JPS6052154A - Incoming call automatic transfer system in private branch of exchange - Google Patents

Abstract

PURPOSE:To decrease the transfer time by discriminating and counting a dial signal from an outgoing subscriber of a trunk line side during talking to transfer an incoming call to a desired extension telephone set depending on the will of the outgoing subscriber. CONSTITUTION:Extension telephone sets 1, 2 are connected to a switch notwork 5 of a private branch of exchange via lines 3, 4 respectively, and the lines 3, 4 and the network 5 are controlled by a central controller 8. Further, a trunk circuit 6 is connected to the network 5, a signal discriminating section 60 of the circuit 6 discriminates a voice signal and a dial signal incoming from a trunk line 7 and a register section 61 counts the dial signal. The counted dial signal is returned to the controller 8. Moreover, the dial signal from the trunk line 7 is received and counted, an incoming call is transferred to the telephone sets 1, 2 depending on the dial signal and the call is connected to the desired telephone sets 1, 2 by the will of the calling subscriber.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic incoming call forwarding system in a private branch exchange.

Conventionally, in a so-called dial-in type private branch exchange, in which an incoming call from a calling subscriber on the central office line is received at a called extension subscriber without going through a central office line relay stand, the incoming call is transferred to another telephone extension. In this case, the calling subscriber requests the subscriber who first answered the call to transfer the call to another extension telephone. However, this method has the disadvantage that the transfer process takes time and the calling subscriber is forced to wait during that time, which is very inconvenient.

It is an object of the present invention to eliminate the above-mentioned drawbacks by discriminating and counting dial signals from a subscriber on the central office line side during a call.
An object of the present invention is to provide an automatic incoming call forwarding system in a private branch exchange that allows an incoming call to be transferred to a desired extension telephone according to the intention of a calling subscriber.

According to the present invention, a private branch exchange is provided with a discriminating means for discriminating between a dial signal and a voice signal arriving from a central office line during a call, and a counting means for receiving and counting the dial signals, An automatic incoming call forwarding system in a private branch exchange is obtained, which is characterized in that the incoming call is forwarded to a called extension subscriber in response to a dial signal from the calling party.

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an incoming call forwarding system in a private branch exchange according to the present invention.

In the figure, each private branch exchange has line circuits 3 and 4.
A switch network 5 connected to extension telephones 1 and 2 via a trunk circuit 6, a central office line 7 accommodated in the switch network 5 via the trunk circuit 6, line circuits 3 and 4, and a switch network 57. and a central control unit 8 connected to the trunk circuit 6 and controlling a predetermined connection sequence. The trunk circuit 6 includes a signal discriminator 60 that discriminates between a dial signal arriving from the office line and a call voice signal, and a register section 61 that counts the dial signals from the signal discriminator 60.

Next, the operation of this embodiment will be explained. When an incoming call arrives from the central office line 7, the trunk circuit 6 closes a loop under the control of the central controller 8 and returns a response signal to the central office line 7, as is generally known. - The power signal discrimination section 60 then discriminates whether the signal arriving from the office line 7 is a call voice signal or a dial signal, and if the latter (for example, an extension number of the extension telephone 1), the dial signal is sent to the register section 61. After receiving and counting, this information is transferred to the central controller 8. The central control unit 8 performs predetermined control based on this information as is generally known, and the extension telephone 1 connects the line circuit 3 - switch network 5 (link ■) - trunk circuit 6 - office line 7
A calling subscriber (not shown) is connected to the calling subscriber (not shown), and a communication state is established between the calling subscriber and the extension telephone 1. In this call state, if the calling subscriber wishes to transfer the incoming call to another telephone extension (e.g. extension 2), the calling subscriber must first dial a special number (e.g. push-button dial "Kaoru" and/or " When "" is pressed), a special number signal is sent to the central office line 7. The signal discrimination unit 60 discriminates the special number signal and sends a transfer request signal as a result.

The number is transferred to the central control unit 8 via the register section 61. In response to the transfer request signal, the central control unit 18' prepares to receive the next transfer destination extension number, controls the trunk circuit 6, and causes the office line 7 to send back a reception preparation completion signal (for example, a dial tone). Next, when the calling subscriber dials the extension number of the transfer destination (for example, extension telephone 2), the signal discrimination section 60 discriminates this dial signal and sends it to the register section 61. The register unit 61 receives and counts the transfer destination extension number and transfers the transfer destination number information to the central control unit 8.

As is generally known, the central control device 8 performs predetermined control based on this forwarding destination number information, and performs bye-5. Since the link [Yes] of the network 5 is set □ and the link ■ is canceled, the incoming call from the calling subscriber is sent to station a7. Trunk circuit 6. Switch network 5 (link ■),
It is connected to the extension telephone 2 via the line circuit 4.

Next, FIG. 2 is a circuit block diagram showing an example of the configuration of the main part of the trunk circuit in FIG. 1, and FIG.
b) is the first special number signal pattern of the input in FIG. FIG. 7 is a waveform diagram showing a second example.

In FIG. 2, the trunk circuit includes a signal discrimination section 60.degree. register section 61, and a trunk control section 62 for controlling the inside of the trunk circuit.

The signal discrimination unit 60 includes a high band group filter (hereinafter referred to as HPF) 600 for separating and comparing the dial signal coming from the office line 7 into a high band group and a low band group according to the frequency.

Inkporator (hereinafter referred to as IPL) 602. compa v
-p604 and low band group filter (hereinafter referred to as LPF)
601.

IPL603. The comparator 605 and the signals from the oscillator 608 generate the necessary clocks and the HPF 60
0.

LPF601. It consists of a clock generator (hereinafter referred to as CLKG) 606 that supplies to the IPL 602 and 603, and a level adjuster (hereinafter referred to as LADJ) 607 that adjusts the threshold level of the comparators 604 and 605, and the register section 61 is connected to the comparator 6, respectively.
A control circuit that detects and controls the 04°605 output (hereinafter referred to as CTL)
)610.

611 and CTL 610. A code expansion circuit (hereinafter referred to as CNV) that converts the 611 output into a 4-bit code 612
and a latch circuit that latches the CNV612 output (hereinafter)
LAT) 613 and a buffer (hereinafter referred to as BU) for outputting the contents of LAT 613 to the trunk control unit 62.
F) 614 and a CLKG 615 that supplies necessary clocks to the CTLs 610 and 611. Furthermore, the trunk control unit 62 is configured by a firmware program. Note that the signal discriminator 60. Register section 61. All the components of the trunk control section 62 are common ones.

As shown in Table 1, the diamond η signal from a generally known calling telephone (push-button telephone) is a two-frequency superimposed signal of a low frequency band (LPG) and a high frequency band (HFG).

Table 1 Therefore, the dial signal coming from the office line 7 is HPF 6
00. LPF 601 and xb each I-IFG,
It is divided into LPG, IPL 602.603 and Combare 604. It is limited at 605. After these combinations are detected, CNV61
2, the code is converted to LA'L'613゜BUF 61
4 pins according to the input dial signal via 4)
It is output as a (hexadecimal) code.

The trunk control unit 62 checks the time of this 4-bit code and repeatedly checks the code to determine whether the input dial signal is a transfer request signal or not.

Table 2 shows the correspondence between the dial signal and the 4-picto code output from the register section 61.

Table 2 Here, register section output or dial-X (i.e. 101
0)'! Or die? If the dial + (that is, 1100) is detected, the trunk control unit 62 determines this signal as a transfer request signal, but the trunk control unit 62 recognizes this signal as a transfer request signal.
It is thought that 2 misclassifications occur.

To avoid this, special number signal patterns as shown in FIG. 3 are used, and the trunk control section 62 can check the signal intervals and repetitions of these patterns to make accurate determinations.

In the first example shown in Fig. 3(a), the Fi special number signal is a pattern consisting of a dial arrow for 5 seconds or more, silence for 5 seconds or more, and a dialer for 5 seconds or more, and as shown in Fig. 3(b). In the second example shown, the special number signal pattern of the first example is repeated twice with intervals of silence of 5 seconds or more. Therefore, the control section 62 is the first. In the second example, each time is 15 seconds or more.

The transfer request signal is determined only after 35 seconds or more has elapsed. It goes without saying that the special number signal pattern may be arbitrarily determined other than those exemplified here.

As is clear from the above explanation, according to the incoming call automatic forwarding method in the private branch exchange of the present invention, incoming calls can be forwarded to a desired extension telephone according to the intention of the calling subscriber.
There is an effect that it is not necessary to make a transfer request to the called telephone, and the transfer process can be carried out in a short time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the incoming call forwarding system in a private branch exchange of the present invention, FIG. 2 is a circuit block diagram showing an example of the configuration of the main part of the trunk circuit in FIG. 1, and FIG. (a) and (b) are waveform diagrams showing first and second examples of input special number signal patterns in FIG. 2, respectively. In the figure, 1.2...extension telephone, 3.4...
...Line circuit, 5...Switch network, 6...Trunk circuit, 7...,...
Office line, 8...Central control unit, 60゛...
・Signal discrimination section, 61...Register section, 62...
...Trunk control section, 600...
High band group filter (HPF), 601...Low band group filter (LPIi''), 602, 603...
...Inkvolator (IPL), 604.605...
...Comparator, 606,615...
Clock generator (CLKG), 607...
...Level adjuster (LADJ), 608...
Oscillator, 610.611... Control circuit (CTL
), 612... Code expansion circuit (CNV), 6
1'3... Latch circuit (LAT), 614...
...Py77 (BUF). 7・-mi＼

Claims (1)

[Claims] A private branch exchange is provided with a discriminating means for discriminating between a dial signal and a voice signal arriving from the central office line during a call, and a counting means for receiving and counting the dial signals, and a dial from a caller on the central office line side is provided. An automatic incoming call forwarding system in a private branch exchange, characterized in that the call is forwarded to a called extension subscriber in response to a signal.