JPS63144628A - Private paging system - Google Patents

Abstract

PURPOSE:To expand the receptible range by a slave set with a small transmission output not affecting interference to other sets by allowing plural transmitters to send a signal to call a specific slave set sequentially by the start from a terminal equipment. CONSTITUTION:A private branch of exchange 4 or an operation console 5 is operated to send an ID and a data for a specific slave set from a terminal equipment to a transmitter 2a through a signal line 6. The transmitter 2a receives the signal and a control section 24 applies carrier sense and modulates an identification ID, an ID of a sender 2a, an ID of a destination transmitter 2b, an ID for a slave set to be called and a data by a transmission section 22 and radiates the result from an antenna 21 as a radio wave for a predetermined number of times. The transmitter 2b receives it, identifies each ID and sends an ACK signal, applies the same operation as the sender 2a and radiates the result from the antenna 21 as a radio wave. The transmitter sends the ID to call the specific slave set, the data and the ID of the transmitter to be started next sequentially. When any of the slave sets exists within the reception range of the transmitter, the slave set receives the signal.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a local paging system in which a terminal device wirelessly calls a specific child device via a transmitter.

(Prior Art) A conventional in-premises paging system is equipped with one transmitter having a transmission output on the order of IW, and calls child devices located in a wide range at one time. In addition, since it is difficult to cover a wide area with a single low-power transmitter, such as in a campus wireless station, conventional bag devices equipped with multiple transmitters to call slave devices require a signal line from the terminal device. It was meant to connect to all transmitters.

(Problems to be Solved by the Invention) The disadvantage of the former is that the output power of the transmitter is large and may adversely affect electronic equipment installed nearby. The disadvantage of the latter is that many signal lines must be wired to connect the signal lines to all the transmitters. In addition, simultaneous transmission may cause interference depending on the location.

(Means for Solving the Problems) In order to solve the above-mentioned drawbacks, the present invention provides the following system.

In a campus paging system that calls a specific hanging device wirelessly from a terminal device via a transmitter, it is equipped with a plurality of transmitters, and upon activation from the terminal device, the first transmitter sends a signal to call a specific hanging device and the next transmitter. When the second transmitter, which is activated next, receives the above-mentioned calling signal, it sends out a signal that calls a specific hanging device, and a signal that calls a specific hanging device. An in-plant paging system in which the transmitters sequentially perform a calling operation for a specific hanging device so as to send out a calling signal composed of a calling signal for a third transmitter that is subsequently activated.

An embodiment of the present invention will be described below based on the drawings.

(Example) Fig. 1 is a schematic diagram of an on-premises paging system that is an embodiment of the present invention, Fig. 2 is a system diagram of a transmitter, Fig. 3 is a system diagram of a hanging device, and Fig. 4 is a sequence flow. It is a diagram.

1 is a terminal device, 2a, 2b,... 2x is a transmitter, 3 is a hanger, 4 is a private branch exchange, 5 is an operation console, 6.7 is a signal line, 8 is a power supply line, 9 is It is within the reception range.

21 is a transmitting/receiving antenna, 22 is a transmitting section, 23 is a receiving section, 24 is a control section, and 25 is a power supply section. In FIG. 1, the transmitter 2a is connected to the terminal device 1 by a signal line 6, and therefore receives DC power from the terminal device 1. The signal for calling a specific hanging device is superimposed on the direct current of the signal line 6.

Further, since the transmitter 2x is also connected to the terminal device 1 by the signal line 7, it receives DC power from the terminal device 1.

A signal sent from the transmitter 2x is superimposed on the signal line 7. Power for transmitters other than transmitters 2a and 2x is supplied from a nearby commercial power source.

The operation of the local paging system shown in FIG. 1 will be explained below.

The terminal device 1 performs control to call a specific hanging device 3 by controlling the private branch exchange 4 or by operating the operator console 5.

The terminal device 1 sends the hanger ID and data of the specific hanger 3 to the transmitter 2a via the signal line 6. Here, the data is the telephone number or message of the calling telephone displayed on the display 36 of the specific handset 3.

When the transmitter 2a inputs the hanger ID and data, the control unit 24 performs carrier sense using the antenna 21 and the receiving unit 23 to confirm that radio waves in the same band are not emitted from other sources. The transmitting unit 22 sends the identification ID which is the identification signal shown in FIG. It is modulated and emitted from the antenna 21 as a radio wave a predetermined number of times.

Note that carrier sensing is also performed before emitting radio waves in the following operations.

This radio wave is received by the antenna 21 of the transmitter 2b, further demodulated by the receiving section 23, reaches the control section 24, and is stored. When the control unit 24 identifies that the identification ID is that of its own system and that the transmission destination is its own ID B, it sends an ACK signal and the ID of the transmission source transmitter 2a.
A is modulated by the transmitter 22 and emitted from the antenna 21 as a radio wave.

If the transmitter 2a receives an ACK signal from the transmitter 2b and an A signal which is the sender ID after completing a series of transmissions, it will not transmit again. The transmitter 2b performs the same operation as the transmitter 2a after a time T has elapsed since transmitting the ACK signal. That is, the control section 24 of the transmitter 2b
is the identification ID shown in FIG. 4, B which is the ID of the source transmitter 2b, C1 slave unit D which is the ID of the destination transmitter 2c, and data are modulated by the transmitter 22 and emitted as radio waves from the antenna 21. do.

As described above, the transmitter sequentially sends a signal to call a specific hanging device 3, that is, the hanging device ID and data, the ID of the transmitter to be activated next, and the like. Therefore, if the called slave device 3 is within the receiving range of any of the transmitters, the hanger 3 receives the calling signal with the antenna 31, demodulates it with the receiving section 32, and inputs the demodulated output to the control section 33.

When the control unit 33 identifies that the input hanger ID is its own, it controls the calling unit 37 to generate a ringing sound, converts the input data, and displays it on the display unit 36. Here, the person carrying the hanger 3 looks at the display section 36 and understands the message etc.

The last activated transmitter 2 It emits as a radio wave and also sends the hanger ID and data to the signal line 7 connected to the terminal device.

The terminal device 1 receives the hanger ID and data from the transmitter 2a.
When it is determined that the transmitter is the same as the one sent to the transmitter, it is determined that all the transmitters have finished transmitting, and after sending a termination signal from the operator console or private branch exchange, the operation is terminated.

FIG. 5 shows a local paging system which is another embodiment of the present invention. In this example, the transmitter that starts transmission and the transmitter that ends transmission are both used. FIG. 6 is a system diagram of a dual-purpose transmitter. Since the start of transmission is the same as that shown in FIG. 1, the explanation will start from the time when the transmitter 2a responds to the call from the last activated transmitter 2n. The transmitter 2a receives the radio wave from the transmitter 2n, demodulates it in the receiver 23, and receives the identification I.
D, ID of source transmitter 2n N1 destination transmitter 2
The A1 child device ID, which is the ID of a, and data are taken into the control unit 24.

The control unit 24 has an identification ID that belongs to its own system,
Furthermore, when it is determined that the destination ID is A, it sends back an ACK signal and an N signal to the transmitter 2n. Further, the control unit 24 sends the hanging device ID and data to the signal line 6. The operation after this is the same as in the embodiment described above.
In this embodiment, by considering the transmission order of the transmitters, the signal line 7 from the terminal device 1 to the last activated transmitter as shown in FIG. 1 is made unnecessary.

FIG. 7 is a schematic diagram of a local paging system according to another embodiment of the present invention. The operation of this embodiment is also similar to that of the second embodiment. However, it is necessary that the control unit 24 of the transmitter has a function of determining the ID of the transmitter that is the next destination by identifying the ID of the transmitted source transmitter.

For example, when the received radio wave is from the transmitter 2a, the transmitter 2b shown in FIG. A signal incorporating the ID of the destination transmitter 2a is sent out.

Therefore, in the system shown in FIG. 7, the transmitter is activated in the following order upon activation from the terminal device 1.

Terminal device 1 - transmitter 2 a-2b -2c -2d -
2e → 2d → 2e → 2d → 2C → 2b → 2a → terminal device.

Furthermore, in the local paging system shown in FIG. 7, the transmitter is 2 a-2b −+ 2 C42d −+ 2e
(7) When transmitting in sequence and stopping transmission up to the transmitter 2e, or in the case of the in-house paging system shown in FIG. , the call signal for the second specified hanging device is started to be sent when a time has elapsed until a transmitter far enough away to avoid interference transmits.

By sending out call signals for different hanging devices one after another in this way, a large number of hanging devices can be called in a unit time.

The invention is not limited to the embodiments described above.

For example, in the embodiment, power is supplied to the transmitter using a signal line, but it may be provided separately from the line that transmits data, or if the transmitter is not connected to a signal line, it may be supplied depending on the situation. A DC power source may be used instead of a commercial power source.

(Effects of the Invention) As explained above, the local paging system of the present invention can expand the reception range of the handset with a small transmission output that does not interfere with other devices.

Furthermore, since multiple transmitters do not transmit at the same time, interference such as interference does not occur.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a campus paging system that is an embodiment of the present invention, Fig. 2 is a system diagram of a transmitter, Fig. 3 is a system diagram of a hanging device, Fig. 4 is a sequence flow diagram, and Fig. 5 6 is a schematic diagram of a local paging system as another embodiment, FIG. 6 is a system diagram of a transmitter, and FIG. 7 is a schematic diagram of a local paging system as another embodiment. 1...Terminal device, 2al 2bl...
2x...Transmitter, 3...Slave unit, 4...
...Private branch exchange, 5...Operation console, 6.7.
·····Signal line. Patent applicant: Kanda Tsushin Kogyo Co., Ltd.

Claims (1)

[Claims] In a local paging system that wirelessly calls a specific slave device from a terminal device via a transmitter, it includes a plurality of transmitters, and upon activation from the terminal device, the first transmitter sends a signal to call a specific slave device and the next transmitter. When the second transmitter that is activated next sends out a calling signal consisting of a signal that calls the second transmitter, after receiving the above calling signal, the second transmitter that starts next sends a signal that calls a specific slave device, and 1. A local paging system characterized in that the transmitters sequentially perform a paging operation for specific slave devices so as to send out a paging signal composed of a signal for paging a third transmitter that is subsequently activated.