JP2859786B2 - Wireless communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication system, and more particularly, to a radio communication system in which a master station broadcasts a plurality of slave stations in a predetermined area via a radio relay station. 2. Description of the Related Art Conventionally, local governments such as municipalities have made emergency calls for disaster prevention to multiple slave stations (notification towers) in remote villages and villages via a radio relay station such as a mountaintop from a master station in an urban area. And a so-called disaster-prevention administrative radio communication system that broadcasts ordinary administrative communication items.
Today, the use of such communication systems is diversifying, and in addition to the unilateral notification from the master station as described above, a specific local station in the area is independently broadcast to a plurality of other slave stations. Is done. Therefore, there is a demand for providing a wireless communication system that efficiently realizes such a complex function with low cost and high reliability.

[0002]

2. Description of the Related Art FIG. 4 is a diagram showing the configuration of a conventional radio communication system. In the figure, 10 is a master station in an urban area, 1 is its console, 2 is a microphone, 3 is a speaker, and 4 is a voice such as an administrative notice. A storage unit for storing a message, a digital selective calling signal for selecting one or more slave stations to be broadcasted, etc., 5 is a transceiver (T / R), 6 is a switch means for switching a signal line. (SW), 7 is a control unit for performing main control of the master station 10, 8 is an antenna, 9 is a wired connection unit,
Reference numeral 20 denotes a radio relay station provided at, for example, a mountaintop;
Its antenna, 24 ₂ frequency f ₁ of the receiver (R _X), 38 is a relay unit, the 25 ₁ frequency f ₂ of the transmitter (T _X), 60 _1, 60 ₂ provided on the land of frontier A slave station constituted by a notification tower or the like, 61 is its antenna, 62 is a speaker, 63 is a receiver (R _X ), 64 is a microphone for local broadcasting, and 65 is a modem (M).

In the master station 10, an operator operates the console 1
To enter the special number of the slave station group you want to report. The control unit 7 connects between a and b of the switch means 6 according to a transmission request from the console 1 and
The corresponding address of the storage unit 4 is accessed according to the special number from. As a result, a digital selective calling signal for one or more slave stations in a predetermined format corresponding to the special number is read from the storage unit 4, and the selective calling signal is transmitted from the transceiver 5 to the wireless relay station 20. You.

[0004] radio relay station 20 transmits the digital selective call signal received in the predetermined area from the transmitter 25 ₁ again reproduced in the relay portion 38, between the thereby selection of made a slave station A wireless broadcast channel is formed. In the master station 10, the control section 7 connects between c and b of the switch means 6 after transmitting the digital selective calling signal. Next, the operator inputs an emergency call from the microphone 2 and the call is sent to the wireless relay station 2.
0, a nearby inhabitant is notified through the receiver 63 and the speaker 62 of the selected slave station.

[0005] By the way, today, such a request for disaster prevention administrative radio communication system is diversified, for example, set a specific slave station 60 ₁ with the district communications office,該地District Communication Station 60
_One to one or two or more other slave stations 60 are selected to perform a district broadcast unique to the district. Conventionally, in order to perform such districts broadcasting, certain slave station 60 ₁ and the master station 1
0 and between connected by wire, or specific slave station 60 ₁ and one or more other between the slave station 60 was connected by wire.
In the former case, it stores the message you want to district broadcast by accessing the base station 10 from a particular slave station 60 ₁ temporarily in the storage unit 4 of the base station 10, remote control or parental from slave station 60 ₁ this Broadcasting is performed by the operator of the station 10 by the above method. In the latter case also, a particular from the slave station 60 ₁ other desired slave station directly to the calling by wire, is to broadcast simultaneously messages spoken by the microphone 64 from the speaker 62 of each slave station.

[0006]

However, according to the above-mentioned conventional method, it is necessary to lay a wire every time a slave station is installed. Generally, wire laying is costly and communication reliability is low. In addition, home-based receivers have become widespread today in each home, and in such a situation, laying wires is inefficient and extremely uneconomical.

An object of the present invention is to provide a radio communication system capable of efficiently performing low-cost and highly-reliable district broadcasting without hindering broadcast from the original master station.

[0008]

The above-mentioned problem is solved, for example , by referring to FIG.
Is solved. That is, the wireless communication system of the present invention (1) is a wireless communication system in which the master station 10 broadcasts a plurality of slave stations 60 _{1 to} 60 _n in a predetermined area via the wireless relay station 20. A local communication station 40 provided in the area for transmitting a broadcast to the radio relay station 20 at a frequency different from that of the master station 10;
0 and the broadcast from the regional communication station 40
A mode in which the broadcast from the master station 10 is relayed preferentially.
In which and a radio relay station 20 relays to a plurality of slave stations 60 ₁ to 60 _n are switched by.

[0009]

In the figure, since the local communication station 40 is in a predetermined area, it can directly communicate with the radio relay station 20. Therefore, the local communication station 40 transmits a broadcast to the wireless relay station 20 at a frequency different from that of the master station 10. In the radio relay station 20, since the transmission frequencies of the master station 10 and the local communication station 40 are different, they can be distinguished and received without interference. Therefore,
The radio relay station 20 gives priority to the broadcast from the master station 10 and the broadcast from the local communication station 40 to the broadcast from the master station 10.
Switching depending on the mode of relaying a plurality of slave stations 60 ₁
Relays to ~60 _n.

Therefore, it is not necessary to lay a wire in order to perform the district broadcasting as in the related art, and the district broadcasting with low cost and high reliability can be efficiently performed. Also from the original master station
Broadcasting from the district communication station without disturbing broadcasting
To multiple slave stations with the same reliability as broadcast from the master station.
Can be relayed to In addition, such priority relay switching control function,
To prepare for a wireless relay station common to the master station and the regional communication station
Broadcast from the parent station and broadcast from the district communication station
Can be efficiently realized at low cost. Preferably the invention
In (2), in the present invention (1), the wireless relay station 20 relays the first relay route A for relaying the broadcast from the master station 10 and the broadcast from the regional communication station 40. Switching means 36 for switching between the first and second relay routes A and B, and switching control of the switching means 36 by detecting a contention of transmission from the master station 10 and the local communication station 40. And a switching control unit 34 that gives priority to the master station 10.

Therefore, the broadcast from the master station 10 is not prevented. Also preferably, in the present invention (3)
In the present invention (1), the radio relay station 20
A signal generating unit 35 for generating a selective call signal for forming a broadcast channel to one or more slave stations corresponding to the selected special number of the slave station received from the master station or the local communication station.
Is provided. That is, the function for selecting a slave station, which is conventionally provided in the master station 10, is aggregated in the radio relay station 20, and this is shared by one or more regional communication stations 40 efficiently at low cost. > Can be used.

Preferably, in the present invention (4),
In the present invention (1), the local communication station 40 includes the receiving unit 46 for receiving the relay signal of the wireless relay station 20 and the receiving unit 4.
6, a signal processing unit 54 for monitoring the content of the received signal , and a receiving unit 4 based on the output of the monitoring result of the signal processing unit 54.
6 when receiving the relay signal other than that originated the own station, and a transmission controller 53 for controlling so as not to transmit from the district communication station 40.

This prevents transmission conflicts between the master station 10 and the plurality of regional communication stations 40 from occurring, and effectively stops useless transmissions from the regional communication stations 40 when a conflict is detected. I do.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Will be described in detail. The same reference numerals are the same throughout the drawings.
Or, a corresponding part shall be indicated. FIG. 2 shows the wireless communication of the embodiment.
Is a diagram showing a configuration of a communication system, in which 20 is an embodiment
Wireless relay stations, 21 to 23 have their antennas, 24, 25
Is the transceiver (T / R), and 26 is the details in FIG.
Is a relay control unit, and 27 is a receiver (R_X), 60 ₁, 6
0_Three, 60_FourIs a child station, 40 is a district communication station of the embodiment,
41 is the console, 42 is the microphone, 43 is the speed
F, a communication control unit 44 whose details are shown in FIG.
45 is a transmitter (T_X) And 46 are receivers (R_X), 47
Antenna.

The broadcast from the master station 10 is received by the radio relay apparatus 20 by the frequency f _1, it is relayed to a plurality of slave stations 60 and district communication stations 40 in the district by the frequency f _2. The broadcast from the district communication station 40 is received by the frequency f ₃ to the wireless relay device 20, it is relayed to a plurality of slave stations 60 and district communication stations 40 in the district by the frequency f _2. Although not shown, a plurality of district communication stations 40 may exist in the district.

FIG. 3 is a diagram showing a configuration of a main part of the wireless communication system of the embodiment. FIG. 3A is a block diagram of the wireless relay station 20 of the embodiment, in which 26 is a relay control unit, 31, 32, and 37 are demodulation and reproduction units (R) of received signals,
33 is a signal processing unit, 34 is a control unit, 35 is a signal generation unit,
36 is a switch means (SW), A is a first relay route for relaying broadcast from the master station 10, and B is a regional communication station 40.
2 is a second relay route for relaying a broadcast from.

The priority control of the master station 10 by the control unit 34 can be realized by various methods. An example of a simple method is to use the master station 10
And a method for controlling the switch means 36 based on the presence or absence of a carrier signal received from the local communication station 40. In this case, the signal processing unit 33 receives the detection signals of the reception carriers from the reproduction units 31 and 32, respectively, and
To enter.

The control section 34 connects between be of the switch means 36 while the carrier detection signal of the master station 10 is ON,
Thus, the broadcast from the master station 10 is relayed and transmitted to the plurality of slave stations 60. Further, the control unit 34 keeps the connection between be of the switch means 36 unchanged even if the carrier detection signal of the local communication station 40 is turned on while the carrier detection signal of the master station 10 is on. As a result, the broadcast from the master station 10 is relayed and maintained, and the broadcast from the regional communication station 40 is ignored.

Further, the control unit 34 controls the switching of the switching means 36 while the carrier detection signal of the local communication station 40 is ON.
e are connected to each other, whereby the broadcast communication from the regional communication station 40 is relayed to the plurality of slave stations 60. The control unit 3
In a case where the carrier detection signal of the master station 10 is turned on while the carrier detection signal of the district communication station 40 is on, the connection of the switch means 36 is switched once between d and e to generate a signal generation unit 4. A predetermined end signal is transmitted from 35, and thereafter, the connection of the switch means 36 is switched between be and relay transmission of the broadcast from the master station 10 is performed.

The relay control unit 26 of the embodiment is the same as that of the conventional master station 10.
Is provided with a function for selecting a slave station, which can be shared by one or more regional communication stations 40. The signal processing unit 33 receives the demodulated and reproduced digital control signals from the reproducing units 31 and 32, performs necessary processing, and inputs the processed signals to the control unit 34. When receiving the digital control signal of the communication start request from the master station 10, the control unit 34 connects between d and e of the switch means 36 and controls the specific slave station included in the digital control signal. A special number signal for designating a group is extracted, and the corresponding address of the signal generator 35 is accessed by the special number. Thus, from the signal generator 35 digital selective calling signal of the corresponding slave station is read out, the signal is sent to a plurality of slave stations 60 and district communication stations 40 in the district from the transceiver 25 ₁ You. Then, a broadcast relay communication path is formed with each of the specific slave stations and the like receiving this.

Next, the control unit 34 connects between be of the switch means 36 and relays the voice signal from the master station 10. Then, when receiving a digital control signal of a communication end request from the master station 10, the connection of the switch means 36 is switched between de and e, and the predetermined end signal is transmitted from the signal generator 35. The communication start request and the communication end request from the regional communication station 40 are processed in the same manner as described above.

FIG. 3B is a block diagram of the local communication station 40 according to the embodiment. In FIG. 3, reference numeral 44 denotes a communication control unit, 51 denotes a signal generation unit, 52 denotes switch means (SW), 53 denotes a control unit, and 54 denotes a control unit. Denotes a signal processing unit, and 55 denotes a received signal reproducing unit. The signal processing unit 54 receives the detection signal of the received carrier from the reproducing unit 55 and transmits the signal to the control unit 53. Also,
The signal processing unit 54 detects a predetermined end signal from the digital signal demodulated and reproduced by the reproduction unit 55 and notifies the control unit 53 of the detection of the end signal.

When there is a received carrier with a frequency f ₂ from a source other than the local station, the control unit 53 displays the fact on the console 41 so that the operator can notify the local area communication station 40 of the area. It does not broadcast. At this time, the control unit 53 may connect the switch means 52 with the switch ba and add the broadcast message part received at the frequency f ₂ to the speaker 43. Also, under the operation to secure the confidentiality of the information for each district, if this district communication station 4
If “0” is not selected, the received message signal is not unconditionally applied to the speaker 43.

In any case, the detection of the presence / absence of the received carrier signal of the frequency f ₂ by the signal processing section 54 is always performed in the plurality of local communication stations 40. Thereby, the master station 10 and the plurality of regional communication stations 40 in the wireless relay station 20 are
This prevents transmission conflict between them. If the received carrier signal of frequency f ₂ is not detected, the slave station for example headman want to tell the Problem by operating the console 41 6
Enter the special number of group 0. The control unit 53 responds to the transmission request from the console 41 by using the dc
At the same time, the special number is sent to the signal generator 51. As a result, a digital control signal of a communication start request of a predetermined format including the designated special number is output from the signal generator 51, and the signal is transmitted from the transmitter 45 to the wireless relay station 20. Upon receiving this, the radio relay station 20
The corresponding digital selective calling signal is transmitted to the plurality of local stations 60 and the local communication station 40 in the area, and a radio broadcast communication path is formed with each of the specific mobile stations receiving the signal. .

In the local communication station 40, the control unit 57
After transmission of the number signal, the connection between a and c of the switch means 52 is made.
You. Next, the village chief inputs a contact message from the microphone 42
The message is sent to the radio relay station 20 and the selected slave station.
Is notified to the inhabitants via the receiver 63. By the way,
The local communication station 40 transmitting the message signal is the radio relay station 2
Frequency f from 0_TwoTo detect the received carrier signal
Will be. However, the control unit 53 transmits
Frequency detected after transmission starts and before transmission end is sent
f _TwoFor the received carrier signal of
Can be considered as a received carrier signal based on transmission
Then, the broadcast transmission of the message is continued as it is.

On the other hand, since the master station 10 starts the broadcast transmission at an arbitrary timing, the broadcast transmission from the master station 10 may be started during the broadcast transmission by the regional communication station 40. In such a case, in the wireless relay station 20, the broadcast transmission by the local communication station 40 is forcibly terminated together with the transmission of the predetermined end signal, and the broadcast transmission from the master station 10 is started instead.

On the other hand, the local communication station 40 whose broadcast transmission has been forcibly terminated receives a predetermined end signal at the frequency f ₂ before the local station transmits the transmission termination request. The control unit 53 knows that the forced termination has occurred, and stops the broadcast transmission of its own message. This allows
The transmission of a message that has become meaningless can be stopped immediately.

In the above-described embodiment, the radio relay station 20 detects broadcast contention based on ON / OFF of each carrier detection signal. However, the transmission start request from the master station 10 and the local communication station 40 is not required. Broadcast contention may be detected based on the signal and the transmission end request signal. Also,
In the above embodiment, the broadcast from the master station 10 and the district communication station 4
The case where the contention with the broadcast from 0 is determined in real time and the relay is immediately switched on the spot has been described, but the present invention is not limited to this. For example, in the case where the broadcast from the master station 10 overlaps during the broadcast from the district communication station 40, a predetermined end signal is transmitted for the broadcast from the district communication station 40 and the master Switching to the relay of the broadcast from the station 10, during which the wireless relay station 20 temporarily stores the broadcast (message) from the regional communication station 40, and then the broadcast from the master station 10 ends. The broadcast which has been interrupted from the district communication station 40 may be restarted.

[0029]

As described above, the radio communication system according to the present invention has the above-mentioned configuration, so that low-cost and highly reliable local broadcasting can be efficiently performed without hindering the broadcast from the original master station. I can do it.

[Brief description of the drawings]

FIG. 1 is a diagram showing the basic configuration of the present invention.

FIG. 2 is a diagram illustrating a configuration of a wireless communication system according to an embodiment;

FIG. 3 is a diagram illustrating a configuration of a main part of the wireless communication system according to the embodiment;

FIG. 4 is a diagram showing a configuration of a conventional wireless communication system.

[Explanation of symbols]

10 master station 20 a radio relay station 40 district communication station 60 ₁ to 60 _n slave station

Claims (4)

(57) [Claims] 1. A wireless communication system for performing broadcast communication from a master station to a plurality of slave stations in a predetermined area via a wireless relay station, wherein the master station is a regional communication station provided in the area. before different to that for transmission of a broadcast to the radio relay station at a frequency, and a broadcast from the broadcast and district communication station from the master station
A wireless communication system comprising: a wireless relay station that switches to a plurality of slave stations by switching in a mode in which a broadcast from the master station is preferentially relayed . 2. A radio relay station, a first relay route for relaying broadcast from the master station, a second relay route for relaying broadcast from district communication station, the first and second and switching means for switching the second relay routes, and a switching control unit that detected and the switching <br/> exchange switching control means contention transmission from the master station and district communication station performed by the master station to the priority The wireless communication system according to claim 1 , comprising: 3. The radio relay station according to claim 1, wherein a selection channel for forming a broadcast channel to one or more slave stations corresponding to the selection special number of the slave station received from the master station or the regional communication station. The wireless communication system according to claim 1 , further comprising a signal generation unit that generates a call signal. 4. A district communication station, a receiving section that receives a relay signal of the radio relay station, a signal processing unit for monitoring the content of the received signal of the reception unit, based on the output of the monitoring result of the signal processing unit Te, when the receiving <br/> signal portion is receiving a relay signal other than that originated the own station is controlled so as not to transmit from the district communication station
The wireless communication system according to claim 1 , further comprising a transmission control unit.