KR100220903B1 - Automatic redialing method of a switching system - Google Patents

Abstract

The present invention relates to a method for automatic redialing of a private exchange. When a user who knows a password of a private exchange side dials a telephone number of a user who wants to call after making a call through an arbitrary trunk line of the private exchange, the private exchange recognizes this. After confirming the password, the system automatically performs redialing by occupying another arbitrary CO line and connects the CO line that has been automatically redialed with the CO line dialed by an external user so that the external user can make effective use of the private line. It's a way to do it.

Description

Automatic redialing method of private exchange

1 is a system block diagram illustrating an automatic redialing method of a private exchange according to the present invention.

2 is a flowchart illustrating a process of performing an automatic redialing function of a private exchange according to FIG.

* Explanation of symbols for main parts of the drawings

1,5 trunk line interface unit 2: dial signal detection unit

3: tone generating unit 4: call generation unit

5: trunk line interface unit 6: controller

7 memory unit 8 dialing generation unit

9: tone detection unit

The present invention relates to the function of a private exchange, and more particularly, to a method for automatically redialing by occupying the trunk line of a private exchange so that an external user can efficiently use the private exchange.

In general, when an external user wants to directly call a private exchange extension subscriber, the private exchange user requests a private office dedicated trunk line to the telephone company so that the external user can directly call the private exchange extension subscriber.

That is, when the external user dials the corresponding dedicated trunk line of the extension subscriber who wants to call, the private exchange exchanges the corresponding extension number of the private exchange subscriber desired by the external user. After detecting and reading the extension number relay signal, connect the corresponding station. Such a function is called a direct inward dialing (DID) function. If an external user wants to make a call with an extension subscriber by performing a DID function, the private exchange user having a DID function can apply to a private office. In addition, although the existing private telephone exchange occupied the trunk line and the extension telephone call method, an external user could make a call with the desired extension subscriber, but there was no function to make an external call using the trunk line of the extension subscriber side private exchange.

The present invention has been made to provide such a function. When an external user who stores a password of a private exchange side including an extension subscriber who wants to make a call makes a call through a predetermined trunk line of the private exchange, and then dials, The purpose of the present invention is to provide a method for external users to make external calls by using a CO line on the private exchange side by checking the password and performing automatic redialing by occupying another CO line not occupied by the external user. .

In order to achieve the above object, the present invention relates to a redialing method of a private exchange, wherein a dial-up signal which enables a call between trunk lines is controlled, and a dialing signal detection unit is read to read a dialing signal flowing into the trunk line A and stored in the memory unit. And a dial generation unit for automatically redialing a dial signal stored in a memory unit according to a command of the controller and transmitting the same through the trunk line B. An external user dialed through the trunk line A occupies the trunk line B to make an external call. It is characterized by providing an automatic redialing method of a private exchange that enables.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a system block diagram for explaining the redialing function of the private exchange according to the present invention, in which the internal trunk line of the private exchange is designated as the trunk line A and the trunk line B. FIG. CO line interface units 1 and 5 for connecting and connecting the CO lines A and CO lines to the system, and a telephone line connecting portion 4 for enabling communication between these CO lines A and B, and a dial flowing from the occupied CO line Dial signal sensing unit 2 for detecting a signal, a control unit 6 for controlling the operation of the components to which the dial signal input through the dial signal detecting unit 2 is applied, and according to the command of the control unit 6 A tone generating unit 3 for transmitting a dial tone signal to an external user-side handset, a memory unit 7 storing a dial signal read from the dial signal detecting unit 2 by the control unit 6, and a control unit 6 Dial generation unit 8 for regenerating the corresponding dialing signal read from), and tone detection unit 9 for detecting whether the corresponding CO line to which the redialing signal is transmitted is busy or available, and detecting a dial tone capable of calling. The rain.

In FIG. 1, when an external user who knows the password that can use this private exchange occupies the trunk line A and dials, the tone generating unit 3 listens to the dialing tone signal according to the command of the control unit 6. It transmits through trunk line A and connects the dial signal detection part 2 so that it may be. When the dial signal detecting unit 2 detects an input dial signal, the control unit 6 reads the dial signal and stores the dial signal in the memory unit 7. At this time, the controller 6 sequentially stores the dialing signals inputted, dials at a predetermined order, and if it is detected that there is no other dialing input even after a predetermined time elapses, the controller 6 determines that the dialing is completed and stores them in the memory unit 7. If it is determined that the password matches the private exchange, the automatic redialing function is performed through other CO lines. The automatic redialing function first occupies the trunk line B and controls the tone detector 9 in accordance with a control command of the controller 6 to check the available state of the trunk line B. When the tone is detected, the trunk line B is disconnected and the tone detection unit 9 is monitored by reoccupying after a predetermined time elapses. When the available tone that CO line B is determined to be available to call is confirmed, the dial signal entered through the original CO line A is automatically redialed. The redialing signal is sent to the desired subscriber via the trunk line interface unit 5 and the trunk line B through the dial generating unit 8.

If the dialing signal read from the controller 6 to the memory unit 7 does not match the password, an error tone is sent to the external user through the trunk line A, and then the trunk line A is cut off. When the redialing through the CO line is completed and the dial tone signal is confirmed through the tone detector 9, the controller 6 controls the call path connection unit 4 to connect the call path between the CO line A and the CO line B to external users. Allows external calls through C.O.

FIG. 2 is a flowchart illustrating an automatic redialing process of the private exchange performed according to the control command of the system controller according to FIG.

In FIG. 2, when an external user dials after occupying the private exchange A, 10, the tone generating unit 3 is controlled to send a dialing tone signal for the external user to confirm (11). By connecting and controlling the signal detection unit 2 (12), the dial signal inputted through the trunk line interface unit 1 is read out and stored in the memory unit 7 (14). If no dial signal is input even after a predetermined time has elapsed (13), timing out to confirm that the dialing signal input is completed (15), and analyzing the memorized dialing signal (16) to determine whether it matches the password of the private exchange. If it is determined that the dialing signal and the private exchange password match (17), the automatic redialing function is performed (18).

The automatic redialing routine 18 first occupies the trunk line B, which is another trunk line in the private exchanger (19), and then controls the tone detector 9 to check the state of the trunk line B. That is, when the dial tone is detected from the trunk line B (20), the dialing signal input through the trunk line A is automatically redialed and transmitted (21), and when the tone available through the tone detector 9 is transmitted (22), By controlling the call path connection unit 4 connects the communication path between the trunk line A and the trunk line B (27).

If the available tone is not transmitted after dialing and a busy tone occurs (22), the CO line B is disconnected (23), waits for a predetermined time (24), and then returns to the occupation mode of the CO line B again (19).

On the other hand, if it is determined that the memorized dial signal analysis result does not match the password of the private exchange (17), an error tone is transmitted through the trunk line A (25), and the trunk line A is cut off (26).

As described above, in the present invention, when an external user performs dialing by occupying trunk line A, the controller detects this and confirms the password of the private exchange side, and then automatically redials the input dial signal by occupying another trunk line B. Through this method, external users on the CO line can make a call.

Claims (3)

In the automatic redialing method of a private exchange, a dial signal inputted to a corresponding trunk line A is controlled by controlling a connection part 4 and a dial signal detecting unit 2 to enable a call between trunk lines A and B. The control unit 6 which reads and stores and analyzes the memory unit 7 and the dial signal detected by the dial signal detecting unit 2 according to the command of the control unit 6 are automatically reconfigured through the corresponding trunk line B. FIG. A method for automatic redialing of a private exchange having a dial generator (8) for transmitting dialing to allow an external user who has dialed through a corresponding trunk line (A) to make an external call through the trunk line (B). The dial input according to claim 1, wherein the dial tone is transmitted by checking a dial signal received by the trunk line A in response to a control command by the controller 6, and controlling the dial signal detection unit 2. After checking whether there is a signal, if there is a dial signal input, the dial signal is stored in the memory unit 7, and if there is no dialing signal input even after a predetermined time elapses after the dialing is input in a predetermined order, the dialing is completed. Analyzing the stored dial signal; and if it is determined that the password matched the private exchange side use password, performing the automatic redialing routine by occupying the trunk line B; If the analysis result does not match the password used on the private exchange side, an error tone is sent to the trunk line A, and the trunk line A is An automatic redialing method of a private exchange comprising a process of disconnecting. 3. The automatic redialing routine according to claim 2, wherein the automatic redialing routine occupies the trunk line B, checks a dial tone through the tone detector 9, and then transmits the stored dial signal, and performs a call after dialing. When the sound is recognized, the process of cutting off the trunk line B, waiting for a predetermined time, and then returning to the occupied mode of the trunk line B again; Automatic redialing method of a private exchange characterized in that the process consisting of connecting the channel.