JPS592412B2 - Communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a communication device that employs a wireless communication method centered around one base station using common radio waves.

Conventionally, when attempting to use this type of communication method, if a particular station forms a communication path, other stations sharing the radio waves will be unable to make a call even if they wish to do so, and other stations' calls will be interrupted. Therefore, companies or organizations with mutual interests cannot share a single radio wave or base station.

Furthermore, if one station is forming a communication path and another station intentionally or accidentally emits radio waves, there is a problem in that the communication is interrupted and smooth communication is not possible. The present invention eliminates these drawbacks by making all calls by reservation controlled by specific tone signals, and by limiting the time a station occupies the channel to a fixed amount of time.
Furthermore, the present invention provides a communication device configured to restrict transmissions from other stations while that station is busy.

Examples of this device will be described below.

First, the communication station controllers of multiple companies and organizations that are shared, and the slave stations attached to them, are divided into individual tones and squelch only for companies or organizations that correspond to the transmitted individual tone signals (i.e., tone squelch). method) Formed by communication method. If the slave station wants to make a reservation for a call, and the line is empty, the slave station's busy lamp will of course be off, so the slave station will transmit for about one second. The base station receives this signal, stores it in the memory in the exchange control unit, inputs it to the vacant address of the shift register, and the base station also transmits the same individual tone frequency (
At the same time, a 1 KHz call instruction signal is superimposed on the tone frequency and transmitted for about 3 seconds. still,
The communication path formed at this time is held for a certain period of time T1 (for example, 1 minute), and if neither the communication station controller nor the slave station transmits (responses) within T2 (for example, 5 seconds). , or when T1 time has elapsed since the start of the call, the call is automatically disconnected. On the other hand, the same applies when reserving a call from the communication station controller. Next, reservations when the call path is busy will be explained. Reservations for calls from slave stations can only be made while the busy lamp is off.
Here, the operation of the busy lamp will be explained. In a general busy display, in the case of a two-frequency simplex communication system, the transmitter of the base station is always in a transmitting state, so the busy lamp is always in a lit state. This makes smooth control difficult, so in this system, when one of the slave stations is transmitting, the receiver of the base station receives the radio waves, and the transmitter sends out a signal called a pilot tone. It has a function that lights up the busy lamp and restricts transmission from all other slave stations. Therefore, a reservation for a call from a slave station can only be made when the busy lamp is off. In this case, the message is sent and the reservation is made when the busy lamp goes out. The base station detects the individual tones of the reservation, stores them, and inputs them in order into empty addresses in the shift register. On the other hand, when making a reservation from the controller side, since the controller and the base station are connected by a wired line, the reservation can be made whether the line is busy or idle. Embodiments of the present invention will be described in detail below with reference to the drawings.

However, in the drawing, one line is chosen from among multiple lines for convenience of explanation.
The explanation will be given using two lines as an example. FIG. 1 shows a system diagram of a base station. 1a to 1n are communication station controllers (hereinafter referred to as controllers) given to each subscriber; 2a to 2n are press talk switches; 3a to 3n are busy indicator lamps; 4a
~4n are reception display lamps, 5a~5n are transmission display lamps, 6a~6n are center control consoles, 7a~7n are subscriber units, 8a~8n are audio input/output terminals, 9a~9n are reception control terminals, 10a~ 10n is a control voltage terminal of an audio input/output switch, 1'a to 1'n is a control voltage terminal of a call instruction signal switch, 11 is an exchange, 12a to 12n are memories, 13 is a shift register, and 14a to 14n are first Timer, 15 is a second timer, 16 is a receiver, 17 is a transmitter, 18 is a detector, 19 is a communication instruction signal switch, 20
is a call instruction signal oscillator, 21 is a switch, 22 is a pilot tone oscillator, 22/ is a tone oscillator, and 23
is the pilot tone oscillation control input terminal, 24 is 6 to 27
25 is an audio input/output switch, 26 is a receiving antenna, and 27 is a transmitting antenna.

Fig. 2 is a system diagram of the slave station, where 28 is a receiving section, 29 is a transmitting section, 30 is a receiving speaker, 31 is a transmit/receive switch, 32 is an antenna, and 33 is a tone squelch section. It becomes one and becomes an oscillator during transmission.

34 is a pilot tone detection unit, 35 is a transmission limit switch, 36 is a microphone for transmitting speech, 37 is a busy indicator lamp, 38
Hail press talk switch.

When the line is idle, the transmission limit switch 35 of the slave station operates to allow transmission for 1 second, so when the press talk switch 38 is connected, the tone squelch section 33 and the transmitter 29 operate, allowing transmission and reception. The selector switch 31 is switched and the individual tone frequencies are transmitted via the antenna 32.

The base station 24 receives the individual tone frequency sent from the slave station with the receiving antenna 26, passes it through the receiver 16, and sends it to the detector 1.
8a-18n. There are as many detectors 18a to 18n as the number n of companies or organizations that share them, and they detect which of them the transmitted tone frequency corresponds to, and the detector of that frequency transmits the output to the next stage. Here, for ease of explanation, it is assumed that a slave station corresponding to a subscriber of the controller 1a has transmitted, and that the wave detector 18a has detected the signal. The detector 18a converts the detected output into a logic signal and transmits it to the subscriber unit 7a through the reception control terminal 9a. The subscriber unit 7a inputs the transmitted logic signal to the memory 12a of the exchange 11, and the memory 12a inputs the transmitted logic signal to the shift register 13.
Enter it at address 1. At this time, the shift register 13 drives the first timer 14a corresponding to the memory 12a by 1 and transmits a call enable signal to the subscriber unit 7a. Subscriber unit 7a receives this and connects control voltage terminals 10a and 1
``From a, the call instruction signal switch 19 and the tone oscillator 22
'' and a control voltage to the audio input/output switch 25. The call instruction signal switch 19 activates the call instruction signal oscillator 20 and transmits it to the transmitter 17 and receiver 16. is audio input/output switch 2
5 and the center control console 6 through the audio input/output terminal 8a.
a to the controller 1a. In other words, a call instruction has been given to the slave station and controller 1a. This is because most of the control signals used in this communication system use signals outside the voice band, and even if the group is given the right to make a call, some audible There is a risk that you will not notice unless you are notified by a signal. For this reason, a call instruction signal using an audible frequency is used to ensure reliable recognition. On the other hand, since the signal transmitted to the transmitter 17 oscillates at the individual tone frequency in the tone oscillator 22/ to which a control voltage is simultaneously applied from the control voltage terminal 10a, the signal is a form in which the individual tone frequency and the call instruction signal are superimposed. The signal is then transmitted through the transmitting antenna 27 for, for example, 3 seconds.

This means that a call path for about 1 minute is established (calls are permitted) to that company or organization. Note that the call instruction signal is sent for about 3 seconds, but if the controller 1 or any of its slave stations performs a transmit press operation within 3 seconds, the sending of the call instruction signal is stopped at the same time as the press.

That is, when the controller 1 presses the button, a set signal is applied to the control voltage terminal 1 via the center control console 6a and the subscriber unit 7a to stop the operation of the call instruction signal oscillator 20. On the other hand, when the slave station presses transmit, the output from the receiver 16 is detected by the detector 18 and transmitted to the subscriber unit 7 via the reception control terminal 9, and a reset signal is given to the control voltage terminal 1. It will be.
Note that while the communication path is being configured, individual tone signals from the slave stations are detected but not stored. Furthermore, since the communication path has been formed, the subscriber unit 7 that is currently talking gives a busy indication signal to the other subscriber units via the connection line between each subscriber unit, and the subscriber unit 7 that receives the signal The unit 7 lights up the call indicator lamp 3 of the controller 1 through the control console 6. On the other hand, if neither the controller 1 nor the slave station is pressed for more than T2 (approximately 5 seconds) after the call instruction signal is issued and the call path is established, the second timer 1
5, the reservation in the shift register 13 is automatically set and the communication path is disconnected.

However, if either the controller 1a or the slave station transmits, the timer 15 is set through the reception control terminal 9a, so that the communication path T1 (approximately 1 minute) is maintained. Next, to explain the case where a call is reserved from the controller 1 side, the receiver 1
The signal is directly inputted from the controller 1 to the memory 12 via 6 and 7 without passing through 6 and the detector 18, and then inputted into the shift register 13.

When the line is connected in this way and a call is started from the slave station to the base station (controller 1 side), when radio waves are received from the slave station, the pilot tone oscillation control input terminal 23 of the output of the detector 18 sends a control signal from the terminal, activates the switch 21, connects the output of the pilot tone oscillator 22 to the transmitter 17, and while the slave station is transmitting, transmits a pilot tone that restricts transmission to all slave stations except that slave station. Select. A pilot tone is an out-of-band signal similar to a tone squelch, and is used to prevent a slave station from interfering with a call when another slave station is transmitting. It has the function of sending out a control signal called a pilot tone from the base station, and regulating the transmission by slave stations that are not on a call.

The slave station that receives this pilot tone is detected by the pilot tone detector 34, displays the busy indicator lamp 37, and operates the transmission restriction switch 35 to be absolutely unable to transmit.

Next, when the slave station finishes transmitting, the pilot tone will no longer be sent out, so the busy indicator lamp 37 will turn off, and if the pre-talk switch 38 is turned on, the transmission limit switch 35 will be turned off.
The transmission operation lasts about 1 second. That is, if the call is busy, the reservation can be made when the busy display lamp 37 goes out as described above. In this way, when the slave station is busy, reservations can be made from the controller at any time when the busy display 37 goes out.

The circuit operation for reservation during a busy line is almost the same as that for an idle line, except that the reservation signal is held in the shift register 13 according to the reservation order of other reserved stations, including the busy station, so that the call is not interrupted. The lines are connected in the order in which the reservations are shifted in order.

On the other hand, if the busy station is in your own group, you can hear the voice when the controller 1 transmits, so you can talk to the controller 1 within the line holding time.

All calls are made after receiving a call instruction signal.

In other words, the slave station is subject to transmission restrictions by the transmission restriction switch 35, but since the individual tone frequency of its own group is sent along with the call instruction signal, the slave station detects the individual tone frequency and uses its output to limit transmission. switch 35
Since the transmission time can be reset, transmission for one second or longer is possible.
However, even in this case, when another slave station is transmitting, the pilot tone will be superimposed, so naturally the transmission restriction switch 35 will be set. Note that in the embodiments described above, the numbers specifically listed are for ease of explanation, and the values of time, frequency, etc. have been changed, or some functions of this device have been omitted or It is easy to embody such means, such as additions.

As described above, according to the present invention, in cases where one communication line is shared by multiple companies or organizations, one specific group does not monopolize the line for a long time, and moreover, multiple companies sharing the line can Alternatively, a wireless device can be obtained in which the confidentiality of calls between groups can be protected even if the groups have mutual interests. Furthermore, by using this device, it is possible to construct a highly reliable communication line in mobile radio that is smooth and free from interference, and its effects are extremely large. Furthermore, as the effective use of radio waves is being widely talked about, using this device means that the functionality of the original communication method is not lost, and a smooth and highly reliable communication path is obtained, making it effective and effective. be.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a base station of a communication device according to an embodiment of the present invention, and FIG. 2 is a block diagram of a slave station of the same. 1... Base communication station controller, 12...
Memory, 13...Shift register, 24...
...Base communication station.

Claims (1)

[Claims] 1 Communication center controllers installed and connected by wire to multiple companies or organizations and slave stations belonging to each company or organization share one base station to make calls, and also A means for dividing into groups and identifying them with individual tone signals using a tone squelch method to eliminate communication between different groups and ensuring communication secrecy, and for reserving a call, transmitting the individual tone signals from a slave station. means for receiving and detecting the signal at the base station, means for storing the detected individual tone signals in the order of detection, and transmitting the call instruction signal and the individual tone signal to the slave station in the stored order. and a means for sending a call instruction signal to the communication station controller, and a means for limiting communication for a certain period of time if the slave station and controller that received the call instruction start communication within a predetermined time. to form and maintain a communication path,
When a slave station is transmitting, the base station transmits a control signal called a pilot tone, and a regulating means for restricting transmission by slave stations other than the slave station in use, thereby interfering with communication of the slave station in use. A communication device that is characterized by ensuring stable communication without any interference.