JPH02295236A - Radio communication equipment - Google Patents

Abstract

PURPOSE:To omit the necessity to set the master station equipments at plural positions by setting the transmission/reception antennas connected to the master station equipment at plural different positions. CONSTITUTION:A master station equipment 1 is prepared together with plural slave station equipments 2, and the equipment 1 is connected to the equipments 2 via the bidirectional radio communication circuits. The antennas A1-An of the equipment 1 are set at plural different positions where the equipments 2 are moved or set. A switch circuit 12 which connects selectively one of antennas A1-An to a transmission/reception circuit 11 and a control circuit 13 which controls the circuit 12 are set between the circuit 11 and the antennas A1-An. Thus it is not required to prepare the equipments 1 in each area.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a wireless intercom device, a cordless telephone, and other devices that use low-power radio waves to enable one master station device and a plurality of slave station devices to share a frequency and communicate with each other. It is used for wireless communication equipment that performs direct communication.

[Conventional technology]

Wireless intercom devices and cordless telephones are legally and technically limited in their transmitting power and receiving sensitivity, and it is not possible to simply increase the transmitting power even if an attempt is made to expand the usage area of the wireless device. Taking a wireless intercom device used for centralized management of a building as an example, if a master station device is installed in a central control room and this master station device and multiple portable slave station devices are used, the number of floors to be managed is If there are a large number of slave stations moving on each floor and radio waves cannot reach them from a single master station, a master station may be installed on each of the many floors or control areas, and the master station and central control room A wired voice line and control line will be installed between the Cordless telephones also have restrictions on their usage area, and in order to expand their usage area, it is necessary to install a separate master station device.

[Problem to be solved by the invention]

A master station device is generally expensive, and it is not economical to install a large number of master station devices. Moreover, in order to centrally control a large number of master station devices, additional equipment is required, which has the disadvantage of becoming increasingly expensive and requiring complicated operation.

It is an object of the present invention to provide an inexpensive and easy-to-operate device that is suitable for the above-mentioned situations in which wireless communication devices are used.

[Means to solve the problem]

The present invention enables a plurality of antennas to be installed on one master station device, and connects the plurality of antennas to the transmission/reception circuit of the master station device by switching them.In the communication standby state, the antennas are periodically switched. The present invention is characterized in that an automatic control means is provided which switches the scanning to the antenna and continuously connects to the antenna capable of communication when communication is started.

[Effect]

When there are multiple areas where communication cannot be performed by one master station device, antennas are installed in each area and the connections of the antennas are switched and utilized. It is inexpensive because there is no need to install a master station device in each area. Since the antenna connection is automatically switched, no particularly complicated simulation is required.

〔Example〕

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention. In this example, the present invention is implemented in a wireless ink phone device for building management.

This device includes one master station device 1 and multiple slave station devices 2.
(only one is shown in the figure), and the master station device 1 and slave station device 2 are connected by a bidirectional wireless communication line. In this example, the master station device 1 is placed in a central control room of a building, and the slave station device 2 is a portable device carried and used by a manager or security guard. Each slave station device 2 includes a transmitting and receiving circuit.

This wireless communication line has one frequency, and this frequency is commonly used by the plurality of slave station devices 2.

Here, the feature of the present invention is that a plurality of transmitting/receiving antennas of the master station device are provided (A. to An), and the plurality of antennas At - An are different from each other when the slave station device is moved or installed. The transmitting/receiving circuit 11 and the plurality of antennas A1 to An are arranged at a plurality of positions, in this example, on each floor of a building, and between the transmitting and receiving circuit 11 of the master station device 1 and the plurality of antennas A1 to An. a switching circuit 12 that selectively connects one of the switching circuits 12 to 12;
It is equipped with a control circuit 13 for controlling the . The switching circuit 12 and each antenna At-An are connected by a coaxial cable or a parallel pair cable.

This switching circuit 12 is composed of n semiconductor switches.

This control circuit 13 scans and switches the connection of the switching circuit 12 periodically when the master station device 1 and the slave station device 2 are in a communication standby state, and the connection between the master station device 1 and the slave station device 2 is switched. When the terminals are in a communication state, control is performed so that the signal level of the slave station device 2 received by the master station device 1 is continuously connected to one antenna that is equal to or higher than a predetermined level.

This control circuit 13 automatically operates according to the output clock signal of the clock signal generation circuit 32 when the mode switch 31 is set to automatic and the master station device 1 and slave station device 2 are in a communication standby state. The control circuit 33 generates a periodic signal, and in accordance with this, the selection control circuit 34 sequentially scans the semiconductor switches of the switching circuit 12 to open and close one by one. That is, among the n semiconductor switches of the switching circuit 12, only one is always closed and the others are open, and the closed semiconductor switches are controlled to be replaced in turn. The period from when one semiconductor switch closes until the next semiconductor switch opens is 20 to 30 m.
Set to S. One scanning period is approximately 100 mS depending on the number of semiconductor switches.

In this state, when one call button of the slave station device 2 is pressed and a radio wave is transmitted, the radio wave is transmitted to the receiver 2 of the transmitting/receiving circuit 11.
2 received. This reception level is detected by the reception level detection circuit 35, and when the reception level is equal to or higher than a predetermined value, a detection output is sent out, and the automatic control circuit 33 stops sending periodic signals. As a result, the switching circuit 12 stops scanning, and the semiconductor switches that are closed at that time are continuously closed. Communication is performed in this state.

When making a call from the master station device 1, the control C of the master station device 1
Transmission control is performed from P024.

First, simultaneous calling will be explained. This is used when summoning security guards from the central control room. At this time, a calling signal is transmitted from the transmitting circuit 22. This calling signal is transmitted over at least one scanning period of the switching circuit 12. The slave station device 2 receives the calling signal from one of the nearby antennas. The ringing signal causes the slave station device 2 to emit a ringing tone. The person carrying the slave station device 2 hears the ringing tone and presses the call button of the slave station device 2. This results in the same state as when a call is made from the slave station device, and when the receiving circuit 21 of the master station device 1 receives the radio waves from the slave station device 2 and the reception level is above a predetermined level, the switching circuit 12
switching scanning is stopped. Communication is performed in this state.

Communication is performed between a master station device 1 and one slave station device 2.

FIG. 2 is a time chart of this operation.

To perform a selective call, press the mode switch 3 of the control circuit 13.
1 to manual mode, selects and connects to the antenna in the area where the other party's slave station device 2 is located, and transmits a calling signal. The following procedure is the same as when making a call from the master station device 1 described above. The scanning range of the switching circuit 12 can also be set to be limited to some antennas rather than all antennas by operation.

Further, in order to perform selective calling, a configuration may be adopted in which selection is performed using an audio frequency signal. That is, the master station device 1
modulates the calling signal with an audio frequency signal, demodulates this audio frequency signal to the slave station device 2, and detects a selective call to itself by detecting the presence or absence of a frequency assigned to itself from the demodulated output. The configuration is as follows. It is preferable to use a PB dial signal as the audio frequency signal. That is, the slave station device 2 is connected to the PB dial signal from "0" to "9".
'' and modulate the calling signal from the master station device 1 with any of the PB dial signals "0" to "9" to perform selective calling. On the other hand, the slave station device 2 is configured to send a paging detection output when it detects a modulated signal of a number assigned to itself from among "0" to "9" of the PB dial signal.

To explain the case where the mode switch 31 of the control circuit 13 is switched to manual mode, after the communication line is set in automatic mode and communication is started, the mode switch 31 is switched to manual mode and the communication condition is further improved. It can be controlled to select the antenna.

The invention can be implemented with cordless telephones as well. In this case, the selective use of multiple frequencies, in which the frequency to be used is not necessarily one, but one selected from multiple frequencies, is well known and complies with standards for connection procedures. Since it is possible to do so, a detailed explanation will be omitted here. Others can be understood from the above embodiments.

〔Effect of the invention〕

In this way, in the device of the present invention, the transmitting/receiving antennas connected to the master station device are provided at a plurality of different positions and used by switching between them, so there is no need to arrange the master station device at a plurality of different positions, making it economical. It is true. Furthermore, although there is only one master station device, it is easy to imitate.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention. FIG. 2 is an operation time chart of the control circuit. DESCRIPTION OF SYMBOLS 1... Master station device, 2... Slave station device (a plurality of similar devices are provided, but only one is shown in the figure), 11... Transmission/reception circuit, 12... Switching circuit, 13... control circuit.

Claims (1)

[Scope of Claims] 1. A master station device including a transmitting/receiving circuit, and a plurality of slave station devices connected to the master station device by a bidirectional wireless communication line and each including a transmitting/receiving circuit; In a wireless communication device in which one line frequency or a small number of frequencies are commonly used by the plurality of slave station devices, a plurality of antennas for transmitting and receiving the base station device are provided, and each of the plurality of antennas is connected to a slave station. The device is moved or installed at a plurality of different positions, and between the transmitting/receiving circuit of the master station device and the plurality of antennas, one of the transmitting/receiving circuits and the plurality of antennas is selected. a switching circuit that connects the master station device and the slave station device, and when the master station device and the slave station device are in a communication standby state, the connection of the switching circuit is periodically scanned and switched, and the connection between the master station device and the slave station device is switched. Wireless communication characterized by comprising a control circuit that continuously connects to an antenna such that the signal level of the slave station device received by the master station device is equal to or higher than a predetermined level when the communication state with the station device is established. Device.