JPS59168759A - Communication system - Google Patents

Abstract

PURPOSE:To use a line in common for data communication and calling by discriminating automatically a signal transmitting a data communication request at incoming call depending whether a modulation and demodulation section detects the signal. CONSTITUTION:A modulating and demodulating device 12 incorporating a network controller is connected to the line 2 via a switching device 13. After the modulating and demodulating device 2 closes the line to the incoming call from the caller side, a calling code from the caller side is led to a calling code detecting section 29 via a switching section 27 from a demodulating section 24. When the detection section 29 detects the calling code, a detection signal is transmitted to a control section 31, which decides the code as a data communication request. In case of the incoming aiming at a call, since no calling code is detected in the timing of calling code receiving, the cobtrol section 31 decides it as a calling incoming signal from personnel and rings a ringer 33.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a communication system that selectively performs data communication or telephone communication using a telephone switched line such as the subscriber telephone network of Nippon Telegraph and Telephone Public Corporation as a transmission path.

A conventional communication system of this type is shown in FIG. In the figure, Da)Ob) is a modem and is connected to the exchange (3) via a subscriber telephone line (2aX2b). The modem (la) ('lb) each has a line control unit (
It consists of a modem unit (hereinafter referred to as NCU) (4a), (4b), a modem unit (hereinafter referred to as IVD) (5a), (5b), and MD and NCLI are the line installed by Nippon Telegraph and Telephone Public Corporation (hereinafter referred to as Public Corporation). Protective device (hereinafter referred to as PD) (6
a) Connected via (6b). Also, MLl (
5a) (5b) is a data communication terminal (hereinafter referred to as DTE)
(71X7b), respectively. Please note that the telephones M (8a) and (8b) installed by the public corporation are equipped with converters (91
X9b) are connected to the internet line (21
) are connected as shown below. Other members of the network are indicated by swords.

Next, the operation will be explained. First, the line (2aX2b)
I will explain a little bit about data communication. Here DTE
(7a) We will explain what happens when a call is made from the side.

First, a dialing operation is required to call the other party using the red and white telephone line. For this operation, the NCU (4a) is an automatic white type, and it is the JJTE (7a) and NCLI'
(4a) lTi dedicated interface line (not shown)
Joining the other party from LIT3 (7a) to NCU (4a) using fireflies i, c 74. (telephone number), and the NCU (4a) automatically dials it. As a result, the exchange (3) captures the line (2b) and uses the NCU
' Sends a call signal to N'CU (4b), N'CU Cab) informs DTE (7b) via IVID (5b) that there is a call, and N'CU Cab) sends a call signal to NCU (4b) via IVID (5b).
b) connects line (2b)! , 7N are tied.

At the same time, NCU (4a) responds with
Transmit the response to a), and according to the instructions, connect line (2a) to ~1
Connect with D (5a). Through the above operations, a transmission path has been established between each other, so the DTE (7a) (7b) connects the MD (6a) (5b) to the telephone (8aX'8) respectively.
b) Explain the call operation from (10a) or (tab). Attached telephone (10a) u” ha (10b
) Normal NCU (4aX4b) It is separated from the line by the internal switch. This is because the line is connected to a circuit within the NCU that detects a calling signal in order to automatically receive a call. Therefore, when using the attached telephone, the user must first operate the switch. Also, this phone (8
aX8b), as is clear from Figure 1, the converter (
If you do not operate 92X9b), you will not be able to connect to the line, so dial after switching. As described above, in order to dial for a call with these telephones, a switch operation must be performed in advance.

Next, the telephone (8a) (8b) (10a) or (10
The case where subscriber αυ dials b) for the purpose of making a phone call will be explained. For example, when a call signal flows to line (2b), the DTE
(7b), the NCU (4b) closes the line and connects the line (2b) to the MD (5b), so the attached telephone (
10b) or this telephone (8b) cannot be used. However, if the aforementioned N'CU (4b) switch is switched to the attached telephone (10b) in advance, the calling signal will be guided to the attached telephone (10b), so a person can answer and a conversation can be made.

The conventional communication method is as described above, so NCU
Calls from the network are always sent to 1) TE unless the switch is operated.
Since the connection is made to the side, it is impossible to receive calls for the purpose of talking. On the other hand, if the switch on the NCU is switched to the attached telephone side, calls can be made, but a person must operate the switch on the NCU each time a call is received for the purpose of data communication. A major drawback was that it became difficult to use a single line for both data communication and phone calls.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional devices. The purpose of the present invention is to provide a communication method that allows a line to be used for both data communication and telephone calls by automatically determining whether the line is a telephone line or not.

An embodiment of the present invention will be described below with reference to the drawings. Second
In the figure (■ is a modem with a built-in network control device, which is connected to the line (2) via a disconnector. 1
It is connected to the line (2) via the contact (II) and the disconnector On. and a busy tone generating section.In addition, (21) is a flow line ring, (F) is a coupling capacitor, and a line (2), a modulation section (■) and a repeater ψ1 section (c) are a line protection device (6). (26) is the calling signal detection section, (a) is the switching section, (c) is the interface section with the DTE (7), and the wire is the calling code detection section. )
is a calling code generator, 0◇ is a control circuit, and ) is a ringer. Note that the signals on signal line 03 (b) are named signal A and double signal, respectively.

Next, the operation will be explained. First, a method for determining whether the calling party is a day/evening communication device or a person when receiving a call will be explained. When making a call from a modem, a calling code is sent at a certain time immediately after the line is closed in response to a response from the called side, requesting data communication from the modem on the young priest's side. Therefore, if the calling code can be detected at the time of incoming call, it is determined that the call requested data communication, and if not, it is determined that the call requested conversation.

Now, a detailed description will be given based on the timing diagram shown in FIG. 3 and FIG. 2. The modem (6) receives an incoming call (16H2 with ζ
When the calling signal is detected by the calling signal detection section (26), the signal A (2) is turned on and transmitted to the control section 0υ. Control unit IM
I) operates CMLα by itself and connects the line (2) to the demodulator (c). At this time, the direct current loop of the line (2) is maintained by the current flow ring (21), and is AC coupled to the demodulator (b) by the capacitor (a). Now, the calling code reception timing after the line is closed is the timing at which the calling code that can be sent by the same device on the calling side is received, as described above. During this period, the output of the demodulation section (c) is guided to the calling code detection section (4) by the switching section).
When the calling code is detected, signal B (signal) is turned on and input to the control unit CIXI. The calling code sending timing on the calling side is almost the same timing as the calling code receiving timing shown in FIG. It is sent to the modulation unit So via the switching unit @. Therefore, when signal B turns on, the control section determines that the call is a request for data communication, and indicates to 1) TE (7) that a calling signal has been detected by turning on CI. In other words, this CI
is a simulated signal, unlike the CI of the conventional device. This is because the line has already been closed and the CI, which should normally be output in synchronization with the paging signal, is output after the line is closed. After this C1 output, it is a normal so-called modem interface handwriting, and as shown in Figure 8, when ER is turned on from DT'E indicating terminal device ready, CI is turned off, and after a certain period of time after ER is turned on, modem ready is indicated. D
R is turned on and communication begins. Communication ends with E.
In response to an instruction from the DTE to turn off R, the control unit 0υ restores the CML relay α and opens the line.

Next, we will explain the case where there is M (N) for the purpose of a call from a general subscriber. In this case, the calling code from the calling side is not detected within the calling code reception timing shown in Figure 3, so the S ``A-Obe 01) determines that the call is from a person, and sounds the ringer.The caller learns of the incoming call by the ringer sound, and responds by off-hooking the attached phones Ha, bl (IQ). The operation is as follows. First, the DC voltage from the Raikoku (1) is always applied to the attached telephone slot via the off-hook detection section (B), and the attached JIA telephone is disconnected from the line (2). If the caller goes off-hook, the off-hook detection section μ produces an off-hook state using the direct current flowing through it and notifies the control section 0]), so the control section 1 ((1) is the T relay gQ CkL relay qη , and connect the attached telephone ucl to line (2). Now you can make calls using the attached telephone (1 (i) with just one finger. Note that the off-hook detection will stop the proverbial one-bird movement. .If there is no response from the notifier despite ringing of the ringer, in order to prevent invalid suspension,
The timer in the control unit 6]) stops the ringer c1 second and restores the Cp stop reset aη to open the line.

Next, a call from the attached telephone uQ will be explained. The sequence is such that the caller can dial without having to perform cumbersome switch operations. That is, if the off-hook detection unit QΦ detects that the caller is off-hook, the T-relay α-chin is restored, the attached telephone 4 is connected to the line (2), and dialing can be performed in exactly the same manner as the normal telephone &4 operation. If this device θ'4 is in use, the line C1,I will not be restored and a busy tone will be sent to the attached telephone line to indicate that it is in use. show.

As described above, according to the communication system of the present invention, the function of transmitting a signal requesting data communication prior to data communication is narrowed down by using the built-in modulation/demodulation function. Added to this feature, it is possible to automatically determine whether an incoming call is for communication or a phone call, and there is no need to use a disconnect switch when using an AD phone, and one line can be used for both data communication and phone calls. There is.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a conventional communication method, Fig. 2 is a block diagram showing a communication method according to an embodiment of the present invention, and Fig. 8 is a block diagram showing a communication method according to an embodiment of the present invention. FIG. (2)...'Switching machine green, (3)...Switchboard, (
7)... Data communication A6 end, (■... Sender side or receiving side modulation/demodulation device, ■... Modulation section, (c)... Demodulation section, Threat... Interface section, (4 )...Calling code detection unit, )...Calling code generation unit, Cυ
...control unit, (c)...ringer. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Agent Shin Kinno - Figure 1 Figure 8

Claims (2)

[Claims] (1) In a communication system that includes a modem that is connected to a telephone exchange line and has a built-in network control unit, and that selectively performs data communication or telephone communication through the same telephone exchange line, in response to an incoming call from the modem on the calling side. , the receiving modem immediately closes the line, and the transmitting modem then switches the input of the built-in modulation section and inputs the calling code to the modulation section for a fixed period of time, thereby transmitting the calling tone. , the receiving side modulation/demodulation device demodulates with a built-in demodulation section, and inputs the demodulated output to a calling code detection section;
A communication system characterized in that, by detecting the code, the receiving side modem determines that the calling side is requesting data communication, and outputs a CI signal to indicate an incoming call. (2) When a calling code is not detected, the caller is determined to be a person and the ringer is activated to prompt the called party to answer on the telephone.
The communication method according to claim 1, characterized in that the communication method is made to move.