KR19980039570A - How to avoid toll free calls - Google Patents

Abstract

end. The technical field to which the invention described in the claims belongs

The present invention relates to a private switching system, and more particularly, to an apparatus and method for preventing toll free telephone service.

I. The technical problem that the invention is trying to solve

Although the conventional toll free telephone service is a relatively convenient function, there is a problem that the charge of the receiver is increased by using the service function indiscriminately when the receiving party uses a public telephone instead of an individual. Therefore, this problem is solved.

All. Summary of Solution of the Invention

In the private exchange system, there is provided an apparatus and method for blocking the toll service function according to the needs of the administrator.

la. Important uses of the invention

How to avoid toll free calls.

Description

How to avoid toll free calls

The present invention relates to a private switching system, and more particularly, to an apparatus and method for preventing toll free telephone service.

In general, the national telephone station has been provided with a convenient call service (collect call service) in which the receiver pays the phone charge is a widely used trend. In Korea, if the calling party dials a specific number to the toll-free telephone company, the operator of the telephone company checks the name of the called subscriber, the name of the caller, and dials the caller where they want. When the call was received, the caller was informed that the call was toll free and the call was answered. However, the toll-free telephone service as described above has a relatively convenient function, but there is a problem in the charge of the receiver when the receiver is a publicly used telephone rather than an individual. For example, if the call is from a company office, a shared telephone, or for a private use of a telephone at a particular location, the caller is charged because the caller receives the call freely. In the aspect of managing a company or an organization, a need for a method of preventing the toll-free service function has emerged.

Accordingly, an object of the present invention is to provide a method for blocking a toll service function according to the needs of an administrator in a private exchange system.

In order to achieve the above object, the present invention provides a method for preventing a toll free call in a private exchange system,

When the incoming call is initially received, ringing the ring to the called station after receiving the called number, and when the incoming station is hooked off, transmits a response completion signal to the local exchange side for a predetermined time from the local exchange side. Waiting for a response confirmation signal to be generated, and when there is a response confirmation signal from the local exchange, open a trunk line for a predetermined time so that the local exchange side releases the originating signal when the call is requested by the toll service. And restoring a call by continuously opening a trunk line when the call signal is released during the call release time during the call release time, and the call signal during the call release time during the call release time. If you do not release the call, the call is considered a normal call and the loop is connected to form a call. It is characterized by made of an step.

1 is a block diagram of a general system for performing a toll free call protection function according to an embodiment of the present invention.

Figure 2 is a block diagram of a general telephone applied to the present invention.

3 is a block diagram of a general private exchange system applied to the present invention.

4A, 4B, and 4C are timing diagrams for implementing a method for preventing a toll free call service according to an embodiment of the present invention.

5A and 5B are control flowcharts for implementing a method for preventing a toll free call service according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 is a block diagram of a general system for performing a toll free call protection function according to an embodiment of the present invention, wherein a calling line is connected to a local exchange 100 by a subscriber line, and the local exchange 100 And the receiving private exchange 110 is connected to the digital telephone line (E1) 130 and the analog telephone line 140, respectively, when a call is generated from the calling telephone. The calling telephone → subscriber line 120 → the national exchange. (100) → digital trunk line 130 or analog trunk line 140 → receiving side private exchange 110 → receiving extension telephone in this order to form a call. In this case, the local exchange and the private exchange are basically in charge of the same exchange service, but show differences in terms of their subscriber capacity and service. In addition, the general telephone and the private exchange system mounted on the caller or receiver will be described with reference to FIGS. 2 and 3.

Figure 2 is a block diagram of a general telephone applied to the present invention, the microcomputer 200 performs overall control in the system, the ROM (ROM) for controlling the operation of the phone and the RAM (RAM) for storing the general data Have The dial unit 230 transmits the dial under control from the microcomputer 200. The trunk line circuit unit 210 scours the trunk line C.O by the control from the microcomputer 200. The call circuit unit 220 forms a call under control from the microcomputer 200.

Figure 3 is a block diagram of a general private exchange system applied to the present invention, the central processing unit 300 controls the overall operation of the private exchange system, in particular generates a control signal to prevent the toll service function. The digital trunk 302 relays data of the E1 level (2.048 Mbps / 30CH) or the T1 level (1.544 Mbps / 24CH) that is carried over the digital trunk line. The analog trunk 304 receives and receives data transmitted through the analog trunk line. A time switch 310 switches the PCM data of the digital exchange. A plurality of highways (HW1, HW2 ..., HWn) 328 multiplex the PCM data of each module (trunk, DLI, SLI, etc.) in the digital exchanger to 32CH to provide the time switch ( 310 is switched by the time switch 310 to transmit data to different parts. At this time, the quantity of the highway 328 is determined according to the capacity of the exchange. The DLI module 312 interfaces with a plurality of digital telephones (ie, key phone telephones) 320 for extension. The SLI module 314 interfaces by connecting a plurality of general telephones 322 for extension. The signal transmitter module 316 generates DTMF, R2MFC, TONE, etc. as a part for generating all signals in the private exchange. The signal receiver module 318 receives DTMF, R2MFC, TONE, etc. as a part for receiving all signals that are encoded into the private exchange and transmits them to the CPU 300.

Therefore, when looking at the incoming call operation of the private exchange, the digital trunk line or the analog trunk line is ringed (loop trunk) or occupied (digital trunk: E1 class) when the digital trunk 302 or analog trunk 304 At ring or occupancy signal is detected, the detected incoming signal is transmitted to the central processing unit (300). The CPU 300 enables the highway channel connected to the trunk, allocates the channel of the signal receiver 318 not occupied by another port (if the dial type is set to DTMF, Assigns a DTMF receiver, and if the dial type is set to R2MFC, allocates an R2MFC receiver.), And the corresponding channel of the highway connected to the assigned signal receiver 318 and the highway channel of the occupied trunk are connected. The pre-allocated time switch 310 is connected so that the PCM signal can be transmitted to the signal receiver 318. Eventually, the above operation is performed to receive and interpret DTMF or R2MFC signals, and to ring the extension number to be connected. At this time, if the extension telephone is a digital telephone (key phone), the corresponding subscriber is connected through the DLI module 312, and if the extension telephone is an analog telephone (key phone), the subscriber is connected through the SLI module 314. Then, when the corresponding subscriber telephone hooks off, the state is transmitted to the CPU 300. At this time, the central processing unit 300 detects that the extension subscriber is hooked off to stop the ring ringing to the corresponding station, using the corresponding channel and time switch 310 of the trunk line highway trunk channel of the DLI or SLI Connect. Then, if a voice signal is inputted to the digital trunk line, the digital trunk 302 is loaded on one channel of Highway 1, and if the voice signal is inputted to the analog trunk line, the digital signal is outputted from the analog trunk 304 It will be replaced with PCM, which will be loaded on one channel of Highway 4. Then, the corresponding PCM signal is transmitted to the time switch 310 through the corresponding highway. In this case, the time switch 310 switches to output the PCM signal through a corresponding output side highway connected to the DLI module 312 or the SLI 314 module. Thereafter, the PCM signal transmitted through the corresponding output side highway is decoded into an analog signal through the DLI module 312 or the SLI 314 module so that a call can be made with the extension subscriber.

4A, 4B, and 4C are timing diagrams for implementing a method for preventing a toll free service according to an embodiment of the present invention, and FIG. 4A is a ring incoming state timing diagram in a conventional private exchange, and FIG. 4B is a ring When the incoming call is received, the exchange is allowed to release the incoming call for a certain period of time. If the incoming call is released during that time, it indicates the timing to automatically release the incoming call because there was a request for toll free service. 4C shows a timing for connecting a call when the incoming call is not released during the release period in FIG. 4B.

Hereinafter, the toll-free service prevention control flowchart of FIGS. 5A and 5B will be described with reference to the block diagrams of FIGS. 1, 2, and 3 and the timing diagrams of FIGS. 4A, 4B, and 4C.

FIG. 5A is a control flowchart for implementing a method for preventing a toll free phone service in a private exchange according to an embodiment of the present invention. FIG. 5A shows steps 602 to 620, and FIG. 5B shows steps 622 to 634.

Therefore, the flowchart to be described below describes when the ring is occupied representatively through the digital trunk line. First, in step 602 of FIG. 5A, the CPU 300 initializes the system. Then, in step 604 to 606 the central processing unit 300 detects whether the ring is occupied by the digital trunk 302 and receives the called number through the signal receiver 318 when the ring is occupied. At this time, the timing of receiving the called number is the same as that of the sections 402 and 502 of FIGS. 4B and 4C. Then, in step 608, the central processing unit 300 rings a ring to the corresponding key phone through the DLI module 312. Then, in step 610 to 614, the central processing unit 300 detects whether the corresponding key phone telephone ring is ringed and hooks off, and occupies the trunk line loop for a predetermined time (about 1 second) when the hook is off. Operate. At this time, the timing of the hook-off to occupy is the same as the sections 404 and 504 of FIGS. 4B and 4C. Thereafter, in step 616 to 620, the central processing unit 300 checks the started timer to detect whether the preset time is reached, and when the set time is reached, opens the trunk line and operates the release waiting timer. At this time, the trunk line exchanger releases the call generated during the release waiting period when the generated call requests the toll free service. Therefore, the timing of the section is the same as the sections 406 and 506 of Figs. 4B and 4C. Thereafter, in step 622 of FIG. 5B, the CPU 300 checks the started release wait timer to detect whether a preset time has come. At this time, if the local exchange releases the trunk line before the set time (i.e., when the generated call is toll free), the routine returns to step 604 of FIG. 5A after releasing the looped trunk line. However, when the CO line exchanger does not release the CO line even after the set time, the central processing unit 300 detects that it is a general call and performs steps 626 to 630 to connect the CO line loop and call the corresponding extension subscriber. Connect to make a normal call. Then. Finally, the central processing unit 300 performs steps 632 to 634 to detect the end of the call by the extension subscriber and releases the CO line when the call is terminated and returns to step 604 of FIG. 5A. At this time, the timing of the release waiting period is the same as the sections 408 and 508 of FIGS. 4B and 4C, and the timing when the toll-free service is requested is the same as the sections 510 to 512 of FIG. 4C, and 410 of FIG. 4B when the general call is made. Same as interval.

As a result, in order to perform the toll-free service prevention as described above, communication between the local exchange and the private exchange as shown in Table 1 and Table 2 is required. In this case, Table 1 shows a line signal in a typical digital trunk line, and Table 2 shows a line signal for preventing toll service in a digital trunk line.

condition Omni-directional signal Backward signal Remarks af bf ab bb Idle / Restore Complete One 0 One 0 IDLE Occupation completed 0 0 One 0 SEIZURE Occupation confirmation completed 0 0 One One SEIZURE ACK Response completed 0 0 0 One ANSWER Complete omnidirectional release One 0 0 One CLEAR FORWARD Completed backward release One 0 One One CLEAR BACKWARD Backward recovery completed One 0 One 0 RELESE GUARD Blockade One 0 One One BLOCK

condition Omni-directional signal Backward signal Remarks af bf ab bb Idle / Restore Complete One 0 One 0 IDLE Occupation completed 0 0 One 0 SEIZURE Occupation confirmation completed 0 0 One One SEIZURE ACK Response completed 0 0 0 One ANSWER Response Confirmation (CLB) 0 0 0 0 COLLECT CALL BLOCKING ANSWER CONFIRM Release Wait (CLB) 0 0 0 One COLLECT CALL BLOCKING WAIT CONFIRM Complete omnidirectional release One 0 0 One CLEAR FORWARD Completed backward release One 0 One One CLEAR BACKWARD Backward recovery completed One 0 One 0 RELESE GUARD Blockade One 0 One One BLOCK

As described above, the present invention provides a method of blocking a toll service function according to the needs of an administrator in a private exchange system, thereby reducing the phone charges caused by indiscriminate use of the toll service.

Claims (1)

In a method for preventing toll free telephones in a private exchange system, Ringing the ringing party after receiving the ringing number when the ring ringing is initially received; Waiting for a response acknowledgment signal generated from the local exchange side for a predetermined time after the response completion signal is transmitted to the local exchange side when the incoming station is hooked off; Opening a trunk line for a predetermined time when there is a response confirmation signal from the local exchange, and waiting for the local exchange to release the incoming signal when the incoming call is a toll-free service request; Restoring a call by continuously opening a trunk line when the originating signal is released during the originating signal release waiting time from the local exchange side; Preventing toll free calls in a private exchange system comprising the step of forming a call by connecting a loop when the call is regarded as a general call when the call is not released during the call release time. How to.