JPH06291723A - Security radio system - Google Patents

Abstract

PURPOSE:To provide a security radio system which is capable of preventing the interference between systems and performing a smooth communication even when plural systems are introduced. CONSTITUTION:A radio channel where communication traffic amount is least is selected based on the information for the prescribed period of the use status of each reception channel obtained by deciding whether each reception channel is used in other systems or not, while periodically performing an operation changing the reception channels of the radio line between a master radio equipment 5 and a slave radio equipment 6 successively all over the reception ranges, this selected radio channel is set as the radio channel of a main system, and a communication is performed between the master radio equipment 5 and the slave radio equipment 6 by using this radio channel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to security information collected by a terminal device which is installed in, for example, a gas consumer and which is connected to a telephone line via a wireless line to collect security information such as gas leakage. The present invention relates to a security wireless system for transmitting a message to a center device via a wireless line and a telephone line.

[0002]

2. Description of the Related Art As a radio equipment for data transmission which does not require a license of a radio station, there is a specific low power radio with an output of 10 mW or less, which is used for a teleconverter / telemeter, a pager, a medical telemeter, etc. Classified into
A frequency is assigned to each application.

In these systems using the specific low power radio, data communication can be performed between devices installed at distant places by using the radio. However, the device is further connected to a telephone line to be remotely connected. Data transmission to a center installed on the ground has conventionally been legally prohibited. That is, wireless data communication and telephone line data communication cannot be performed at the same time.

However, on May 15, 1992, a "small power security wireless station" that can simultaneously perform wireless data communication and telephone line data communication was approved, and it became possible to use it for security purposes. .

A general system configuration diagram of this security wireless system is shown in FIG. In FIG. 1, the wireless portion is a terminal network control device 4 installed in a customer and a terminal device 7 having a built-in sensor, and wireless devices 5 and 6 are installed between them.

The "small power security wireless station" standard enables simultaneous wireless communication and telephone line communication, and also defines "carriers" specified by conventional specific low power radios for teleconverters / telemeters. "Sense" and "procedures for setting communication frequency" have been removed from the regulations, allowing users to freely set communication procedures.

That is, in the conventional specific low power radio, it was necessary to perform communication before confirming that the frequency (channel) was not used, but in the low power security radio station, I no longer need it.

[0008]

As a result, the degree of freedom in system design when constructing a security wireless system is increased, but when a plurality of security wireless systems are introduced, interference may occur due to channel competition between the systems. There was a problem that the sex increased.

The present invention has been made in view of the above,
It is an object of the present invention to provide a security wireless system capable of preventing interference between systems and performing smooth communication even when a plurality of systems are introduced.

[0010]

In order to achieve the above object, the security wireless system of the present invention is such that a terminal device is connected to a telephone line via a wireless line and the security information collected by the terminal device is connected to the wireless line and the telephone. A security wireless system for transmitting to a center device via a line, the receiving channel changing unit periodically performing an operation of sequentially changing the receiving channel of the wireless line over the entire receiving range, and the receiving channel changing unit periodically. Judgment means for judging whether or not each reception channel which is sequentially changed is used by another system, and obtaining the usage status of each reception channel, and a predetermined usage status of each reception channel obtained by the judgment means. Selection means for selecting the wireless channel with the least communication traffic volume based on the information in the period, and this selection And summarized in that and a setting means for setting a radio channel as the radio channel of the system.

The security wireless system of the present invention is a security wireless system in which a terminal device is connected to a telephone line via a wireless line and the security information collected by the terminal device is transmitted to the center device via the wireless line and the telephone line. In the system, clock means for generating an output signal for each predetermined communication time zone, and in response to the output signal of the clock means,
Receiving channel changing means for sequentially changing the receiving channel of the wireless circuit over the entire receiving range, and determining whether or not each receiving channel sequentially changed by the receiving channel changing means is used in another system, and receiving each Determining means for obtaining the usage status of the channel, selecting means for selecting the wireless channel with the least communication traffic volume based on the information of the usage status of each reception channel obtained by the determining means in a predetermined period, and the selected wireless The gist is to have setting means for setting a channel as a wireless channel of the present system.

[0012]

In the security wireless system of the present invention, it is determined whether or not each receiving channel is used by another system while periodically performing the operation of sequentially changing the receiving channel of the wireless line over the entire receiving range. The wireless channel with the least communication traffic volume is selected based on the obtained information on the usage status of each receiving channel in a predetermined period, and the selected wireless channel is set as the wireless channel of the present system.

Further, in the security wireless system of the present invention, in response to an output signal generated from the clock means at every predetermined communication time zone, the receiving channels of the wireless line are sequentially changed over the entire receiving range while each receiving channel is changed. Is used by another system, the wireless channel with the least communication traffic is selected based on the information on the usage status of each receiving channel obtained for a predetermined period, and the selected wireless channel is selected. Set as the system's wireless channel.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram showing the configuration of a master wireless device applied to the security wireless system according to the embodiment of the present invention. The master radio shown in the figure is a terminal network control device (T-NC) in the security radio system shown in FIG.
U) which constitutes the master radio 5 connected to
The parent wireless device 5 wirelessly communicates with the child wireless device 6 connected to the terminal device 7, thereby receiving security information from the terminal device 7 via the child wireless device 6, and receiving the received security information from the terminal device 7. Network control device 4, subscriber telephone line exchange 3, and automatic transmission / automatic reception network control device (AA-NC)
U) 2 is transmitted to the center device 1.

The master radio 5 shown in FIG. 2 has an antenna 51 for receiving a radio signal from the slave radio 6, and the signal received by this antenna 51 is supplied to a radio reception circuit 53 via a duplexer 52. To be done. Further, the duplexer 52 is supplied with a transmission signal from the wireless transmission circuit 54, and transmits the transmission signal to the slave wireless device 6 via the antenna 51. That is, the duplexer 52 is a circuit that prevents a signal received by the antenna 51 from sneaking into the wireless transmission circuit 54 and a transmission signal from the wireless transmission circuit 54 from sneaking into the wireless reception circuit 53, that is, a switch circuit. .

A radio reception signal supplied from the antenna 51 to the radio reception circuit 53 via the duplexer 52, that is, 40
The radio signal in the 0 MHz band is amplified by the high frequency amplifier 531 and supplied to the frequency mixer 533. Then, in the frequency mixer 533, the signal is mixed with the signal from the local oscillating section 532, and the mixed signal is supplied to the intermediate frequency amplifier 534 as an intermediate frequency signal which is a signal of the difference between the signal and the F signal.
It is supplied to the M detector 536. The FM detector 536 detects the intermediate frequency signal and extracts the radio band from the voice band (0 to 5).
Demodulate a signal of about kHz).

The voice band analog signal demodulated by the FM detector 536 is supplied to the FSK demodulation circuit 55, demodulated as a serial digital signal, that is, received data, and supplied to the control circuit 57 including a CPU.

The FM detector 536 has a built-in carrier sense circuit and has a function of discriminating whether or not a radio signal (carrier) is received on the reception channel. Further, the wireless transmission circuit 54 is supplied with a transmission channel setting signal from the control circuit 57, and thereby generates a carrier wave (400 MHz band) of the transmission channel.
The carrier wave from the local oscillator 543 is supplied to the frequency modulator 542. The frequency modulator 542 is FSK
The transmission signal converted into the analog signal in the voice band is supplied from the modulation circuit 56, and the transmission signal is supplied to the local oscillator 543.
Is mixed with a carrier wave from the RF generator to generate an FM-modulated radio transmission signal and is supplied to the power amplifier 541. The power amplifier 541 amplifies this FM-modulated radio transmission signal,
It is supplied to the antenna 51 via the duplexer 52. The FSK modulation circuit 56 converts a serial digital signal, which is the transmission data from the control circuit 57, into a voice band analog signal and supplies the analog signal to the frequency modulator 542.

The control circuit 57 can supply an arbitrary transmission channel setting signal to the local oscillating unit 543 to change the oscillation frequency of the local oscillating unit 543, thereby changing the transmitting channel freely.

Further, the control circuit 57 is connected with a channel use information storage section 58, a clock circuit 59, and a T-NCU interface circuit 50. The channel usage information storage unit 58 is a memory circuit for recording communication traffic information in another security wireless system obtained by the method described later. The clock circuit 59 includes a channel use information storage unit 5
8 has a function of notifying the control circuit 57 of a predetermined communication time zone for obtaining communication traffic information in another security wireless system recorded in 8. The T-NCU interface circuit 50 is an interface circuit for transferring communication data obtained from the terminal device 7 by wireless communication with the slave radio 6 to the terminal network control device 4.

The slave radio 6 shown in FIG. 1 does not have the channel use information storage section 58 in the circuit configuration of the master radio 5 shown in FIG. 2, and the terminal device 7 is used instead of the T-NCU interface circuit 50. The circuit configuration is the same as that of the parent wireless device 5 except that there is an interface circuit with.

FIG. 3A is a flow chart showing the operation of the parent wireless device 5 shown in FIG. That is, in this process, all the usage states of the other security wireless system are determined, the communication traffic information of the other security wireless system is obtained, and this information is recorded in the channel usage information storage unit 58. .

In the processing for obtaining the communication traffic information shown in FIG. 3A, as shown in FIG. 3B, the elapsed time is divided into a plurality of time sections t ₁ , t ₂ , t ₃ ,. Each of them is divided into t _m , the usage statuses of all the reception channels are checked within each time t, and the usage statuses thus obtained are recorded in the channel usage information storage unit 58 as shown in FIG. 3C. .

The processing of the flowchart shown in FIG. 3A will be described. In FIG. 3 (a), first, the variable i that defines the receiving channel for checking the usage status is set to 1 (step 110), the receiving channel is set to 1, and the frequency of this receiving channel 1 is set to the local part of the wireless receiving circuit 53. The control circuit 57 controls to set the oscillation frequency of the oscillator 532 (step 120). Then, in this state, while controlling the antenna 51 to receive a radio signal from another security radio system, the FM
The control circuit 57 checks the "carrier sense signal" from the carrier sense circuit of the detector 536 (step 1).
30).

If the carrier sense signal is on, it is possible to identify that another security radio system is using this channel (step 1).
40) Also, if the carrier sense signal is in the off state, it is possible to identify that other security is not using this channel (step 150), and therefore the presence or absence information of this carrier sense information, that is, the channel. The usage information or non-usage information of is stored in the channel usage information storage unit 58 (steps 140 and 150).

When the above operation is completed for the receiving channel 1, the variable i is incremented by +1 (step 1
60), the next reception channel is set, and the operation of checking whether or not another security wireless system is also used for this channel is repeated until the number of channels N (step 170). The usage statuses of other security wireless systems for all the reception channels are checked by, and the results of the usage statuses are recorded in the channel usage information storage unit 58 as shown in FIG. 3C.

After recording the usage statuses of all channels for time segment t ₁ in this way, the next time segment t ₂ is recorded.
Similarly, starting from the reception channel 1, the use statuses of all the reception channels in this time segment t ₂ are shown in FIG.
It is recorded in the channel usage information storage unit 58 as shown in (c). This operation is continuously performed for each time segment, and FIG.
Channel usage status information as shown in (c) is recorded in the channel usage information storage unit 58.

As shown in FIG. 3 (c), when the use status information of each receiving channel is recorded in the channel usage information storing unit 58 for each time segment a continuous, time as shown in FIG segment t _k To the latest time segment t _m , the usage status is accumulated for each channel, and the communication traffic amount for each channel is calculated from this. Then, of the calculated communication traffic, the channel with the least communication traffic is selected as the communication channel.

FIG. 4 shows this state. As shown in the figure, when the parent wireless device 5 receives security information such as a gas leak alarm from the terminal device 7 via the child wireless device 6, the communication channel selected as described above is referred to as “channel setting information”. Is transmitted to the slave wireless device 6, and thereby the communication channel of the slave wireless device 6 is changed.

FIG. 5 is a view similar to FIG. 3 of a security wireless system according to another embodiment of the present invention. In contrast to the embodiment shown in FIG. 3, the embodiment shown in FIG. 3 cyclically checks the usage statuses of all channels, while the embodiment shown in FIG. The only difference is that the channel usage status of only the band is recorded.

That is, as shown in FIG. 5B, predetermined communication time zones t ₁ , t ₂ , t ₃ , ... T of the day
The usage status of each channel between _m is checked, and this usage status is recorded in the channel usage information storage unit 58 as shown in FIG.

In addition, in the flowchart shown in FIG. 5A, step 1 in the flowchart shown in FIG.
Before step 10, step 105 of checking whether or not it is in a predetermined communication time zone by an output signal from the clock circuit 59.
, Except that the other functions are exactly the same.

In such an embodiment, for example, a security system that does not require urgentness, for example, a terminal device has a function of coping with abnormal conditions such as a gas shut-off function, and regularly notifies the center device of maintenance information. It is used in a system that does.

[0034]

As described above, according to the present invention,
While periodically performing the operation of sequentially changing the reception channel of the wireless line over the entire reception range, or in response to the output signal generated at every predetermined communication time zone from the clock means,
While sequentially changing the reception channels of the wireless line over the entire reception range, it is determined based on the information on the usage status of each reception channel obtained by determining whether each reception channel is being used by another system during a predetermined period. Since a wireless channel with a small amount of communication traffic is selected and this selected wireless channel is set as the wireless channel of this system, even if multiple security wireless systems are installed, interference due to channel contention with other security wireless systems will occur. Can be prevented, and smooth and efficient communication can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a security wireless system.

FIG. 2 is a block diagram showing a configuration of a parent wireless device applied to the security wireless system according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram including a flowchart showing an operation of the parent wireless device shown in FIG.

FIG. 4 is an explanatory diagram showing a communication channel changing operation in the security wireless system using the parent wireless device shown in FIG.

FIG. 5 is an explanatory diagram including a flowchart similar to FIG. 3 showing an operation of a parent wireless device applied to a security wireless system according to another embodiment of the present invention.

[Explanation of symbols]

 1 center device 3 switch 4 terminal network controller 5 master radio 6 slave radio 7 terminal device 53 radio receiver circuit 54 radio transmitter circuit 56 FSK modulation circuit 57 control circuit 58 channel usage information storage unit 59 clock circuit 532 local oscillator unit

Claims (2)

[Claims] 1. A security wireless system for connecting a terminal device to a telephone line via a wireless line and transmitting the security information collected by the terminal device to the center device via the wireless line and the telephone line. Reception channel changing means for periodically performing an operation of sequentially changing the reception channel over the entire reception range, and whether or not each reception channel which is sequentially changed by the reception channel changing means is used in another system. Judgment means for making a judgment and obtaining the usage status of each reception channel, and selection means for selecting the wireless channel with the smallest communication traffic volume based on the information of the usage status of each reception channel obtained by the judgment means in a predetermined period. And setting means for setting the selected wireless channel as a wireless channel of the present system. A security wireless system characterized in that 2. A security wireless system in which a terminal device is connected to a telephone line via a wireless line, and security information collected by the terminal device is transmitted to a center device via the wireless line and the telephone line, and a predetermined communication is performed. Clock means for generating an output signal for each time zone, receiving channel changing means for sequentially changing the receiving channel of the wireless line over the entire receiving range in response to the output signal of the clock means, and the receiving channel changing means for sequentially Judgment means for judging whether or not each reception channel to be changed is used by another system, and obtaining the usage status of each reception channel, and a predetermined period of the usage status of each reception channel obtained by the judgment means. The selection means for selecting the wireless channel with the least amount of communication traffic based on the information in A security wireless system comprising: a setting unit configured to set as a wireless channel of the system.