JPH09135229A - Line switching device for digital communication system - Google Patents

Abstract

(57) Abstract: A line switching device of a digital communication system including a wireless line having a redundant configuration, wherein switching of a redundant configuration of N + m (m ≧ 1) of an auxiliary signal in a wireless section is realized with a simple configuration. The task is to do. SOLUTION: Switching information inserting means 4 of a transmitting side terminal device 4
b, when one of the active wireless lines 2 is about to switch to one of the standby wireless lines 3, the switching information is used as an auxiliary signal from the corresponding auxiliary signal inserting / removing means 4a to overrun the main signal of the frame structure. Insert it into the card. The switching information dropping means 5b of the relay device 5 transfers the switching information to the auxiliary signal inserting / removing means 5
Obtain via a. Auxiliary signal switching means 5 of the relay device 5
Based on the switching information obtained from the switching information dropping means 5b, the reference numeral c indicates the auxiliary signal, which has been inserted / removed in the overhead of the main signal transmitted through the abnormal line of the working wireless line 2, in the standby wireless line 3. Switch to insert and remove to the overhead of the main signal transmitted over one.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line switching device for a digital communication system including a wireless line having a redundant structure, and more particularly to an SDH (Synchronous Digital Hierarch).
y) The present invention relates to a line switching device for performing a line switching of a working backup line of a wireless line section in a corresponding multiplex digital communication system.

In recent years, standardization by SDH has been promoted worldwide along with the digitization of main trunk line communication networks. A wireless line unit may be incorporated in such an SDH network. In such a wireless line unit, N + m (N indicates the number of working lines, m is a line specific to the wireless line, in order to cope with a failure in the propagation path such as fading. Indicates the number of protection lines, and N> m ≧ 1) switching by a redundant configuration is required. That is, when any one of the N working lines has a failure, switching to one of the m protection lines shared by the working lines is performed. This switching needs to be performed not only for the main signal but also for the auxiliary signal. The auxiliary signal is an RSHO (Regen
erator Section Over head), MSOH (Multiple Sect
ion Over head), RFCOH (Radio Frame Complementa
ry Over Head) is used for transmission / reception.

In the wireless section, the main signal (STM-
1, 155.52 Mbps) is not performed, media exchange between optical signals and wireless signals, wireless relay, etc. are performed. However, such wireless terminal devices and wireless intermediate relay devices are mutually connected, and such devices and optical It is required to be able to communicate with the optical transmission terminal equipment in the signal section by using the auxiliary signal. The signals transmitted as auxiliary signals include
There are telephone meeting signals, main signal switching control signals, supervisory control signals, and the like.

That is, as shown in FIG. 21, stations A and F, which are optical transmission terminal devices, and a station B, which is a wireless terminal device,
In a system including station E and stations C and D that are wireless intermediate relay devices, for example, station A and station D in section A, or station C and station E in section B transmit auxiliary signals. It is required to be able to perform small-capacity communication by using it.

[0005]

2. Description of the Related Art When transmitting and receiving an auxiliary signal in a wireless section, if the amount of information is small, the auxiliary signal is transmitted by using the overhead of the main signal transmitted by one or several working radio lines. In order to carry out transmission and to make a redundant configuration for these auxiliary signals, the overhead of the main signal transmitted by one or several of the working radio lines is further used, and 1 + 1 redundancy is provided for each auxiliary signal. It was possible to take a configuration.

However, recently, 64 kbps and 2
There is a demand for transmitting a small amount of Mbps information as an auxiliary signal, and the amount of information transmitted as an auxiliary signal tends to increase. Therefore, it has become necessary to use the overhead of all the lines of the current wireless line for transmitting the auxiliary signal. In such a case, it is not possible to take a 1 + 1 redundant configuration for each auxiliary signal. Therefore, it is necessary to take an N + m (m ≧ 1) redundant configuration for the auxiliary signal as well as the main signal.

By the way, the wireless intermediate relay devices (stations C and D) do not switch the working spare line of the main signal, but simply amplify the main signal. When the main protection line switching of the main signal is performed between the stations B and E), the line switching information of the main signal is not notified to the wireless intermediate relay device. Therefore, for example, when the wireless intermediate relay device and the wireless terminal device perform communication using the auxiliary signal via the active wireless line that is the target of switching, the communication is suddenly cut off. . In order to avoid such a situation, in the wireless intermediate relay device,
It is necessary to switch the working auxiliary line for the auxiliary signal.

In this case, a technique to be used as a reference for switching an auxiliary signal to be used as a working spare is disclosed in, for example, Japanese Patent Laid-Open No. 53-12.
No. 8212. According to this, a plurality of working wireless lines and one spare wireless line are provided between two terminal station devices, and a relay device is provided in the middle of these working wireless lines and spare wireless lines. The auxiliary signal is transmitted using one of the working radio lines, and the auxiliary line of the main signal is used as the auxiliary line of the auxiliary signal. The above line configuration is provided in two systems, one for upstream and one for downstream.

In this active protection switching method, the relay device intercepts the auxiliary signal transmitted in the direction opposite to the main signal transmission direction, and extracts the active backup switching signal due to the failure of the main signal contained therein. To do. The relay device switches the working protection of the auxiliary signal based on the working protection switching signal of the main signal.
In this way, in synchronism with the switching of the active spare of the main signal,
It realizes the switching of the working auxiliary signal of the auxiliary signal in the relay device.

Further, as disclosed in, for example, Japanese Patent Laid-Open No. 5-327650, the switching state of the working spare at the terminal station is collected by a polling method at a specific terminal station, and the relay device intercepts the collected switching information. Then, there is a method of recognizing the switching state.

[0011]

However, Japanese Patent Application Laid-Open No.
The switching method shown in Japanese Patent No. 128212 is applied to N +
If an attempt is made to apply to the switching of auxiliary signals of m (m ≧ 1) redundant configuration, the processing after interception will become very complicated, and the scale of the device configuration will increase. In addition, this Japanese Patent Laid-Open No.
In the switching method disclosed in Japanese Patent Laid-Open No. 3-128212, since the information obtained as a result of interception does not include the information for specifying the line to be switched among the plurality of active wireless lines, which active wireless line There is also a problem that it is unclear whether or not the auxiliary signal should be switched to the backup radio line.

Further, in the switching information collection by polling as disclosed in Japanese Patent Laid-Open No. 5-327650, it takes a very long time to collect the information. Therefore, the time difference between the main signal line switching and the auxiliary signal line switching is great. Will become bigger. Therefore, in the worst case, after the main signal failure is restored and the line is switched back, the auxiliary signal is switched for the first time, and the auxiliary signal is transmitted on the unused backup line. May cause a disconnection.

The present invention has been made in view of the above points, and N + m (m ≧ m) of an auxiliary signal in a wireless section.
It is an object of the present invention to provide a line switching device for a digital communication system, which realizes the switching of the redundant configuration of 1) with a simple configuration.

[0014]

In order to achieve the above object, the present invention, as shown in FIG. 1, includes a plurality of optical lines 1 each for transmitting a main signal in a frame structure having an overhead, The same number of active wireless lines 2 as the plurality of optical lines 1, at least one standby wireless line 3, and a plurality of optical lines 1 located at both ends of the active wireless line 2 and the standby wireless line 3, respectively.
And terminal devices 4 and 6 on the transmitting side and the receiving side for selectively connecting to the working wireless line 2 and the standby wireless line 3,
The relay device 5 provided in the middle of the working radio line 2 and the backup radio line 3, and the two terminal station devices 4, 6 and the relay device 5, respectively, are provided to insert an auxiliary signal into the overhead, Auxiliary signal inserting / removing means 4a, 5a for dropping an auxiliary signal from the overhead, and the transmitting side terminal device 4
A switch for inserting one of the working radio lines 2 to one of the spare radio lines 3 into the overhead from the corresponding auxiliary signal inserting / removing means 4a as an auxiliary signal when the one of the active radio lines 2 is about to switch. Switching information dropping means 5b for dropping the switching information from the overhead by means of the information inserting means 4b and the corresponding auxiliary signal inserting / removing means 5a provided in the relay device 5.
And the auxiliary signal inserted into and removed from the overhead of the main signal transmitted via the one of the working radio lines 2 based on the switching information obtained from the switching information dropping means 5b provided in the relay device 5. A line switching device for a digital communication system, characterized in that it has auxiliary signal switching means 5c for switching so as to insert / remove with respect to the overhead of the main signal transmitted via said one of the spare radio lines 3. Provided.

In the above-mentioned structure, usually, each main signal composed of optical signals respectively inputted through a plurality of optical lines 1 is converted into a radio signal by the transmitting side terminal device 4,
It is output to the same number of active wireless lines 2 as the number of optical lines 1. These main signals are relayed by the relay device 5 to reach the receiving end terminal device 6, are converted into optical signals by the receiving end terminal device 6, and are output to the optical line. The receiving-side terminal device 6 monitors each main signal sent from the active wireless line 2, and when detecting any abnormality in any of them, notifies the transmitting-side terminal device 4 of that fact.
Notification is made via a wireless line (not shown) whose transmission direction is opposite. As a result, the transmission-side terminal device 4 and the reception-side terminal device 6
Means to switch the abnormal working wireless line to one of the standby wireless lines 3.

By the way, in the switching information inserting means 4b of the transmitting side terminal device 4, one of the active wireless lines 2 is the standby wireless line 3
When switching to one of the above, the switching information is inserted as an auxiliary signal into the overhead of the main signal of the frame structure from the corresponding auxiliary signal inserting / removing means 4a. The switching information includes at least the identification code of the working wireless line having an abnormality. The switching information dropping means 5b of the relay device 5 obtains the switching information via the auxiliary signal inserting / removing means 5a. The auxiliary signal switching means 5c of the relay device 5 is based on the switching information obtained from the switching information dropping means 5b.
So that the auxiliary signal inserted into or removed from the overhead of the main signal transmitted through the abnormal line of the above is inserted into or removed from the overhead of the main signal transmitted through the one of the standby radio lines 3. , Switch.

As described above, since the relay device 5 obtains the switching information, the auxiliary signal inserted / removed via the abnormal line of the working radio line 2 is also transmitted to the relay device 5 by the one of the backup radio lines 3. You will be able to insert and remove via.

If the one identification code of the spare radio line 3 is further inserted in the switching information, it is possible to easily cope with the switching of the redundant configuration of N + m (m> 1) of the auxiliary signal in the wireless section. .

Thus, the switching of the N + m (m ≧ 1) redundant configuration of the auxiliary signal in the wireless section is realized with a simple configuration.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. First, the principle configuration of the first embodiment will be described with reference to FIG. In the first embodiment,
A plurality of optical lines 1 each transmitting a main signal in a frame structure with an overhead, an active radio line 2 of the same number as the plurality of optical lines 1, and at least one standby radio line 3;
Terminal devices 4 on the transmitting side and the receiving side, which are located at both ends of the working wireless line 2 and the standby wireless line 3, and selectively connect a plurality of optical lines 1 to the working wireless line 2 and the standby wireless line 3. , 6 and the relay device 5 provided in the middle of the working wireless line 2 and the standby wireless line 3, and the two terminal station devices 4, 6 and the relay device 5, respectively, and inserts an auxiliary signal in the overhead. Auxiliary signal inserting / removing means 4a, 5a for removing the auxiliary signal from the overhead.
Is provided in the transmission side terminal device 4, and the
When one tries to switch to one of the standby wireless circuits 3, the switching information inserting means 4b for inserting the switching information as an auxiliary signal from the corresponding auxiliary signal inserting / removing means 4a into the overhead and the relay device 5 are used. Based on the switching information provided by the corresponding auxiliary signal inserting / removing means 5a and the switching information dropping means 5b for dropping the switching information from the overhead, and the switching information provided by the switching information dropping means 5b provided in the relay device 5, The auxiliary signal inserted into and removed from the overhead of the main signal transmitted via the above-mentioned one of the working wireless circuits 2 is transferred to the standby wireless circuit 3
Auxiliary signal switching means 5 for switching so as to insert into and remove from the overhead of the main signal transmitted via said one of
c.

Next, a detailed configuration of the first embodiment will be described with reference to FIGS. FIG. 2 is a configuration diagram showing the overall configuration of the first embodiment. Explaining along the transmission path in the right direction in the figure, the optical transmission terminal station device 11 terminates, for example, three optical signal lines, converts them into electric signals, and sends them to the wireless terminal station device 12. The wireless terminal device 12 has three active wireless lines M1 to M3 and, for example, one standby wireless line PR.
The OT is connected to the wireless terminal device 12, and the wireless terminal station device 12 performs line switching for the working spares. The wireless intermediate relay device 1 is provided in the middle of the working wireless lines M1 to M3 and the standby wireless line PROT.
3, 14 are connected to perform a relay operation such as amplification of a main signal and insert / remove an auxiliary signal. Wireless terminal device 15
Selectively takes out three lines from the three working radio lines M1 to M3 and one spare radio line PROT and sends them to the optical transmission terminal station device 16. The optical transmission terminal device 16 converts an electric signal into an optical signal and sends it out to three optical signal lines. The same transmission line as above is also provided in the left direction.

The terminal device 4 of FIG. 1 corresponds to the wireless terminal device 12 of FIG. 2, the relay device 5 of FIG. 1 corresponds to the wireless intermediate relay device 13 and the wireless intermediate relay device 14 of FIG. The terminal station device 6 of FIG. 1 corresponds to the wireless terminal device 15 of FIG.

FIG. 3 is a diagram showing a frame structure of a signal used in the first embodiment. That is, the main signal is mounted on the payload, and SOH (Se
the auxiliary signal for all sections to RFC
OH (Radio Frame Complementary Over Head) is equipped with an auxiliary signal related to the wireless section. Therefore, signals are transmitted in the form F1 on both sides of each of the optical transmission terminal devices 11 and 16 of FIG. 2, and the wireless terminal device 12, the wireless intermediate relay devices 13 and 14, and the wireless terminal device 15 of FIG. Form F2 between each
The signal is transmitted in.

FIG. 4 is a block diagram showing the internal structure of the optical transmission terminal station device 11 of FIG. In this figure, only the part related to the processing of the auxiliary signal in the right direction is shown. That is, in the optical transmission terminal device 11, the SOH inserting / removing unit 18a is provided for each line.
~ 18c are provided. SOH insertion / removal section 18a-18c
Takes out the auxiliary signal inserted in SOH,
An auxiliary signal is inserted into SOH. Thick line arrows in and out of the blocks in the figure show the flow of the main signal, and thin line arrows show the flow of the auxiliary signal (the same applies to each of the figures described below). The configuration of processing the auxiliary signal in the left direction is the same as that of FIG. In addition, the optical transmission terminal device 1
Since 6 also has basically the same configuration as the optical transmission terminal station device 11, the description of the optical transmission terminal station device 16 is omitted.

FIG. 5 is a block diagram showing the internal structure of the radio terminal station device 12 of FIG. In this figure, the portion related to the signal transmitted to the right is mainly shown. That is, SOH insertion / removal units 19a to 19c are provided for each line. SO
The H insertion / removal units 18a to 18c take out (drop) the auxiliary signal inserted into the SOH and insert (insert) the auxiliary signal into the SOH.

The working standby switching section 20 normally connects the three main signals sent from the left optical transmission terminal station device 11 to the right working radio lines M1, M2 and M3, respectively. When any one of the working radio lines M1, M2 and M3 is abnormal, the main signal to be sent to the abnormal line is connected to the standby radio line PROT at the same time (so-called transmission). These connections are made by a control signal from the transmission switching control unit 23.

RFC is used for the working radio lines M1, M2 and M3.
The OH insertion units 21a to 21c are provided respectively, and the backup radio line PROT is provided with the RFCOH insertion unit 21d. The RFCOH inserters 21a to 21d insert an auxiliary signal into RFCOH. The auxiliary signals inserted here are auxiliary signals (order wire signal, 2
Mbps call signal, supervisory control signal, etc.) and a switching control signal for instructing switching between transmission and reception. The switching control signal is
There is an identification code of an abnormal line, which will be described later, sent from the transmission switching control unit 23. Furthermore, the working wireless lines M1, M2, M
3 are provided with TX 22a to 22c, and the standby radio line PROT is provided with TX 22d. TX22
a to 22d convert each main signal including the auxiliary signal into a radio signal and send it out.

The transmission switching control unit 23 has a working spare switching unit 2
0 to control the line switching of the working backup line,
The control of insertion of various auxiliary signals with respect to the above is described later in detail with reference to FIG.

Although not shown, the wireless terminal device 12 has a processing unit for a signal transmitted to the left. The configuration is the same as the configuration of the processing unit in the right direction of the wireless terminal station device 15 which will be described later with reference to FIG. Four RFCOH drop-off units 24 forming the leftward processing unit of the wireless terminal device 12.
A switching control signal is also extracted from the transmission switching control unit 23.
Sent to

FIG. 6 is a block diagram showing the internal structure of the wireless intermediate relay devices 13 and 14. The wireless intermediate relay device 13 and the wireless intermediate relay device 14 have the same configuration. In this figure, the portion related to the signal transmitted to the right is mainly shown. That is, the RXs 26a to 26c and the RFCOH dropping unit 27a to the working radio lines M1, M2, and M3.
27c are provided respectively, and the backup radio line PROT is provided with the RX 26d and the RFCOH dropping unit 27d. RXs 26a to 26d are receiving units that respectively receive the radio signals sent by each line. RFCOH dropout part 2
7a to 27d take out various auxiliary signals from RFCOH and send them to the reception switching / sending / sending unit 31. Reception switching / transmission unit 3
Among the various auxiliary signals sent to 1, the identification code of the abnormal line described later is also included.

Further, SOH insertion / removal units 28a to 28c and RFCOH insertion unit 29a are connected to the working radio lines M1, M2 and M3.
To 29c and TXs 30a to 30c are provided respectively, and the SOH insertion / removal units 28d and R are connected to the backup radio line PROT.
An FCOH insertion part 29d and a TX 30d are provided. The SOH inserting / removing units 28a to 28d take out the auxiliary signal inserted into the SOH and insert the auxiliary signal into the SOH. The RFCOH insertion parts 29a to 29d are R
An auxiliary signal related to the wireless section transmitted from the reception switching / sending / sending unit 29 is inserted into the FCOH. TX30a-30d
Converts each main signal including the auxiliary signal into a radio signal and sends it to the right.

The reception switching / sending / sending unit 31 follows the switching control signal (identification code of the abnormal line) relating to the reception SW switching sent from the RFCOH dropping units 27a to 27d, according to the RFCO.
Three of the four various auxiliary signals sent from the H drop units 27a to 27d are selected and sent to the user. This operation will be described later with reference to FIG. 9 showing the internal configuration of the reception switching / sending / sending unit 31. Further, the reception switching / transmission unit 31
In accordance with the switching control signal (identification code of the abnormal line) relating to the transmission sent from the RFCOH dropping units 27a to 27d, each auxiliary signal sent from the user to the RFCOH insertion units 29a to 29c when various auxiliary signals are not transmitted. Send,
During transmission of various auxiliary signals, various auxiliary signals sent from the user are sent to the RFCOH insertion sections 29a to 29c and the RFC.
It is sent to the OH insertion section 29d. This operation will also be described later with reference to FIG.

Although not shown, each of the wireless intermediate repeaters 13 and 14 of FIG. 6 has a processing unit for a signal transmitted to the left. The configuration is the same as the configuration of the processing unit in the right direction shown in FIG. A switching control signal is also sent to the reception switching / sending / sending unit 31 from the four RFCOH dropping units 32 that form the leftward processing unit.

FIG. 7 is a block diagram showing a detailed internal structure of the wireless terminal device 15 of FIG. In FIG. 7, a portion relating to a signal transmitted to the right is mainly shown. That is, RX 34a to 3 are connected to the working radio lines M1, M2 and M3.
4c and RFCOH dropouts 35a to 35c are provided respectively, and the backup radio line PROT is provided with RX 34d and RFCOH dropouts 35d. RX34a-3
Reference numeral 4d is a receiving unit that receives a radio signal transmitted through each line. The RFCOH dropout parts 35a to 35d are R
An auxiliary signal such as an identification code of an abnormal line, which will be described later, is taken out from the FCOH and sent to the reception switching control unit 39. When there is no abnormality in any of the working radio lines M1, M2, M3, the working standby switching unit 36 has a left RFCOH dropping unit 3
Connection is made so that the three main signals sent from 5a to 35c are output to the right side, and the working radio lines M1, M2, M3 are connected.
When any one of the lines is abnormal, connection is made so that the main signal sent by the two lines excluding the abnormal line and the standby radio line PROT is output to the right. This connection is made by a control signal from the reception switching control unit 39.

SOH insertion / removal units 37a to 37c are provided on the three lines connected to the active spare switching unit 36, respectively. The SOH insertion / removal units 37a to 37c take out the auxiliary signal inserted into the SOH or insert the auxiliary signal into the SOH.

The fault detection unit 38 monitors each main signal, and when there is an abnormality in them, informs the reception switching control unit 39 of which line the fault has occurred. Upon receiving such a failure notification, the reception switching control unit 39 causes the RFCOH insertion unit 4 described later to
1 to send a switching control signal for instructing parallel transmission of the main signal, or to receive switching control signals for main signal transmission / reception response from the RFCOH dropping units 35a to 35d to control the switching of the active spare line by the active spare switching unit 36. To do. Further, the receiving SW switching is performed by receiving the switching control signal of the identification code of the abnormal line from the RFCOH dropping units 35a to 35d. Details of these will be described later with reference to FIG. Although not shown, the wireless terminal device 15 has a processing unit for a signal transmitted to the left. The configuration is the same as the configuration of the processing unit in the right direction of the wireless terminal station device 12 described in FIG. Four RFCs configuring the left processing unit of the wireless terminal device 15
The reception switching control unit 39 also sends a switching control signal to the OH insertion unit 40.

The operation of the first embodiment having the above configuration will be described with reference to the sequence diagram shown in FIG. In FIG. 8, “terminal station” indicates the wireless terminal station devices 12 and 15, and “middle station” indicates the wireless intermediate relay devices 13 and 14. Also, "G
"O" indicates the transmission direction of the main signal (to the right), and "RETU"
"RN" indicates the opposite direction (to the left). Hereinafter, description will be given along the numbers given to the respective steps of the sequence.

[S1] A failure occurs in the main signal transmitted through any of the working radio lines M1, M2, M3. In the following, the description will proceed assuming that a failure has occurred in the working wireless line M1.

[S2] The fault detecting unit 38 of the wireless terminal device 15 (FIG. 7) detects the fault and notifies the reception switching control unit 39 of the fault on the fault line M1. [S3] The reception switching control unit 39 sends a switching control signal for instructing parallel transmission of the main signal to the RFCOH insertion unit 40, and the RFCOH insertion unit 40 inserts the switching control signal into the RFCOH in the "RETURN" direction. This switching control signal includes information for identifying the faulty line.

[S4] This switching control signal is taken out by the RFCOH dropping unit 24 of the wireless terminal device 12 (FIG. 5) and sent to the transmission switching control unit 23. The transmission switching control unit 23,
The active spare switching unit 20 is instructed to send and receive, and the active spare switching unit 20 performs line connection so that the main signal output to the faulty line M1 is simultaneously output to the standby wireless line PROT.

[S5] At the same time as the transmission in step S4, the transmission switching control unit 23 causes the RFCOH insertion units 21a to 21d.
Then, the switching control signal of the main signal transmission / response is sent, and the RFCOH insertion units 21a to 21d insert the switching control signal into RFCOH.

[S6] RF of the wireless terminal device 15 (FIG. 7)
The COH dropping units 35a to 35d send this switching control signal to R
It is taken out from the FCOH and sent to the reception switching control unit 39. When the reception switching control unit 39 receives the switching control signal of the main signal transmission / reception response, it activates the working protection switching unit 36, and the working protection switching unit 36 transfers the main signal obtained from the fault circuit M1 to the protection wireless line PROT. Switch to get from.

[S7] At the same time as the transmission of the main signal in step S4, the transmission switching control unit 23 (FIG. 5) sends the identification code of the faulty line M1 to the RFCOH insertion units 21a to 21c as a switching control signal to insert the RFCOH insertion. The units 21a to 21c insert the switching control signal into RFCOH. The identification code is made up of 2 bits because there are three active wireless lines. For example, "01" is set as a failure of the working wireless line M1,
“10” is assigned to the fault of the working radio line M2, “11” is assigned to the fault of the working radio line M3, and “00” is assigned when there is no fault. Of course, if the number of active wireless lines increases, the number of bits of the identification code will increase accordingly.

[S8] The transmission switching control section 23 inserts the identification code in step S7 and, at the same time, transmits the RF of the faulty line M1.
The various auxiliary signals inserted into COH are also sent to the RFCOH insertion section 21d so that they are also inserted into the RFCOH of the spare radio line PROT.

[S9] R of the wireless intermediate relay device 13 of FIG.
The FCOH dropping units 27a to 27d take out the switching control signal of the identification code from the RFCOH, perform the backward protection of a predetermined number of stages, and then send it to the reception switching / transmission unit 31. This backward protection method adopts a well-known technique in the related art.

On the basis of the extracted identification code, the reception switching / transmission / sequencing section 31 sends various auxiliary signals corresponding to the identification code from the RFCOH insertion section 29a of the faulty line M1 to the backup radio line PROT. RF
The COH insertion portion 29d inserts the RFH into the RFCOH (that is, sends it in parallel) and sends it out in the "GO" direction.

[S10] Simultaneously with the transmission of various auxiliary signals in step S9, the reception switching / transmission / reception unit 31 takes out the RFCOH dropping unit 27a of the fault line M1 corresponding to the extracted identification code from the RFCOH. Various auxiliary signals in the "GO" direction are sent to the backup wireless line PROT through RFCOH.
The dropout portion 27d is switched so as to be taken out from RFCOH.

[S11] In the wireless intermediate relay device 14 of FIG. 6, the same processing as step S9 is performed. [S12] In the wireless intermediate relay device 14 of FIG. 6, the same processing as step S10 is performed.

[S13] R of the wireless terminal device 15 (FIG. 7)
The FCOH dropping units 35a to 35d take out the switching control signal of the identification code from the RFCOH and receive the reception switching control unit 39.
Switches the various auxiliary signals in the “GO” direction, which are obtained from the RFCOH by the RFCOH dropping unit 35a of the faulty line M1 corresponding to the identification code, so that the RFCOH dropping unit 35d of the backup radio line PROT obtains them from RFCOH.

FIG. 9 shows the wireless intermediate relay devices 13, 1 of FIG.
It is a block diagram which shows the internal structure of the reception switching / transmission parallel part 31 of FIG. Steps S9 and S11 in which the right half in the figure performs the transmission
Corresponding to step S1, the left half performs reception SW switching
0, corresponding to S12.

The receiving switching / sending / sending unit 31 is provided with an active wireless line M.
Three comparators 31a to 31c are provided corresponding to 1 to M3, and one of the input terminals of each of the comparators 31a to 31c has the RFCOH dropping unit 2 of FIG.
From 7a to 27d, the identification codes extracted from them are respectively input, and individual codes "01", "10", and "11" are input to the other input ends. The comparator 31a compares the both input digital data, and when they match, outputs a match signal to the selectors 31d and 31e.
Output to Similarly, the comparator 31b outputs the coincidence signal to the selectors 31f and 31g, and the comparator 31c outputs the coincidence signal to the selectors 31h and 31i. Comparators 31a-31
Since the codes respectively input to the other input terminals of c correspond to the identification codes of the working radio lines M1 to M3, each match signal is generated only when the corresponding working radio line has a fault. Will be output.

Various auxiliary signals extracted from the RFCOH of the spare radio line PROT by the RFCOH dropping unit 27d of FIG. 6 are input to one input terminals of the selectors 31d, 31f and 31h. Further, at the other input end of the selector 31d, the RFCOH dropping unit 27a of FIG.
Various auxiliary signals taken out from the RFCOH of No. 1 are input. Similarly, the other input end of the selector 31f is connected to FIG.
RFCOH dropping unit 27b is the RFC of the working radio line M2.
Various auxiliary signals extracted from the OH are input, and the other input end of the selector 31h is connected to the RFCOH dropping unit 2 of FIG.
Various auxiliary signals taken out from the RFCOH of the working radio line M3 are inputted to the 7c. Selectors 31d, 31f, 3
1h selects various auxiliary signals from the working wireless line side and outputs them to the user when the match signal is not input, but when the match signal is input, various auxiliary signals from the standby wireless line side are selected. Operates to select and output to the user. Therefore, for example, the working wireless line M1
When a failure occurs in the input signal and the coincidence signal is input to the selector 31d, the selector 31d changes various auxiliary signals to be output from the active wireless line M1 to the standby wireless line PROT. In this case, since the same various auxiliary signals have been previously transmitted to the working radio line M1 and the standby radio line PROT, the reception of the various auxiliary signals in the "GO" direction by the wireless intermediate relay devices 13 and 14 is thereby performed. Line switching is realized.

Various auxiliary signals are inputted from the user to one input terminal of each of the selectors 31e, 31g and 31i. These auxiliary signals are simultaneously sent to the RFCOH insertion unit 29a of FIG. 6 in the working radio line M1, and to the RFCOH of FIG. 6 in the working radio line M2.
It is also sent to the insertion section 29b at the same time, and is also sent to the RFCOH insertion section 29c of FIG. The other input end of the selector 31e is connected to the selector 3
The output of the selector 31i is input to the other input terminal of the selector 31g.
Nothing is input to the other input terminal of i. Selector 3
The output end of 1e is connected to the RFCOH insertion unit 29d of the backup radio line PROT. Selectors 31e, 31g,
Each 31i selects and outputs the signal at the other input end when no match signal is sent, and selects and outputs the signal at one input end when the match signal is sent. Therefore, when there is no abnormality in any of the working lines and no match signal is sent to all of the selectors 31e, 31g, 31i, the protection radio line PROT
No signal is output to the RFCOH insertion unit 29d. Further, when there is an abnormality in the working wireless line M1 and a coincidence signal is sent to the selector 31e, the RFCOH of the working wireless line M1 is transmitted.
The various auxiliary signals sent to the inserting section 29a are also output to the RFCOH inserting section 29d of the backup radio line PROT and are sent in parallel. Similarly, when the working wireless line M2 has an abnormality and a coincidence signal is sent to the selector 31g, various auxiliary signals sent to the RFCOH insertion unit 29b of the working wireless line M2 are sent to the RFCOH insertion unit 29d of the standby wireless line PROT. Is also output. Furthermore, if there is an abnormality in the working wireless line M3 and a match signal is sent to the selector 31i,
The various auxiliary signals sent to the RFCOH insertion unit 29c of the working wireless line M3 are RFCOH of the standby wireless line PROT.
It is also output to the insertion unit 29d.

As described above, in the first embodiment, the optical transmission device terminal devices 11 and 16 and the wireless terminal devices 12 and 1 are used.
5. Communication using the auxiliary signal with each of the wireless intermediate relay devices 13 and 14 does not depend on the communication medium and does not complicate the hardware configuration of the wireless intermediate relay devices 13 and 14. It will be possible.

Further, in order to inform the wireless intermediate relay devices 13 and 14 of the faulty wireless line, it is only necessary to send an identification code of several bits. Therefore, the scale of the hardware configuration of the wireless intermediate relay devices 13 and 14 is particularly large. Can be made smaller.

Furthermore, since the wireless intermediate relay devices 13 and 14 perform reception switching simultaneously with transmission of various auxiliary signals, the switching is completed very quickly. That is, the auxiliary signal is 64 kbp
When used for s or 2 Mbps digital communication, it is desirable to shorten the time from the occurrence of a failure in the working wireless line to the completion of switching to the backup wireless line as much as possible.
On the other hand, the fact that the transmission of the main signal has started can be regarded as the switching of the main signal almost normally. Therefore, if the auxiliary signal is also switched in accordance with the transmission timing of the main signal, the switching will be completed very quickly.

By the way, the auxiliary signal inserting / removing means 4a shown in FIG.
Corresponds to the RFCOH insertion parts 21a to 21d in FIG.
The switching information insertion means 4b of FIG. 1 corresponds to the transmission switching control unit 23 of FIG. 5, the auxiliary signal insertion / removal means 5a of FIG. 1 corresponds to the RFCOH dropping units 27a to 27d of FIG. 6, and the switching of FIG. The information dropping means 5b includes the RFCOH dropping section 27a-
27d, the auxiliary signal switching means 5c shown in FIG.
This corresponds to the reception switching / sending / sending unit 31.

In the above-described first embodiment, the number of optical signal lines and the number of working wireless lines are three, and the number of standby wireless lines is one, but N optical signal lines and working wireless lines are used. The number of backup radio lines may be set to m (N is an arbitrary integer, m is an arbitrary integer having a relationship of N>m> 1). When a plurality of backup radio lines are provided, the transmission switching control unit 23 to the RFCOH insertion unit 2 in FIG.
As the switching control signal sent to 1a to 21d, the identification code of the faulty working radio line and the identification code of the spare radio line to which the faulty line should be switched are required.

Next, a second embodiment will be described. The configuration of the second embodiment is basically the same as the configuration of the first embodiment shown in FIGS. Therefore, the second embodiment will be described by diverting the configuration shown in FIGS. The second embodiment is different from the first embodiment in the operations of the transmission switching control unit 23 of FIG. 5, the reception switching / transmission unit 31 of FIG. 6, and the reception switching control unit 39 of FIG. 7. Is.

FIG. 10 is a sequence diagram showing the operation of the second embodiment. In this sequence diagram, FIG.
Steps having the same contents as those in the sequence diagram of the first embodiment shown in FIG. Hereinafter, description will be given along the numbers given to the respective steps of the sequence.

[S15] At the same time as the reception switching of the main signal in step S6, the reception switching control unit 39 (FIG. 7) switches to RFCOH.
The identification code of the faulty line M1 is sent to the inserting section 40 as a switching control signal, and the RFCOH inserting section 40 inserts the switching control signal into RFCOH.

[S16] The reception switching control unit 39 inserts the identification code in step S15 and, at the same time, the RFCOH dropping unit 35a of the faulty line M1 obtains from RFCOH.
Various auxiliary signals in the "O" direction are sent to the R of the protection radio line PROT.
The FCOH dropping unit 35d is switched so as to obtain it from RFCOH.

[S17] The RFCOH dropping unit 32 of the wireless intermediate relay device 14 of FIG. 6 extracts the switching control signal of the identification code from the RFCOH, performs backward protection of a predetermined number of stages, and then sends it to the reception switching / transmission parallel unit 31. send.

On the basis of the extracted identification code, the reception switching / transmission / sequencing section 31 sends the various auxiliary signals inserted into the RFCOH from the RFCOH insertion section 29a of the faulty line M1 corresponding to the identification code to the backup radio line PROT. RF
It is also inserted from the COH insertion portion 29d into the RFCOH (that is, in parallel) and sent out in the "GO" direction.

[S18] Simultaneously with the transmission of various auxiliary signals in step S17, the reception switching / transmission / reception unit 31 takes out the RFCOH dropping unit 27a of the fault line M1 corresponding to the extracted identification code from the RFCOH. Various auxiliary signals in the "GO" direction are sent to the RFCO of the standby wireless line PROT.
The H drop-off portion 27d is switched to be taken out from RFCOH.

[S19] In the wireless intermediate relay device 13 of FIG. 6, the same processing as step S17 is performed. [S20] In the wireless intermediate relay device 13 of FIG. 6, the same processing as step S18 is performed.

[S21] RF of the wireless terminal device 12 of FIG.
The COH dropping unit 24 takes out the switching control signal of the identification code from the RFCOH and sends it to the transmission switching control unit 23. The transmission switching control unit 23, based on the extracted identification code,
From the RFCOH insertion section 21a of the fault line M1 to RFCOH
The various auxiliary signals inserted in the
The ID code is also sent to the RFCOH insertion part 21d and the identification code is sent.

As described above, in the second embodiment, the switching of the auxiliary signal is interlocked with the switching timing of the main signal receiving side. That is, it is desirable that the auxiliary signal including the monitoring information is not interrupted when the line is switched. Therefore, if it is confirmed that the line switching of the main signal is completely completed and then the process switches to the switching of the auxiliary signal, the device failure in the working standby switching unit 36 of the wireless terminal device 15 that performs the reception switching of the main signal. Even if occurs, continuous interruption of the auxiliary signal can be avoided.

Next, a third embodiment will be described. The configuration of the third embodiment is basically the same as the configuration of the first embodiment shown in FIGS. Therefore, the third embodiment will be described by diverting the configuration shown in FIGS. The third embodiment is different from the first embodiment in the operations of the transmission switching control unit 23 of FIG. 5, the reception switching / transmission unit 31 of FIG. 6, and the reception switching control unit 39 of FIG. 7. Is.

FIG. 11 is a sequence diagram showing the operation of the third embodiment. In this sequence diagram, FIG.
Steps having the same contents as those in the sequence diagram of the first embodiment shown in FIG. Hereinafter, description will be given along the numbers given to the respective steps of the sequence.

[S23] At the same time as the transmission of the main signal in step S4, the transmission switching control unit 23 (FIG. 5) sends the identification code of the faulty line M1 to the RFCOH insertion units 21a to 21c as a switching control signal to insert the RFCOH. Parts 21a to 21c
Inserts the switching control signal into RFCOH.

[S24] The transmission switching control section 23 sends the various auxiliary signals inserted in the RFCOH of the faulty line M1 to the RFCOH insertion section 21d simultaneously with the insertion of the identification code in step S23, and the standby radio line PROT. RFCO
Insert in H and send.

[S25] The RFCOH dropping units 27a to 27d of the wireless intermediate relay device 13 of FIG. 6 take out the switching control signal of the identification code from the RFCOH and perform the backward protection of a predetermined number of steps, and then the receiving switching / transmission paralleling unit. Send to 31.

On the basis of the extracted identification code, the reception switching / transmission / sequencing section 31 sends various auxiliary signals corresponding to the identification code from the RFCOH insertion section 29a of the faulty line M1 to the backup radio line PROT. RF
It is also inserted from the COH insertion portion 29d into the RFCOH (that is, in parallel) and sent out in the "GO" direction.

[S26] In the wireless intermediate relay device 14 of FIG. 6, the same processing as step S25 is performed. [S27] Simultaneously with the switching of reception of the main signal in step S6,
The reception switching control unit 39 (FIG. 7) sends the identification code of the faulty line M1 to the RFCOH insertion unit 40 as a switching control signal,
The RFCOH insertion unit 40 sends the switching control signal to the RFCOH.
Insert

[S28] The reception switching controller 39 inserts the identification code in step S27 and, at the same time, the RFCOH dropping unit 35a of the faulty line M1 obtains from RFCOH.
Various auxiliary signals in the "O" direction are sent to the R of the protection radio line PROT.
The FCOH dropping unit 35d is switched so as to obtain it from RFCOH.

[S29] The RFCOH dropping unit 32 of the wireless intermediate relay device 14 of FIG. 6 takes out a switching control signal of the identification code from the RFCOH, performs backward protection of a predetermined number of stages, and then sends it to the reception switching / transmission unit 31. send.

The reception switching / transmission unit 31 uses the RFCOH dropping unit 2 of the fault line M1 corresponding to the extracted identification code.
The various auxiliary signals in the “GO” direction that were taken out from RFCOH by 7a are switched by the RFCOH dropping unit 27d of the backup radio line PROT so as to be taken out from RFCOH.

[S30] In the wireless intermediate relay device 13 of FIG. 6, the same processing as step S29 is performed. In this way, the auxiliary signal transmission is started at the main signal transmission timing, and the auxiliary signal reception side switching is started at the main signal reception side switching timing. Therefore, since the reception side switching is performed after the auxiliary signal transmission is performed on the opposite transmission side, the instantaneous interruption time can be shortened and the reliable switching can be performed.

It should be noted that the wireless intermediate relay devices 13 and 14 and the wireless terminal device 15 are each provided with a phase adjusting device as shown in FIG. 12 so as to correct the phase shift of the auxiliary signal between the working spares during reception switching. May be. That is,
The data phase comparison unit 42 compares the phases of various auxiliary signals sent from the working line and various auxiliary signals sent from the protection line, and based on the comparison result, the data phase adjustment unit 43 performs phase matching of both auxiliary signals. To do. The reception changeover switch unit 44 executes line changeover on the basis of both auxiliary signals having undergone phase adjustment.

As a result, non-interruption switching of the auxiliary signal is realized, and a high-quality line for the auxiliary signal of 64 kbps or 2 Mbps can be provided. Next, a fourth embodiment will be described.

The configuration of the fourth embodiment is basically the same as the configuration of the first embodiment shown in FIGS.
Therefore, the fourth embodiment will be described by diverting the configuration shown in FIGS. The fourth embodiment differs from the first embodiment in that the transmission switching control unit 23 of FIG.
These are operations of the reception switching / sending / sending unit 31 of FIG. 6 and the reception switching control unit 39 of FIG. 7.

FIG. 13 is a sequence diagram showing the operation of the fourth embodiment. Since this sequence is basically the same as the sequence of the third embodiment, the steps having the same contents as those of the sequence of the third embodiment are given the same step numbers and the description thereof is omitted. . Hereinafter, description will be given along the numbers given to the respective steps of the sequence.

[S32] The reception switching control unit 39 of FIG.
In step S23, when the identification code of the faulty line M1 is sent as the switching control signal and the reception switching of the main signal in the working backup switching unit 36 is completed, the RFCOH insertion unit 4
0, the identification code of the faulty line M1 is sent as a switching control signal, and the RFCOH inserting section 40 sends the switching control signal to the RFC.
Insert in OH.

That is, when the transmission rate of the signal for switching the main signal is higher than the transmission rate of the signal for switching the various auxiliary signals, the various auxiliary signals are sent before the instruction to send the various auxiliary signals is given to all stations. There is a possibility that a signal reception switching instruction may start to be notified. Therefore, in the wireless intermediate relay device 14 close to the receiving-side wireless terminal device 15, even though the wireless intermediate relay device 13 has not yet transmitted and received various auxiliary signals, the wireless intermediate relay device 14 performs reception switching. There is a problem that it ends up. For this reason, the receiving-side wireless terminal device 15 sends the reception switching instruction of various auxiliary signals only after the reception switching of the main signal is completed and the identification code for instructing the transmission of various auxiliary signals is received. I am trying to do it.

On the other hand, in the case of switching back the line, it is necessary to cancel the transmission switching of the partner station after canceling the reception switching.
Step S33 is a step corresponding to such a case.

In FIG. 14, the number T (T) of the working line for transmitting various auxiliary signals to be transmitted by the transmitting-side wireless terminal device 12 to another station and the receiving-side wireless terminal device 15 are different. Is a diagram showing the number R (T) of the working line to be switched to receive various auxiliary signals, which is transmitted to the station. In the figure, "TSWN
o. "Is the number of the working line on which the transmission-side wireless terminal device 12 is transmitting the main signal, and" RSW No. "is the number of the working line on which the receiving-side wireless terminal device 15 is switching the reception of the main signal. Is. Further, “T (R)” is sent from the transmitting-side wireless terminal station device 12, the working line number received by the receiving-side wireless terminal station device 15, and “R (R)” is the receiving-side wireless terminal station device 15.
This is the working line number sent from the wireless terminal device 12 on the transmitting side.

Next, a fifth embodiment will be described. The configuration of the fifth embodiment is basically the same as the configuration of the first embodiment shown in FIGS. 2 to 7. Therefore, the fifth embodiment will be described by diverting the configuration shown in FIGS. The fifth embodiment is different from the first embodiment in the operation of the transmission switching control unit 23 of FIG. 5, the reception switching / transmission unit 31 of FIG. 6, and the reception switching control unit 39 of FIG. 7. Is.

FIG. 15 is a sequence diagram showing the operation of the fifth embodiment. Since this sequence is basically the same as the sequence of the third embodiment, the steps having the same contents as those of the sequence of the third embodiment are given the same step numbers and the description thereof is omitted. . Hereinafter, description will be given along the numbers given to the respective steps of the sequence.

[S35] The transmission switching control section 23, simultaneously with the insertion of the identification code in step S23, also sends various auxiliary signals inserted into the RFCOH of the faulty line M1 to the RFCOH insertion section 21d, and the backup radio line PROT. RFCO
Insert in H and send. When this transmission is completed, the transmission switching control unit 23 sends a completion signal via RFCOH.
To the receiving switching / sending / sending unit 31 of the wireless intermediate relay device 13.

[S26] The RFCOH dropping units 27a to 27d of the wireless intermediate relay device 13 of FIG. 6 take out the switching control signal of the identification code from the RFCOH, perform the backward protection of a predetermined number of stages, and then perform the reception switching / transmission paralleling unit. Send to 31.

On the basis of the extracted identification code, the reception switching / transmission / sequencing section 31 sends the various auxiliary signals inserted into the RFCOH from the RFCOH insertion section 29a of the faulty line M1 corresponding to the identification code to the backup radio line PROT. RF
It is also inserted from the COH insertion portion 29d into the RFCOH (that is, in parallel) and sent out in the "GO" direction. When this transmission is completed, the reception switching / transmission unit 31 sends a completion signal to the RFCO.
It is sent to the reception switching / transmission parallel unit 31 of the wireless intermediate relay device 14 of FIG. 6 via H.

[S37] In the wireless intermediate relay device 14 of FIG. 6, the same processing as step S26 is performed. When the transmission is completed here, the reception switching / transmission unit 31 sends a completion signal to the reception switching control unit 39 of the wireless terminal device 15 of FIG. 7 via RFCOH.

[S38] When the identification code is inserted in S27 due to the reception switching of the main signal, the reception switching control unit 39 receives the switching / sending / receiving unit 3 of the wireless intermediate relay device 14.
If the completion signal is sent from 1, the RF of the faulty line M1
"GO" that COH dropout part 35a got from RFCOH
Directional auxiliary signals are sent to the RFC of the standby radio line PROT.
The OH dropping unit 35d is switched so as to obtain it from RFCOH.

[S39] The RFCOH dropping unit 32 of the wireless intermediate relay device 14 of FIG. 6 extracts the switching control signal of the identification code from the RFCOH, performs backward protection of a predetermined number of steps, and then sends it to the reception switching / transmission unit 31. send.

If the reception switching / sending / sequencing unit 31 sends a completion signal from the reception switching / sending / sending unit 31 when the switching control signal for the identification code is sent,
RF of the faulty line M1 corresponding to the extracted identification code
The various auxiliary signals in the “GO” direction that the COH dropping unit 27a has extracted from the RFCOH are transferred to the standby radio line PROT.
The RFCOH dropout part 27d is switched to take out from the RFCOH.

[S40] The RFCOH dropping unit 32 of the wireless intermediate relay device 13 of FIG. 6 takes out the identification code switching control signal from the RFCOH, performs backward protection of a predetermined number of stages, and then sends it to the reception switching / transmission unit 31. send.

When the switching control signal of the identification code is sent, if the completion signal is sent from the transmission switching control section 23 of the wireless terminal device 12, the reception switching / sending / sending section 31 takes out the extracted identification. RFCOH of the fault line M1 corresponding to the code
"GO" that the dropout part 27a was taking out from RFCOH
Directional auxiliary signals are sent to the RFC of the standby radio line PROT.
The OH dropping portion 27d is switched so as to be taken out from RFCOH.

As described above, even if there is an instruction to switch reception of various auxiliary signals, after confirming that the partner station has completed transmission of various auxiliary signals, reception switching of various auxiliary signals of the own station is performed. To do. This prevents the problem that the station receiving the various auxiliary signals will switch the reception when the various auxiliary signals cannot be normally transmitted due to equipment failure or the like that performs the parallel transmission at each station. Therefore, the line switching of various auxiliary signals can be performed more accurately.

Next, a sixth embodiment will be described. The configuration of the sixth embodiment is basically the same as the configuration of the first embodiment shown in FIGS. Therefore, the sixth embodiment will be described by diverting the configuration shown in FIGS. The sixth embodiment differs from the first embodiment in that the transmission switching control unit 23 and the RFCOH of FIG. 5 are different.
Insertion unit 21d, reception switching / transmission unit 31 of FIG. 6, RFCO
H drop section 27d, RFCOH insert section 29d, reception switching control section 39 and RFCOH drop section 3 of FIG.
It is an internal configuration of 5d.

FIG. 16 shows a configuration added to the reception switching / sending / sending unit 31, the RFCOH dropping unit 27d, and the RFCOH inserting unit 29d of the wireless intermediate relay device 13 of FIG. That is, the firmware 46 is provided in the reception switching / transmission unit 31, and the various setting registers 47 are provided in the RFCOH dropping unit 27d and the RFCOH inserting unit 29d, respectively. The configuration shown in FIG. 16 has the transmission switching control unit 23 and the RFCOH insertion unit 21d of the wireless terminal device 12 of FIG. 5, the reception switching / transmission parallel unit 31, and the RFCOH dropping unit 27d of the wireless intermediate relay device 14 of FIG. , And the RFCOH insertion unit 29d, and the reception switching control unit 39 and the RFCOH dropping unit 35d of the wireless terminal device 15 of FIG. 7, are similarly provided. However, in the following, the wireless intermediate relay device 1 of FIG.
Only the case provided in No. 3 will be described.

The reception switching / sending / sending unit 31 of the wireless intermediate relay device 13 is provided with firmware 46. The firmware 46 is composed of a switching number register 46a, a supervisory control setting unit 46b including a CPU, and an information storage memory 46c. It The method of processing various auxiliary signals for each of the working lines M1 to M3 in the wireless intermediate relay device 13 is preset in the setting information storage memory 46c according to a user's instruction. There are termination processing and transparent processing as methods of processing various auxiliary signals. Termination processing means the wireless intermediate relay device 13
In the above, the process of dropping or inserting various auxiliary signals is referred to, and the transparent process refers to the process of allowing various auxiliary signals to be transmitted (through) in the wireless intermediate relay device 13 without being inserted or removed.

The switching number register 46a contains the RFCOH
The switching control signal of the identification code obtained from the dropout portions 27a to 27d is input and stored. This identification code represents the abnormal working wireless line. The monitoring control setting unit 46b is
The processing method of the working wireless line corresponding to the identification code stored in the switching number register 46a is described in the information storage memory 46.
It is read from c and written in various setting registers 47.

In this case, there are two setting registers 47, one of which is the RFCOH dropping unit 2 of the protection radio line PROT.
In 7d, the other is RFCOH of the backup radio line PROT
It is provided in the insertion portion 29d. The RFCOH dropping unit 27d and the RFCOH inserting unit 29d perform termination processing or transmission processing with reference to the processing method written in their respective setting registers 47. That is, the wireless intermediate relay device 13
If the abnormal working radio line is terminating various auxiliary signals in, the backup radio line PROT's RFCOH
The dropping unit 27d and the RFCOH inserting unit 29d also perform termination processing, and when the abnormal working radio line in the radio intermediate relay device 13 is transparently processing various auxiliary signals, the RFCOH dropping unit of the standby radio line PROT. The transparent processing is also performed in the 27d and the RFCOH insertion section 29d.

As a result, even if the method of processing various auxiliary signals for each of the working lines M1 to M3 in the wireless intermediate relay device 13 is different, the method of processing various auxiliary signals for each of the working lines M1 to M3 respectively matches. It becomes possible to execute the processing of various auxiliary signals in the backup radio line PROT by the processing method.

The timing for inputting the switching control signal for the identification code to the switching number register 46a may be the timing shown in the first embodiment or the timing shown in the second embodiment.

Next, a seventh embodiment will be described. The configuration of the seventh embodiment is basically the same as the configuration of the first embodiment shown in FIGS. 2 to 7. Therefore, the seventh embodiment will be described by diverting the configuration shown in FIGS. The seventh embodiment is different from the first embodiment in that the transmission switching control unit 23 and the RFCOH of FIG. 5 are different.
Insertion unit 21d, reception switching / transmission unit 31 of FIG. 6, RFCO
H drop section 27d, RFCOH insert section 29d, reception switching control section 39 and RFCOH drop section 3 of FIG.
It is an internal configuration of 5d.

FIG. 17 shows a configuration added to the reception switching / sending / sending unit 31 of the wireless intermediate relay device 13 of FIG.
Note that the configuration shown in FIG. 17 has the transmission switching control unit 23 and the RFCOH insertion unit 21d of the wireless terminal device 12 of FIG. 5, and the reception switching / transmission parallel unit 31, R of the wireless intermediate relay device 14 of FIG.
FCOH dropout section 27d and RFCOH insertion section 29
d, and the reception switching control unit 3 of the wireless terminal device 15 of FIG.
9 and the RFCOH dropout unit 35d are similarly provided, but hereinafter, only the case where they are provided in the wireless intermediate relay device 13 of FIG. 6 will be described.

The reception switching / sending / sending unit 31 of the wireless intermediate relay device 13 includes a monitoring control setting logic unit 50 and a comparison register 5.
1a to 51c are provided. The supervisory control setting logic unit 50 is instructed by the user on a method of processing various auxiliary signals in the wireless intermediate relay device 13 of each of the working wireless lines M1 to M3.
According to this instruction, the supervisory control setting logic unit 50 writes the identification code of the working wireless line instructed to terminate in the comparison registers 51a to 51c. For example, if the wireless intermediate relay device 13 is instructed to terminate all of the active wireless lines M1 to M3, the comparison registers 51a to 51c respectively have "01", "10", "1".
If "1" is written and only the active wireless line M1 is instructed to perform termination processing, "01" is written in the comparison register 51a.

The switching control signal of the identification code obtained from the RFCOH dropping units 27a to 27d is input to and stored in the switching number register 49, and this identification code is input to the comparator 52a. Comparator 52a
Compares the identification code from the switching number register 49 with the identification code written in the comparison register 51a, and when they do not match, sends the identification code from the switching number register 49 to the comparator 52b. Comparator 52
b compares the identification code from the comparator 52a with the identification code written in the comparison register 51b, and when they do not match, sends the identification code from the comparator 52a to the comparator 52c. Comparator 52c
Compares the identification code from the comparator 52b with the identification code written in the comparison register 51c, and when they do not match, sends a mismatch signal to the command unit 53. When the command unit 53 receives the disagreement signal, the command unit 53 determines that the transparent intermediate process is specified as the processing method in the wireless intermediate relay device 13 of the working wireless line having the abnormality, and the RFCOH dropping unit 27d of the standby wireless line PROT and The RFCOH insertion unit 29d is also instructed to perform the transparent processing.
If the command unit 53 does not receive the inconsistency signal, it judges that the processing method in the wireless intermediate relay device 13 of the working wireless line having the abnormality is that the termination processing is designated, and the RFCOH dropout of the standby wireless line PROT is dropped. The terminal 27d and the RFCOH insertion unit 29d are also instructed to perform termination processing.

Note that the supervisory control setting logic unit 50 writes the identification code of the working radio line instructed to be terminated in each of the comparison registers 51a to 51c in accordance with the instruction from the user. Alternatively, the identification code of the active wireless line for which the transparent processing is instructed may be written in each of the comparison registers 51a to 51c.
However, in this case, when the command unit 53 receives the disagreement signal, the wireless intermediate relay device 1 of the working wireless line having the abnormality is
In the processing method in 3, it is judged that the termination processing is designated, and the RFCOH dropping unit 2 of the backup radio line PROT
7d and the RFCOH insertion unit 29d are also instructed to perform termination processing.

As described above, in the seventh embodiment, the sixth
The control speed can be increased as compared with the control device using firmware as in the above embodiment. Next, an eighth embodiment will be described.

The configuration of the eighth embodiment is basically the same as the configuration of the sixth embodiment. Therefore, the eighth embodiment will be described by diverting the configuration of the sixth embodiment shown in FIG.

In the eighth embodiment, the mounting positions of various auxiliary signals for each working line M1 to M3 in the wireless intermediate relay device 13 in RFCOH are set in the setting / setting information storage memory 46c in advance according to a user's instruction. Is set. That is, in SDH, the RFCOH that should carry various auxiliary signals
There may be multiple locations within. For example, 64k open to users
The service line (user channel) of bps is usually F
It can be set to either 1 byte or L1 byte. Therefore, depending on the line, the user channel may be set to F1 byte or L1 byte. Therefore, even when various auxiliary signals are switched from the abnormal working wireless line to the protection wireless line PROT, it is necessary to know in advance which overhead position each auxiliary signal is mounted on the abnormal working wireless line.

The switching number register 46a contains the RFCOH
The switching control signal of the identification code obtained from the dropout portions 27a to 27d is input and stored. This identification code represents the abnormal working wireless line. The monitoring control setting unit 46b is
The auxiliary signal mounting position (F1 byte or L1 byte) of the working wireless line corresponding to the identification code stored in the switching number register 46a is read from the information storage memory 46c and written in various setting registers 47.

In this case, there are two various setting registers 47, one of which is the RFCOH dropping unit 2 of the protection radio line PROT.
In 7d, the other is RFCOH of the backup radio line PROT
It is provided in the insertion portion 29d. The RFCOH dropping unit 27d and the RFCOH inserting unit 29d perform termination processing by referring to the auxiliary signal mounting positions written in their own setting registers 47. That is, for example, the wireless intermediate relay device 13
If the abnormal working wireless line is equipped with various auxiliary signals in the L1 byte, the RF of the standby wireless line PROT
In the COH dropping section 27d and the RFCOH inserting section 29d, various auxiliary signals are dropped from the L1 byte,
Insert in 1 byte.

As a result, in the wireless intermediate relay device 13, RFCOH of various auxiliary signals is supplied to each of the working lines M1 to M3.
Even if the mounting positions are different for each of the working lines M1 to M1
The various auxiliary signals are dropped by the backup radio line PROT at the mounting positions corresponding to the mounting positions of the various auxiliary signals for each M3.

The timing at which the switching control signal for the identification code is input to the switching number register 46a may be the timing shown in the first embodiment or the timing shown in the second embodiment.

Further, the eighth embodiment may be combined with the sixth embodiment or the seventh embodiment. Next, a ninth embodiment will be described.

The configuration of the ninth embodiment is basically the same as the configuration of the first embodiment shown in FIGS.
Therefore, the ninth embodiment will be described by diverting the configuration shown in FIGS. The ninth embodiment differs from the first embodiment in that the transmission switching control unit 23 and the RFCOH insertion unit 21d in FIG. 5, the reception switching / transmission parallel unit 31, the RFCOH dropping unit 27d in FIG. The RFCOH insertion unit 29d, and the reception switching control unit 39 and RF of FIG.
It is an internal configuration of the COH dropout portion 35d.

FIG. 18 shows a configuration added to the reception switching / sending / sending unit 31 of the wireless intermediate relay device 13 of FIG.
The configuration shown in FIG. 18 has the transmission switching control unit 23 and the RFCOH insertion unit 21d of the wireless terminal device 12 of FIG. 5, and the reception switching / transmission parallel unit 31, R of the wireless intermediate relay device 14 of FIG.
FCOH dropout section 27d and RFCOH insertion section 29
d, and the reception switching control unit 3 of the wireless terminal device 15 of FIG.
9 and the RFCOH dropout unit 35d are similarly provided, but hereinafter, only the case where they are provided in the wireless intermediate relay device 13 of FIG. 6 will be described.

In the reception switching / sending / sending unit 31 of the wireless intermediate relay device 13, the monitoring control setting logic unit 55 and the information register 5 are provided.
7a to 57c are provided. The supervisory control setting logic unit 55 is instructed by the user about the mounting positions of various auxiliary signals in the RFCOH in the wireless intermediate relay devices 13 of the working wireless lines M1 to M3. This mounting position is indicated by the F1 byte or the L1 byte, as described in the eighth embodiment. The monitoring control setting logic unit 55 follows this instruction and
Write the mounting positions of various auxiliary signals in the wireless intermediate relay device 13 of the working wireless line M1 in the information register 57a,
Write the mounting positions of various auxiliary signals in the wireless intermediate relay device 13 of the working wireless line M2 in the information register 57b,
The mounting positions of various auxiliary signals in the wireless intermediate relay device 13 of the active wireless circuit M3 are written in the information register 57c.

The switching control signal of the identification code obtained from the RFCOH dropping units 27a to 27d is input to and stored in the switching number register 56, and this identification code is input to the corresponding line number selection unit 58. The corresponding line number selection unit 58 reads the mounting positions of various auxiliary signals stored in the information register corresponding to the identification code sent from the switching number register 56, and reads out the RFC of the spare wireless line PROT.
It is sent to the OH dropout section 27d and the RFCOH insertion section 29d. RFCOH dropout portion 27d and RFCOH insertion portion 2
9d is a backup radio line PRO based on the mounting position sent.
Various auxiliary signals are dropped from the predetermined mounting position of TRFCOH, or various auxiliary signals are inserted into the predetermined mounting position of RFCOH.

As described above, in the ninth embodiment, the eighth
The control speed can be increased as compared with the control device using firmware as in the above embodiment. The ninth embodiment is the same as the sixth embodiment or the seventh embodiment.
You may make it combine with embodiment of this.

Next, the tenth embodiment will be described.
The configuration of the tenth embodiment is the same as that of the first embodiment shown in FIGS.
The configuration is basically the same as that of the embodiment. Therefore, the tenth embodiment will be described by diverting the configuration shown in FIGS.

FIG. 19 is a block diagram showing the structure of the tenth embodiment. This configuration is equivalent to the wireless terminal device 1 of FIG.
2, the wireless intermediate relay devices 13 and 14 of FIG. 6 and the wireless terminal station device 15 of FIG. 7 are provided. Here, the case of being provided in the wireless intermediate relay device 13 of FIG. 6 will be described.

In this case, there are three auxiliary signal input alarm detectors 60, which are provided in the RXs 26a to 26c of the working radio lines M1 to M3 of the radio intermediary relay device 13, respectively. Then, the auxiliary signal input alarm detection unit 60 monitors whether or not there is an abnormality in the various auxiliary signals sent through the corresponding working line, and if there is an abnormality, outputs an alarm signal to the auxiliary signal reception switching determination unit 61. Auxiliary signal reception switching determination unit 61
Is provided in the reception switching / sending / sending unit 31 of the wireless intermediate relay device 13, and the auxiliary signal reception switching unit 62 includes the RFCOH dropping units 27a to 27d and the RFCOH insertion units 29a to 29d.
Is equivalent to

When the auxiliary signal reception switching determination unit 61 does not receive the alarm signal, the auxiliary signal reception switching unit 62 prohibits the auxiliary signal reception switching unit 62 from switching various auxiliary signals from the abnormal working radio line to the backup radio line PROT. This is because when the alarm signal is not received, the working wireless line having an abnormality in the main signal does not have an abnormality in the various auxiliary signals, so that it is not necessary to intentionally switch.

As a result, the standby radio line P is set only when an abnormality occurs in various auxiliary signals sent on the active radio line.
ROT is used for various auxiliary signals to minimize switching.

Incidentally, the auxiliary signal input alarm detection unit 60 is set to the TX 22a of the working radio line of the radio terminal station device 12 of FIG.
22c, the auxiliary signal reception switching determination unit 61 is provided in the transmission switching control unit 23, and the auxiliary signal reception switching unit 62 is provided.
May correspond to the RFCOH insertion parts 21a to 21d. In addition, the auxiliary signal input alarm detection unit 60
RX34a of the working wireless line of the wireless terminal device 15 of FIG.
To 34c, and the auxiliary signal reception switching determination unit 61 is provided.
Is provided in the reception switching control unit 39, and the auxiliary signal reception switching unit 62
May be made to correspond to the RFCOH dropping parts 35a to 35d.

Next, the eleventh embodiment will be described.
The configuration of the eleventh embodiment is the same as that of the first embodiment shown in FIGS.
The configuration is basically the same as that of the embodiment. Therefore, the eleventh embodiment will be described by diverting the configuration shown in FIGS.

FIG. 20 is a block diagram showing the structure of the eleventh embodiment. This configuration is equivalent to the wireless terminal device 1 of FIG.
2, the wireless intermediate relay devices 13 and 14 of FIG. 6 and the wireless terminal station device 15 of FIG. 7 are provided. Here, the case of being provided in the wireless intermediate relay device 13 of FIG. 6 will be described.

The auxiliary signal input alarm detector 64 is provided in the RX 26d of the standby wireless line PROT of the wireless intermediate relay device 13.
Is provided. Then, the auxiliary signal input alarm detector 6
Reference numeral 4 monitors whether or not there is any abnormality in the various auxiliary signals sent through the protection line, and if there is abnormality, outputs an alarm signal to the auxiliary signal reception switching determination section 65. The auxiliary signal reception switching determination unit 65 includes the reception switching / transmission unit 31 of the wireless intermediate relay device 13.
The auxiliary signal reception switching unit 66 is provided in the RFCOH dropping units 27a to 27d and the RFCOH inserting units 29a to 29.
It corresponds to 9d.

When receiving the alarm signal, the auxiliary signal reception switching determination section 65 prohibits the auxiliary signal reception switching section 66 from switching various auxiliary signals from the abnormal working radio line to the backup radio line PROT. This is because if an alarm signal is received, even if there is an error in the main signal, even if there is a slight error in the various auxiliary signals, it is possible to disconnect the line if communication is possible. By determining that this is the next best method than using a protection line.

As a result, the spare radio line PROT is used for various auxiliary signals only when it is confirmed that the various auxiliary signals sent by the spare radio line PROT are not abnormal. It is possible to prevent disconnection of the auxiliary signal line.

The auxiliary signal input alarm detection unit 64 is provided in the TX 22d of the backup radio line of the wireless terminal device 12 of FIG. 5, and the auxiliary signal reception switching determination unit 65 is provided as the transmission switching control unit 2.
3, the auxiliary signal reception switching unit 66 may correspond to the RFCOH insertion units 21a to 21d. Further, the auxiliary signal input alarm detection unit 64 is provided in the RX 34d of the standby radio line of the wireless terminal device 15 of FIG. 7, the auxiliary signal reception switching determination unit 65 is provided in the reception switching control unit 39, and the auxiliary signal reception switching unit 66 is provided. , RFCOH dropout parts 35a-35
You may make it correspond to d.

In the above second to eleventh embodiments, description has been made assuming that there are three working radio lines and one backup radio line, but the same as the first embodiment. In the eleventh embodiment as well, the number of active wireless lines may be N and the number of standby wireless lines may be m (N>m> 1).

[0138]

As described above, according to the present invention, when the working radio line is about to switch to the protection radio line, the transmitting side terminal device uses the switching information as an auxiliary signal to cause an overrun of the main signal of the frame structure. Insert in the head. The relay device obtains the switching information and inserts the auxiliary signal inserted into and removed from the overhead of the main signal transmitted via the working radio line into the overhead of the main signal transmitted via the backup radio line. Switch to insert and remove.

Thus, the switching of the redundant configuration of N + m (m ≧ 1) of the auxiliary signal in the wireless section is realized with a simple configuration. Further, the switching information should include at least the identification code of the working wireless line having the abnormality. This makes it possible to provide a device having a small hardware scale.

Further, the transmission timing and switching timing of the auxiliary signal are determined according to the transmission timing and switching timing of the main signal. This will accelerate the switching time of the auxiliary signal,
It is possible to reliably switch the auxiliary signal or realize non-instantaneous switching.

In the relay station or the like, the processing method for the auxiliary signal may be a mixture of termination processing and transparent processing for each working line, or the mounting position of the auxiliary signal to the overhead may be different for each working line. In this case, it is possible to switch to the backup line depending on the processing method and mounting position.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a configuration diagram showing an overall configuration of the first embodiment.

FIG. 3 is a diagram showing a frame structure of a signal used in the first embodiment.

FIG. 4 is a configuration diagram showing an internal configuration of an optical transmission terminal device.

FIG. 5 is a configuration diagram showing an internal configuration of a wireless terminal device on the transmission side.

FIG. 6 is a configuration diagram showing an internal configuration of a wireless intermediate relay device.

FIG. 7 is a configuration diagram showing an internal configuration of a wireless terminal device on the receiving side.

FIG. 8 is a sequence diagram showing the operation of the first embodiment.

FIG. 9 is a configuration diagram showing an internal configuration of a reception switching / sending / sequencing unit of the wireless intermediate relay device.

FIG. 10 is a sequence diagram showing an operation according to the second embodiment.

FIG. 11 is a sequence diagram showing an operation of the third embodiment.

FIG. 12 is a diagram showing a phase adjustment device.

FIG. 13 is a sequence diagram showing the operation of the fourth embodiment.

FIG. 14 is a number T (T) of a working line to which various auxiliary signals are to be sent and transmitted by the transmitting-side wireless terminal device to another station.
FIG. 3 is a diagram showing a working line number R (T) to be switched by the receiving side wireless terminal device to another station for receiving various auxiliary signals.

FIG. 15 is a sequence diagram showing the operation of the fifth embodiment.

FIG. 16: Reception switching / transmission / transmission unit of the wireless intermediate relay device, RF
It is a figure which shows the structure added to a COH dropping part and an RFCOH insertion part.

FIG. 17 is a diagram showing a configuration added to a reception switching / sending / sending unit of the wireless intermediate relay device.

FIG. 18 is a diagram showing a configuration added to a reception switching / transmission parallel unit of the wireless intermediate relay device.

FIG. 19 is a block diagram showing a configuration of a tenth embodiment.

FIG. 20 is a block diagram showing the structure of an eleventh embodiment.

FIG. 21 is a configuration diagram showing an entire conventional communication system.

[Explanation of symbols]

 1 a plurality of optical lines 2 a plurality of working wireless lines 3 at least one standby wireless line 4 transmitting side terminal device 4a auxiliary signal inserting / removing means 4b switching information inserting means 5 relay device 5a auxiliary signal inserting / removing means 5b switching information dropping means 5c Auxiliary signal switching means 6 Receiving side terminal device

Claims (15)

[Claims] 1. A line switching device of a digital communication system including a wireless line having a redundant structure, wherein a plurality of optical lines each transmitting a main signal in a frame structure having an overhead, and the plurality of optical lines. The same number of working wireless lines, at least one standby wireless line, and the plurality of optical lines located at both ends of the working wireless line and the standby wireless line, with respect to the working wireless line and the standby wireless line. A terminal device on the transmitting side and a terminal device on the receiving side that perform selective connection, a relay device provided in the middle of the working wireless line and the standby wireless line, and two relay devices provided on the two terminal device and the relay device, respectively. An auxiliary signal inserting / removing means for inserting an auxiliary signal into the overhead or dropping the auxiliary signal from the overhead; Vignetting, of the current radio channel 1
Switching information inserting means for inserting the switching information into the overhead from the corresponding auxiliary signal inserting / removing means as the auxiliary signal when one of them is about to switch to one of the backup radio lines. Switching information dropping means for dropping the switching information from the overhead by means of a corresponding auxiliary signal inserting / removing means, and based on the switching information obtained from the switching information dropping means provided in the relay device. , The auxiliary signal inserted into and removed from the overhead of the main signal transmitted via the one of the working radio lines is compared with the overhead of the main signal transmitted via the one of the backup radio lines. A line switching device for a digital communication system, comprising: an auxiliary signal switching means for switching so as to be inserted and removed. 2. The switching information inserted into the overhead by the switching information insertion means is an identification code for identifying at least the one of the working wireless lines. 1. A line switching device for a digital communication system according to 1. 3. The auxiliary signal switching means, based on the switching information obtained from the switching information dropping means,
From the reception of the auxiliary signal inserted in the overhead of the main signal transmitted via the one of the working radio lines to the overhead of the main signal transmitted via the one of the backup radio lines. Auxiliary signal reception switching means for switching to reception of the inserted auxiliary signal, based on the switching information obtained from the switching information dropping means,
Auxiliary signal transmission for simultaneously inserting an auxiliary signal into the overhead of the main signal transmitted via the one of the working radio lines and the overhead of the main signal transmitted via the one of the standby radio lines A line switching device for a digital communication system according to claim 1, further comprising: 4. The auxiliary signal reception switching means and the auxiliary signal parallel transmission means start the main signal parallel transmission of the transmitting side terminal station device prior to the switching of the main radio signal from the working radio channel to the backup radio channel. 4. The line switching device for a digital communication system according to claim 3, wherein the operation is started at each timing. 5. The auxiliary signal reception switching means and the auxiliary signal transmission / reception means each start operation at a switching timing of the receiving side terminal device from the working radio line to the protection radio line regarding a main signal. The line switching device for a digital communication system according to claim 3. 6. The auxiliary signal parallel transmission means starts operation at a main signal parallel transmission start timing of the transmission side terminal station device prior to switching of the main radio signal from the working radio line to the backup radio line, 4. The digital communication system according to claim 3, wherein the auxiliary signal reception switching unit starts operation at a switching timing of the receiving side terminal station device from the working wireless line to the standby wireless line regarding a main signal. Line switching device. 7. The auxiliary signal reception switching means has a phase of an auxiliary signal obtained from the one of the working radio lines and a phase of an auxiliary signal obtained via the one of the backup radio lines. 4. The line of the digital communication system according to claim 3, further comprising: a phase adjusting unit for adjusting the reception of the auxiliary signals, wherein the auxiliary signal reception switching unit performs reception switching of both auxiliary signals after the phase adjustment is completed by the phase adjusting unit. Switching device. 8. A storage unit which is provided at least in the relay device and which stores processing information as to whether each auxiliary signal transmitted through the plurality of working wireless lines should be transparently processed or terminated in its own device. And, at least based on the switching information obtained by the switching information dropping means and the processing information stored in the storage means provided in the relay device, operating the auxiliary signal switching means for performing termination processing, or 2. The line switching device for a digital communication system according to claim 1, further comprising: a deciding unit for deciding whether to stop the operation. 9. A register which is provided in at least the relay device and which stores an identification code of an active wireless line for which an auxiliary signal is to be transparent processed within itself, or an identification code of an active wireless line to be terminated. At least the auxiliary signal switching unit which is provided in the relay device, compares the switching information obtained by the switching information dropping unit with the identification code stored in the register, and performs termination processing based on the comparison result. The line switching device of the digital communication system according to claim 1, further comprising: a control unit that operates and stops the operation. 10. At least the relay device,
Storage means for storing position information indicating a byte position in the overhead in which each auxiliary signal transmitted through the plurality of working wireless lines is mounted; and a storage means provided at least in the relay device and obtained by the switching information dropping means. On the basis of the switching information and the position information stored in the storage means, the auxiliary signal inserted / removed at a predetermined byte position of the overhead of the main signal transmitted via the one of the working wireless circuits, 2. The digital communication according to claim 1, further comprising: switching means for switching so as to insert / remove with respect to a predetermined byte position of an overhead of a main signal transmitted via the one of the backup radio lines. System line switching device. 11. At least the relay device,
Detection means for detecting an abnormality in the auxiliary signal inserted / removed in the overhead of the main signal transmitted via the one of the working radio lines, and provided at least in the relay device, The line switching device of the digital communication system according to claim 1, further comprising: a prohibiting unit that prohibits the operation of the auxiliary signal switching unit when the detecting unit has not detected an abnormality. 12. The relay device is provided at least,
Detection means for detecting an abnormality in the auxiliary signal inserted / removed in the overhead of the main signal transmitted through the one of the backup radio lines; and at least the relay device, The line switching device of the digital communication system according to claim 1, further comprising: an operation control unit that operates the auxiliary signal switching unit only when the detecting unit does not detect an abnormality. 13. A line switching device of a digital communication system including a wireless line having a redundant structure, wherein a plurality of optical lines each transmitting a main signal in a frame structure having an overhead, and the plurality of optical lines. The same number of working wireless lines, at least one standby wireless line, and the plurality of optical lines located at both ends of the working wireless line and the standby wireless line, with respect to the working wireless line and the standby wireless line. A terminal device on the transmitting side and a terminal device on the receiving side that perform selective connection, a relay device provided in the middle of the working wireless line and the standby wireless line, and two relay devices provided on the two terminal device and the relay device, respectively. An auxiliary signal inserting / removing means for inserting an auxiliary signal into the overhead or dropping the auxiliary signal from the overhead; It provided 1 of the working radio channel
Switching information inserting means for inserting the switching information into the overhead from the corresponding auxiliary signal inserting / removing means as the auxiliary signal when one of them is about to switch to one of the standby radio lines, and the relay device and Provided to each of the terminal devices, the corresponding auxiliary signal insertion and removal means, switching information dropping means for dropping the switching information from the overhead, provided in the relay device and the receiving side terminal device, Based on the switching information obtained from the corresponding switching information dropping means,
From the reception of the auxiliary signal inserted in the overhead of the main signal transmitted via the one of the working radio lines to the overhead of the main signal transmitted via the one of the backup radio lines Auxiliary signal reception switching means for switching to reception of the inserted auxiliary signal, provided on the relay device and the transmission side terminal device, based on the switching information obtained from the corresponding switching information dropping means,
Auxiliary signal transmission for simultaneously inserting an auxiliary signal into the overhead of the main signal transmitted via the one of the working radio lines and the overhead of the main signal transmitted via the one of the standby radio lines A line switching device for a digital communication system, comprising: 14. A signal provided in the receiving-side terminal device, which indicates completion of switching of the receiving-side terminal device from the working wireless line to the standby wireless line regarding a main signal, and corresponding switching information dropping means. When receiving the switching information,
Means for operating each of the auxiliary signal reception switching means provided in the relay device and the receiving side terminal device; and a means provided in the transmitting side terminal device, from the working wireless line for the main signal to the backup wireless line When a signal indicating the start of main signal transmission of the transmitting side terminal device prior to the switching and the switching information from the corresponding switching information dropping means are received, the relay device and the transmitting side terminal device are 14. The line switching device for a digital communication system according to claim 13, further comprising: a means for operating each of the auxiliary signal transmitting and transmitting means provided. 15. The overhead of the main signal transmitted through the one of the working radio lines and the backup are provided by corresponding auxiliary signal transmitting / receiving means provided in the relay device and the transmitting side terminal device. Further comprising an end signal output means for outputting an end signal indicating the end when inserting the auxiliary signal at the same time into the overhead of the main signal transmitted via the one of the wireless lines, 14. The line switching device for a digital communication system according to claim 13, wherein each of the auxiliary signal reception switching means operates only when receiving the termination signal from the corresponding termination signal output means.