KR20020054648A - Trace Method of Error Location Using Vocoder - Google Patents

Abstract

PURPOSE: A method for tracing error location by using a vocoder is provided to promptly cope with inferior call by grasping location of inferior call via several loop back test, and effectively add diagnosing function of a system without extra cost. CONSTITUTION: PCM data are input and output through a high-speed digital data bus(10) by using a serial port of a vocoder(20) and an encoder(40) of the vocoder(20) transforms PCM data into sound packets for transmitting to a selector(50). In a packet loop back, the vocoder(20) returns sound packets received from the selector(50), to the selector(50) without any processing. In a vocoder packet loop back, the vocoder(20) passes the sound packets received from the selector(50) through a decoder(30) for transforming into PCM data, passes PCM data through the encoder(40) for making into the sound packet, and returns PCM data to the selector(50). In a PCM loop back, the vocoder(20) returns PCM data received from an exchange to the exchange(60) without any processing. In a vocoder PCM loop back, the vocoder(20) passes PCM data through the encoder(40) for transforming into the sound packets, passes the sound packets through the decoder(30) for transforming into PCM data, and returns the PCM data to the exchange(60).

Description

Trace Method of Error Location Using Vocoder

The present invention relates to a method for efficiently locating an error location when a problem such as a call failure occurs in a complex system such as a mobile communication system. Particularly, the present invention relates to a location where an error occurs by controlling the flow of voice data and packets using a vocoder. Error tracking method using vocoder to find.

In a mobile communication system, a voice coder (Vocoder) that converts voice data (PCM sound) into a voice packet and restores it is essential for efficient transmission between wireless sections.

Here, the PCM sound refers to a pulse code modulation (PCM) of the voice signal and the digital signal.

The vocoder has the function of converting voice data received from the exchange into voice packets and of converting voice packets received from the wireless base station into voice data.In conventional mobile communication systems, the vocoder / selector module in the BCS (Base Station Controller) It is implemented with DSP (Digital Signal Processor) for real time processing.

The vocoder / selector module is composed of one processor serving as a functional selector, several DSPs serving as vocoder functions and MT8980, which is a kind of high-speed digital data line switch.

1 is a block diagram showing the structure of a conventional vocoder.

As shown in the drawing, PCM data is input and output through the high-speed digital data bus (ST-BUS) 10 using the serial port of the vocoder 20, and the encoder 40 in the vocoder receives the received PCM data. The packet is converted into a packet and delivered to the selector 50.

Here, ST-BUS is a high-speed digital data bus devised by US Mitel.

In addition, the voice packet from the selector 50 is input and output through the parallel port of the vocoder, and the decoder 30 in the vocoder converts the received voice packet into PCM data and exchanges the switch 60 through the high-speed digital data bus 10. Will be delivered to

The selector 50 selects and releases an appropriate vocoder 20 when there is a call allocation / release request from the exchange 60, and exchanges a voice packet with the vocoder 20 at a predetermined time interval.

That is, the selector 50 transmits the voice packet received from the wireless base station to the vocoder 20, receives the voice packet from the vocoder 20, and delivers the voice packet to the wireless base station, and controls the operation of the vocoder 20. To do so.

One selector 50 is responsible for a plurality of vocoder to send and receive data at regular time intervals using a parallel port for high-speed data transmission and reception with each vocoder.

The vocoder 20 is implemented with a DSP and is composed of an encoder 40 for making a voice packet from voice data and a decoder 30 for converting the voice packet into voice data.

The encoder 40 converts the 64K bps PCM voice data received from the exchanger 60 into an 8K bps voice packet for transmission in the radio section, and transmits it to the selector 50. The decoder 30 receives the selector 50. It is in charge of the function of converting a voice packet into voice data and transmitting it to the exchange 60.

Therefore, the vocoder 20 exchanges 64K bps PCM voice data with the switch 60 through serial input and output, and exchanges 8K bps voice packets with the selector 50 through parallel input and output.

MT8980, a high-speed digital data switch, is a module that controls the flow of high-speed digital data bus (ST-BUS). It establishes the voice data path between the exchange and vocoder and sends the voice data corresponding to the corresponding channel in serial input / output of the corresponding vocoder. In charge of the function to connect to.

The MT8980 thus controls the voice data flow between the exchange and the vocoder.

In the existing mobile communication system, a process of converting voice data transmitted from an exchange into voice packets and transmitting them to a wireless base station, and converting voice packets received from the base station into voice data and distinguishing the flow of data transmitted to the exchange are described below. Same as

First, in the process of converting voice data into voice packets, the selector selects an appropriate vocoder according to the call allocation request of the exchange and controls the MT8980, a high-speed voice data switch, to transmit voice data of the corresponding channel and the corresponding vocoder through the serial port. Connect via

The vocoder buffers 64K bps of voice data in a fixed block unit (20ms) through the serial port, and then the encoder module in the vocoder converts the voice data block into 8K bps of voice packet.

The converted voice packet is delivered to the selector through the parallel port at the request of the selector.

A selector that processes multiple vocoders receives a packet at a time interval of 20 ms for each vocoder and transmits a voice packet to a wireless base station.

Secondly, in the process of converting a voice packet into voice data, the selector transmits an appropriate voice packet to the vocoder of the corresponding channel every 20 ms in consideration of the state of the voice packet received from the wireless base station.

That is, if the voice packet is damaged, the selector transmits error frame data to the vocoder.

The decoder module in the vocoder converts the received voice packet into voice data of 64K bps and transmits it to the exchange through the serial port.

At this time, the path of the voice data between the vocoder and the exchange is set by the MT8980.

However, when a communication failure occurs in a mobile terminal or a general telephone due to the damage of voice data and a packet to an exchange that transmits and receives a conventional voice data and a wireless base station that transmits and receives a voice packet, a mobile communication system Due to the complex path of the voice data in the system, it is difficult to locate the bad location.

Accordingly, the present invention was created to improve the above problems, and when a call failure occurs in a mobile communication system, adjustment of the flow of voice data and voice packets in the vocoder and the selector module to find the location and cause of the failure The purpose is to implement a function that can loop back at various points to enable this, and to provide a method for estimating the location and cause of the call failure by using the result.

1 is a block diagram showing the structure of a conventional vocoder

2 is a block diagram showing the structure of a vocoder according to the present invention.

The present invention relates to a method for efficiently locating an error location when a problem such as a call failure occurs in a complex system such as a mobile communication system. Particularly, the present invention relates to a location where an error occurs by controlling the flow of voice data and packets using a vocoder. Error tracking method using vocoder to find.

The present invention is characterized by being able to track the error location for a bad call using the loopback function through the vocoder.

This invention comprises a first loopback for returning the voice packet received from the selector to the selector without any processing by the vocoder; A second loopback converting the voice packet received from the selector through the decoder into voice data, and then converting the voice packet back to the encoder input to reconvert the voice packet back to the selector; A third loopback which returns the voice data received from the exchange to the exchange without any processing by the vocoder; And a fourth loopback that converts the voice data received from the exchanger through the encoder into voice packets, and then converts the voice data back to the decoder input to reconvert the voice data back to the exchanger.

In addition, the present invention is characterized in that the determination of the error tracking when using the loopback function is determined by a call test between the wireless terminal and the wireless terminal, the wireless terminal and the wired terminal.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

2 is a block diagram showing the structure of a vocoder according to the present invention.

As shown in the drawing, PCM data is input and output through the high-speed digital data bus (ST-BUS) 10 using the serial port of the vocoder 20, and the encoder 40 in the vocoder receives the received PCM data. The packet is converted into a packet and delivered to the selector 50.

The path A is packet loopback, in which the vocoder 20 does not process any voice packets received from the selector 50 and returns the voice packets to the selector 50.

Path B is a vocoder packet loopback, in which the vocoder 20 converts the voice packet received from the selector 50 into the PCM through the decoder 30, and then passes through the encoder 40 to make a voice packet to selector 50. To return.

Path C is a PCM loopback, in which the vocoder 20 does not process the PCM data received from the switch 60 and returns the PCM data to the switch 60.

The path D is a vocoder PCM loopback, and the vocoder 20 passes the encoder 40 through the encoder 40 to make a voice packet, and then passes the decoder 30 to convert the PCM data into PCM data. To 60).

In the present invention, some of the above loopback functions are defined.

First, the packet loopback is a method in which the vocoder returns the voice packet received from the selector to the selector without any processing, and the encoder and the decoder in the vocoder do not operate at this time.

Using this function, it is possible to diagnose the network elements of the terminal, the wireless section and the selector in the system. The diagnosis is made through the call test at the two wireless terminals.

Second, the vocoder packet loopback is a method in which a vocoder converts a voice packet received from the selector into a voice data after passing through a decoder, and then converts the voice packet back to an encoder input to reconvert the voice packet to a selector.

Using this function, it is possible to perform the diagnosis of the network elements and the vocoder itself up to the terminal, the radio section and the selector in the system.

Third, the PCM loopback is a method in which the vocoder returns voice data received from the exchange to the exchange without any processing. The encoder and decoder in the vocoder do not operate at this time.

This function enables the diagnosis of network elements such as Mobile Switching Center (MSC) including ST-BUS after vocoder, and the diagnosis can be judged by echo quality of tester's voice in the telephone. Diagnostic results for this function can be determined.

Fourth, the vocoder PCM loopback is a method in which the vocoder converts the voice data received from the exchange into an audio packet after passing through the encoder, and then converts the voice data back to the decoder input to convert the voice data back to the exchange.

This function enables not only the test of the vocoder itself but also the diagnosis of network elements such as MSC including ST-BUS, and the judgment of the diagnosis is carried out through the echo quality of the tester's voice in the landline telephone. The diagnosis result can be determined.

In general, mobile communication systems verify their function and stability through call tests.

Two mobile communication terminals are used for the packet loopback and vocoder packet loopback, and two wired telephones are used for the PCM loopback and the vocoder PCM loopback.

In addition to the loopback functions listed above, various loopback functions may be added at various points as necessary.

Thus, in the present invention, the call test using the four loopback functions described above can be used to determine the location of a malfunction such as a call failure in the mobile communication system.

If the error location tracking method using the vocoder according to the present invention has an abnormality in the call quality, it is possible to quickly cope with the call failure because it can determine the approximate location of the call failure through a few simple loopback test.

And because these features are implemented only in software, you can add effective system diagnostics at no additional cost.

In addition, this function can be used as a method of verifying the network element when developing other network elements as well as call quality.

Claims (3)

In the error location estimation method using a vocoder in a mobile communication system, An error location tracking method using a vocoder, which tracks an error location for a call failure using a loopback function through a vocoder. 2. The apparatus of claim 1, wherein the loopback comprises: a first loopback for returning the voice packet received from the selector to the selector without any processing by the vocoder; A second loopback converting the voice packet received from the selector through the decoder into voice data, and then converting the voice packet back to the encoder input to reconvert the voice packet back to the selector; A third loopback which returns the voice data received from the exchange to the exchange without any processing by the vocoder; And a fourth loopback converting the voice data received from the exchanger through the encoder into voice packets, and then converting the voice data back to the decoder input to reconvert the voice data back to the exchanger. . The error location tracking method of claim 1, wherein the error location tracking when the loopback function is used is determined by a call test between the wireless terminal and the wireless terminal and a call test between the wireless terminal and the wired terminal. Way.