JP2000134344A - Radio communications system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communications system with which the success rate of communication in a radio zone is improved and alarm moving to a center is prevented. SOLUTION: Any abnormality such as gas leakage occurs and a detector 8 transmits an alarm signal to a wireless hand set 7 (step 40). For example, as the first retry (1-(1)} of first transmission, the wireless hand set 7 transmits the alarm signal containing transmission time information and transmission time number information or the like to a wireless base unit 6. When the wireless base unit 6 cannot receive the signal for the 1-(1)st time because of any factor (step 41), after the lapse of one minute, the wireless hand set 7 performs 1-(2)nd transmission and the wireless base unit 6 normally receives the signal (step 42). The wireless base unit 6 analyzes the transmission time information and transmission time number information of the received signal and transmits the alarm signal to the center 2 (step 43). When the wireless hand set 7 performs 1-(3)rd transmission and the wireless base unit 6 normally receives the signal (step 44), the wireless base unit 6 analyzes the transmission time information and transmission time number information of the received signal and does not transmit the alarm signal to the center 2 when it is already transmitted to the center 2.

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 for transmitting an alarm in conjunction with an alarm attached to a gas meter or the like.

[0002]

2. Description of the Related Art Conventionally, when a gas leak or the like is detected indoors,
Wireless communication systems for reporting to centers have been developed.
The wireless master unit is connected to the center via a telephone line and performs communication. The wireless handset is connected to a detector that detects a gas leak or the like. When the detector detects a gas leak or the like, an alarm signal is transmitted to the wireless slave, and the wireless slave transmits an alarm signal to the wireless master when receiving the alarm signal. The wireless base unit is
The received information is analyzed and reported to the center via a telephone line.

[0003]

In such a conventional system, when the wireless slave unit is dedicated to transmission, the wireless slave unit cannot confirm that transmission to the wireless master unit has been normally performed. Retry transmission is performed multiple times to improve the communication success rate.

FIG. 6 shows a communication procedure when an alarm signal is transmitted from the detector 108 to the center 102. As shown in FIG. 6, for example, when the detector 108 detects an abnormality such as a gas leak, the alarm signal is transmitted to the wireless slave device 107 (step 110). For example, upon receiving the alarm signal, the wireless slave device 107 first performs the first transmission as the wireless master device 106.
Retry transmission of an alarm signal three times (step 111,
Step 112, Step 114). The first alarm signal is not normally received by the wireless master device 1-6, and the first and first signals are normally received. In this case, the radio cell station 106 transmits the first-time alarm signal and the first-time alarm signal normally received to the center 102 (steps 113 and 115).

[0005] Therefore, there is a problem that each time the wireless master device 106 receives the retry transmission from the wireless slave device 107 normally, the wireless master device 106 notifies the center of the duplicated information.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a wireless communication system that improves the communication success rate in a wireless section and prevents transfer to a center. It is in.

[0007]

According to the present invention, there is provided a radio base station connected to a center, and a radio base station connected to a detector. A wireless communication system in which communication is performed between the center and the detector by performing communication with the wireless slave, wherein the wireless slave is a signal transmitted from the detector when an alarm is issued. Is transmitted to the wireless master device a plurality of times, together with transmission time information and transmission count information,
A wireless communication system characterized by analyzing the received transmission time information and transmission count information, transmitting a signal that has not been transmitted to the center, and not transmitting a signal that has already been transmitted.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of a wireless communication system 1 according to an embodiment of the present invention. As shown in FIG. 1, the wireless communication system 1 includes a center 2, a communication control device 3, a telephone line 5, a wireless master unit 6, a wireless slave unit 7, a detector 8, and the like.

The center 2 and the wireless base unit 6 are connected via a telephone line 5, and the wireless base unit 6 and the wireless slave unit 7 use radio waves of a low power wireless standard or the like. Connected wirelessly. The wireless handset 7 is connected to a detector 8 for detecting a gas leak or the like. Both the wireless master unit 6 and the wireless slave unit 7 are driven using a battery or a commercial AC power supply as a power supply.

When the detector 8 detects a gas leak or the like, it sends an alarm signal to the wireless handset 7, and the wireless handset 7 sends an alarm signal to the wireless master unit 6 when receiving the alarm signal. The wireless master device 6 analyzes the received information and notifies the center 2 via the telephone line 5.

FIG. 2 is a block diagram showing the configuration of the wireless master device 6. The wireless master device 6 includes a network communication control circuit 11, a message information control circuit 12, a modem circuit 13, a power supply circuit 14, a timer control circuit 15, an antenna 16, and the like. Power supply circuit 1
4 supplies power to each unit. The timer control circuit 15 sends a time signal to the message information control circuit 12 periodically. The antenna 16 is connected to the modulation / demodulation circuit 13 and
Is transmitted to the modulation / demodulation circuit 13. Modulation / demodulation circuit 1
3 demodulates the received signal. The message information control circuit 12
The received message from the modulation / demodulation circuit 13 is analyzed. The network communication control circuit 11 sends the analyzed received message to the center 2 via the telephone line 5.

FIG. 3 is a block diagram showing the configuration of the wireless handset 7. The wireless slave device 7 includes a modulation transmission circuit 21, a message information control circuit 22, a signal detection circuit 23, a power supply circuit 24, a timer control circuit 25, an antenna 26, and the like. Power supply circuit 2
4 supplies power to each unit. The timer control circuit 25 sends a time signal to the message information control circuit 22 periodically. The signal detection circuit 23 detects the alarm signal sent from the detector 8 and transmits the alarm signal to the message information control circuit 22. The electronic message information control circuit 22 creates an electronic message for transmitting information such as gas leakage, and the modulation sending circuit 21 modulates the electronic message and sends the modulated electronic message from the antenna 26.

In the present embodiment, when the detector 8 detects a gas leak or the like, an alarm signal is transmitted to the wireless slave unit 7, and the wireless slave unit 7 transmits an alarm signal to the wireless master unit 6 when receiving the alarm signal. Send When sending an alarm signal, in order to prevent false reports when wireless communication is not possible due to some accidental cause (fading, power failure, instantaneous noise, etc.)
Perform multiple retries. The retry method includes a method of retrying at a time interval, a method of retrying by changing a frequency channel, and a method of retrying a combination of these.

In the signal, transmission time information and transmission number information are transmitted. FIG. 4 shows a case where the wireless slave device 7 to the wireless master device 6
FIG. 3 is a format diagram of a signal 30 transmitted to the STA. As shown in FIG. 4, the signal 30 has transmission time information 31, transmission number information 32, and an alarm signal 33. Transmission count information 32
Sets two types of information: the number of transmission opportunities and the number of retries within the transmission opportunity.

The wireless master device 6 performs carrier sense intermittently when driven by a battery. In the case of AC power drive, a signal is continuously received. When receiving the signal from the wireless handset 7, the transmission time information 31 and the transmission count information 32 of the received signal 30 are analyzed, and it is determined whether or not the alarm signal 33 has already been transmitted to the center 2. If the alarm signal has not been transmitted to the center 2, the wireless master device 6 transmits the alarm signal via the telephone line 5. If the alarm signal has already been transmitted to the center 2, the alarm signal is not transmitted to the center 2.

A communication procedure for notifying the alarm signal from the detector 8 of the present embodiment to the center 2 will be described in detail. FIG. 5 shows a communication procedure for notifying the center 2 of an alarm signal from the detector 8. As shown in FIG. 5, an abnormality such as a gas leak occurs, and the detector 8 transmits an alarm signal to the wireless handset 7 (step 40). For example, the wireless handset 7 retransmits the signal 30 three times every minute as the first transmission to the wireless master device 6, and transmits the signal 30 to the wireless base device 6 at a five-minute interval as the second transmission. Retry transmission 3 times every minute. This is repeated the specified number of times.

First, as the first transmission retry (hereinafter referred to as the first time), the wireless slave device 7 transmits an alarm signal carrying transmission time information, transmission count information, and the like to the wireless master device 6. For example, the wireless master device 6 cannot receive the first time for some reason (step 41). One minute later, the wireless handset 7
Transmits the first time, and the wireless master device 6 normally receives (step 42). The radio cell station 6 analyzes the transmission time information 31 and the transmission number information 32 of the received signal, and transmits an alarm signal to the center 2 (step 43). Subsequently, the wireless slave device 7 transmits the first time, and the wireless master device 6 normally receives (step 44). The radio cell station 6 analyzes the number of transmission opportunities in the transmission time information 31 and the number of transmissions information 32 of the received signal and the number of retries in the transmission opportunity, and the number of transmission opportunities in which the alarm signal has already been transmitted to the center 2 ( 1), the number of retries (2) and its transmission time information, and the number of transmission opportunities (1), the number of retries (3) and the transmission time information 31 are compared.

Next, a second transmission is performed at an interval of 5 minutes from the first transmission. For example, the wireless handset 7
The second signal is transmitted, and the radio cell station 6 cannot receive the signal for some reason (step 45). Subsequently, the wireless handset 7
-The second signal is transmitted, and the wireless master device 6 receives the signal normally (step 46). The radio cell station 6 analyzes the transmission time information 31 and the transmission count information 32 in the received signal, determines that the alarm signal has already been transmitted for the first time, and does not transmit it to the center 2. Similarly, the second normally received signal (step 47) is not transmitted to the center 2.

As described above, according to the present embodiment, wireless handset 7 carries out retry transmission with transmission time information 31 and transmission count information 32 placed on the alarm signal from detector 8. The received signal information is analyzed to determine whether or not the information should be transmitted to the center 2. If the information has already been transmitted, the information is not transferred to the center 2, so that the communication between the wireless slave device 7 and the wireless master device 6 can be performed. The communication success rate can be increased, and reporting of duplicate information to the center 2 can be prevented. Further, it is also possible that the wireless slave device 7 is dedicated to transmission and the wireless master device 6 is dedicated to reception.

The frequency at which a signal is transmitted from the wireless handset 7
The retry frequency is set as an internal setting of the wireless master device 6 and the wireless slave device 7 and can be changed from the center 2 and a setting device (not shown). Further, in the present embodiment, the retry method is a method of retrying at intervals of time, but there is a method of retrying by changing the frequency channel or a method of retrying by combining them. For example, FIG.
In the retry method indicated by (1), there is a method of performing check transmission by changing the frequency channel immediately after the check transmission of 1-, and similarly, performing check transmission by changing the channel respectively immediately after the check transmission of 1- and 1-.

[0021]

As described above in detail, according to the present invention, it is possible to provide a radio communication system which can improve the communication success rate in the radio section and prevent the transmission to the center.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a wireless communication system 1 according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a wireless master device 6;

FIG. 3 is a block diagram showing a configuration of a wireless handset 7;

FIG. 4 is a signal 3 transmitted from the wireless slave device 7 to the wireless master device 6.
0 format diagram

FIG. 5 is a diagram showing a communication procedure for transmitting an alarm signal from the detector 8 to the center 2.

FIG. 6 shows a detector 10 in a conventional wireless communication system.
8 shows a communication procedure for transmitting an alarm signal to the center from FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Wireless communication system 2 ... Center 3 ... Communication control device 5 ... Telephone line 6 ... Wireless base unit 7 ... Wireless slave unit 8 ... Detector 11 ... Network Communication control circuit 12 Message information control circuit 13 Modulation / demodulation circuit 14, 24 Power supply circuit 15, 25 Timer control circuit 16, 26 Antenna 21 Modulation transmission circuit 22 …… Message information control circuit 23 ……… Signal detection circuit

 ──────────────────────────────────────────────────続 き Continued from the front page F term (reference) 2G060 AA01 AE19 AE40 HC07 HC10 HD01 HD02 HD07 HE10 5C087 AA02 AA60 BB12 BB18 BB46 DD01 EE07 EE14 FF01 FF02 GG29 GG43 5K067 AA26 AA33 BB27 DD28 DD51 EE12 GG07 GG10 VV06

Claims (2)

[Claims] 1. A wireless master unit connected to a center and a wireless slave unit connected to a detector, wherein communication is performed between the wireless master unit and the wireless slave unit, whereby the center And a wireless communication system in which communication is performed between the detector, wherein the wireless slave device, at the time of an alarm, a signal sent from the detector,
A plurality of times, together with transmission time information and transmission number information, are transmitted to the radio cell station, and the radio cell station analyzes the received transmission time information and transmission number information and is not transmitted to the center. A wireless communication system that transmits a signal and does not transmit a signal that has already been transmitted. 2. The wireless communication system according to claim 1, wherein the wireless handset transmits a signal a plurality of times at intervals of time or by changing frequency channels.