KR0134721B1 - Paging method in exchange system - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION The invention described in the claims relates to a DISA control method for controlling an external caller to directly call an extension subscriber of a private exchange.

2. Technical problem to be solved by the present invention: In the conventional DISA calling method, the other party must know in advance the DISA calling method by sending an internal dial tone in response to a call. The present invention allows the other party to talk to the subscriber in the premises even if they are not aware of the DISA calling method.

3. Summary of Solution of the Invention: In response to a ring call from a CO line, a ringback tone is transmitted to a ring back tone to the caller of the CO line, and an extension subscriber corresponding to a dial digit received from the CO line is called. do.

4. Significant Use of the Invention: Extension Subscriber Calling Device in Private Switching System

Description

Direct Call Control Method of Direct Station Subscriber in Switching System

1 is a block diagram of a portion of a typical private premises automatic switching system.

2 is a direct extension subscriber call control flow diagram of a conventional private branch auto attendant system.

3 is a flowchart of direct extension subscriber call control of a private branch auto attendant system according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an incoming call of an automatic switching system. In particular, an extension subscriber call for controlling an external caller to directly call a subscriber of a private premises automatic switching system (hereinafter referred to as a private switching system) is provided. Hereinafter referred to as DISA).

DISA typically refers to a function that allows an external caller to directly call an extension subscriber housed in a private switching system. In order to perform this function, the trunk line connected to the trunk line of the private switching system must be allocated to the DISA line.

When a ring signal is received from the local switching system to the trunk line of the private switching system allocated to the DISA line, the control unit in the private switching system sends an internal dial tone to an external caller, and the dial transmitted from the external caller. It is an incoming method of receiving a signal and accessing a corresponding extension subscriber.

1 is a block diagram of a portion of a private premises automatic switching system, which includes a trunk 12 for interfacing a line between at least one CO line to COn with a private switching system or a private switching system and a trunk line and detecting a ringing call. And the trunk line CO1 to CON of the trunk 12 connected to the trunk 12 and the plurality of extension subscribers STN1 to STNn and in response to a switching control signal. Network 14 for switching and connecting to one of the channels, a CDP (Call Procedure Detector) 18 for detecting a tone to be connected to the network 14 and outputting call progress information, and a ring detection signal RD In response to the dial digit received at the same time as connecting the DISA line of the trunk 12 to the CDP 18 through the network 14 in response to an input of a). The control unit 16 is connected to one of the station subscribers STN1 to STNn.

2 is a direct extension subscriber call control flow diagram of a conventional switching system.

First, with reference to FIG. 1 and FIG. 2, the control method of DISA comprised in the private exchange system by the prior art is demonstrated.

A public telephone subscriber, now connected to an external trunk line subscriber, for example, a Public Switching Telephone Network (PSTN) (not shown), calls one of the trunk lines CO 1 to COn of the trunk of FIG. When dialing the telephone number corresponding to the telephone number, a ring signal is sent from the PSTN, as is well known. Of course, the ring signal transmitted from the PSTN is transmitted to the trunk line corresponding to the DISA telephone number of the private switching system.

The trunk 12 in the private exchange system configured as shown in FIG. 1 detects a ring signal input to one trunk line of the trunk lines CO1 to COn and transmits the ring detection signal RD to the controller 16. Output At this time, the controller 16 is in a state of searching for whether the ring detection signal RD is input in step 20 of FIG. 2. In this state, when the ring detection signal RD is input from the trunk 12, the controller 16 searches whether the trunk line to which the current ring detection signal RD is received is a DISA line in step 22. If it is determined in step 22 of FIG. 2 that the ring line received is not a DISA line, the controller 16 controls the network 14 in step 34 of FIG. 2 to reach the corresponding subscriber station. Connected CO lines.

If the CO line to which the ring signal is received is a previously set DISA line, the controller 16 controls the network 14 to connect an output of a tone generator (not shown) to the corresponding CO line. . That is, by connecting the output of the tone generator (not shown) to the DISA so that the dial tone output from the tone generator is sent to the external CO line subscriber. The controller 16 searches whether a dial signal is detected from the trunk line within a preset dial detection time DT.

By the operation of the control unit 16 of the private switching system as described above, the CO line subscriber, i.e., the external caller, is newly listening to the dial tone supplied from the private switching system. At this time, when the external caller dials the extension number or function number of the extension subscriber of the private exchange, which is known in advance, it is input to the controller 16 through the trunk 12 and the network 14. When the dial signal is received through the above path, the controller 16 searches for the valid dial in step 28 of FIG.

If it is determined that the received dial is valid as a result of the above search, the controller 16 controls the network 14 to connect the station subscriber and the trunk line corresponding to the received dial signal. Therefore, the DISA function is completed by the above operation. If it is determined that the dial is not detected within DT time in step 26 of FIG. 2 or that the dial received in step 28 of FIG. 2 is not valid, the controller 16 controls the trunk 12 in step 32 of FIG. To recover the incoming trunk line. That is, cut off the line.

However, the conventional DISA control method operated as described above has been inconvenient to use by a person who does not know the DISA function by sending a dial tone generated from the inside of the private exchange system to the other party in response to a ring call.

That is, when an external person who does not know the DISA line calls the DISA line, a new dial tone, which is not recognized in advance, is heard and confused, which causes a problem of hanging up the phone.

Therefore, there was a lot of inconvenience for those who did not recognize the DISA line in advance. Therefore, the conventional control method has a problem of limiting the person using the DISA line. In addition, the conventional control method has a problem of unnecessarily increasing the number of calls by automatically blocking an incoming call when a valid dial is not input within a certain time after receiving a ring through the DISA line.

Accordingly, an object of the present invention is to provide a ring back tone inside a private switching system to an external user when a ring is received on a DISA line, and to reach an extension subscriber corresponding to the received dial digit. The present invention provides a direct extension subscriber call control method.

Another object of the present invention is direct extension subscriber call control of a private switching system that automatically switches an incoming call to a predetermined extension subscriber even if a ring signal for calling an extension subscriber is not input from an external caller after the ring is received on the DISA line. In providing a method.

In order to achieve the above object, the present invention provides a direct extension subscriber call control method of a private switching system for forming a call path between a trunk line and an extension subscriber, wherein a line retrieval process for retrieving whether a trunk line receiving a ring signal is a DISA line authorization. And a ringback tone transmission process for transmitting an internal ringback tone to the trunk line in response to determining that the ring-destination line is a DISA line in the line retrieval process, and the dial digit is received within a preset dial detection time from the trunk line. A dial digit reception search process for searching whether a call is made; an extension subscriber call process for transmitting a ring to the extension subscriber corresponding to the received dial digit in response to the reception of a dial digit from a trunk line within the dial detection time; Incoming CO line when it is determined that it is not a DISA line during the search process Line status retrieval process that sends out ring to designated station subscriber and detects busy tone from CO line, and line recovery process detects busy tone from CO line and cuts line. do.

Hereinafter, an operation of an embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a flow chart of a direct subscriber subscriber call control of the pope system according to the present invention, wherein the CO line to which a ring signal is received is searched for a DISA line, and the ringing and receiving line is determined to be a DISA line. A ringback tone transmission process for transmitting an internal ringback tone to the trunk line in response to a message, a dial digit reception search process for searching whether a dial digit is received within a preset dial detection time from the trunk line, and the dial detection time In response to the reception of the dial digit from the CO line, an extension subscriber calling process that transmits an incoming ring to an extension subscriber corresponding to the received dial digit, and transmits a ringback tone when it is determined that it is not a DISA line in the line searching process. And a line state search process for detecting busy tone from the trunk line, In the line state retrieval process, a line recovery process detects a busy tone from a trunk line and blocks the line.

Now, when the external CO line subscriber connected to the PSTN dials the telephone number of the CO line set to DISA line among the CO lines CO1 to COn of the trunk of FIG. 1, a ring signal is transmitted from the PSTN as is well known. do.

At this time, the trunk 12 detects the ring signal that reaches the DISA line as described above in FIG. 1 and outputs the ring detection signal RD to the controller 16. At this time, the control unit 16 is in the state of searching whether the ring detection signal RD is input in step 36 of FIG. 3, and when the ring detection signal RD is input from the trunk 12, the trunk line currently received in step 38 is received. Check if the line is a DISA line.

If it is determined in step 38 of FIG. 3 that the CO line receiving the ring is DISA, the controller 16 controls the tone generating device (not shown) and the network 14 in step 40 of FIG. Send an internal ringback tone to an external caller. Thus, external callers will continue to listen to the ringback tone. That is, initially, the ringback tone transmitted from the PSTN is heard, and after being connected to the DISA line of the private exchange system, the ringback tone is supplied from the tone generator in the private exchange system.

Subsequent actions depend on the behavior of the external caller. That is, when an external caller who dials the telephone number of the DISA line recognizes the DISA line by ringback tone supplied from the private exchange system and dials the extension subscriber's number, the caller is directly connected to the extension subscriber and does not recognize the DISA line. If no action is taken, an incoming ring is sent to the extension subscriber who is designated in advance on the DISA line and the extension subscriber is called. Its operation is performed as follows.

The control unit 16 that transmits the ringback tone by performing 40 process of FIG. 3 searches whether a dial signal is detected from the trunk line within a preset dial detection time DT in step 42 of FIG. At this time, when the external caller who is aware of the DISA line dials the extension subscriber number or function number of the extension subscriber of the private exchange which is known in advance, it is input to the control unit 16 through the link 12 and the network 14. When the dial signal is received through the above path, the controller 16 searches for the valid dial in step 44 of FIG. 3. If it is determined that the received dial is valid as a result of the above search, the controller 16 controls the network 14 in step 46 of FIG. 3 to connect the station subscriber with the station subscriber corresponding to the received dial signal. Therefore, the DISA function is completed by the above operation.

If it is determined that the dial signal is not detected within the above-described step 42 DT time, or if the dial signal received in step 44 is not valid, the controller 16 turns off, that is, recovers the CO line received by the ring in step 47. Search. At this time, the determination of whether to turn off the line is performed by counting the time as usual and searching for whether the set time has ended. If it is determined in step 47 that the line is not turned off, the controller 16 controls the network 14 in FIG. 48 in FIG. 48 to transmit a ring to the extension subscriber to which the trunk line is designated. That is, according to the preset CO line ring mode, the ring is sent to a predetermined extension subscriber to notify that there is an incoming call from the CO line.

Step 48 of FIG. 3 is also performed when it is determined that the trunk line received by the ring is not a DISA line in step 38 of FIG. 3. In step 48 of FIG. 3, the controller 16 that performs the trunk line ring mode searches whether the incoming CO line is a DISA line at 50 fixed in FIG. 3. When it is determined that the incoming CO line is not a DISA line, the controller 16 performs call processing when a ring signal is received through the general CO line.

If it is determined in step 50 of FIG. 3 that the terminating trunk line is a DISA line, the controller 16 searches whether there is a CPD 18 in the switching system in step 54 of FIG.

If it is determined in step 54 of FIG. 3 that there is a CDP, the controller 16 controls the network 14 to connect the CDP 18 to a port of the DISA line to detect a tone received from the called station line. In step 56, it is searched whether a busy tone is detected as an output of the CPD 18. Therefore, when the external caller calls the DISA line and does nothing (dialing) by the above operation, it can be seen that the call is automatically sent to the designated subscriber of the CO line.

In the above state, when an external caller who hangs on a CO line does not answer for a certain time and an external caller hangs up, a busy tone is transmitted from the PSTN, which means that the CDP (through the trunk 12 and the network 14) is transmitted. 18). At this time, the control unit 16 recovers the incoming trunk line by controlling the trunk 12 when the information supplied from the CDP 18 is busy tone. That is, the line is blocked.

If it is determined in step 54 that there is no CDP, the controller 16 searches whether the preset DISA ring off time (RT) has elapsed in step 58 of FIG.

That is, when the extension subscriber to which the call is designated for a certain time does not respond, the controller 16 controls the trunk 12 to recover the call destination line. That is, the line is blocked. Therefore, if the external caller calls the DISA line of the private exchange system, the internal subscriber does not need to call DISA. For example, you can talk to the operator.

As described above, the present invention can use the DISA line as a general CO line by transmitting an internal ringback tone to the caller in response to a call of the DISA line, thereby maximizing the use efficiency of the CO line.

Claims (3)

In a method of controlling a private subscriber call directly by a private switching system that forms a communication path between a trunk line and an extension subscriber, a line retrieval process for retrieving whether a trunk line receiving a ring signal is a DISA line and a ring-in call line in the line retrieval process; A ringback tone transmission process for transmitting an internal ringback tone to the trunk line in response to determining that it is a DISA line, a dial digit reception search process for searching whether a dial digit is received within a preset dial detection time from the trunk line; An extension subscriber calling process for transmitting a ring to the extension subscriber corresponding to the received dial digit in response to the reception of the dial digit from the trunk line within the dial detection time; and upon determining that it is not a DISA line in the line search process. CO line forwards ring to designated extension At the same time, a direct line call control of a private switching system comprises a line state searching process for detecting busy tone from a trunk line and a line recovery process for detecting a busy tone from the main line and cutting off the line. Way. 2. The method of claim 1, wherein the extension subscriber call process comprises: a dial digit retrieval process for retrieving whether the received dial digit is valid; An extension direct effect control method of a private exchange system, characterized by consisting of an extension ring transmission process for transmitting a. The method according to claim 1 or 2, further comprising the step of performing the line state searching process when a dial signal is not received within a preset dial detection time.