JPS61228764A - Voice call system - Google Patents

Abstract

PURPOSE:To make it possible to realize an outgoing/incoming proceduring using an oscillator having the same oscillating frequency by sending out immediately a busy tone to each terminal unit from a central unit when a tone signal with a frequency for a call from any terminal unit is sent out and prohibiting a voice call by the terminal unit which is not transmitting the tone signal. CONSTITUTION:With the call of any terminal unit TU, an f1 terminal outgoing 31 is transmitted to a central unit CU from a corresponding f1 oscillation control part 24. The central unit CU receives and discriminates the f1 terminal outgoing 31 at an f2 oscillation control part 14 and an f2 central outgoing 32 is transmitted to each terminal unit TU from the central unit CU. The corresponding terminal unit TU is made possible to call (33) with the central unit CU by the control of frequencies f1 and f2. The voice call of the terminal unit which is not corresponding is compulsorily prohibited by the busy signal of the frequency f2 and the impossibility of the call is continued until the turning-off of the busy signal. A recovery after the completion of the call is as follows: a system is returned to a normal standby state by an f1 terminal outgoing turn-off 34 and an f2 central outgoing turn-off 35 and is placed under the next re-call cycle 36.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a voice communication system in community antenna television (hereinafter referred to as rcATVJ).

〔overview〕

The present invention provides a voice communication system in which a voice call is made between a central device and all terminal devices via a CATV two-way line, in which the central device prioritizes and recognizes incoming call signals from any terminal device. , immediately sends a busy signal to each terminal device,
Only the corresponding terminal device can make voice calls with the central device,
By performing control to disable calls with other terminal devices, the call procedure can be realized by only switching on and off a single oscillator for both the central device and the terminal devices, and all the terminal devices can use oscillators with the same frequency. Therefore, the hardware of the central unit can be significantly reduced.

[Conventional technology]

The initial purpose of CATV was to receive TV signals from remote locations, but later on, the coaxial cables used to distribute signals to each home had greater transmission capacity, and the use of optical fiber cables began to emerge. Since it was possible to secure a large number of cable channels, CATV was able to provide its own independent broadcasting and two-way communication services in addition to distributing (retransmitting) television station image signals. A typical example of this two-way communication is security services,
■Automatic fire detection, ■Emergency notifications such as theft and disasters, ■Emergency notifications from each house to the management center, and ■Multiple emergency broadcasts such as disaster occurrence information and evacuation guidance. However, most of these are for data transmission such as monitoring data,
Voice calls using intercoms or telephones are rarely used.

However, there is an increasing need for CATV multi-purpose services that can be used in addition to monitoring services to make voice calls. In this case, a telephone communication system is required that allows easy procedures for making and receiving calls.

Conventionally, there have been few examples of such voice calls, and the technology has not been established. In particular, the call originating/receiving procedures and address identification are different from normal telephone exchanges, and are often complicated by computer-controlled data communication procedures such as polling.

[Problem that the invention seeks to solve]

In this way, in the conventional case where the address data of all terminal devices is accessed from a central location by polling and calls made by the corresponding terminal device are identified, the longer the polling time is, the longer the call origination time is, and the need for emergencies such as security services is required. It becomes a problem when you need it.

In addition, for data communication of address data and call data, both the central equipment and the terminal equipment must be equipped with a modem, and it should be considered that the audio modulation and demodulation technology for the C and ATV bands alone would require a considerable amount of hardware. This also poses a problem in terms of economic efficiency.

The present invention has been made by focusing on these conventional problems, and provides a voice communication system in which the calling/receiving procedure is realized by using only a single oscillator in both the central device and the terminal device, without performing the calling/receiving procedure by polling. The purpose is to provide a method.

[Means for solving problems]

The present invention provides a voice communication system that includes means for performing voice communication between a central device and each terminal device via a CATV two-way line, in which each terminal device has a tone of a calling frequency on the line. The central device includes means for receiving a tone signal on the calling frequency, and means for transmitting a tone signal on the busy frequency to the line in response to the received output of the means. and each terminal device further includes a means for receiving a tone signal of the busy frequency, and a means for receiving a tone signal of the busy frequency, except when the tone signal of the calling frequency is being transmitted in response to a signal received by the means. The present invention is characterized by comprising means for prohibiting a means for making a voice call.

[For production]

The present invention realizes this procedure by switching on and off only the oscillators of a single oscillation frequency in both the central device and the terminal device, without performing a call originating/receiving procedure using polling. That is,
When a tone signal on the calling frequency is sent from any terminal device, the central device recognizes the incoming call and immediately sends a busy tone to each terminal device, thereby eliminating any terminal device that is not sending out a tone signal on the calling frequency. Voice calls are prohibited.

Therefore, only the corresponding terminal device can confirm the address and communicate with the central device.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. In FIG. 1, a central unit CU and a plurality of terminal devices T
Ui<i is a positive integer) are connected by a communication line 101. The central unit CU includes a communication device 11, an audio modulation/demodulation section 12, an oscillator 13 with an oscillation frequency f2, and an f2 oscillation control section 1.
4 and a destination operation section 15. The terminal device TU includes a communication device 21, an audio modulation/demodulation section 22, and an oscillation frequency f.
1 oscillator 23 and f9 oscillation control section 24. The communication devices 11.21 send out audio outputs 201.202 to the audio modulation/demodulation sections 12.22, respectively, and control outputs 203.204 to the oscillation control sections 14.24, respectively. The f2 oscillation control unit 14 of the central unit CU controls incoming calls at frequency f1 and outgoing calls at frequency f2. Similarly, f of the terminal device TU, the oscillation control unit 24 controls the reception of the frequency ft and the transmission of the frequency f. The destination operation section 15 stores the address of the terminal device of the destination, and its output is connected to the f2 oscillation control section 14 .

FIG. 2 is a diagram illustrating a call and its connection procedure.

When any terminal device TU makes a call, the corresponding f1
An f1 end untransmitted signal 31 is transmitted from the oscillation control unit 24 to the central unit CU. The central unit CU is its f.

The terminal call 31 is identified as an incoming call by the f7 oscillation control unit 14, and the f22 central call 32 is transmitted from the central unit CU to each terminal unit TU. The corresponding terminal bag WTU has a frequency f.

By controlling the and f2, it is possible to talk to the central bag ICU (33
)become. For terminal devices TU that do not correspond, voice communication is forcibly prohibited by the busy signal of frequency ft, and the communication inability continues as long as the busy signal is not interrupted. After the call is completed, recovery is performed by returning to normal standby by disconnecting the f1 end call 34 and disconnecting the f12 central call 35, and then starts the next call re-call cycle 3.
It becomes 6.

FIG. 3 is a time chart illustrating a call connection using the voice call system of the present invention.

A case where there are two terminal devices TU will be explained.

When the terminal device TUI transmits the terminal transmission 41 of frequency f, the central unit CU identifies the incoming call and sends f22.
The central signal 42 is sent out. Terminal unit TU.

When the F22 central call 42 is received, the call becomes possible. A voice call 43 is performed between the central unit CU and the terminal unit T U + after the parties confirm each other's addresses over the phone. At that time, even if f and terminal transmission 44 are transmitted from the terminal device T U z, a call cannot be made unless f22 central communication 42 is disconnected. After the voice call 43 ends, the f1 end non-call period 41 of the terminal device TU is completed, and then the terminal bag MT U z starts a voice call 45, and the f1 end non-call period 44 is a voice call period. Continue until completion of 45. When the communication between the two terminal devices TU1 and TU2 is completed, the f1 terminal untransmitted calls 41 and 44 are disconnected, and the f1 and central call calls 42 are completed.

FIG. 4 is a diagram showing the occupied band arrangement of CATV frequency bands.

Oscillation frequencies f and f2 for outgoing and receiving calls, carrier wave frequency f3 for downlink calls in full-duplex communication, and carrier wave frequency f4 for uplink calls
shows the arrangement. Reference numbers 51 and 52 indicate the downlink communication band and the uplink communication band, respectively.

〔Effect of the invention〕

As explained above, the present invention allows the central device and the terminal devices to use oscillators with the same oscillation frequency and to implement the call/receive procedure by intermittent oscillators, thereby significantly reducing the hardware of the central device. be able to. That is, since the hardware of the central device and the hardware of the terminal devices are the same, and there is no need for address identification, there is an excellent effect that the device can be made smaller.

In particular, the voice communication method of the present invention can sufficiently handle functions such as administrative entry in a CATV network within an apartment complex and interphone calls between residences, and can achieve its purpose. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 is a diagram explaining a call and its connection procedure. FIG. 3 is a time chart illustrating call connection using the voice call system of the present invention. FIG. 4 is a diagram showing the occupied band arrangement of CATV frequency bands. CU...Central unit, TU...Terminal device, 11.21
...Intercom phone, 12.22...Audio modulation/demodulation section, 13.
... 12 oscillator, 14...ft oscillation control section, 15.
...Call destination operation section, 23...f. Oscillator, 24...f1 oscillation control unit, 31...f, terminal call, 32...fz central call, 33...voice call, 34...f1 end not calling, 35... f22 Central communication disconnection, 36...next call cycle, 41...f,
Terminal origination, 42...f22 Central communication, 43...Voice call, 44...f, Terminal origination, 45...Voice call, 5
1... 51... Downlink call band, 52... Uplink call band.

Claims (1)

[Claims] (1) In a voice communication system that is equipped with a means for performing voice communication between a central device and each terminal device via a CATV bidirectional line, each terminal device receives a tone signal of a calling frequency on the line. The central device includes means for receiving a tone signal on the calling frequency, and means for transmitting a tone signal on the busy frequency to the line in response to the received output of the means. Further, each of the terminal devices has means for receiving a tone signal of the busy frequency, and a means for receiving the tone signal of the busy frequency, and a means for receiving the tone signal of the busy frequency, except when the tone signal of the calling frequency is being transmitted. A voice communication method characterized by comprising: means for prohibiting a means for making a telephone call.