KR100342490B1 - Link multiplexor in telecommunication system and method thereof - Google Patents

Abstract

end. The technical field to which the invention described in the claims belongs

The present invention relates to a multiplexing apparatus and method of a communication system.

I. The technical problem to be solved by the invention

It is possible to efficiently implement multiplexing of links in a communication system.

All. Summary of Solution of the Invention

SUMMARY OF THE INVENTION In accordance with an aspect of the present invention, in a link multiplexing apparatus of a communication system, a multiplexing unit connected to a system interface, a multiplexing unit for multiplexing an input signal, a demultiplexing unit connected to a system interface, and demultiplexing an input signal, And a matching interface unit having a plurality of transceivers for transmitting and receiving a signal, and a plurality of ports, each of which transmits and receives an interface with an internal system, and outputs signal transmission / reception alarm information for each port. A port connection unit connected to the matching interface unit and the multiplexing and demultiplexing unit and connecting a port between the multiplexing unit and the demultiplexing unit and the matching interface unit by a predetermined control signal, and transmission / reception alarm information for each port; And a control unit for outputting the control signal for selecting a port according to the present invention. Shall be.

la. Important uses of the invention

Used for multiplexing communication systems.

Description

LINK MULTIPLEXOR IN TELECOMMUNICATION SYSTEM AND METHOD THEREOF}

The present invention relates to a communication system, and more particularly, to a multiplexing apparatus and method.

In general, a communication system is multiplexed to cope with elements that interfere with communication, such as a hernia of a device or a failure due to cable aging. Such multiplexing may include multiplexing cables and multiplexing boards, and usually have a redundant structure.

1 is a schematic block diagram of a redundant device in a conventional communication system.

Conventionally, the output of a physical device 1 port is connected to two transceivers (HFBR-5205 or HFCT-5205), and the input is selectively used according to the signal state (Signal Detect) detected by the transceiver. have. After all, there is only one link, but the cable is multiplexed. However, if there is an error in the physical device itself, there is no other way to prevent data loss than to multiplex the board itself. The result is the waste of using two boards and four pairs of cables to run one physical link. Also, considering the failure rate of physical devices, board multiplexing itself is meaningless.

On the other hand, there are 1: 1, 1: n, 1 + 1 schemes for link multiplexing of the system. The 1: 1 method is to secure one surplus communication path for one communication path and change the communication path according to an error state. The 1: n method secures one redundant communication channel for a plurality of active communication paths and changes the communication path according to an error state. In the 1 + 1 method, a signal is transmitted through two communication paths and a signal is selectively received at a receiving side. The multiplexing method has advantages and disadvantages, and the 1: n multiplexing method has an advantage that the initial investment cost of the system is low, but there is a problem in that it cannot cope with two or more errors. The 1: 1 multiplexing method can immediately deal with each channel error occurrence, but there is a problem that the initial investment cost is high because an extra channel must be secured for each channel. The multiplexing method of 1 + 1 is similar to the multiplexing method of 1: 1, but has the advantage of high data transmission accuracy and system stability.

Therefore, when a system designed with a specific multiplexing structure in consideration of a communication environment is required to change to a different multiplexing structure according to a subsequent communication environment change, there is a problem that all devices must be replaced.

It is therefore an object of the present invention to provide an apparatus and method for multiplexing links.

Another object of the present invention is to provide an apparatus and method capable of changing the multiplexing scheme without replacing the hardware.

Another object of the present invention is to provide an apparatus and a method for automatically changing a transmission path in response to an error of a link.

In order to achieve the above object, the present invention provides a multiplexing device of a link in a communication system, which is connected to a system interface, a multiplexer for multiplexing an input signal, and a system interface for demultiplexing an input signal. A demultiplexer, a plurality of transceivers for transmitting and receiving signals to and from the outside, and a plurality of ports, and the transceivers are connected to each of the plurality of ports to interface signals with an internal system, and to transmit and receive signal transmission / reception alarm information for each port. A matching interface unit for outputting, a port connection unit connected to the matching interface unit and the multiplexing and demultiplexing unit, and connecting a port between the multiplexing unit and the demultiplexing unit and the matching interface unit by a predetermined control signal; Output the control signal for selecting a port according to the transmission / reception alarm information for each port It characterized by a control unit provided for the box.

1 is a schematic block diagram of a redundant device in a conventional communication system.

2 is a diagram illustrating a signal flow in a 1 + 1 multiplexing structure according to an embodiment of the present invention.

3 is a schematic block diagram for selectively switching a multiplexed path according to an embodiment according to the present invention.

4 is a diagram illustrating a control signal generation circuit diagram for path selection according to an embodiment of the present invention.

5 illustrates a schematic circuit configuration of a controller for multiplex path selection according to an embodiment of the present invention.

6 illustrates a schematic circuit configuration of a switching unit for selectively switching a multiplexed path according to an embodiment according to the present invention.

7 is a schematic block diagram for selectively switching a multiplexed path according to an embodiment according to the present invention.

8 is a control flowchart for connecting multiplexed links according to an embodiment according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Specific details appear in the following description, which is provided to aid a more general understanding of the present invention, and it should be understood by those skilled in the art that the present invention may be practiced without these specific details. It will be self explanatory. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

2 is a diagram illustrating a signal flow in a 1 + 1 multiplexing structure according to an embodiment of the present invention.

3 is a schematic block diagram for selectively switching a multiplexed path according to an embodiment according to the present invention.

4 is a diagram illustrating a control signal generation circuit diagram for path selection according to an embodiment of the present invention.

5 illustrates a schematic circuit configuration of a controller for multiplex path selection according to an embodiment of the present invention.

6 illustrates a schematic circuit configuration of a switching unit for selectively switching a multiplexed path according to an embodiment according to the present invention.

7 is a schematic block diagram for selectively switching a multiplexed path according to an embodiment according to the present invention.

8 is a control flowchart for connecting multiplexed links according to an embodiment according to the present invention.

First, a configuration according to an embodiment of the present invention will be described with reference to FIG. 7.

The multiplexers 711 and 712 are connected to a system interface, and output a first reception operation signal RxEnb [0: 3] according to a second reception state signal Rxclav [0: 3] of FIG. 3. Multiplex the signal and pass it to the system interface.

The demultiplexers 721 and 722 are connected to the system interface, and according to the second transmittable state signal Txclav [0: 3] of FIG. 3, the first transmit operation signal TxEnb [0: 3] of FIG. 3. Outputs the signal and demultiplexes the input signal to the system interface.

Transceiver 751, 761, 771, 781, 752, 762, 772, 782 performs an operation for transmitting and receiving a signal with the outside (in the present invention, showing another base station apparatus), the transmitter and the receiver is a pair It is.

Matching interface unit (STM matching interface unit: 741, 742) is transmitted by the second receiving operation signal (RDENB [0: 3] in FIG. 3) and the second transmitting operation signal (WRENB [0: 3] in FIG. 3). And a plurality of ports on which the receiving unit operates or stops, and outputs a first reception state signal RCA [0: 3] according to the presence or absence of a reception signal for each port, and the first transmission state signal according to the transmission possible state. (TCA [0: 3]), and outputs transmission / reception alarm information for each port, and the transmission / reception unit is connected to each port to interface a signal with an internal system, and outputs transmission / reception alarm information for each port.

Port connections 731 and 732 are based on a second control signal (MODE, MonSel [0: 1], APS_SEL [0: 1] in FIG. 3) and the first reception state signal RCA [0: 3] and The first transmittable state signal TCA [0: 3] is converted into a second receive state signal (Txclav [0: 3] in FIG. 3) and a second transmittable state signal (TxEnb [0: 3] in FIG. 3). Will output Further, the first transmission operation signal TxEnb [0: 3] and the first reception operation signal RxEnb based on the second control signal (MODE, MonSel [0: 1], APS_SEL [0: 1] of FIG. 3). [0: 3]) outputs a second transmission operation signal (WRENB [0: 3] in FIG. 3) and a second reception operation signal (RDENB [0: 3] in FIG. 3), and the matching interface unit ( 741, 742 and the multiplexer 711, 712 and the demultiplexer 721, 722, and the multiplexer 711, 712, the demultiplexer 721, 722, and the matching interface unit. Variable ports 741 and 742 are connected.

A circuit configuration of the port connection unit 310 will be described below with reference to FIG. 6.

The port connector 310 includes four multiplexers (MULTIPLEXOR: 311, 312, 313, and 314). The first multiplexer 311 selects a part of the first reception state signals RCA 0 to 3 and the first transmittable state signals TCA 0 to 3 by MonSel 0 and MonSel 1 to select the second reception state signal ( Rxclav 0 and 1 and the second transmittable state signal Txclav 0 and 1 are outputted. Also, the second reception operation signals RDENB 0 and 1 are output according to the first reception operation signals RxEnb 0 and 1 output from the multiplexer 320.

The second multiplexer 312 selects a part of the first reception state signals RCA 2 and 3 and the first transmittable state signals TCA 2 and 3 according to the mode, and selects the second reception state signals Rxclav 2 and 3. ) And second transmittable state signals Txclav 2 and 3. In addition, the demultiplexer 330 outputs the second transmission operation signals WRENB 0, 1, 2, and 3 according to the first transmission operation signals TxEnb 0, 1, 2, and 3.

The third multiplexer 313 outputs the second reception operation signal RDENB 2 according to the first reception operation signals RxEnb 0 and 2 output from the multiplexer 320 by MODE and APS_SEL 0.

The fourth multiplexer 314 outputs the second reception operation signal RDENB_3 according to the first reception operation signals RxEnb 1 and 3 output from the multiplexer 320 by MODE and APS_SEL 1.

The controllers 701 and 702 may control the second control signal (MODE, MonSel [0 of FIG. 3) in response to port transmission / reception alarm information (RALM [0: 3] of FIG. 3) and user inputs SEL 0 and SEL 1. : 1], APS_SEL [0: 1]) is output. In this case, the controller may be configured as an EPLD (Electronic Programmable Logic Device).

A circuit configuration of the controllers 701 and 702 will be described with reference to FIG. 5 as follows.

The first buffer 302 buffers the multiplexing scheme (MODE signal of FIG. 3) and user input information (SEL 0, SEL 1) for port selection from the local data bus.

The calculation unit 301 selects the signal APS_SEL based on the transmission / reception alarm information for each port (RALM [0: 3] of FIG. 3) and the output signals MODE, ENB SEL 0 and SEL 1 output from the first buffer 302. 0, APS_SEL 1) is output.

The latch 303 generates an interrupt signal according to port transmit / receive alarm information (RALM [0: 3] in FIG. 3) and clears the interrupt signal (APS_CONF_RDB) upon user confirmation.

The second buffer 304 buffers the user input information MODE, SEL 0, SEL 1, the selection signals APS_SEL 0, APS_SEL 1, and the transmission / reception alarm information for each port (RALM [0: 3] in FIG. 2). Output to the local data bus.

At this time, the signal output from the controller 300 to the port connector 310 includes MonSel [0: 1], which is the logical product of the selection signal (APS_SEL 0, APS_SEL 1) and the multiplexing method (MODE signal in FIG. 3). This is the signal output by. The circuit configuration for the signal can be made using end gates 390 and 391 as shown in FIG. The MonSel [0: 1] signal is used for port selection at the port connection.

Hereinafter, a configuration and flow of a signal for a control operation according to an exemplary embodiment of the present invention will be described with reference to FIGS. 3 to 7.

First, a signal MODE for selecting a multiplexing method is received from a user. The signal for selecting the multiplexing scheme is composed of 1 bit in the embodiment of the present invention, but may be increased according to the type. In the embodiment of the present invention, two multiplexing methods, 1 + 1 multiplexing and 1: N, are selected. In this case, the selected 1: N multiplexing scheme becomes a 1: 1 multiplexing scheme. The user input information SEL 0 and SEL 1 for port selection is a signal for selecting a port for operation among the ports '0' to 'm'. For example, if the matching interface 111 has four ports, the selection signal becomes a 2Bit signal in proportion to the number of ports. In addition, the signal for automatically connecting the port includes an ENB signal indicating whether to connect the port by user selection or an alarm state or a default value.

Transmitting / receiving alarm information for each port (RALM [0: 3] in FIG. 3) indicates an alarm state of a port and is information indicating an error state due to cable disconnection or short circuit. Based on the above-described signal, a basic signal for selecting a multiplexing scheme according to an embodiment of the present invention and automatically connecting ports according to an alarm state is shown in the following table.

D0 D1 D2 D3 D4 D5 D6 D7 MODE ENB SEL 0 SEL 1 RALM 0 RALM 1 RALM 2 RALM 3

The signals used in the above table are described based on data values in the following table as an example of four ports.

signal data Contents MODE 0 1: N multiplexing mode (or 1: 1 mode) One 1 + 1 multiplexing mode ENB 0 Enable People Picker One Disable People Picker SEL 0 0 0 operation, 2 stops (standby) One Operation 2, Stop 0 (Standby) SEL 1 0 1 operation, 3 stops (standby) One 3 motions, 1 stop (standby) RALM [0: 3] 0 Steady state One Alarm state (error state)

The matching interface 111 having four ports may have two structures of 1 + 1. In the embodiment of the present invention, 0 and 2 are paired and 1 and 3 are paired and thus 1 + 1. It will form a structure of 1. At this time, data is simultaneously transmitted to the operating channel (FIG. 2 WORKING CHANNEL) and the protection channel (PROTECTION CHANNEL). In addition, the receiving end may check the reception state to select one of an operating channel (FIG. 2 WORKING CHANNEL) and a protection channel (PROTECTION CHANNEL) to receive a signal.

By using the above-described signal, the control unit 300 automatically connects the port by using the alarm state of the port, the multiplexing mode selection, and the use of the user port selection. In this case, data comparison for generating the selection signals APS_SEL 0 and APS_SEL 1 is shown in the following table.

Reset MODE Select Control Bits RALM Status Bits Port select Control ENB SEL 0 SEL 1 RALM 0 RALM 1 RALM 2 RALM 3 APS_SEL0 APS_SEL1 0 - - - - - - - - 1: 1 mode (by-pass) S / W One 0 - - - - - - - One 0 0 0 - - - - 0 0 H / W One 0 - - - - One 0 0 One - - - - 0 One One One - - - - One One One - - 0 - 0 - Previous state - - - 0 - One - 0 - - - One - 0 - One - - - One - One - Previous state - - - - 0 - 0 - Previous state - - - 0 - One - 0 - - - One - 0 - One - - - One - One - Previous state

Table 4 below shows the port connection according to the alarm state of the port when the 1 + 1 mode is selected in Table 3 and the user selection is not used.

RALM Status Bits Port select RALM 0 RALM 1 RALM 2 RALM 3 APS_SEL0 APS_SEL1 0 - 0 - Keep old - 0 - One - 0 port selection - One - 0 - 2 port selection - One - One - Keep old - - 0 - 0 - Keep old - 0 - One - Port 1 selection - One - 0 - 3 port selection - One - One - Keep old

As described above, 'APS_SEL 0' is for controlling ports 0 and 2, and 'APS_SEL 1' is for controlling ports 1 and 3. Therefore, when a port is selected by user selection (ENB 0), 'APS_SEL 0' and 'APS_SEL 1' are determined by 'SEL 0' and 'SEL 1', and when user selection is not used (ENB 1) The port selection is made by the alarm status (RALM 0 ~ 3). In addition, if the alarm condition does not occur or both ports (ports 0 and 2, 1 and 3) are in error state, the previously selected port is continuously selected and connected.

Referring to Figure 8 will be described below the control flow according to an embodiment of the present invention.

If the mode selected in step 800 is a 1 + 1 multiplexing mode, the method proceeds to step 810 to determine whether to use the port value selected by the user. That is, it checks whether the value of ENB is '0'. If the value of the ENB is '0', the process proceeds to step 820 where the port is connected by a multiplex link of 1 + 1 using the port selected by the user. However, if the value of ENB is '1', that is, if the value selected by the user is not used, the port is connected by the alarm condition. The connection of ports according to the alarm condition is described in the above description of Tables 3 and 4. Step 840 illustrates a case where a 1: n (1: 1) multiplexing mode is selected. In this case, all links are bypassed to connect respective corresponding ports.

In the following, an example will be described with reference to FIGS. 3 to 6.

The matching interface 111 has four ports and each port has a transceiver. At this time, the preset basic data is the same as selecting 1 + 1 multiplexing method, using user selection, and using port 0 and 1. And each port alarm condition is good. Table 5 below shows only control data for port connection in the above situation in Table 3.

MODE Select Control Bits RALM Status Bits Port select ENB SEL 0 SEL 1 RALM 0 RALM 1 RALM 2 RALM 3 APS_SEL0 APS_SEL1 One 0 0 0 - - - - 0 0 One 0 - - - - One 0 0 One - - - - 0 One One One - - - - One One

First, when reception data is generated to each port and transmission state data is generated, the matching interface unit 111 transmits the first reception state signals RCA 0 to 3 and the first transmission state signal to the port connection unit 310. TCA 0 ~ 3) will be transmitted. On the other hand, referring to Table 3, the generation process of the control signals MODE, MonSel, and APS_SEL input to the port connection unit 310 is as follows. MODE signal is '1' because 1 + 1 is selected by user, and alarm value is normal state, so all values of '0' are inputted. In addition, according to Table 5, 'SEL 0' and 'SEL 1' become '0' and 'SEL 1' becomes '0'. Therefore, 'APS_SEL 0' output from the calculator 301 of FIG. 5 becomes '0' and 'APS_SEL 1' becomes '0'. At this time, since the alarm state is normal, the interrupt signal INTERRUPT is not generated by the latch. In addition, since the signal of 'MonSel' has a mode of '1', 'MonSel 0' becomes '0' and 'MonSel 1' also becomes '0' according to the value of 'APS_SEL'. The table below shows the control signals.

MODE Select Control Bits RALM Status Bits Port Select & MonSel ENB SEL 0 SEL 1 RALM 0 RALM 1 RALM 2 RALM 3 APS_SEL0MonSel 0 APS_SEL1MonSel 1 One 0 0 0 0 0 0 0 0 0

The following describes the control operation of the port connection unit 310.

First, the operation of the first multiplexer 311 of FIG. 6 will be described.

Since the MonSel_0 and MonSel_1 input are '0', the first multiplexer 311 outputs 'RCA 0' as 'Rxclav_0' and 'TCA 0' as 'Txclav 0'. The first multiplexer 311 outputs an input of 'RCA 1' to 'Rxclav_1' and outputs a 'TCA 1' to 'Txclav 1'.

In the second multiplexer 312, since the Mode signal is '1', the I1A, I1B, I1C, and I1D terminals connected to ground are output to Txclav_2, Txclav_3, Rxclav_2, and Rxclav_3. Therefore, the signals input to the multiplexer 320 and the demultiplexer 330 by the first and second multiplexers 311 and 312 are shown in Table 7 below.

Rxclav_0 One Txclav_0 One Rxclav_1 One Txclav_1 One Rxclav_2 0 Txclav_2 0 Rxclav_3 0 Txclav_3 0

Therefore, 'RxEnb' and 'TxEnb' output from the multiplexer 320 and the demultiplexer 330 are shown in Table 8 below.

RxEnb_0 0 TxEnb_0 0 RxEnb_1 0 TxEnb_1 0 RxEnb_2 One TxEnb_2 One RxEnb_3 One TxEnb_3 One

Table 7 and Table 8 change the data value because the Enb signal becomes 'ACTIVE LOW'.

'RxEnb' and 'TxEnb' output from the multiplexer 320 and the demultiplexer 330 are output by 'RDENB' and 'WRENB' by the first to fourth multiplexers 311, 312, 313, and 314. do.

First, the output by the first multiplexer 311 is as follows. Since the MonSel_0 and MonSel_1 signals are '0', the signal of RxEnb_0 is output to RDENB_0, and the signal of RxEnb_1 is output to RDENB_1.

Looking at the output of the third multiplexer 313, since Mode is '1' and 'APS_Sel 0' is '0', the 3.3v signal connected to the I2A stage is output to RDENB_2.

Looking at the output of the fourth multiplexer 314, since Mode is '1' and 'APS_Sel 1' is '0', the 3.3v signal connected to the I2A stage is output as RDENB_3.

The output by the second multiplexer 312 is as follows. Since the mode is '1', the signal of TxEnb_0 is output to WRENB_0 and the signal of TxEnb_1 is output to WRENB_1. The signal of TxEnb_2 is output to WRENB_2 and the signal of TxEnb_3 is output to WRENB_3. That is, signals are transmitted through 0 and 1, and 2 and 3 do not operate.

Table 9 shows 'RDENB' and 'WRENB' final output values.

RDENB_0 0 WRENB_0 0 RDENB_1 0 WRENB_1 0 RDENB_2 One WRENB_2 One RDENB_3 One WRENB_3 One

In the embodiment of the present invention, only the control in the multiplexing scheme of 1 + 1 has been described, but port selection may be automatically performed in other multiplexing modes.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims below, but also by the equivalents of the claims of the present invention.

As described above, the present invention provides a single board by connecting or blocking a port for data transmission / reception between the multiplexer, the demultiplexer, and the matching interface according to user selection information and port state according to a preset multiplexing method and port selection. It can be used to perform link multiplexing, to change the multiplexing scheme without hardware replacement, and to automatically change the transmission path in case of link error.

Claims (14)

In the multiplexing device of the link of the communication system, A multiplexer which is connected to a system interface and multiplexes an input signal, A demultiplexer connected to a system interface for demultiplexing an input signal, A plurality of transceivers for transmitting and receiving signals to the outside, A matching interface unit having a plurality of ports, each of the transceiver units connected to each of the plurality of ports to interface signals with an internal system, and output signal transmission / reception alarm information for each port; A port connection unit connected to the matching interface unit and the multiplexing and demultiplexing unit, and connecting a port between the multiplexing unit and the demultiplexing unit and the matching interface unit by a predetermined control signal; And a control unit for outputting the control signal for selecting a port according to the transmission / reception alarm information for each port. The method of claim 1, wherein the control unit, A first buffer for buffering user input information for multiplexing and port selection from a local data bus, An operation unit for outputting a selection signal based on the transmission / reception alarm information for each port and an output signal output from the first buffer; A latch for generating an interrupt signal according to the transmission / reception alarm information for each port and clearing the interrupt signal upon user confirmation; And a second buffer for buffering the user input information, the selection signal, and transmission / reception alarm information for each port and outputting the buffer to the local data bus. The method of claim 1, wherein the port connection portion, And a multiplexer for connecting the multiplexer, the demultiplexer, and the port of the matching interface unit by a multiplexing signal and a selection signal according to the transmission / reception alarm information and user input information for port selection. . In the multiplexing device of the link of the communication system, A multiplexer which is connected to a system interface, outputs a first reception operation signal according to a second reception state signal, and multiplexes an input signal; A demultiplexer connected to the system interface, outputting a first transmission operation signal according to a second transmittable state signal, and demultiplexing an input signal; A plurality of transceivers for transmitting and receiving signals to the outside, It has a plurality of ports that the transmission and reception unit is operated or stopped by the second reception operation signal and the second transmission operation signal, and outputs the first reception status signal according to the presence or absence of the reception signal for each port, according to the transmission possible state A matching interface unit for outputting a first transmittable status signal, outputting transmission / reception alarm information for each port, connecting the transmission / reception unit for each port to interface a signal with an internal system, and outputting transmission / reception alarm information for each port; , Outputting the first reception state signal and the first transmittable state signal as a second reception state signal and a second transmittable state signal based on a second control signal; and the first transmission operation based on a second control signal. Outputs a second transmission operation signal and a second reception operation signal according to a signal and a first reception operation signal, and is connected to the matching interface unit, the multiplexer, and the demultiplexer, and the multiplexer and the demultiplexer; A port connection unit for variably connecting the ports of the matching interface unit; And a controller configured to output the second control signal in response to the transmission / reception alarm information for each port and a user input. The method of claim 4, wherein the control unit, A first buffer for buffering user input information for multiplexing and port selection from a local data bus, An operation unit for outputting a selection signal based on the transmission / reception alarm information for each port and an output signal output from the first buffer; A latch for generating an interrupt signal according to the transmission / reception alarm information for each port and clearing the interrupt signal upon user confirmation; And a second buffer for buffering the user input information, the selection signal, and transmission / reception alarm information for each port and outputting the buffer to the local data bus. The method of claim 4 or 5, wherein the port connection portion, And based on the second control signal, output a second transmission operation signal and a second reception operation signal according to the first transmission operation signal and the first reception operation signal, and based on the second control signal, the first reception state. And a multiplexer for outputting a second receive state signal and a second transmittable state signal in accordance with a signal and said first transmittable state signal. In the link multiplexing method of a communication system, And connecting or blocking a port for data transmission / reception between the multiplexer, the demultiplexer, and the matching interface according to user selection information and port status according to a preset multiplexing method and port selection. The method of claim 7, wherein the connection of the port, Wherein the port selected by the user and the port with incoming data are connected. The method of claim 7, wherein the connection of the port, And a port selected by the user and being in a transmittable state is selected. The method of claim 8 or 9, wherein the connection of the port, If the state of the port is an alarm, the other port is selected. 8. The method of claim 7, wherein blocking of the port is If the port is in an alarm state, blocking the corresponding port. The method of claim 7, wherein the connection or disconnection of the port, A method of connecting or disconnecting a port according to a multiplexing scheme, an alarm state of a port, transmission or reception of a port, and a reception state. In the link multiplexing method of a communication system having a matching interface having a multiplexer and a demultiplexer and a plurality of ports, When the 1 + 1 multiplexing method is selected, the process of checking whether the selection of the port is made by the preset value, When the selection of the port is made by the preset value, connecting the port by the preset value irrespective of an alarm state for each port; Connecting the ports according to the alarm state for each port if the selection of the port is not made by the preset value; If the 1 + 1 multiplexing method is not selected, connecting the port by a default value. The method of claim 13, wherein if the 1 + 1 multiplexing scheme is not selected, Bypassing each port by setting a 1: 1 multiplexing method.