
Although the recovery is controlled, the channel code detector Cr1 (
206) detects the channel code and thereby indicates the usage status of the protection line at its receiving end.

In the route backup method, when all working lines are normal,
For example, a protection line is used to transmit television signals or audio signals, and when a failure occurs in the working line, the protection line is switched over to the working line. According to the embodiment shown in FIG. 19, information indicating the type of signal being transmitted on the protection line' can be sent to the protection line at the same time, and therefore the operational status of the protection line can be monitored. As an example of such a channel code, for example, when using a 5-hit signal for the channel code, 2 bits are used for this purpose, ``11'' is used for free line, and ``01'' is used for free spare TV signal transmission. , "10°" can be allocated to free spare voice signal transmission, and the remaining 3 bits can be used to send channel capacity information. Using this channel capacity information, the circuit configuration shown in FIG. 16 can be changed to configure a line corresponding to each transmission channel.

Furthermore, the method of the present invention can also be applied to the purpose of monitoring by transmitting information indicating the reception full state to the sending side. When Zunawara line switching is performed, if a fault is discovered in that line, processing such as sending-end parallelization is performed, but
In such a case, an instruction can be sent back from the receiving side to the sending side by modulating the subcarrier using a code to perform switching control. An example of such a case will be described below.

[Fifth example] FIG. 20 shows a fifth embodiment of the present invention.

In the figure, only the upstream working floor 1 line and protection line, and the downlink current, working floor 1 line and protection line are shown in the communication system consisting of an uplink line and a downlink line provided between terminal stations A and B. , the same parts as in Fig. 2 are shown with [J at the end of the uplink and D at the end of the downlink, and TPIAII (101-
Ill), -'fP1flrl (101-Ill
)-Basepant signal input terminal, TPl, B11 (
201-Ill).

-, rl to T-th (201-ID), , - is Heath hand signal output terminal, 5G11 (109-U)
, 5GII (109-11) are uplink and downlink switching signal generators, and 5DILI (207-10
> , - is the uplink working line switching signal detection unit, 5DPU
(,2Q7-pH) is the uplink protection line switching signal detection unit;
5DIO (207-]+11, -- is a downlink working line switching signal detection unit, 5IIPD (207-PD) is a downlink protection line switching signal detection unit, Sl?U (20B-U
) and SRD (20B-D) are uplink and downlink switching command receiving units, respectively.

In the system shown in FIG. 20, if a fault occurs in the uplink working line N[11, for example, the switching signal generating unit SGD (109-11) at terminal station B sends, for example, -JN, as information indicating the status of the receiving side. The current No. code ~ indicating the 1 line sending end parallel command is the switching signal generator 5GII (109
, D ) and the pattern generator PGID (10
6-In> together with the pattern of the system code is applied to the modulator MOrl111, (107-jD), thereby generating a modulated subcarrier to the synthesis circuit +11Arl (102-Ill).

It is sent out via the branch circuit old BD (103-][+1.Receiving unit RXID (202-In
) connected to the switching signal detection unit 511111 (207
-111) and downlink protection line receiving unit RXPD
Switching signal detection unit 5IIP connected to (202-PD)
D (207-PD) detects this code and notifies the detection result to the downlink switching command receiving unit SRD (20B-+1) as channel switching control information. Switching command receiving section SI? Based on this, rl (208-D) determines whether the sending end parallel command has been generated for the current m1 line, and switches the switch 5W for the line at terminal A.
Switch the IAU (105-III) to the protection line side and make the sending ends parallel. As a result, the signal of the pattern generator PGIU (106-10) of the uplink No. 1 line is sent to the uplink 1lki1 line and the -1- protection line.

Pattern detector DETPI+ (205-PHI) connected to the receiving section RXPI+ (202-PI) of the protection line
> detects this code, terminal station B determines that the uplink protection line has been successfully connected, and communication will thereafter be performed via this protection line.

Figure 21 shows the switching signal generator SGI+ (109-1)
', 5Grl (109-D). In the figure, a code setting section 71 is configured to set a code consisting of a certain pattern by, for example, a switch operation. The latch section 72 reads this pattern together with the switching signal for each frame in response to the frame timing signal from the frame timing generation section 73 and holds it as a parallel signal, and the parallel-to-serial conversion section 74 converts this into a serial signal. and output as a pattern signal. The clock generating section 75 is necessary for the operation of the frame timing generating section 73 and the parallel/serial converting section 74 and supplies a lock.

FIG. 22 shows an example of the configuration of a switching signal, and shows that a three-hit code is assigned to each unit in response to a command indicating sending end parallelism and switching standby. 23 shows the switching signal detection section 5DIII' (207
-III) , , , -, 5SOPI+ (207
-Pll), S old 11 (207-ID>
, -=, 5IIPro (207-pH>) shows a configuration example. In the figure, 76 is a synchronization detection circuit, which generates a frame synchronization signal from data input and clock input. Direct code detection The circuit 78 detects various codes shown in FIG. 22 from this output, and outputs channel switching control information based on this.

In the embodiment shown in FIG. 20, the information code indicating the status of the receiving side when line switching control is performed is
It is multiplexed with the system code of the k11 line and transmitted to the sending side, but there is no problem with only one line on the working floor.
Current use 11k11. Information codes indicating the receiving side status of both the N line and the protection line may be multiplexed with the system code of each line.

[Sixth Embodiment] FIG. 24 shows the configuration of a sixth embodiment of the present invention. In the same figure, the same parts as in FIG. 20 are indicated by the same numbers, and MODIIIX (110-II
I).

MODPUX (110-pH>, MODIDX
(110-111), MOrlPDX (11
0-PD) is an information code indicating the status of the receiving side.
Roll (2
o9=to), -, Rpu (209-Pll), R
ID (209-ID).

-, RPD (209-P!1) is a receiving section that does not include a demodulator, DFMIU (210-IU), -,
DI! MPII (210-PI).

IIEMIIIX (211-Ill), I]E
MP[IX (211-pH), IIEMID (
210-Ill) , -, rlEMPD(210-P
D), DEMIDX (211-I+)).

nPMPIIX (211-Prl) are respectively modulators MOrllU (107-III), -, Mon
pu (1o7'-pHo'+ Mar++uX(1
10-Ill).

MOnI'llX (110-pH)', MOrll
ll (107-III) , -, MOITr'n
(+07-Pn)', MODIIIX (110
-Ill), MODP[lX (+1O-Pll
) is a demodulator that demodulates the modulated signal.

In the embodiment shown in FIG. 24, information indicating the status of the receiving side is transmitted to the sending side as a modulated signal using a sub-jull transmission different from the system code in the working No. 1 line and the protection line. In other words, when transmitting status information from terminal station A, switching signal generator 5Gll (109
-1) Added to the modulator open UX (110-Ill) of the color 1a replacement signal car 1-rQ working M1 line and the modulator MOIIPUX (110-Pll) of the uplink protection line,
As a result, a modulated wave is generated using a subcarrier of a frequency different from that of the system code, and is sent to terminal station B via each line. At terminal station B, each receiver RI
Demodulator DH old ux connected to U (209-Ill)
(2t1-111), and receiver RPII (209-r
demodulator rlEMPIIX (2) connected to 'U)
1-pH) to detect the switching code. The switching command receiving unit 5RII (20B-11) thereby performs necessary switching control. Similarly, when transmitting information indicating the state of the receiving side from terminal station B to terminal station A, the switching signal is sent from the switching signal generating unit 5GD (109D) to the modulator MO11111X (110-10) of the active positive 1 line.
) and the downlink protection channel modulator MOIIPDX (110-
pH), the variable eight frequencies are added to terminal B.
sent to. At terminal station B, each receiver RIII
(209-ID) 2-connected demodulator I'IF, old DX (2]111]) and receiver RPrl (209-
PD) 2-connected demodulator rlEMPflX (21
1-PD) to detect the switching code, and the switching command receiving section 5RD (20B-11) performs the required switching control based on this.

In the embodiment shown in FIG. 24, the status information code on the receiving side and the monitoring code 1 are transmitted by different sub-11Q transmission waves, so the circuit configuration is different from that in the embodiment shown in FIG. Although it is more complicated than the case, there is an advantage that the frame structure can be made partial because there is no need to multiplex and synthesize two codes.

〔Effect of the invention〕

As explained above, according to the line switching system of the present invention, the sub-temporal transmission wave is modulated and transmitted by the code signal at sending 1ull, and received (0, which is then decirculated and detected: +-1
- The normal line is interrupted by a signal, the active system and the protection system are switched to each other, and the recovery system is restored. Also, the line configuration of the protection system is changed, the connection status of the protection system is monitored, and the reception It is possible to perform various advanced switching controls, such as controlling the line switching on the sending side by returning the status of the received signal to the sending side as a code signal. By measuring the error rate and judging it at the same time as the code signal, you can more reliably determine whether the line is normal and
- It is possible to execute FJJ change control as described above.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the basic configuration of the present invention, Fig. 2 is a diagram showing the first embodiment of the invention, Fig. 3 is a diagram showing an example configuration of a pattern generator, and Fig. 4 is a diagram showing a clock generator. Figure 5 is a diagram showing an example configuration of a pattern generator, Figure 6 is a diagram showing an example configuration of an FSK modulator, and Figure 6 is a diagram showing an example configuration of a pattern generator.
FIG. 7 is a diagram showing an example configuration of a K modulator, FIG. 7 is a diagram showing an example configuration of an ASK modulator, FIG. 8 is a diagram showing an example configuration of an FSX demodulator, and FIG. 9 is a diagram showing an example configuration of a PSK demodulator. 10 is a diagram showing an example of the configuration of an ASK demodulator, FIG. 11 is a diagram showing an example of the configuration of a pattern detector, FIG. 12 is a diagram showing a second embodiment of the present invention, and FIG. 13 is a diagram showing an example of the configuration of a pattern detector. FIG. 14 is a diagram showing another configuration example of the bit error rate detection circuit, FIG. 15 is a diagram showing the third embodiment of the present invention, and FIG. 17 is a diagram showing an example of the configuration of a channel code detection section. FIG. 18 is a diagram showing an example of the configuration of the channel code.
The figure shows a fourth embodiment of the invention, FIG. 20 shows a fifth embodiment of the invention, FIG. 21 shows an example of the configuration of a switching signal generator, and FIG. 22 shows a switching signal generator. A diagram showing an example of the configuration of the signal, Fig. 23 A diagram showing an example of the configuration of the beam J change signal detection section, Fig.
FIG. 4 is a diagram showing a sixth embodiment of the present invention. +11A, ll2A, -, IIN8, liver: synthesis circuit 11
18.112B, -, IINB: Branch circuit ■old, M
OD2. −, MOON, MOnP: Modulator, PG
M, PG2. -, PGN, PGP: pattern generator, IIETI, DET2. -, IIETN,
DETII: pattern detector, TXI, TX2. −
, TXN, TXP: transmitter, RXIRX2. -, RX
N, RXP: Receiving unit, SWI8, SW] rl, S IC
, 5W2A, 5W2B, S oath 2C, -, SWN 8, S cut NR. S scale NC + changeover switch,

Claims (1)

[Claims] 1. Consisting of a plurality of working lines and protection lines, the transmitting side of each line modulates and transmits a carrier wave with a multiplexed signal, and the receiving side demodulates the received signal. In a route protection communication system that regenerates the original signal and switches to a protection line in the event of a failure of the working line, a subcarrier is modulated with a code signal on the transmitting side of each line and combined with the main signal. and means (200) for demodulating the subcarrier modulated signal received on the receiving side of each line to detect a code signal, and detecting the code signal by detecting the code signal. A line switching method characterized by determining whether the line is normal and performing necessary switching control. 2. The code signal is a single code signal, and the control performed by detecting the code signal is mutual switching and restoration between the working system and the protection system, as set forth in claim 1. line control method. 3. The code signal consists of a first code signal and a second code signal, and the normality of the line is determined by detecting the first code signal, and the required switching is performed by the second code signal. The line control system according to claim 1, characterized in that the line control system performs control. 4. The line control system according to claim 3, wherein the control performed by detecting the second code signal is a change in the line configuration of a standby system. 5. The line control system according to claim 3, wherein the control performed by detecting the second code signal is monitoring of the operating state of the standby system. 6. The code signal consists of a first code signal and a second code signal sent back from the receiving side to the sending side, and the second code signal is
A patent claim characterized in that the control performed by detecting the code signal is necessary line switching control on the sending side based on the state on the receiving side that is returned from the receiving side to the sending side by the code signal. The line control method described in item 3. 7. A patent claim characterized in that the first code signal and the second code signal are transmitted as modulated waves of different subcarriers from the receiving side to the sending side via one working system and one protection system. The line control method described in item 6. 8. Consisting of multiple working lines and protection lines, the transmitting side of each line modulates a carrier wave with a multiplexed signal and transmits it, and the receiving side demodulates the received signal and returns the original signal. In a communication system using a route protection method in which communication is performed by switching to a protection line in the event of a failure of the working line, a means (100 ), and the receiving side of each line includes means (200) for demodulating the received subcarrier modulated signal to detect a code signal, and means (300) for measuring the bit error rate of the received signal. A line switching system characterized in that the normality of the system is determined based on the detection of the code signal and the measured value of the bit error rate, and necessary switching control is performed. 9. The code signal is a single code signal, and the control performed by detecting the code signal is mutual switching and restoration between the working system and the protection system, as set forth in claim 8. line control method. 10. The code signal consists of a first code signal and a second code signal, and the normality of the line is determined by detecting the first code signal, and the required switching is performed by the second code signal. 9. The line control system according to claim 8, wherein the line control system performs control. 11. The line control system according to claim 10, wherein the control performed by detecting the second code signal changes the line configuration of the standby system. 12. The line control system according to claim 10, wherein the control performed by detecting the second code signal is monitoring of the operating state of the standby system. 13. The code signal consists of a first code signal and a second code signal sent back from the receiving side to the sending side, and the control performed by detecting the second code signal is based on the code signal. 11. The line control system according to claim 10, wherein the line switching control is performed on the sending side based on the state of the receiving side that is returned from the receiving side to the sending side. 14. A patent claim characterized in that the first code signal and the second code signal are transmitted as modulated waves of different subcarriers from the receiving side to the sending side via one working system and one protection system. The line control method described in item 13.