JP5369680B2 - Wireless relay device and communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio relay device capable of surely communicating various information between devices for controlling or monitoring an opposite device even when a failure occurs during transmitting and receiving a synchronous transfer mode signal even with the opposite device, and to provide a communication method. <P>SOLUTION: In a SDH (Synchronous Digital Hierarchy) transmission system, the radio relay device multiplexes information between the devices transmitted and received to/from the other opposite device on an RFCOH (Radio Frame Complementary Overhead) added to an STM (Synchronous Transfer Mode) 1 signal including a SOH (Section Overhead). <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a communication technology of a radio relay apparatus compatible with SDH (Synchronous Digital Hierarchy).

  In recent years, the construction of SDH compatible digital multiplexing systems (hereinafter referred to as SDH transmission systems) is being promoted in various countries. In particular, in a geographical environment including a mountainous area or a strait, there is an increasing demand for a wireless relay device compatible with SDH, which is relatively easy to construct a transmission network.

  Generally, in an SDH transmission system, a digital signal is transmitted by a standardized STM (Synchronous Transfer Mode) frame format. In this case, for example, an STM-1 (155.52 Mbps) frame (synchronous transfer mode signal) is composed of a section overhead (hereinafter, SOH: Section Overhead) and a payload. And between the radio relay apparatuses facing each other provided in the radio section of the SDH transmission system, the STM-1 frame is transmitted with a radio transmission overhead (RFCOH; Radio Frame Complementary Overhead) added thereto.

  In the SDH transmission system, various pieces of information between devices for controlling or monitoring the devices (such as line switching control information, order wire information, DCC (Data Communication Channel) information, trace information, error information, etc.) between facing wireless relay devices ). Conventionally, these inter-device information is arranged in fixed areas in the SOH and RFCOH. For example, the overwire information is arranged in the E1 byte of the SOH, and the DCC information is arranged in the D1 to D3 bytes of the SOH.

The SDH transmission system is also disclosed in, for example, the following Patent Documents 1 and 2.
Japanese Patent Laid-Open No. 7-107013 JP-A-9-135229

  In an SDH transmission system, a method of synchronizing a plurality of devices in a network with a single master clock source has been adopted. However, in recent years, for example, in developing countries, a master clock is used to construct a transmission network at a low cost. The source may not be installed. In such a case, there is a problem that frame loss may occur in communication between the facing radio relay apparatuses. When such a problem occurs, information is not exchanged between the devices, so control for switching the main line to the auxiliary line cannot be performed, and / or one of the wireless relay devices can be remotely connected to the opposite device. It becomes impossible to access, and this interferes with the maintenance work of the wireless relay device.

The above problem will be described with reference to FIGS. FIG. 7 is a diagram illustrating an SDH transmission system including a master clock source. FIG. 8 is a diagram illustrating an SDH transmission system that does not include a master clock source. In each figure, communication is performed between the wireless relay device and the multiplexing device in the wired section, and communication is performed between the wireless relay devices facing each other in the wireless section.
In the SDH transmission system shown in FIG. 7, a master clock source 1 is provided, and a clock generated by the master clock source 1 serves as a reference clock for the multiplexing device 4. Based on predetermined data in an uplink (or downlink) signal (STM-1 frame) generated in synchronization with this reference clock, other devices (wireless relay device 2, wireless relay device 3, and multiplexing device 5) ), The clock processing unit regenerates the reference clock. Thus, in the SDH transmission system shown in FIG. 7, synchronization based on a common clock (so-called intra-network synchronization) is realized among all devices in the transmission network.

  On the other hand, in the SDH transmission system shown in FIG. 8, since no master clock source is provided, each signal (STM-1 frame) on the uplink or downlink in the system is transmitted by ITU-T (International Telecommunication Union Telecommunication Standardization Sector). ) Can be affected by the maximum allowable radio frequency deviation of ± 4.6 ppm. When this deviation occurs in both the uplink and downlink, a maximum deviation of 9.2 ppm occurs between the radio relay apparatuses facing each other, resulting in a frame loss.

  In view of the above-described viewpoints, the object of the present invention is to be able to communicate various inter-device information for controlling or monitoring a device when a failure occurs in the transmission and reception of the synchronous transfer mode signal with the opposite device. It is an object of the present invention to provide a wireless relay device and a communication method with improved performance.

This wireless relay device and communication method are compatible with SDH, and the second overhead is added to the synchronous transfer mode signal including the first overhead, and the information between devices transmitted to and received from other devices facing each other. Are multiplexed.
Preferably, in the wireless relay device and the communication method, the first communication mode for transmitting / receiving the inter-device information in a state inserted in the first overhead, or the first communication mode for transmitting / receiving the inter-device information in a state multiplexed in the second overhead. Two communication modes are configured to be selected.

  ADVANTAGE OF THE INVENTION According to this invention, when a failure arises in transmission / reception of a synchronous transfer mode signal between opposing devices, possibility that various apparatus information for controlling or monitoring an apparatus can be communicated can be improved.

(1) 1st Embodiment (1-1) SDH transmission system Hereinafter, 1st Embodiment of the radio relay apparatus of this invention is described. The radio relay apparatus according to the embodiment is a multiple radio relay apparatus arranged at both ends of a radio section in an SDH transmission network having no master clock source. A communication method between the SDH transmission system including the wireless relay device and the wireless relay device will be described with reference to FIG. FIG. 1 is a diagram for explaining a schematic configuration and a communication method of an SDH transmission system including a wireless relay device in this embodiment.

  In the SDH transmission system shown in FIG. 1, the radio relay device 10 and the radio relay device 11 are opposed to each other in the radio section. The wireless relay device 10 includes a signal processing unit 20 and a monitoring control unit 30, and the wireless relay device 11 includes a signal processing unit 21 and a monitoring control unit 31. A signal processing unit (transmission / reception unit) in each wireless relay device transmits and receives uplink or downlink signals between the wireless relay devices.

As shown in FIG. 1, in this SDH transmission system, transmission / reception of signals between wireless relay apparatuses in a wireless section is performed in the STM-1 frame (155.52 Mbps) in the standardized STM frame format with a wireless transmission overhead of 15.552 Mbps. (Hereinafter referred to as RFCOH; Radio Frame Complementary Overhead). This STM-1 frame is composed of a section overhead (hereinafter referred to as SOH) and a payload.
SOH and RFCOH are embodiments of the first overhead and the second overhead, respectively.

In this SDH transmission system, information between devices transmitted and received between wireless relay devices is given from an external device (not shown). Each monitoring control unit uses the 2048 Kbps (2.048 Mbps) communication signal (hereinafter, abbreviated as “WS” or “WS signal” as appropriate) secured as an optional band in the RFCOH. The information is generated by mapping, and information between devices is extracted from the received communication signal. As shown in FIG. 1, in this SDH transmission system, communication signals are transmitted and received in a redundant configuration (WS_X signal, WS_Y signal) between wireless relay apparatuses.
That is, the radio transmission unit 23 of the radio relay apparatus 20 adds the RFCOH including the WS_X signal and the WS_Y signal to the uplink STM-1 frame and transmits the frame to the radio relay apparatus 21. Then, the STM-1 frame and RFCOH are received by the wireless reception unit 26 of the wireless relay device 21. Similarly, the wireless transmission unit 27 of the wireless relay device 21 adds the RFCOH including the WS_X signal and the WS_Y signal to the downlink STM-1 frame and transmits the frame to the wireless relay device 20. Then, the STM-1 frame and RFCOH are received by the wireless reception unit 24 of the wireless relay device 20.

  As described above, since the master clock source is not provided in the SDH transmission system shown in FIG. 1, each signal (STM-1 frame) on the uplink or downlink in the system is defined by ITU-T. The maximum allowable radio frequency deviation of ± 4.6 ppm can be affected. When this deviation occurs in both the uplink and the downlink, a maximum deviation of 9.2 ppm occurs between the radio relay apparatuses facing each other. Therefore, if the inter-device information is inserted into the SOH of the STM-1 frame, there is a possibility that the inter-device information cannot be exchanged between the devices due to the loss of the STM-1 frame. Therefore, in this embodiment, the inter-device information is mapped to a communication signal (WS signal) secured in the RFCOH. Note that in consideration of the communication capacity (2048 Kbps) of the communication signal secured in the RFCOH, it may be mapped to the communication signal by limiting only the important information among devices.

Note that a communication capacity of 2048.2048 Kbps is secured for the communication signal (WS signal) on the wireless line. Then, the supervisory control unit of one of the radio relay apparatuses generates a 2048 Kbps WS signal, and inserts (stuff processing) a dummy bit corresponding to 0.2048 Kbps (= 100 ppm) into the 2048 Kbps WS signal, thereby obtaining 2048.2048 Kbps. The WS signal is transmitted from the wireless transmission unit. In the other wireless relay apparatus, after the wireless reception unit receives the 2048.2048 Kbps WS signal, the dummy bits are removed (destuffing process), and the monitoring control unit acquires the 2048 Kbps WS signal.
In the following description, the WS signal communication capacity is mainly described based on 2048 Kbps, which is the communication capacity in the monitoring control unit.

(1-2) Configuration of Communication Signal (WS Signal) Next, the configuration of the WS signal will be described with reference to FIG. FIG. 2 is a diagram illustrating a configuration of a communication signal (WS signal) and a method for mapping information between devices to a WS signal. Both the WS_X signal and the WS_Y signal in the redundant configuration have the same configuration as the WS signal shown in FIG.

In FIG. 2, (d) RSC (Radio Service Channel) signal, (e) OWE1 signal (E1 bit of overwire signal), (f) DCC (Data Communication Channel) signal are (b) 2MCLK ( (A) Example of mapping to WS signal based on 2.048 MHz clock). That is, an example is shown in which an RSC signal (832 Kbps), an OWE1 signal (64 Kbps), and a DCC signal (192 Kbps) are multiplexed into a 2.048 Mbps WS signal frame.
Specifically, in the example shown in FIG. 2A, one frame of WS signal (corresponding to 256 clocks (CLK)) is an RSC signal corresponding to 104 clocks in order after a predetermined frame pattern bit corresponding to 16 clocks. , An OWE1 signal corresponding to 8 clocks, a DCC signal corresponding to 24 clocks, and a free area corresponding to 104 clocks (all 0). The wireless relay device according to the present embodiment incorporates this WS signal into RFCOH, and performs transmission / reception with another opposing wireless relay device. At this time, as shown in FIG. 1, the WS signal is sent at a timing based on the clock of the transmission clock source in the monitoring control unit.

  As shown in FIG. 2, in the wireless relay device of the present embodiment, inter-device information transmitted / received between other opposing wireless relay devices is multiplexed into a communication signal (WS signal) provided in RFCOH. I am doing so. Therefore, even if the frame of the synchronous transfer mode signal (STM-1 frame) cannot be detected due to the maximum deviation allowed by the radio frequency between the opposing radio relay apparatuses (frame loss), in this radio relay apparatus, Inter-device information can be transmitted and received without being affected by the frame loss of the synchronous transfer mode signal.

In FIG. 2, the RSC signal (832 Kbps), OWE1 signal (64 Kbps), and DCC signal (192 Kbps) are all included as the inter-device information, which is about half the WS signal communication capacity (2048 Kbps). There is enough room for capacity. For this reason, even when the maximum deviation allowed in the radio frequency between the radio relay apparatuses facing each other occurs, the possibility of losing the inter-device information mapped to the WS signal by inter-device communication is very low.
Furthermore, the WS signal has tolerance (correction capability on the receiving side) against a deviation of 100 ppm of the band by the stuff / destuff processing described above, and the WS signal communication capacity (2048 Kbps) in the monitoring control unit. On the other hand, even if more inter-device information than that illustrated in FIG. 2 is multiplexed, the possibility of losing the inter-device information by inter-device communication is very low.

  As described above, in the wireless relay device according to the present embodiment, the inter-device information for controlling or monitoring the communication between devices with the other opposing wireless relay device is the STM- that is the synchronous transfer mode signal. Instead of one frame of SOH, it is mapped to a communication signal in RFCOH and transmitted / received. As a result, even if the wireless relay device of this embodiment is provided in an SDH transmission system that does not have a master clock source, it is not affected by the deviation of the synchronous transfer mode signal that accompanies the radio frequency deviation. Inter-device information can be reliably transmitted to and received from the relay device.

(2) Second Embodiment Next, a second embodiment of the wireless relay device will be described. In each of the following embodiments, an SDH transmission system provided with a wireless relay device is the same as that shown in FIG. Also in each of the following embodiments, a case where an RSC signal, an OWE1 signal, and a DCC signal are mapped to a WS signal as an inter-device information for controlling or monitoring inter-device communication will be described as an example (FIG. 2).

In the wireless relay device of the present embodiment, the first communication mode in which the inter-device information is transmitted / received while being inserted in the SOH of the STM-1 frame (synchronous transfer mode signal), or the inter-device information is mapped to the WS signal in the RFCOH. A selection unit for selecting one of the second communication modes for transmitting and receiving is provided in the monitoring control panel.
Hereinafter, with reference to FIG. 3 and FIG. 4, the configuration of the wireless relay device 10 of the present embodiment will be described with a particular focus on the monitoring control unit 30. FIG. 3 is a block diagram illustrating a main part of the wireless relay device 10. FIG. 4 is a diagram illustrating a configuration example of the monitoring control panel 32 of the wireless relay device 10.

(2-1) Configuration of Radio Relay Device First, referring to FIG. 3, the monitoring control unit 30 includes a monitoring control panel 32 and a relay communication auxiliary panel 34. The monitoring control panel 32 includes a serial interface (serial I / F) 36, a MUX / DMUX unit 50 (multiplexing unit), a selection unit 60, a monitoring control processing unit 90, an RSC (Radio Service Channel) processing unit 92, an RPS (Radio). A protection switch) processing unit 93, a VF / DGTL processing unit 94, an OWE1 processing unit 95, a hub (HUB) 96, and a LAN (Local Area Network) / WAN (Wide Area Network) processing unit 97. The relay communication auxiliary board 34 includes a BU / UB converter 71, a clock source 72, and a PLL (Phase Locked Loop) 73.

  In FIG. 3, the OWE1 processing unit 95 is communicably connected to an external device (not shown) and inputs / outputs an OWE1 signal to the selection unit 60. The LAN / WAN processing unit 97 is communicably connected to an external LAN network device or a WAN network device (not shown) via the hub 96 and inputs / outputs a DCC signal to the selection unit 60. The RSC processing unit 92 is connected to an RPS processing unit 93 that processes switching information between devices and a VF / DGTL processing unit 94 that processes a digital order wire signal, and an RSC signal (RSC_X signal, RSC_Y signal) to the selection unit 60. (Redundant configuration).

The selection unit 60 inputs RSC_X signal, RSC_Y signal, OWE1 signal, and DCC signal as inter-device information from the RSC processing unit 92, OWE1 processing unit 95, and LAN / WAN processing unit 97, respectively. When transmitting, the inter-device information is output to either the serial interface 36 or the MUX / DMUX unit 50 in accordance with a command from the monitoring control processing unit 90. Further, when receiving the RSC_X signal, the RSC_Y signal, the OWE1 signal, and the DCC signal as the inter-device information, the selection unit 60 inputs the inter-device information from either the serial interface 36 or the MUX / DMUX unit 50, The data is output to the RSC processing unit 92, the OWE1 processing unit 95, and the LAN / WAN processing unit 97.
A configuration example of the selection unit 60 will be described later with reference to FIG.

When the MUX / DMUX unit 50 receives the RSC_X signal, the RSC_Y signal, the OWE1 signal, and the DCC signal from the selection unit 60, the MUX / DMUX unit 50 multiplexes these signals to generate a 2048 Kbps WS signal (WS_X, WS_Y) to assist relay communication. It outputs to the board 34. Further, when the WS signal (WS_X, WS_Y) is input from the relay communication auxiliary board 34, the MUX / DMUX unit 50 separates the WS signal, extracts the RSC_X signal, the RSC_Y signal, the OWE1 signal, and the DCC signal, and selects them. To the unit 60.
A configuration example of the MUX / DMUX unit 50 will be described later with reference to FIG.

  The monitoring control processing unit 90 is mainly composed of a microcontroller and performs control processing for the entire monitoring control panel 32. For example, the monitoring control processing unit 90 sends a command related to the selection operation to the selection unit 60.

In the relay communication auxiliary board 34, the BU / UB converter 71 includes a UB converter 81 and a UB converter 82 (see FIG. 4). The BU / UB converter 71 converts the received WS signal from a bipolar code, which is a transmission code suitable for the radio section, to a unipolar code, which is a transmission code suitable for the carrier section (BU conversion). At the same time, the WS signal to be transmitted is converted from a unipolar code to a bipolar code (UB conversion).
The clock source 72 is a clock source that generates a clock serving as a reference when sending a WS signal, and a clock having a frequency (for example, 79 MHz) sufficiently higher than 2.048 MHz that is a reference frequency when generating a WS signal. Is configured to generate The PLL 73 performs phase synchronization with the received signal in order to perform reception processing.

The serial interface 36 performs input / output processing of the signal of the STM-1 frame having the 0-system / 1-system redundant configuration with the signal processing unit 20. When the STM-1 frame is output to the signal processing unit 20, the serial interface 36 places the OWE1 signal from the selection unit 60 in the E1 byte of the SOH, and converts the DCC signal from the selection unit 60 into D1 to D3 bytes of the SOH. Multiplexed as if they were arranged. On the other hand, when the STM-1 frame is input from the signal processing unit 20, the serial interface 36 separates the STM-1 frame, extracts the OWE1 signal and the DCC signal from the SOH, and outputs them to the selection unit 60.
In addition, the serial interface 36 performs input / output processing of redundant signals (RSC_X signal, RSC_Y signal) of the RSC signal with the signal processing unit 20. This RSC redundant signal is provided corresponding to RFCOH added to the STM-1 frame of the 0-system / 1-system redundant configuration. The RSC signal is incorporated into the RFCOH RSC (Radio Service Channel) in the signal processor 20.

With the above-described configuration, when applying the first communication mode, the monitoring control unit 30 transmits the inter-device information (OWE1 signal, DCC signal) to the STM-1 frame (synchronous transfer) via the serial interface 36 (first communication interface). Signal input / output processing is performed with the signal processing unit 20 in a state of being inserted into the SOH of the mode signal). Further, when the first communication form is applied, the RSC signal is incorporated into the RFCOH RSC in the signal processing unit 20.
On the other hand, in the case where the second communication mode is applied, the monitoring control unit 30 communicates with the signal processing unit 20 via the relay communication auxiliary board 34 (second communication interface) (OWE1 signal, DCC signal, Input / output processing of a WS signal multiplexed with (RSC signal). The WS signal is incorporated into RFCOH in the signal processing unit 20.

(2-2) Configuration Example of MUX / DMUX Unit and Selection Unit Next, a configuration example of the MUX / DMUX unit 50 and the selection unit 60 will be described with reference to FIG.
As shown in FIG. 4, the MUX / DMUX unit 50 includes a multiplexer (MUX) 51, separators (DMUX) 52 and 53, a selector (SEL) 54, frame detectors 55 and 56, and a frequency divider 57. . The selection unit 60 includes selectors (SEL) 61 to 67.

  In the following description, when the monitoring control processing unit 90 determines to apply the first communication mode in which the inter-device information is transmitted and received in the state inserted in the SOH of the STM-1 frame (synchronous transfer mode signal), the selection control unit 90 It is assumed that a command C1 is sent to 60. In addition, the monitoring control processing unit 90 sends a command C2 to the selection unit 60 when it is determined that the second communication mode in which the inter-device information is mapped to the WS signal in the RFCOH and transmitted / received is applied. .

In the selection unit 60, the selectors 65, 63, and 61 are selectors that operate during transmission.
When the selectors 65, 63, 61 receive a command C1 from the supervisory control processing unit 90, the RSC signal, OWE1 signal, DCC input from the RSC processing unit 92, OWE1 processing unit 95, and LAN / WAN processing unit 97, respectively. The serial interface 36 is selected as a signal output destination. At this time, as shown in FIG. 4, the RSC signal is output to the serial interface 36 in a redundant configuration of the RSC_X signal and the RSC_Y signal. On the other hand, when the selectors 65, 63, 61 receive the command C2 from the monitoring control processing unit 90, the selectors 65, 63, 61 select the multiplexer 51 of the MUX / DMUX unit 50 as the output destination of the corresponding signal.

In the selection unit 60, the selectors 66, 67, 64, and 62 are selectors that operate during reception.
When the selectors 66, 67, 64, 62 receive the command C1 from the monitoring control processing unit 90, the selectors 66, 67, 64, 62 select the serial interface 36 as an input destination of the corresponding RSC_X signal, RSC_Y signal, OWE1 signal, and DCC signal. To do. On the other hand, when the selectors 66, 67, 64, 62 receive the command C2 from the monitoring control processing unit 90, they select the selector 54 of the MUX / DMUX unit 50 as the input destination of the corresponding signal.

  When receiving the RSC signal, OWE1 signal, and DCC signal corresponding to each of the selectors 65, 63, and 61 from the selectors 65, 63, and 61 at the time of transmission, the multiplexer 51 multiplexes these signals and creates a 2048 Kbps WS signal (WS_X, WS_Y redundant configuration). ) Is generated. The mapping method of the RSC signal, the OWE1 signal, and the DCC signal to the WS signal is as described with reference to FIG.

In order to process the received WS signal (WS_X, WS_Y), a clock 2MCLK (redundant configuration on the X side and Y side) obtained by dividing the clock generated by the clock source 72 of the relay communication auxiliary board 34 to 2.048 MHz, It is supplied from the relay communication auxiliary board 34 to the monitoring control board 32. "
The frame detectors 56 and 55 receive the WS_X signal and the WS_Y signal converted into the unipolar codes by the BU converter 81, respectively, and output the signals to the separators 53 and 52, and the frames of the signals (see FIG. 2 (a) corresponding to 256 clocks) is detected. Then, the frame detectors 56 and 55 output LOF (X) and LOF (Y), which are signals indicating whether or not the frame has been correctly detected, to the selector 54 in units of frames.

Separators 53 and 52 separate the WS_X signal and WS_Y signal into RSC_X signal, RSC_Y signal, OWE1 signal, and DCC signal as inter-device information, and output them.
The selector 54 selects the output signal of either the separator 53 or 52 based on the LOF (X) and LOF (Y) from each frame detector. For example, when only the WS_X signal can be detected correctly, the inter-device signal output by the separator 53 is selected, and the output signal of the separator 52 is ignored. When the frames of both the WS_X signal and the WS_Y signal can be detected, it is determined in advance whether the inter-device signal output by the separator 53 or 52 is selected.

  The frequency divider 57 receives 79 MCLK (for example, 79 MHz clock) as a clock phase-synchronized by the PLL 73, and divides the frequency to a specific frequency necessary for various processes in the monitoring control panel 32.

  As described above, the radio relay apparatus according to the second embodiment transmits the inter-device information in the first communication form or the inter-device information that is transmitted and received in a state in which the inter-device information is inserted in the SOH of the STM-1 frame (synchronous transfer mode signal). A selection unit for selecting one of the second communication forms that are mapped to the WS signal in the RFCOH and transmitted / received is provided in the monitoring control panel, and is configured so that the selection control operation of the selection unit can be controlled by the monitoring control processing unit. The Therefore, even if a failure occurs in the transmission / reception of the synchronous transfer mode signal when the inter-device information is transmitted / received to / from the opposite device in the first communication mode, the inter-device information is transmitted in the second communication mode. By switching so as to transmit and receive, it is possible to return to a state in which information between devices can be transmitted and received. As a case where such a failure occurs, for example, there may be a case where the STM-1 frame (synchronous transfer mode signal) cannot be received correctly because the maximum deviation allowed by the radio frequency between the opposite radio relay apparatuses has occurred.

(3) Third Embodiment Next, a third embodiment of the wireless relay device will be described with reference to FIG. The main part block diagram of the wireless relay device 10a shown in FIG. 5 is different from that of FIG. 3 in that a detection unit 91 is added.
In the wireless relay device of this embodiment, it is assumed that the relay communication auxiliary board 34 (second unit) is configured to be detachable from the monitoring control board 32 (first unit). In FIG. 5, the detection unit 91 is provided to detect the mounting state of the relay communication auxiliary board 34 with respect to the monitoring control board 32 a.

  In this embodiment, when the monitoring control processing unit 90 determines that the relay communication auxiliary board 34 is not mounted on the monitoring control board 32a based on the detection result from the detection unit 91, the inter-device information is set to the STM-1 frame ( The selection unit 60 is controlled so as to apply the first communication mode in which transmission / reception is performed in the state inserted in the SOH of the synchronous transfer mode signal). On the other hand, if the monitoring control processing unit 90 determines that the relay communication auxiliary panel 34 is mounted on the monitoring control panel 32a based on the detection result from the detection unit 91, it maps the inter-device information to the WS signal in the RFCOH. The selection unit 60 is controlled to apply the second communication mode for transmitting and receiving data. The selection process by the selection unit 60 is as described in the second embodiment.

  By providing the detection unit 91 described above, the cost of the wireless relay device can be reduced while maintaining reliability. That is, by making the relay communication auxiliary board 34 optional (it is possible to attach it as an option instead of being attached to the monitoring control board 32a as a standard state), the cost of the wireless relay device can be reduced in the standard state. When a failure occurs in the transmission / reception of the synchronous transfer mode signal to / from the opposite device, the relay communication auxiliary board 34 is attached to switch to the communication with high reliability for the inter-device information by the second communication mode. Is possible. In the monitoring control panel 32a, the components other than the monitoring control processing unit 90, the VF / DGTL processing unit 94, the OWE1 processing unit 95, and the hub 96 (see FIG. 3) are realized by an FPGA (Field Programmable Gate Array). Since it is possible, the cost on the additional hardware for implement | achieving the selection process by the selection part 60 can be suppressed.

In connection with the wireless relay device of this embodiment,
(A) the step of transmitting / receiving information between devices by the monitoring control board 32a when the relay communication auxiliary board 34 is not attached to the monitoring control board 32; and (B) the relay communication auxiliary board 34 being attached to the monitoring control board 32a. And (C) a step of switching so that the inter-device information is transmitted and received by the relay communication auxiliary board 34 by detection by the detection unit 91 is disclosed.

(4) Fourth Embodiment Next, a fourth embodiment of the wireless relay device will be described with reference to FIG. The main part block diagram of the wireless relay device 10b shown in FIG. 6 is different from that of FIG. 3 in that a communication abnormality detection unit 99 is added.
The communication abnormality detection unit 99 detects whether or not the STM-1 frame (synchronous transfer mode signal) from the signal processing unit 20 has been correctly received, and notifies the monitoring control processing unit 90 of the detection result. If the monitoring control processing unit 90 determines that the STM-1 frame has been correctly received based on the detection result from the communication abnormality detection unit 99 (that is, there is no communication abnormality), the inter-device information is transmitted to the STM-1 frame (synchronous transfer). The selection unit 60 is controlled so as to apply the first communication mode in which transmission / reception is performed while being inserted in the SOH of the mode signal). On the other hand, if the monitoring control processing unit 90 determines that the STM-1 frame cannot be correctly received based on the detection result from the communication abnormality detecting unit 99 (that is, there is a communication abnormality), the inter-device information is converted into the WS signal in the RFCOH. The selection unit 60 is controlled to apply the second communication form for mapping and transmission / reception. The selection process by the selection unit 60 is as described in the second embodiment.
Note that any known method can be applied to the communication abnormality detection method based on whether or not a frame can be received.

  According to the wireless relay device of this embodiment, the communication mode (first communication mode, second communication mode) can be switched autonomously within the monitoring control panel in accordance with the detection result of the frame from the signal processing unit 20. it can.

In connection with the wireless relay device of this embodiment,
(D) When the STM-1 frame (synchronous transfer mode signal) is normal, the step of transmitting / receiving the inter-device information inserted in the SOH of the STM-1 frame, and (E) the communication of the STM-1 frame Disclosed is a method comprising: detecting an abnormality; and (F) switching to transmit / receive the inter-device information in a state inserted in the RFCOH by detecting a communication abnormality in the STM-1 frame.

  Regarding the above embodiments, the following additional notes are disclosed.

(Appendix 1)
A wireless relay device corresponding to a synchronous digital hierarchy,
A multiplexing unit that multiplexes inter-device information transmitted / received to / from another device facing the second overhead added to the synchronous transfer mode signal including the first overhead;
A transmission / reception unit for transmitting / receiving the multiplexed inter-device information to / from the other device;
A wireless relay device comprising:

(Appendix 2)
Either a first communication mode for transmitting / receiving the inter-device information inserted in the first overhead or a second communication mode for transmitting / receiving the inter-device information multiplexed in the second overhead. A selection unit for selecting is provided,
The wireless relay device described in appendix 1.

(Appendix 3)
A second unit including a second communication interface for transmission / reception according to the second communication mode is detachably provided to a first unit including a first communication interface for transmission / reception according to the first communication mode,
The selection unit selects the second communication form when it is detected that the second unit is attached to the first unit.
The wireless relay device described in Appendix 2.

(Appendix 4)
The selection unit selects the second communication mode when a communication abnormality of the synchronous transfer mode signal is detected.
The wireless relay device described in Appendix 2.

(Appendix 5)
The inter-device information is a redundant configuration,
The wireless relay device described in appendix 1.

(Appendix 6)
A communication method using a wireless relay device corresponding to a synchronous digital hierarchy,
Multiplexing information between devices transmitted to and received from other devices facing each other into a second overhead added to the synchronous transfer mode signal including the first overhead;
Transmitting and receiving the multiplexed inter-device information to and from the other devices;
A communication method comprising:

(Appendix 7)
Transmitting and receiving the inter-device information by a first unit for transmitting and receiving the inter-device information in a state inserted in the first overhead in the wireless relay device;
Detecting that the second unit for transmitting / receiving the inter-device information multiplexed in the second overhead in the wireless relay device is attached to the first unit;
Switching to transmit and receive the inter-device information by the second unit by the detection; and
The communication method according to appendix 6, wherein the communication method is provided.

(Appendix 8)
When the synchronous transfer mode signal is normal, the step of transmitting and receiving the inter-device information inserted in the first overhead; and
Detecting a communication error in the synchronous transfer mode signal;
Switching to transmit / receive the inter-device information in a state multiplexed in the second overhead by detecting a communication abnormality in a synchronous transfer mode signal;
The communication method according to appendix 6, wherein the communication method is provided.

(Appendix 9)
The inter-device information is a redundant configuration,
The communication method described in appendix 6.

The figure for demonstrating the general | schematic structure and communication method of the SDH transmission system containing the radio relay apparatus of 1st Embodiment. The figure which shows the mapping method of the information between apparatuses with respect to WS signal while showing the structure of a communication signal (WS signal). The block diagram which shows the principal part of the radio relay apparatus of 2nd Embodiment. The figure which shows the structural example of the monitoring control part of the radio relay apparatus of 2nd Embodiment. The block diagram which shows the principal part of the radio relay apparatus of 3rd Embodiment. The block diagram which shows the principal part of the radio relay apparatus of 4th Embodiment. The figure which shows the conventional SDH transmission system provided with the master clock source. The figure which shows the conventional SDH transmission system which is not provided with the master clock source.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Wireless relay apparatus 20 ... Signal processing part 30 ... Monitoring control part 32 ... Monitoring control board 34 ... Relay communication auxiliary board

Claims (5)

A wireless relay device corresponding to a synchronous digital hierarchy,
A multiplexing unit that multiplexes inter-device information transmitted / received to / from another device facing the second overhead added to the synchronous transfer mode signal including the first overhead;
The inter-device information multiplexed and a transceiver for transmitting and receiving to and from the other device,
Either a first communication mode for transmitting / receiving the inter-device information inserted in the first overhead or a second communication mode for transmitting / receiving the inter-device information multiplexed in the second overhead. A selection unit for selecting is provided,
Wireless relay device. A second unit including a second communication interface for transmission / reception according to the second communication mode is detachably provided to a first unit including a first communication interface for transmission / reception according to the first communication mode,
The selection unit selects the second communication form when it is detected that the second unit is attached to the first unit.
The wireless relay device according to claim 1 . The selection unit selects the second communication mode when a communication abnormality of the synchronous transfer mode signal is detected.
The wireless relay device according to claim 1 . A communication method using a wireless relay device corresponding to a synchronous digital hierarchy,
Multiplexing information between devices transmitted to and received from other devices facing each other into a second overhead added to the synchronous transfer mode signal including the first overhead;
Transmitting and receiving the multiplexed inter-device information to and from the other devices;
Transmitting and receiving the inter-device information by a first unit for transmitting and receiving the inter-device information in a state inserted in the first overhead in the wireless relay device;
Detecting that the second unit for transmitting / receiving the inter-device information multiplexed in the second overhead in the wireless relay device is attached to the first unit;
Switching to transmit and receive the inter-device information by the second unit by the detection; and
Characterized by comprising
Communication method. When the synchronous transfer mode signal is normal, the step of transmitting and receiving the inter-device information inserted in the first overhead; and
Detecting a communication error in the synchronous transfer mode signal;
Switching to transmit / receive the inter-device information in a state multiplexed in the second overhead by detecting a communication abnormality in a synchronous transfer mode signal;
The communication method according to claim 4 , further comprising: