KR20160055464A - Method and apparatus for switching of extension call in the private branch exchange - Google Patents

Abstract

The present invention relates to a method and an apparatus capable of determining whether echo cancellation is performed by determining whether a matching circuit is included in a call path and a private branch exchange therefor. A switching apparatus according to the present invention receives an extension call from an extension telephone connected to the private branch exchange, determines whether the matching circuit is included in the path for connecting with a calling party number by using information about the calling party number including the extension call, forms a first switching signal for a switching operation not to perform echo cancellation when the matching circuit is not included in the path for connecting with the calling party number, forms a second switching signal for a switching operation to perform the echo cancellation when the matching circuit is included in the path for connecting with the calling party number, and performs the echo cancellation from the extension call.

Description

TECHNICAL FIELD The present invention relates to a method and an apparatus for switching an extension line in a private branch exchange,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PBX (Private Branch eXchange) field, and more particularly, to an apparatus and method for switching an internal call, which can determine whether echo cancellation is performed by classifying whether or not a matching circuit on a call path for an extension or a trunk line connection is included .

With the advancement of science and technology, a service for transmitting voice signals, image data, text data, or moving picture data between people is becoming popular. Among these data transmission, voice signal transmission service is most frequently used and voice signal transmission is performed through a telephone network.

The transmission of the voice signal was made through a wired telephone network after Alexander Graham Bell invented the telephone. A voice signal providing service for a plurality of users, such as an office or an enterprise, uses a private branch exchange (PBX) to provide a call service between an extension and an extension. PABXs are typically used to provide voice signals to subscribers, but are being used to provide a variety of multimedia services as multimedia technology develops. A system capable of automatically performing telephone exchange is referred to as a Private Automatic Branch Exchange (PABX).

1 is a circuit diagram for echo cancellation in a private automatic exchanger system.

As shown in Fig. 1, the voice data transmitted to the echo canceller 10 for echo cancellation occurring in the private automatic exchanger system includes not only the interfacial interfaces 21 and 24 including the matching device but also the matching device 23, 25, and 26, which are not shown in FIG. However, by attempting echo cancellation on the voice data transmitted from the extension interfaces 22, 23, 25 and 26, which do not require echo removal because it does not include a matching device, unnecessary processing delay delay may occur. When a user of a cordless telephone device such as Wi-Fi or DECT attempts to make a call in a place with a high noise level, the echo canceler 10 mistakes a normal voice signal as an echo signal, There is a problem that the silence phenomenon or the sound of the telephone tone is reduced.

ITU-T G.165 (published on March 3, 1994) BPRA054 Echo Cancellation Software for the TMS320C54x (released January 1, 1997)

The present invention provides an internal call switching method and apparatus capable of determining whether echo cancellation is performed by classifying whether or not a matching circuit on a call path for an extension or a trunk connection is included.

A switching method in a private branch exchange of the present invention comprises the steps of: a) receiving an extension call from an extension telephone apparatus connected to a private branch exchange; b) determining whether a matching circuit is included in a path for a call connection with the other party number using information on the other party number included in the extension call; c) forming a first switching signal for not performing echo cancellation when a matching circuit is not included in a path for a call connection with the counterpart number, Forming a second switching signal for switching to perform echo cancellation if a matching circuit is included on the path for the echo canceling step and performing echo cancellation of the extension arc.

In addition, the switching apparatus in the private branch exchange of the present invention includes: a storage unit for storing information on an extension number and a trunk line number registered in a private branch exchange; When receiving an extension call, determines whether or not a matching circuit is included in a path for a voice call connection with the other party number using information on the other party number included in the extension call, A first switching signal for switching to prevent echo cancellation if the matching circuit is not included in the path for the destination number, A second switching signal for switching to perform the echo cancellation when the echo cancellation is performed; An echo removal unit for performing the echo removal; Wherein when the first switching signal is received, the switch connects the switch to the path for the call connection with the counterpart without going through the echo canceller, and when receiving the second switching signal, And an echo cancellation unit for connecting to the other party through a path for call connection with the counterpart number.

According to the present invention, it is possible to perform unnecessary process delay only when echo cancellation is required in a private branch exchange, and voice call quality can be improved in a severe noise environment.

1 is a circuit diagram for echo cancellation in a private automatic exchanger system;
2 is a configuration diagram of a private branch exchange system according to an embodiment of the present invention;
3 is a configuration diagram of an echo canceller according to an embodiment of the present invention;
4 is a configuration diagram of a switching device according to an embodiment of the present invention.
5 is a configuration diagram of an apparatus for a call connection of a private branch exchange according to an embodiment of the present invention;
6 is a flowchart illustrating a procedure of a switching process according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions will not be described in detail if they obscure the subject matter of the present invention. In the drawings, the same reference numerals are assigned to the components having the same configuration and function, and a detailed description thereof will be omitted.

2 is a configuration diagram of a private branch exchange system according to an embodiment of the present invention.

2, path delay and path loss in the PABX system 200 are important factors affecting the voice quality of the Central Office (CO) 210 . The connection at the central office 210 is generally a four-wire line 221 or 222 and the electrical connection at the subscriber's side to reduce the line cost used between the central office 210 and the telephone set 231, The matching devices 251 and 252 are used to match different line configurations to the four-stranded lines 221 and 222 and the two-stranded lines 241 and 242 in this configuration Can be used. That is, the matching devices 251 and 252 may be operable to match different line configurations of the central and subscriber ends of the PABX system 200. In one embodiment, the circuitry of the matching devices 251, 252 may include a matching transformer. In this configuration, a part of the voice signal transmitted to the circuit units of the matching devices 251 and 252 due to the mismatch of the impedances between the matching devices 251 and 252 and the telephone lines 241 and 242 is a voice signal, And is reflected to the devices 231 and 232 to cause an echo signal which hinders the voice quality. In order to remove the echo signal from the voice communication using the PBX system 200, the PBX system includes an echo canceller, and the echo canceller will be described later with reference to Fig.

3 is a configuration diagram of an echo canceller according to an embodiment of the present invention.

3, the echo canceller 310 includes an adaptive filter 311 and a telephone set 231 and 232 that use a filter coefficient adjusted according to a reception signal from the central office 210 And a subtractor 312 for removing the echo signal from the transmitted transmission signal. From an electrical point of view, the echo canceller 310 is a four port system connected between the central national office 210 and the matching devices 251, 252.

4 is a configuration diagram of a switching device according to an embodiment of the present invention.

4, the switching device 400 includes a storage unit 410, a control unit 420, a switching unit 430, an echo removal unit 440, a CO line interface 450, a wireline extension interface 460, A wireless extension interface 470, and a system bus 480. In one embodiment, the storage unit 410, the control unit 420, the switching unit 430, and the echo removal unit 440 may be provided in a private switching center or a telephone set connected to a private branch exchange, . The storage unit 410, the control unit 420, the switching unit 430 and the echo removal unit 440 may be connected to each other using the system bus 480.

The storage unit 410 may include information on the extension number registered in the private branch exchange and information on the extension number registered in the private branch exchange. In one embodiment, the information on the extension number and the CO line number (i.e., the external line number) registered in the PBX includes information on whether a matching circuit is included in the path for voice call connection with the extension number and the CO line number . ≪ / RTI > If a subscriber tries to establish a voice call with a trunk number that is not stored in the storage unit 410, it may be set that a matching circuit is included in a path for voice call connection with the trunk number. In an embodiment, the storage unit 410 may be a ROM (Read Only Memory), a RAM (Random Access Memory), a CD (Compact Disc) -ROM, a magnetic tape, a floppy disk, Optical data storage, or carrier waves (e.g., transmission over the Internet), but are not limited to such implementations.

When receiving an extension call, the control unit 420 determines whether or not a matching circuit is included in a path for a voice call connection with the other party number by using the information on the other party number included in the extension call, and the matching circuit is included The switching unit 430 may form a first switching signal for operating the switching unit 430 to connect the extension line to the opposite party without going through the echo cancellation unit 440. If the switching unit 430 includes the matching circuit, To the echo cancellation unit 440 to form a second switching signal for connecting the extension line to the path for voice call connection with the other party number through the echo cancellation unit 440. [

When receiving the first switching signal from the control unit 420, the switching unit 430 may directly connect the switch to the path for call connection with the other party's number (extension number or trunk number) without passing through the echo cancellation 440 , And may connect the switch to the echo removal unit 440 when receiving the second switching signal from the control unit 420. [

The echo removal unit 440 may perform an echo removal operation of an extension line connected according to the switching operation of the switching unit 430. [ In one embodiment, the echo removal unit 440 may have the same configuration as that of the echo canceling unit 310 shown in FIG.

The wireline extension interface 460 represents a path for establishing a call connection to an extension number using a wireline telephone device, and the wireless extension interface 470 ) May indicate a path for a call connection to an extension number using a wireless telephone device.

5 is a block diagram of an apparatus for a call connection of a PABX according to an embodiment of the present invention.

As shown in FIG. 5, in one embodiment, the path of the CO lines 511 and 514 for voice call connection to the CO line number includes a matching circuit, and includes a wired and wireless extension interface It is assumed that the paths 512, 513, 515 and 516 do not include matching circuits.

When receiving an extension call from a specific extension phone apparatus through the wired or wireless extension interface 512, 513, 515, 516, the switching apparatus 500 transmits a voice call to the destination number using the information on the destination number included in the extension call It is determined whether or not the matching circuit is included in the path for the call connection. In the case of the CO line interface paths 511 and 514 including the matching circuit, the switching units 521 and 522 are connected to the echo removal unit 530, The call can be connected through the echo canceller 530 and the extension line can be connected to the wired and wireless extension interfaces 512, 513, 515, and 516 that do not include the matching circuit without the echo cancellation 530 The unnecessary echo cancellation process may not be performed by directly connecting the switching units 521 and 522.

6 is a flow chart illustrating a procedure of a switching process according to an embodiment of the present invention.

As shown in FIG. 6, the switching device 500 may receive an extension call from a specific extension phone device via the wired or wireless extension interface 512, 513, 515, and 516 (S610).

The switching device 500 determines whether or not a matching circuit is included in the path for voice call connection with the other party number using the information on the other party number included in the extension call (S620) The switching unit 521 and 522 are connected to the echo removal unit 530 to form a first switching signal for connecting the extension line through the echo removal unit 530 (S630). If the matching circuit is not included in the path for the voice call connection with the other party number, the direct connection between the switching units 521 and 522 is performed without passing through the echo removal unit 530 The unnecessary echo cancellation process may not be performed (S650).

Although the method has been described through particular embodiments, the method may also be implemented as computer readable code on a computer readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and may be implemented in the form of a carrier wave (for example, transmission over the Internet) . In addition, the computer-readable recording medium may be distributed over network-connected computer systems so that computer readable codes can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the above embodiments can be easily deduced by programmers of the present invention.

Although the present invention has been described in connection with certain embodiments thereof, it should be understood that various changes and modifications may be made therein without departing from the spirit and scope of the invention as will be apparent to those skilled in the art to which the invention pertains. something to do. It is also contemplated that such variations and modifications are within the scope of the claims appended hereto.

10: echo canceller 21, 22, 23, 24: station interface
200: PUBLIC EXCHANGE SYSTEM 210:
221, 222, 241, 242: line 231, 232:
251, 252: matching device 310: echo canceller
311 adaptive filter 312 subtractor
400: switching device 410: storage unit
420: control unit 430:
440: Echo cancellation 450: CO line interface
460: Wired station interface 470: Wireless station interface
480: System bus 500: Switching device
511, 514: CO line interface 512, 513, 515, 516: Extension interface
521, 522: Switching unit 530:

Claims (10)

A switching method in a private branch exchange,
comprising the steps of: a) receiving an extension call from an extension telephone apparatus connected to a private branch exchange;
b) determining whether a matching circuit is included in a path for a call connection with the other party number using information on the other party number included in the extension call;
c) forming a first switching signal for not performing echo cancellation when a matching circuit is not included in a path for a call connection with the counterpart number, Forming a second switching signal for switching to perform echo cancellation if a matching circuit is included on the path for the echo canceling step, and performing echo cancellation of the extension arc. The method according to claim 1,
The matching circuit includes:
Stranded lines of the private telephone set and the four-stranded line of the private branch exchange. The method according to claim 1,
And a path for a call connection with the counterpart number including the matching circuit,
A trunk interface path or an extension interface path. The method according to claim 1,
The information on the counterpart number is,
And information on whether or not the matching circuit is included in a path for a call connection with the counterpart number. The method according to claim 1,
The step c)
Determining that the matching circuit is not included when the information on the partner number is an extension number and determining that the matching circuit is included when the information on the partner number is a trunk line number , Switching method. A switching device in a private branch exchange,
A storage unit for storing information on an extension number and a CO line number registered in a private branch exchange;
When receiving an extension call, determines whether or not a matching circuit is included in a path for a voice call connection with the other party number using information on the other party number included in the extension call, A first switching signal for switching to prevent echo cancellation if the matching circuit is not included in the path for the destination number, A second switching signal for switching to perform the echo cancellation when the echo cancellation is performed;
An echo removal unit for performing the echo removal;
Wherein when the first switching signal is received, the switch connects the switch to the path for the call connection with the counterpart without going through the echo canceller, and when receiving the second switching signal, And an echo canceller for transmitting the voice signal through the echo canceller to a path for call connection with the other party number. The method according to claim 6,
The matching circuit includes:
And operable to match the four-stranded line of said private branch exchange with the two-stranded line of said extension telephone set. The method according to claim 6,
And a path for a call connection with the counterpart number including the matching circuit,
Wherein the switching means comprises a trunk interface path or an extension interface path. The method according to claim 6,
The information on the extension number and the trunk line number registered in the private branch exchange,
And information on whether or not the matching circuit is included in the path for call connection with the extension number and the trunk line number. The method according to claim 6,
Wherein,
Determines that the matching circuit is not included when the information on the other party number is an extension number, and determines that the matching circuit is included when the information on the partner number is a trunk line number.

Images