KR100497987B1 - system and method for inspecting IPE for operating TFO - Google Patents

Abstract

The present invention relates to a system for verifying an IPE for TFO operation. In particular, a test transmitter generates a TFO message and a TFO frame and transmits the same to an IPE. The present invention relates to an IPE verification system and method for TFO operation that can check and analyze the IPE operation state by receiving and analyzing and determining whether the IPE has been normally operated.

Among the configuration means for achieving the above invention, the IPE verification system for TFO operation, comprising: a test transmitter for transmitting a TFO message and a TFO frame to the ITE to verify the IPE; An IPE recognizing a TFO message transmitted from the test transmitter and performing an operation for a TFO frame according to the message content; A test receiver for determining whether a TFO message and a TFO frame transmitted from the test transmitter have passed the IPE normally; And a switch configured to switch the TFO message and the TFO frame transmitted from the test transmitter to the test receiver to be transmitted to the test receiver.

On the other hand, the configuration means for the IPE verification method for the TFO operation, by generating a TFO_FILL message and a TFO_TRANS message from the TFO message generator under the control of the test controller included in the test transmitter to any PCM signal generated by the PCM signal generator Carrying it to IPE; After generating the TFO_FILL message and the TFO_TRANS message, the switch moves to the TFO frame generator according to the control of the test controller, and the TFO frame generator generates the corresponding TFO frame under the control of the test controller and loads the TFO frame on the PCM signal to transmit to the IPE. Step 2; After the step 2, the switch is switched back to the TFO message generator under the control of the test controller; The IPE receiving the TFP message and the TFO frame recognizes the TFO message, processes the TFO frame according to the message content, and transmits the TFO message and the TFO frame to the exchange; A step 5 in which the exchange receiving the TFO message and the TFO frame switches and transmits the TFO message and the TFO frame to a test receiver; A sixth step in which the TFO message analyzer analyzes the transmitted TFO message and transmits the result to the test discriminator when the switch switches to the TFO message analyzer under the control of the test discriminator included in the test receiver; A step of allowing the test discriminator receiving the analysis result to control the switch to switch to the TFO frame analyzer, and controlling the TFO frame analyzer by viewing the analysis result received from the TFO message analyzer; A step 8 of controlling the TFO frame analyzer under the control of the test discriminator, extracting data from the input PCM signal, combining the TFO frames, analyzing the data, and transmitting the analysis result to the test discriminator; After step 8, the switch switches to the TFO message analyzer again under the control of the test discriminator, and the test discriminator receiving the TFO end message from the TFO message analyzer determines whether the IPE operates normally by referring to the analysis result. Characterized in that it comprises a; 9 steps to inform the test performer.

Description

Api's verification system for TFO operation and its method {system and method for inspecting IPE for operating TFO}

The present invention relates to a system for verifying an IPE for TFO operation. In particular, a test transmitter generates a TFO message and a TFO frame and transmits the same to an IPE. The present invention relates to an IPE verification system and method for TFO operation that can check and analyze the IPE operation state by receiving and analyzing and determining whether the IPE has been normally operated.

Referring to FIG. 1, a method of connecting a voice call between two terminals in a typical mobile communication system is described. First, a terminal encodes an input voice signal and converts the received voice signal into a packet. Send to MSC. The MSC converts the received packet into an A-law or u-law PCM signal and sends it to the counterpart MSC.

The counterpart MSC encodes the A-law or u-law PCM signal received through the reverse process, converts it into a packet, transmits it to the terminal through an air medium, and then converts the received packet into a voice signal and outputs it.

Therefore, in a mobile communication system, two transcodings are performed for voice call connection between two terminals, resulting in a drop in sound quality. In particular, when transcoding a speech signal compressed at a low data rate, the sound quality degradation can be more easily felt.

However, the reason why the transcoding should be performed is to enable communication even when the voice codecs used by the two terminals are different. Therefore, if the same voice codec is used between two terminals, it is possible to improve the sound quality by transmitting a packet generated at one terminal to the other terminal without transcoding without performing two transcodings.

When the same voice codec is used between the two terminals as described above, a method of transmitting a compressed packet directly to a counterpart terminal without performing transcoding is called a TFO (Tandem Free Operation).

Hereinafter, a configuration means and an embodiment for performing a conventional TFO operation will be described in detail with reference to FIG. 2 showing a block diagram for a conventional TFO operation.

Configuration means for the conventional TFO operation,

A terminal for converting a voice signal generated by a user into a compressed packet or conversely converting a packet into a voice signal;

A RAN for receiving the packet generated by the terminal through air and transmitting the packet to a transcoder in an MSC;

A transcoder unit for converting the PCM signal into compressed packet data or conversely converting the compressed packet data into a PCM signal;

It is characterized in that it comprises a; digital network portion that the PCM signal flows and includes the IPE.

The transcoder unit extracts packet data from the TFO frame transmitted by the RX TFO and transmits the packet data to the RAN during the TFO operation, the RX IU transmitting the received packet data and the decoded PCM signal to the TX TFO, and the received packet. TX TFO that carries data on the lower bits of the received PCM signal and transmits, RX TFO which extracts the packet data contained in the received PCM signal and transmits it to TX IU, and analyzes the message received by the RX TFO. It comprises a TFO protocol that configures the environment for operation and communicates with the MSC.

In order to perform TFO operation, pre-voice communication is required to set TFO operation. The user-generated voice signal is encoded in the terminal A (1), converted into a packet, and then transmitted to the RAN A (2) through an air medium. . The RAN A 2 then transmits the packet received via the air medium to the transcoder A.

The decoder 5 included in the transcoder A decodes the received packet data and then converts the generated voice signal into a 64 Kbps A-law or u-law PCM signal 8 and transmits it. In this case, the IPE 7 may replace the PCM signal by removing echo noise included in the PCM signal or generating a DTMF signal.

When the converted signal is transmitted to the encoder 11 of transcoder B, the encoder converts the packet back into a packet, which is transmitted to the RAN B 13 and transmitted to the terminal B 14 through the air medium. Finally, the terminal B converts the packet back into a voice signal to perform voice communication.

During this process, TX IU (10), RX IU (3), TX TFO (4), RX TFO (9), and TFO protocol (6, 12) of transcoder A and B are used to set the TFO. Send and receive different types of messages. If it is determined that a compatible codec is used between both terminals while performing the above operation, the transcoder no longer operates but operates as a TFO.

In case of TFO operation, the packet generated at the terminal A (1) is transmitted through the air medium at the RAN A (2), and the transmitted packet is transmitted to the RX IU (3) and the decoder 5 of the transcoder A. Done. Decoder 5 in transcoder A decodes the received packet and converts it into a 64 Kbps A-law or u-law PCM signal 8, and RX IU 3 in transcoder A converts the received packet into a TX TFO 4 TX TFO 4 loads the received packet on the decoded PCM signal and transmits the received packet.

At this time, the IPE (7) must ensure that it does not change for the valid lower bits of the PCM signal, the signal passing through the IPE is transmitted to the RX TFO (9) of transcoder B, the RX TFO is a packet data of the received PCM signal Extract only. The extracted packet data is transmitted to the TX IU 10, the TX IU transmits the received packet to the RAN B 13, and the RAN B transmits to the terminal B 14 through the air medium. Finally, terminal B converts the packet back into a voice signal to enable TFO communication between terminals A and B.

As described above, in order for the conventional TFO operation to be performed normally, the IPE must support the TFO. That is, since the MSC is connected to the PCM section, to implement the TFO, a packet must be transmitted in the PCM signal. Therefore, an IPE that modifies the PCM signal, such as an echo noise canceller or DTMF tone generator, must support the TFO function so that messages for TFO setup or TFO frames are not corrupted by the IPE.

However, according to the prior art, there is no guarantee that IPE is properly supporting the TFO operation. Therefore, even when the TFO is in operation, there is a problem that the voice data may be damaged, resulting in poor sound quality.

The present invention has been proposed to solve the above-mentioned conventional problems, and ensures that the TFO operation can be surely supported by performing a function verification for the IPE before or during the TFO operation. It is an object of the present invention to provide an IPE verification system and method for TFO operation that can prevent degradation of voice quality.

The configuration means of the IPE verification system for the TFO operation of the present invention proposed to solve the above technical problem,

A test transmitter for transmitting a TFO message and a TFO frame to the ITE to verify the IPE;

An IPE recognizing a TFO message transmitted from the test transmitter and performing an operation for a TFO frame according to the message content;

A test receiver for determining whether a TFO message and a TFO frame transmitted from the test transmitter have passed the IPE normally;

And a switch configured to switch the TFO message and the TFO frame transmitted from the test transmitter to the test receiver to be transmitted to the test receiver.

The test transmission unit,

A PCM signal generator for generating any PCM signal for carrying a TFO message and a TFO frame;

A test conditioner for controlling a test transmitter to generate and transmit a required TFO message and a TFO frame to the IPE for verifying the IPE;

A TFO message generator for generating a message required by the test conditioner according to a TFO message format;

A TFO frame generator for generating a frame required by the test controller according to a TFO frame type;

And a switch for switching to pass a TFO message or a TFO frame according to the control of the test regulator.

The test receiver,

A TFO message analyzer for extracting a TFO message included in the PCM signal input to the test receiver, analyzing the TFO message, and transmitting the analysis result to a test discriminator;

A TFO frame analyzer for extracting data from corresponding bits of the PCM signal input to the test receiver, combining the TFO frames, analyzing the same, and transmitting the analyzed result to the test discriminator;

A switch for switching signals input to a test receiver to the TFO message analyzer or the TFO frame analyzer under control of a test discriminator;

And a test discriminator for controlling the switch and determining whether the IPE is in normal operation by referring to analysis results received from the TFO message analyzer and the TFO frame analyzer.

On the other hand, the configuration means constituting the IPE verification method for the TFO operation of the present invention,

 Generating a TFO_FILL message and a TFO_TRANS message from a TFO message generator and controlling the test conditioner included in the test transmitter, and transmitting the TFO_FILL message to any PCM signal generated by the PCM signal generator to transmit to the IPE;

After generating the TFO_FILL message and the TFO_TRANS message, the switch moves to the TFO frame generator according to the control of the test controller, and the TFO frame generator generates the corresponding TFO frame under the control of the test controller and loads the TFO frame on the PCM signal to transmit to the IPE. Step 2;

After the step 2, the switch is switched back to the TFO message generator under the control of the test controller, and a step 3 of generating a TFO_NORMAL message from the TFO message generator and loading the PCM signal on the PCM signal is transmitted to the IPE;

The IPE receiving the TFP message and the TFO frame recognizes the TFO message, processes the TFO frame according to the message content, and transmits the TFO message and the TFO frame to the exchange;

A step 5 in which the exchange receiving the TFO message and the TFO frame switches and transmits the TFO message and the TFO frame to a test receiver;

A sixth step in which the TFO message analyzer analyzes the transmitted TFO message and transmits the result to the test discriminator when the switch switches to the TFO message analyzer under the control of the test discriminator included in the test receiver;

A step of allowing the test discriminator receiving the analysis result to control the switch to switch to the TFO frame analyzer, and controlling the TFO frame analyzer by viewing the analysis result received from the TFO message analyzer;

A step 8 of controlling the TFO frame analyzer under the control of the test discriminator, extracting data from the input PCM signal, combining the TFO frames, analyzing the data, and transmitting the analysis result to the test discriminator;

After step 8, the switch switches to the TFO message analyzer again under the control of the test discriminator, and the test discriminator receiving the TFO end message from the TFO message analyzer determines whether the IPE operates normally by referring to the analysis result. Characterized in that it comprises; 9 steps to inform the test performer,

      In step 8, the TFO frame analyzer is characterized by extracting data from the PCM signal by receiving information on how many bits of the input PCM signal from the test discriminator.

Hereinafter, with reference to the drawings will be described in detail a preferred embodiment of the IPE verification system and method for the TFO operation of the present invention.

3 is a block diagram of an IPE verification system for TFO operation according to the present invention, and FIG. 4 is a block diagram of a test transmitter which is a component of an IPE verification system for TFO operation according to the present invention, and FIG. FIG. 6 is a block diagram of an IPE verification method for TFO operation, and FIG. 7 is an exemplary diagram of a TFO message and a TFO frame transmission method.

In FIG. 3, the test transmitter 10 generates a TFO message and a TFO frame to verify the IPE, and transmits the TFO message to the IPE 20. The IPE 20 transmits the TFO message transmitted from the test transmitter 10. It works by recognizing and processing TFO frames according to the message content. A typical example of IPE is changing a PCM signal such as an echo noise canceller or a DTMF tone generator.

The test receiver 40 operates to determine whether the TFO message and the TFO frame that are transmitted from the test transmitter 10 and passed through the IPE 20 are normally received, and the exchange 30 is transmitted from the test transmitter 10. And switch the TFO message and the TFO frame passing through the IPE 20 to be transmitted to the test receiver.

On the other hand, in Fig. 3 (a), the system is configured to pass through the IPE before the TFO message and the TFO frame generated by the test transmitter is switched at the exchange (the configuration is passed through the IPE in the transmission step), unlike the As shown in (b), the system may be changed to the configuration in which the TFO message and the TFO frame generated by the test transmitter are switched at the exchange and then passed through the IPE to the test receiver (the configuration passes through the IPE in the receiving step). Since this is verifying the IPE for TFO operation, it will be obvious that at least one pass through the IPE, whether in the transmit phase or the receive phase, will be apparent.

4 is a block diagram of a test transmitter that is a component of an IPE verification system for TFO operation. The PCM signal generator 11 generates an arbitrary PCM signal for carrying a TFO message or a TFO frame. It works. That is, the PCM signal generator generates a signal corresponding to a signal flowing in the PCM section between the MSCs during the TFO operation.

The test conditioner 15 operates to control the components of the test transmitter to create and send the necessary TFO messages and TFO frames to the IPE to verify the IPE. That is, the switch is controlled to initially generate a TFO_FILL message and a TFO_TRANS message from the TFO message generator, then move the switch to generate a TFO frame from the TFO frame generator, and then move the switch back to the TFO message. Causes the generator to generate a TFO_NORMAL message.

Looking at what the TFO message and the TFO frame mentioned above mean, TFO_FILL tells the IPE a message to indicate that the TFO is starting, and TFO_TRANS tells the IPE to guarantee a few bits of the lower bits of the PCM signal coming forward. TFO frame means arbitrary data to be carried in the lower few bits of the PCM signal, and TFO_NORMAL refers to a message for notifying that the TFO is terminated.

The TFO message generator 12 operates to generate a message required by the test controller 15 in accordance with the TFO message format. The message format generally consists of a header, a message type, and an extension. The header indicates the start of the message, and the end of the message refers to a field indicating the end of the extension. As can be seen, the message type is an identifier that determines whether the current message is a TFO_FILL message or a TFO_TRANS message.

Extensions, on the other hand, may or may not come depending on the message. For example, in case of TFO_FILL message, there is no extension, and in case of TFO_TRANS message, information about how many bits of the PCM signal are transmitted to the TFO frame forwarded to the extension.

The TFO frame generator 13 operates to generate a frame required by the test controller 15 in accordance with the TFO frame format. The frame format is the same as the message format, and is composed of a header, data to be transmitted, and an extension. The header indicates the start of the frame, and the end of the frame can be known by referring to a field indicating the end of the extension. The data you want is located between the header and the extension.

The switch 14 operates to switch to pass a TFO message or TFO frame under the control of the test regulator as described above.

FIG. 5 shows a block diagram of a test receiver, which is a component of an IPE verification system for TFO operation, comprising a test discriminator, a TFO message analyzer, a TFO frame analyzer, and a switch.

The TFO message analyzer 41 extracts and analyzes the TFO message included in the PCM signal input to the test receiver 40 first, and transmits the analysis result to the test discriminator 43. That is, it analyzes the TFO_FILL message first inputted to the test receiver and transmits to the test discriminator 43 that this message is a message for notifying that the TFO is started, and then analyzes the next incoming TFO_TRANS message and loads the data in the future. The TFO frame will come in and send the test discriminator the information that the lower few bits of the PCM signal must be guaranteed. Meanwhile, the result analyzed by the TFO frame analyzer 42, which will be described later, is transmitted to the test discriminator, and then analyzed by the TFO_NORMAL message coming into the test receiver, and the message is transmitted to the test discriminator indicating that the TFO is terminated.

The TFO frame analyzer 42 extracts data from the corresponding bit of the PCM signal input to the test receiver, combines the TFO frames, analyzes them, and transmits the analyzed result to the test discriminator. This bit means the lower number of bits of PCM signal input to the test receiver. The number of bits indicates that the TFO message analyzer analyzes the TFO_TRANS message among the TFO messages and transmits the result to the test discriminator. The test discriminator then informs the TFO Frame Analyzer of the number of bits.

The switch 44 operates to switch the signals input to the test receiver to the TFO message analyzer 41 or the TFO frame analyzer 42 by the control of the test discriminator 43. That is, the control of the test discriminator 43 switches the TFO_FILL message and the TFO_TRANS message coming into the test receiver so that the TFO message analyzer can be input to the TFO message analyzer, and then switches the TFO by the control of the test discriminator. Allow frames to be entered into the TFO frame analyzer, then move the switch again under the control of the test discriminator so that the TFO_NORMAL message can be entered into the TFO message analyzer.

The test discriminator 43 controls the switch 44 and determines whether the IPE is operating normally by referring to the analysis results received from the TFO message analyzer 41 and the TFO frame analyzer 42 and returns the result to the test operator. It works by telling.

 6 is a flowchart illustrating a method for verifying an IPE for TFO operation according to the present invention, and FIG. 7 is an exemplary view illustrating a method of transmitting a TFO message and a TFO frame, with reference to which will be described a preferred embodiment of the present invention.

The TFO message generator generates the TFO_FILL message and the TFO_TRANS message under the control of the test controller included in the test transmitter, and loads the TFO_FILL message and the TFO_TRANS message in sequence on any PCM signal generated by the PCM signal generator (S51 to S52).

The method of loading a TFO message on the PCM signal is transmitted by being loaded on the least significant 1 bit of the PCM signal as shown in FIG. 7A, and replacing a least significant bit of every 16th sample of the PCM signal with a TFO message. . Therefore, since there is a 125 ms time difference for each PCM signal, a total of 10 bits of messages are transmitted during 20 ms (160 PCM signals).

Thus, in the first TFO message format, if the header is 40 bits, where the message type delimiter is to be 20 bits, and the extension is 20 bits, the total message format is 80 bits, so 1280 PCMs are needed to transmit one TFO message. The signal is generated and takes 160ms.

After transmitting one TFO message as described above, the next TFO message or TFO frame is transmitted. At this time, the test controller transmits the TFO message or TFO frame after the time required for transmitting the first TFO message. It controls the switch so that the switch moves.

After generating the TFO_FILL message and the TFO_TRANS message in the TFO message generator, the test controller controls the switch to switch the TFO frame generator and controls the TFO frame generator to generate a frame conforming to the TFO frame type.

Then, the TFO frame generator generates a TFO frame in accordance with the TFO frame format and loads it on the PCM signal. The TFO frame format is as described above, and the method of loading the PCM signal includes a TFO frame on the PCM signal by replacing every PCM signal lower bit with a TFO frame, as shown in FIG. If 16Kbps codec is used, packet data is transmitted to the lower 2 bits of PCM signal. In this case, TFO frame corresponding to 80 bits can generate TFO frame if 40 PCM signals are generated (5 (time). (S53).

After the TFO frame generator generates the TFO frame and loads it on the PCM signal, the switch switches back to the TFO message generator by controlling the test controller, and when the test controller controls the TFO message generator, the TFO message generator generates a TFO_NORMAL message. It mounts on a PCM signal (S54).

The TFO message and the TFO frame generated as described above are transmitted to the IPE. The IPE recognizes the TFO message and processes the TFO frame according to the message content to transmit the TFO message and the TFO frame to the exchange. At this time, the IPE should be guaranteed not to change the corresponding lower bit of the PCM signal in order not to change the TFO frame according to the information contained in the TFO message (S55).

The exchange receiving the TFO message and the TFO frame switches to transmit the TFO message and the TFO frame to the test receiver (S56).

After receiving the TFO message and the TFO frame, the test receiver first switches the switch to the TFO message analyzer under the control of the test discriminator, and then the TFO message analyzer analyzes the incoming TFO message and transmits the result to the test discriminator. Will be In other words, it extracts and combines only TFO message (packet signal) from PCM signal including first incoming TFO_FILL message, then analyzes it and sends it to the test discriminator to indicate that TFO is started, and next incoming TFO_TRANS message is loaded. After extracting only the TFO_TRANS message from the PCM signal, and combining it, the message is analyzed and the result is transmitted to the test discriminator (S57).

Since the TFO_TRANS message has a message for informing some of the lower bits of the PCM signal received in the future, the TFO message analyzer transmits the result to the test discriminator.

The test discriminator receiving the analysis result from the TFO message analyzer controls the switch so that the switch is switched to the TFO frame analyzer, controls the TFO frame analyzer, and how many bits are contained in the lower bits of the incoming PCM signal. Provides information about

The TFO frame analyzer, which is controlled by the test discriminator and receives the corresponding information, extracts the TFO frame from the incoming PCM signal, combines it, analyzes the combined TFO frame, and transmits the result to the test discriminator. That is, the packet information contained in the lower bits of the PCM signal is combined according to the information informed by the test discriminator, and then the combined data is transmitted to the test discriminator (S58).

When the test discriminator receives the analysis result analyzed by the TFO frame analyzer, the test discriminator controls the switch to switch back to the TFO message analyzer. The TFO message analyzer then extracts the TFO_NORMAL message from the PCM signal and combines it. The combined message is analyzed and sent to the test discriminator. That is, the TFO_NORMAL message transmits a message for notifying that the TFO operation is completed to the test discriminator (S59).

The test discriminator receiving the analysis result for the TFO_NORMAL message determines whether the IPE has been normally operated with the analysis result received from the TFO message analyzer and the TFO frame analyzer (S60). For example, the test discriminator may determine whether the IPE is operating normally by matching the TFO frame transmitted from the test transmitter with the TFO frame analyzed by the test receiver. If it does not match, IPE fails to comply with the PCM low bit guarantee message sent in the TFO message and processes the TFO frame, resulting in IPE not functioning normally.

As described above, the test discriminator makes a decision and then informs the test performer of the result of the determination. In this method, the test discriminator may show the result on the display device, or inform the user by an LED or an alarm.

According to the IPE verification system and the method for the TFO operation of the present invention having the above configuration means and embodiments, it is determined whether the IPE supports the TFO normally before the TFO operation or when the TFO operation failure occurs, effectively It can be found that the TFO operation can be performed smoothly, thereby preventing the degradation of the voice signal.

1 is a configuration diagram for a transcoder operation in a mobile communication system.

2 is a functional block diagram for a conventional TFO operation.

3 is a block diagram of an IPE verification system for TFO operation according to the present invention.

4 is a block diagram of a test transmitter that is a component of an IPE verification system for TFO operation according to the present invention.

5 is a block diagram of a test receiver that is a component of an IPE verification system for TFO operation according to the present invention.

6 is a flowchart illustrating an IPE verification method for TFO operation according to the present invention.

7 shows an example of a TFO message and a TFO frame transmission method.

Claims (5)

A test transmitter for transmitting a TFO message and a TFO frame to the ITE to verify the IPE; An IPE recognizing a TFO message transmitted from the test transmitter and performing an operation for a TFO frame according to the message content; A test receiver for determining whether a TFO message and a TFO frame transmitted from the test transmitter have passed the IPE normally; And a switch configured to switch a TFO message and a TFO frame transmitted from the test transmitter to the test receiver to be transmitted to the test receiver. 2. The method according to claim 1, wherein the test transmission unit, A PCM signal generator for generating any PCM signal for carrying a TFO message and a TFO frame; A test conditioner for controlling a test transmitter to generate and transmit a required TFO message and a TFO frame to the IPE for verifying the IPE; A TFO message generator for generating a message required by the test conditioner according to a TFO message format; A TFO frame generator for generating a frame required by the test controller according to a TFO frame type; And a switch for switching to pass a TFO message or a TFO frame according to the control of the test conditioner. The method according to claim 1, The test receiver, A TFO message analyzer for extracting a TFO message included in the PCM signal input to the test receiver, analyzing the TFO message, and transmitting the analysis result to a test discriminator; A TFO frame analyzer for extracting data from corresponding bits of the PCM signal input to the test receiver, combining the TFO frames, analyzing the same, and transmitting the analyzed result to the test discriminator; A switch for switching signals input to a test receiver to the TFO message analyzer or the TFO frame analyzer under control of a test discriminator; And a test discriminator for controlling the switch and determining whether the IPE is in normal operation by referring to analysis results received from a TFO message analyzer and a TFO frame analyzer. Generating a TFO_FILL message and a TFO_TRANS message from a TFO message generator and controlling the test conditioner included in the test transmitter, and transmitting the TFO_FILL message to any PCM signal generated by the PCM signal generator to transmit to the IPE; After generating the TFO_FILL message and the TFO_TRANS message, the switch moves to the TFO frame generator according to the control of the test controller, and the TFO frame generator generates the corresponding TFO frame under the control of the test controller and loads the TFO frame on the PCM signal to transmit to the IPE. Step 2; A third step of generating a TFO_NORMAL message from the TFO message generator by loading the PCM signal on the PCM signal under the control of the test controller after the second step; The IPE receiving the TFP message and the TFO frame recognizes the TFO message, processes the TFO frame according to the message content, and transmits the TFO message and the TFO frame to the exchange; A step 5 in which the exchange receiving the TFO message and the TFO frame switches and transmits the TFO message and the TFO frame to a test receiver; A sixth step in which the TFO message analyzer analyzes the transmitted TFO message and transmits the result to the test discriminator when the switch switches to the TFO message analyzer under the control of the test discriminator included in the test receiver; A step of allowing the test discriminator receiving the analysis result to control the switch to switch to the TFO frame analyzer, and controlling the TFO frame analyzer by viewing the analysis result received from the TFO message analyzer; A step 8 of controlling the TFO frame analyzer under the control of the test discriminator, extracting data from the input PCM signal, combining the TFO frames, analyzing the data, and transmitting the analysis result to the test discriminator; After step 8, the switch switches to the TFO message analyzer again under the control of the test discriminator, and the test discriminator receiving the TFO end message from the TFO message analyzer determines whether the IPE operates normally by referring to the analysis result. 9 steps to inform the test performer; IPE verification method for the TFO operation, characterized in that made, including. The method of claim 4, wherein in the eighth step, The TFO frame analyzer receives the information on how many bits of the input PCM signal from the test discriminator to extract data from the PCM signal, IPE verification method for the TFO operation.