KR20010065941A - Apparatus for duplexing E1 interface board of radio port and radio port controller in wireless local loop system and method for switching E1 interface board - Google Patents

Abstract

PURPOSE: An E1 interface board duplex apparatus between a radio port(RP) and a radio port controller(RPC) in a WLL(Wireless Local Loop) system and duplex switching method using the same is provided to minimize a service stop by connecting one E1 link with two master/slave PBAs, primarily operating the master board, and being instantaneously switched to the slave board when an error is generated in the master board. CONSTITUTION: A master E1 matching board(200) performs an E1 matching between a radio port(RP) and a radio port controller(RPC). A slave E1 matching board(210) performs the E1 matching between the RP and the RPC when an error is generated in the master E1 matching board(200). The master E1 matching board(200) and the slave E1 matching board(210) are installed in the RP and the RPC, respectively. The master E1 matching board(200) has first and second relays(203,206) to be installed in TX/RX sides, respectively and be disabled and enabled according to a provided switching control signal, and a CPU(202) for sensing an error generation of the master E1 matching board(200), providing the switching control signal for disabling the first and second relays(203,206), transmitting a switching signal to the slave E1 matching board(210), and enabling the first and second relays(203,206) to perform an E1 matching operation when a switching request signal is received from the slave E1 matching board(210). The slave E1 matching board(210) includes first and second relays(213,216) to be installed in TX/RX sides, respectively and be disabled and enabled according to a provided switching control signal, and a CPU(212) for sensing an error generation of the slave E1 matching board(210), providing the switching control signal for disabling the first and second relays(213,216), transmitting a switching signal to the CPU(202) of the master E1 matching board(200), and enabling the first and second relays(213,216) to perform an E1 matching operation when a switching request signal is received from the CPU(202) of the master E1 matching board(200).

Description

Apparatus for duplexing E1 interface board of radio port and radio port controller in wireless local loop system and method for switching E1 interface board}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a wireless local loop (hereinafter referred to as a WLL), and more particularly, to a base station in a WLL system that enables an uninterrupted service when an error occurs in an E1 matching device between a base station and a base station controller. The present invention relates to an E1 interface board redundancy device and a duplex switching method using the same.

In general, the WLL system has an advantage that it is much better than the propagation environment of the mobile communication network in terms of use as a communication medium through a wireless channel.

In addition, the line-of-sight environment is secured, and the propagation path loss is about 20 dB / decade, so that it can serve a wider area with the same transmission power. Fading due to multipath is much less than that of point-to-point mobile communication network.

Due to these advantages, the development and research of the WLL system is actively underway, and the accompanying drawings of FIG. 1 show a schematic configuration of a general WLL network having the above advantages.

As shown in Fig. 1, network components include network subscriber station 10, 10 ', subscriber access devices 20, 20', base station 30, 30 ', base station controller 40, WLL switching station ( 50), a base station operating device 60, and the like, and additionally, a data communication matching device 70 (IWF: inter-working function) for data service, a home location register (HLR: Home Location Resister / Authentication Center) ( 80).

In addition, the billing center 100 connected to the network management sensor 90, the WLL switch 50 and the data communication matching device 70 is connected to the base station operating device 60 and the WLL switch 50 is further provided.

Let us explain the interface between the network components in the WLL system network configured as described above.

The subscriber access devices 20 and 20 'and the base stations 30 and 30' use the standard WLL radio access standard as the access standard, and the channel bandwidth is 10 MHz. The connection standard between the base stations 30 and 30 'and the base station controller 40 selects and uses E1 or HDSL, and the signaling method uses LAPD (Link Access Protocol D).

The base station controller 40 and the WLL switch 50 use E1 as a connection standard and use ITU-T.G965 as a signaling method.

In addition, the connection standard between the base station controller 40 and the base station operating device 60 uses Ethernet, and as a signaling method, Simple Network Management Protocol (SNMP), File Transfer Protocol (FTP), TELNET (Telecommunication Network), etc. Use

On the other hand, the base station controller 40 and the data communication matching device 70 uses E1 as the connection standard, and uses LAPD as the signaling method. In addition, the connection between the WLL switch 50 and the data communication matching device 70 uses E1 as the connection standard and R2 is used as the signaling method.

The connection standard between the WLL switch 50 and the home position register 80 uses E1, and IS-41C is used as the signaling method.

Let's look at the operation of the WLL system network connected through the connection standard and the signaling method in more detail.

First, the base station (30, 30 ') is a base station control module (RCP) that performs the overall management function for one base station, a modem module performing a signal processing function related to the CDMA channel, high power / low noise amplification and transmission and reception frequency conversion function RF module for performing the step, and a line connection module for performing the relay line (E1) connection function for matching with the base station controller 40, amplification of the transmission signal in the RF module, low noise amplification of the received signal, frequency down / up It performs conversion, reception of diversity through two antennas, high power / low noise amplification, and transmission / reception frequency conversion.

In addition, the modem module provides CDMA channels (pilot channel, sync channel, paging channel, access channel, signaling channel, traffic channel, packet traffic channel, packet access channel), digital baseband function processing, CDMA channel coding and decoding related functions. Do this.

The line connection module performs data communication with the base station controller 40 with respect to traffic and control information, and performs a relay line (E1 / HDSL) function for matching the base station controller 40.

The base station controller 40, which controls the base stations 30 and 30 ', is composed of a transcoder module, a call processing module, a switching module, and a matching module. The transcoder module is a 64 Kbps Pulse Code Modulation (PCM) voice coding signal. It includes a transcoder that performs the conversion function, and echo cancellation is implemented. In addition, the call processing module performs various call processing functions such as incoming / outgoing call processing support and message processing of the base station, subsystem status management in the base station controller 40, and control signal format between the WLL switch 50 and the subscriber access device. It is a processor that has a redundant structure for system reliability. The switching module also provides a traffic path between the base station matching device and the transcoder in the base station controller 40.

In addition, the matching module is composed of a WLL switch matching module, a base station matching module and a base station operating device (60) matching module, dual WLL switch (50) matching module for installing the base station controller 40 remotely with the WLL switch (50) If so, perform the E1 / G.965 digital heavy accounting function. In addition, the base station matching module performs the E1 / LAPD, HDSL relay line matching function between the base station and the base station control, and the base station operating device matching module performs the Ethernet / SNMP, FTP, TELNET matching function during the base station operating device-base station control period.

Next, the base station operating device 60 operates the base station controller 40, the base stations 30 and 30 ', and the subscriber access devices 20 and 20', and is responsible for maintenance and repair of each device.

As described above, the connection medium between the base station and the base station controller in the WLL system is implemented as an E1 link, and the number of E1 links provided for the base station and the base station control period is defined as 2E1.

Currently, the base station provides subscriber capacity of 30 to 60 channels, and if the base station capacity is further increased to 2FA / 3 sectors, more E1 dedicated lines will be needed. However, it is difficult to rush to E1 leased line if subscriber capacity suddenly surges, as it maintains the possibility of generating 2FA / 3 sector capacity on initial cell plain and does not preempt E1 leased line first.

Conventional CDMA or PCS systems have adopted the E1 transmission scheme, but do not use the optical transmission scheme. The commercialized part of the wireless optical transmission system is the optical repeater of PCS / CDMA, which is installed in the shaded area where the base station radio waves are not transmitted well, and the base station RF frequency is directly loaded on the light and transmitted. After modulating with the RF frequency, it has never been used as a transmission method between the base station and the base station controller to cover the shadow area.

In addition, the E1 link is currently provided through the HDSL or FLC system without directly providing the E1 dedicated line. As the capacity of the E1 dedicated line increases, the size of the HDAL or FLC system to be installed in the telephone company increases.

FIG. 2 is a conceptual diagram of a base station and base station control period E1 link connection in a wireless subscriber network system according to the prior art. Referring to FIG. 2, the base station and base station control period matching device of the conventional WLL system will be described with reference to FIG. 2. As a method of connecting the base stations 30 and 30 'to the base station controllers 40 and 40', it is expensive to newly construct and provide a new E1 dedicated line to all regions requiring the base stations 30 and 30 '. It is provided using HDSL equipment or FLC system that can provide speed and transmission characteristics of 2.048M provided by E1 dedicated line. This is provided by using existing lines by using existing 2W analog lines and priority optical lines.

As shown in FIG. 2, the base station 30, 30 ′ and the base station controller 40 are equipped with an E1 matching device for E1 matching, respectively. The E1 matching device for E1 matching between each of the base stations 30, 30 'and the base station controller 40 will be described with reference to FIG.

3 is a diagram illustrating a detailed configuration of an E1 matching device mounted in a base station and a base station controller in a conventional WLL system.

As shown in FIG. 3, an E1 line interface transformer 110 is an apparatus that matches the electrical characteristics of E1, which is a physical connection method between a base station and a base station controller (HDB3 Level). The ram and transceiver (E1 Framer And Tranceiver) (111) is a device for transmitting and receiving the E1 frame, the clock synchronization unit 112 performs a function to check and recover the error of the input E1 frame and to synchronize.

The HDLC array 113 is a control for processing LAPD between E1 frames, and the time switch 114 is a device that directly performs subchannels in the matching device, and the CPU 120 After the call processing and control information extracted from the HDLC array 113 is analyzed and the information is sent to the upper control unit through the parallel bus control unit 121, the information of the input data is analyzed and the sub-switching information is received for the time. To control the switch 114.

The EPLD 119 is a PLD that handles various clocks and decoders / interrupts used therein, and the ROM 118 is equipped with software for starting the board when the board is powered on. When the application software is loaded and used, it is used as a storage location of the variables in the operation. In addition, a serial input / output port 115 is provided.

As such, the connection medium between the base station and the base station controller in the conventional WLL system is implemented with an E1 link, and the number of E1 links provided for the base station and the base station control period is defined as 2E1. If the actual number of E1 links (when the number of acceptable E1 links per board is less than the number of E1 links provided) and the packet data transmission method are used, the service of the base station may be reduced even if the speed drops to some extent without completely interrupting service in case of a link error or PBA error. To provide subscribers. However, because the standard provides only E1 link of about 2E1 per base station, and the current capacity of E1 matching board is about 4E1 to 8E1, after connecting this 2E1 to one board, if a board error occurs, replace it. Previously, there was a problem that it was difficult to provide a service.

As a result, since the E1 transmission method according to the prior art mostly uses the packet data method, it is possible to transmit data and information even though the transmission speed decreases to some extent before all connected E1 links are completely disconnected.

In addition, the service is controlled by the internal main switch, but the channelized method is used in the WLL system, so it is impossible to control the channel once occupied and the link provided is one board. If a board error occurs during the service by connecting to the base station, there is a problem that can not provide services of all subscribers connected to the base station.

Accordingly, the present invention has been made to solve the above-mentioned problems according to the prior art, the object of the present invention is to connect a single E1 link to two master / slave (Master / Slave) PBA, the master board Is operated first, and the master board transfers to the slave board in the event of an error, thereby providing an E1 interface board redundancy device between the base station and the base station control in the WLL system to minimize service interruption.

Another object of the present invention is to provide a redundancy switching method using an E1 interface board redundancy device between a base station and a base station control in a WLL system using the E1 interface redundancy device.

A feature of the E1 interface board redundancy device between a base station and base station control in a WLL system according to the present invention for achieving the above object is an E1 matching device between a base station and a base station control period E1 matching device of a WLL system. Master E1 matching board for; The slave E1 matching board which performs E1 matching between the base station and the base station controller when an error occurs in the master E1 matching board is mounted on the base station and the base station controller, respectively.

In addition, as another feature of the redundancy apparatus according to the present invention, the master E1 matching board includes: first and second relays mounted on the TX / RX side, respectively disabled or enabled according to a switching control signal provided; a) detects an error in the master E1 matching device, provides a switching control signal for disabling the first and second relays in the event of an error, and then transmits a switching signal to the slave E1 matching board; b) slave E1 When an error occurs in the matching board and the transfer request signal is received from the slave E1 matching board, the controller is configured to control the E1 matching operation to be performed by enabling the first and second relays. First and second relays mounted on the TX / RX side, each of which is disabled or enabled according to the switching control signal provided; a) detecting an error in the slave E1 matching device, providing a switching control signal for disabling the first and second relays in the event of an error, and transmitting a switching signal to a controller of the master E1 matching board; b) When the transfer request signal is received from the controller of the master E1 matching board, the control means for enabling the first and second relay to perform the E1 matching operation.

In addition, in the WLL system according to the present invention for achieving the above object, the feature of the redundant switching method using the E1 interface board redundancy device between the base station and base station control is a master E1 matching board and a slave E1 matching board each having a plurality of relays. In the redundant method of switching the E1 interface between the base station and the base station controller of the WLL system having a WLL system, if the master E1 matching board is driven, after initializing the chips in the master E1 matching board, a plurality of relays in the master E1 matching board Enabling to perform an E1 matching operation normally; Detecting an error occurrence of the master E1 matching board; Disabling the plurality of relays when an error occurs in the master E1 matching board and transmitting a switching signal to the slave E1 matching board; When the transfer signal is received from the master E1 matching board, the slave E1 matching board enables a plurality of relays in the slave board to perform an E1 matching operation between the base station and the base station controller using the slave E1 matching board. Is in.

1 is a block diagram illustrating a general broadband wireless subscriber network system;

2 is a conceptual diagram of a base station and base station control period E1 link connection in a wireless subscriber network system according to the prior art;

3 is a diagram illustrating a detailed configuration of an E1 matching unit mounted in a base station and a base station controller in a wireless subscriber network system according to the prior art;

4 is a block diagram showing an E1 interface board redundancy device between a base station and a base station control in a wireless subscriber network system according to the present invention;

5A and 5B illustrate an operation flowchart of a duplication switching method using an E1 interface board duplication apparatus between a base station and base station control in a wireless subscriber network system according to the present invention.

<Explanation of symbols for main parts of drawing>

200: master E1 registration board 201, 211: memo

202, 212: CPU 203, 213: first relay

204, 214: E1 primer 205, 215: high speed interface unit

206, 216: second relay

Hereinafter, an E1 interface board duplication apparatus between a base station and base station control and a duplication switching method using the same in a WLL system according to the present invention will be described in detail with reference to the accompanying drawings.

4 is a block diagram illustrating an E1 interface board duplication apparatus between a base station and a base station control in a wireless subscriber network system according to the present invention. That is, it is a figure which shows the saint-settle block structure of the E1 interface matching device which has a redundancy structure using a relay. The detailed function is as follows.

First, referring to the master E1 matching board 200 of FIG. 4, the basic configuration of the redundant board is the same as that of FIG. 3, and the difference is that the first and second relays 203 and 206 are additionally configured. The CPU 202 of the 200 and the CPU 212 of the slave E1 matching board 210 are connected in hardware to transmit and receive signals.

First, when looking at the basic prerequisites for redundancy, the first is the exchange of the redundancy transfer signal, which is the CPU (202) of the master E1 matching board 200 and the slave E1 matching board 210 to make the final decision of the matching board. It means that the switching signal between 212) should be the connection diagram, and secondly, the slave E1 matching board 210 should not have any influence on the signal input / output to the outside.

Third, various I / O signals switched from the master E1 matching board 200 to the slave E1 matching board 210 when the transfer signal between the CPUs 202 and 212 of the master and slave E1 matching boards 200 and 210 are transferred to the outside. This should be controlled so as not to affect it. Therefore, the present invention is designed to satisfy the above basic conditions, and in order to implement this, detailed blocks A, B, C, D, and E are configured as shown in FIG. Details of this are as follows.

Block A of the master E1 matching board 200 of FIG. 4 and block D of the slave E1 matching board 210 are blocks that substantially connect and duplicate the E1 link in each board 200 or 210, and the E1 primer. 204 and 214 are the same as the E1 primer and transceiver shown in FIG.

The function of the first relays 203 and 213 is a chip having an on / off function of an input / output E1 signal. Here, although there are various things that can be used instead of the first relays 203 and 213, since there are not many chips that directly turn on / off the differential level electrical E1 signal, the electrical signals of the direct differential level can be easily The relay can be turned on and off.

Originally, both TX / RX side should be used, but when used in RX part, slave E1 matching boot 210 does not install because it forgets E1 sync and cannot synchronize E1 frame, and it is basically a redundant structure. It is omitted because it is necessary to know the control signal inputted by the LAPD process on the first channel.

In addition, the B block of the master E1 matching board 200 and the E block of the slave E1 matching board 210 are blocks for implementing redundancy for the highways inside the system. (206, 216) was added. The reason why the relays 203, 206, 213, and 216 are installed in the blocks A, B, and D and E only in the TX part is that the RX part receives the actual signal and is not affected externally, but is redundant with each other. This is because the other side should not have any effect when one side is in operation.

The C block between the master E1 matching board 200 and the slave E1 matching board 210 is a redundant structure diagram, which is a connection diagram for transmitting and receiving a redundant transfer signal between the CPUs 202 and 212, and connected to each chip. This is a connection diagram that turns on / off the relays 203, 206, 213, and 216.

First, when the master E1 matching board 200 is switched to the slave E1 matching board 210, the first and second relays 203 and 206 in the master E1 matching board 200 are disabled, and the slay E1 The first and second relays 213 and 216 in the matching board 210 enable (Enable). These may be individually enabled / disabled by software, but when implemented in hardware, the first and second relays 203 in the master E1 matching board 200 are not only fast but also suddenly down when the CPUs 202 and 212 are suddenly down. In this case, the hardware may not be able to disable 206).

Hereinafter, a redundant switching method using an E1 interface board redundancy device between a base station and base station control in a WLL system according to the present invention will be described step by step with reference to the accompanying drawings.

FIG. 5 is a flowchart illustrating an operation of a redundancy switching method using an E1 interface board redundancy device between a base station and base station control in a wireless subscriber network system according to the present invention. FIG. 5 is an operation flowchart illustrating a method for switching to a master E1 matching board when an error of the slave E1 matching board occurs.

First, a redundant switching method from the master e1 matching board to the slave E1 matching board will be described with reference to FIG. 5A.

First, the power of the master E1 matching board is turned on (S101), each chip is activated (S102).

Subsequently, the first and second relays 203 and 206 in the master E1 matching board 200 are enabled (S103) to operate the master E1 matching board 200 normally. At this time, error information is often received (S104).

Subsequently, it is determined whether the master E1 matching board 200 is qualitatively operated (S105), and as a result of the determination, when the master E1 matching board 200 does not operate normally, that is, an error in the master E1 matching board 200 occurs. Is generated, the CPU 202 in the master E1 matching board 200 determines whether to transfer the matching board to the slave E1 matching board 210 after receiving an error (S106).

As a result of the determination, when switching to the slave E1 matching board 210 is required, a transfer request signal is sent to the CPU 212 of the slave E1 matching board 210 (S107), and the first and second in the master E1 matching board 200 are transferred. The relays 203 and 206 are both disabled (S108). In other words, it blocks all input and output.

Subsequently, the CPU 202 of the master E1 matching board 200 transmits error occurrence alarm information to the upper controller (S109), and switches to the slave E1 matching board 210 in an operating state (S110).

Subsequently, the CPU 202 of the master E1 matching board 200 determines whether the transfer signal is received from the CPU 212 of the slave E1 matching board 200, and if the transfer signal is not received, the slave E1 matching board continues. In operation 210, when the transfer signal is received, the control unit 200 returns to step S103 to enable the first and second relays 203 and 206 in the master E1 matching board 200 to the master E1 matching board 200. It will be transferred.

Meanwhile, as shown in FIG. 5B, a description will be given of a switching operation to the master E1 matching board 200 when an error occurs in the slave E1 matching board 210.

First, the slave E1 matching board 210 is turned on (S201), and each chip is activated (S202).

Subsequently, the first and second relays 203 and 206 in the slave E1 matching board 210 are disabled (S203) to operate in a slave state (S204). That is, only the analysis of the input LAPD information and IPC information analysis is performed, and the analyzed result is not transmitted.

Subsequently, it is determined whether the transfer request signal is received from the CPU 202 of the master E1 registration board 200 (S205), and as a result of the determination, the transfer request signal is received from the CPU 202 of the master E1 registration board 200. In this case, the first and second relays 213 and 216 in the slave E1 matching board 210 are enabled (S206 and S207), and the slave E1 matching board 210 is normally operated (S208).

Subsequently, it is determined whether the slave E1 matching board 210 is operating normally (S209), and as a result of the determination, when the slave E1 matching board 210 does not operate normally, that is, an error occurs in the slave E1 matching board 210. When the CPU 212 in the slave E1 matching board 201 receives an error, it is determined whether to transfer the matching board to the master E1 matching board 200 (S210).

As a result of determination, when switching to the master E1 matching board 200 is required, a transfer request signal is sent to the CPU 202 of the master E1 matching board 200 (S211), and the first and second in the slave E1 matching board 210 are transferred. The relays 213 and 216 are both disabled (S212). In other words, it blocks all input and output.

Subsequently, the CPU 212 of the slave E1 matching board 210 transmits the error occurrence alarm information to the upper controller (S213).

As a result, in the redundant switching method using the E1 interface board redundancy device between the base station and the base station control in the WLL system according to the present invention, once the master E1 matching board 200 is driven, basic chips are once initialized, and the master E1 matching board 200 is used. Both of the first and second relays 203 and 206 are enabled to perform normal operation.

When an error in the master E1 matching board 200 is detected by the CPU 202 in the master E1 matching board 200, the CPU 202 of the master E1 matching board 200 determines the error of the E1 matching device. If it is determined that it is difficult to perform the function, it sends a switching signal to the slave E1 matching board 210 while disabling all of the first and second relays 203 and 206 in the master E1 matching board 200 and the slave E1 matching board ( The first and second relays 213 and 216 in the 210 are enabled, and the CPU 202 of the master E1 matching board 200 reports the error occurrence information to the upper side. At this time, when the CPU 202 of the master E1 matching board 200 is down, there is no time to determine in software, so it must be connected to the CPU 202 fault signal in hardware to allow the transfer signal to go.

In the WLL system according to the present invention as described above, the E1 interface board redundancy device between the base station and the base station control and the redundancy switching method using the same are redundant of the base station and the base station control period E1 matched board in the WLL system with a board error or CPU failure. By switching to a redundant board without interruption of service, the service can be continuously performed, thereby providing a stable service.

In addition, although the board is added due to redundancy, an error in the E1 processing board between the base station of the WLL system and the base station control station causes a service interruption for the time required to replace it. In particular, due to the small number of E1 links, it can not be bypassed and delivered, so redundancy enables stable service without interruption, no need for urgent replacement personnel, and reduced number of replacement boards for replacement. .

Claims (5)

In the base station and base station control period E1 matching device of the WLL system, A master E1 matching board for E1 matching between the base station and the base station controller; E1 interface redundancy between the base station and the base station controller of the WLL system, characterized in that the slave E1 matching board to perform the E1 matching between the base station and the base station controller when the error occurs in the master E1 matching board, respectively Device. The method of claim 1, The master E1 matching board includes first and second relays mounted on the TX / RX side, respectively, which are disabled or enabled according to a switching control signal provided; a) detecting an error in the master E1 matching device, providing a switching control signal for disabling the first and second relays in the event of an error, and transmitting a switching signal to the slave E1 matching board; b) when an error occurs in the slave E1 matching board and a transfer request signal is received from the slave E1 matching board, the controller is configured to control the E1 matching operation to be performed by enabling the first and second relays. E1 interface board redundancy device between base station and base station control in subscriber network system The method according to claim 1 or 2, The slave E1 matching board includes first and second relays mounted on the TX / RX side, each of which is disabled or enabled according to a switching control signal provided; a) detecting an error in the slave E1 matching device, providing a switching control signal for disabling the first and second relays in the event of an error, and transmitting a switching signal to a controller of the master E1 matching board; b) a base station in a wireless subscriber network system configured to control the E1 matching operation to be performed by enabling the first and second relays when a switching request signal is received from the control unit of the master E1 matching board. E1 interface board redundancy between control and base station control In the E1 interface redundancy switching method between the base station and the base station controller of the WLL system having a master E1 matching board and a slave E1 matching board each having a plurality of relays, When the master E1 matching board is driven, initializing chips in the master E1 matching board and then enabling a plurality of relays in the master E1 matching board to normally perform an E1 matching operation; Detecting an error occurrence of the master E1 matching board; Disabling the plurality of relays when an error occurs in the master E1 matching board and transmitting a switching signal to the slave E1 matching board; When the transfer signal is received from the master E1 matching board, the slave E1 matching board enables a plurality of relays in the slave board to perform an E1 matching operation between the base station and the base station controller using the slave E1 matching board. A dual load switching method using a base station and a base station control period E1 interface redundancy device of the WLL system. The method of claim 4, wherein After switching to the slave E1 matching board, the slave E1 matching board detecting whether an error occurs in its own board; Transmitting a switching signal to the master E1 matching board at the same time as disabling a plurality of relays in its own board when an error occurs in the slave E1 matching board; When the transfer signal is received from the slave E1 matching board, the master E1 matching board is configured to enable E1 matching operation between the base station and the base station controller by enabling a plurality of relays in the master board. Double load switching method using base station and base station control period E1 interface redundancy device.