JP5330189B2 - Wireless disaster prevention system and radio relay node - Google Patents

Description

The present invention relates to a radio disaster prevention system and a radio wave relay node for transmitting a radio message transmitted from a sensor node such as a wireless sensor to a receiver and issuing an alarm.

  Conventionally, in a wireless disaster prevention monitoring system that monitors fires, when multiple wireless fire detectors are installed as sensor nodes in a warning area such as each floor of a building and a fire is detected by the wireless sensor Then, a message indicating a fire is wirelessly transmitted to a wireless reception repeater as a wireless disaster prevention node installed on a floor basis. In addition, a radio wave repeater that is a wireless relay node is installed on the way to relay messages from the wireless sensor.

  The radio reception repeater is connected to the sensor line from the receiver. When a message indicating a fire is received, an alarm current is sent to the sensor line when a relay contact or switching element is turned on to generate a fire alarm signal. Send to receiver. Upon receiving this fire alarm signal, the receiver issues a fire alarm by means such as sound.

  According to such a wireless disaster prevention system, a part of a sensor line generally laid on the ceiling or the like can be eliminated, wiring work is simplified, and the installation location of the sensor is also restricted by wiring. You can decide without. In addition, it can easily cope with system changes such as the addition of sensors.

  In the case of a wireless disaster prevention system, when the distance between the wireless sensor and the wireless reception repeater is long and it is expected that the radio wave will be difficult to reach, the electromagnetic wave is between the wireless sensor and the wireless reception relay. A repeater can be installed to relay radio waves. In addition, when a radio reception repeater and a wireless sensor are actually installed at the time of construction and the radio wave condition is bad, a radio wave repeater can be additionally installed later. By operating the radio wave repeater with a battery, the wiring of the power supply line is unnecessary, and the radio wave repeater can be easily installed. In this way, when the radio wave repeater is operated by a battery, the battery life is shortened if the continuous reception operation is performed. Therefore, the electronic message is intermittently received.

In this intermittent reception, when a fire is detected by a wireless sensor, a message is transmitted over a predetermined transmission time. On the other hand, the receiving side performs carrier sense in a cycle shorter than the transmission time. Since at least one carrier sense is performed during this period, even in asynchronous communication, a message can be reliably received by intermittent reception.

JP 2008-004033 A JP 2001-290209 A

  However, in the intermittent reception in such a conventional wireless disaster prevention system, the carrier sense cycle for intermittent reception is set so as to be shorter than the transmission time, so the carrier sense operation on the receiver side is short. When the operation is performed by a cycle and the operation is performed by a battery, there is a problem that current consumption increases and the battery life is reduced.

  In order to solve this problem, it is possible to lengthen the message transmission time when a fire is detected, and lengthen the carrier sense period to be set shorter than that. There is a problem that the fire response time until the transmission is determined and the carrier sense cycle of intermittent reception cannot be increased unnecessarily.

An object of the present invention is to provide a radio disaster prevention system and a radio relay node that can reduce power consumption by extending a carrier sense period for intermittent reception without affecting fire response time.

(system)
The present invention is composed of a sensor node, a radio relay node, a radio disaster prevention node, and a receiver. The telegram signal transmitted from the sensor node or the telegram signal transmitted from the sensor node via the radio relay node is transmitted to the radio disaster prevention node. In the wireless disaster prevention system that receives and processes the data at the receiver and transmits the processing result to the receiver connected by the signal line.
The sensor node includes an intermittent transmission unit that intermittently transmits by repeating a predetermined message transmission time for continuously transmitting the same message signal and a message suspension time for stopping the message transmission,
The radio relay node
A carrier sense period for setting a carrier sense period when performing a carrier sense N times so that a predetermined carrier sense essential time overlaps at least one of N times of message transmission times that are a plurality of times consecutively across the message pause time. A setting section;
An intermittent reception unit that detects the presence or absence of a carrier of a telegram signal for each carrier sense cycle and processes a telegram received when the carrier detection state continues for a carrier sense essential time or more,
It is provided with.

Here, the carrier sense cycle setting unit
The message transmission time is T1, the message suspension time is T2, the receivable time obtained by subtracting the minimum carrier sense essential time T5 necessary for the reception operation from the message transmission time T1 is T3 (= T1-T5), and the message suspension time T2 is the carrier. When the unreceivable time including the required sense time T5 is T4 (= T2 + T5),
Receivable time T3 and unreceivable time T4 (T3 × N) / {T3 × N + T4 × (N−1)} ≧ 1 / N
The carrier sense period Tcs is {T3 × N + T4 × (N−1)} / N ≧ Tcs ≧ T4 / (N−1)
Set to the range.

For example, when N = 2 times, the carrier sense cycle setting unit sets (T3 × 2) / (T3 × 2 + T4) ≧ 1/2 for the receivable time T3 and the unreceivable time T4.
The carrier sense period Tcs is set to (T3 × 2 + T4) / 2 ≧ Tcs ≧ T4 on the condition that
Set to the range.

For example, when N = 3 times, the carrier sense cycle setting unit sets the receivable time as T3 and the unreceivable time T4, and sets the receivable time as T3 and the unreceivable time T4 (T3 × 3) / (T3 × 3 + T4). × 2) ≧ 1/3
The carrier sense period Tcs is set to (T3 × 3 + T4 × 2) / 3 ≧ Tcs ≧ T4 / 2 on the condition that
Set to a value in the range.

  The carrier sense essential time T5 is a minimum necessary time from when a carrier is detected until a message can be received effectively.

(Radio relay node)
The present invention receives a radio signal intermittently transmitted from a sensor node by repeating a predetermined message transmission time for continuously transmitting the same message signal and a message pause time for suspending message transmission, and relays them to a radio disaster prevention node. In the relay node,
A carrier sense cycle setting unit that sets a carrier sense cycle so that a predetermined carrier sense essential time overlaps at least one of N times of message transmission times that are a plurality of times that are consecutive with a message pause time in between;
An intermittent receiving unit that detects the presence or absence of a carrier of the telegram signal for each carrier sense period and processes a telegram received when the carrier detection state continues for a carrier sense essential time or more;
It is provided with. The determination of the carrier sense period is the same as in the case of the wireless disaster prevention system.

  According to the present invention, in response to intermittent transmission by repeating a predetermined message transmission time for continuously transmitting a message signal and a message suspension time for suspending message transmission, for example, two message transmissions continuously with a message pause time in between By setting the carrier sense cycle for intermittent reception so that the required carrier sense time overlaps with one of the time, carrier sense operation is performed in a cycle longer than the message transmission time, reducing the power consumption by carrier sense When operating with a battery, the battery life can be extended.

Also, even if the fire response time from the detection of the fire to the alarm is determined, the message can be received and processed effectively at any one of the two message transmission times that are continuous with the message pause time in between. Even if the carrier sense period exceeds the message transmission time, intermittent reception that sufficiently satisfies the fire response time constraint can be achieved.

Explanatory drawing which showed embodiment of the wireless disaster prevention system by this invention Explanatory drawing which showed the message format of the radio signal transmitted and received by the radio disaster prevention system of FIG. The block diagram which showed the detail of the wireless sensor and radio wave repeater of FIG. The block diagram which showed the detail of the repeater for radio | wireless reception of FIG. 1, and a P-type receiver Time chart showing intermittent message transmission by wireless sensor Time chart showing the intermittent reception processing by the radio wave repeater of FIG. 3 that effectively receives two transmission messages Time chart showing the case of effectively receiving the second transmission message in the intermittent reception of FIG. Time chart showing the intermittent reception processing by the radio wave repeater of FIG. 3 that effectively receives three transmission messages Time chart showing the intermittent reception process when the third transmission message is effectively received in the intermittent reception of FIG. The flowchart which showed the sensor process by the wireless sensor of FIG. The flowchart which showed the electric wave relay process by the electric wave repeater of FIG. The flowchart which showed the detail of the intermittent reception process by step S13 of FIG. The flowchart which showed the relay process for radio | wireless reception by the radio | wireless receiver repeater of FIG.

  FIG. 1 is an explanatory view showing an embodiment of a wireless disaster prevention system according to the present invention. In FIG. 1, wireless reception repeaters 12-1 to 12-3 functioning as wireless disaster prevention nodes are installed on the first floor of a building 11 to be monitored and pulled out from the P-type receiver 10, which is a fire receiver, by floor. Connected to the sensor lines 18-1 to 18-3.

  Wireless sensors 16-11 to 16-14, 16-21 to 16-24, and 16-31 to 16-34 functioning as sensor nodes are installed on the floors 1F to 3F. Further, in the present embodiment, the radio wave repeater 14 is used to prevent the radio reception repeaters 12-1 to 12-3 from reaching non-reachable signals due to the attenuation of radio waves from the radio sensors that are separated from each other. -1 to 14-3 are installed.

  In each of the wireless sensors 16-11 to 16-34 and the radio wave repeaters 14-1 to 14-3, unique node IDs using device IDs are registered in advance.

  The wireless reception repeaters 12-1 to 12-3, the radio wave repeaters 14-1 to 14-3, and the wireless sensors 16-11 to 16-34 have a wireless network built by floor. For each floor, a network address (hereinafter simply referred to as “address”) is set.

  The wireless sensors 16-11 to 16-14 determine a fire when the smoke concentration or temperature due to the fire exceeds a predetermined threshold, and intermittently send a telegram signal indicating the fire (hereinafter simply referred to as a "telegram"). Wireless transmission.

  In this intermittent transmission, for example, the same telegram data is transmitted 18 times continuously for a predetermined transmission time T1, and is repeated three times with a predetermined transmission pause time T2, and then the transmission is unique to the wireless sensor. The transmission operation of transmitting the same message data 18 times continuously over the predetermined transmission time T1 is repeated three times with the predetermined transmission pause time T2 in the same manner, with one random pause time T6. The transmission operation is as follows.

  In each of the radio wave repeater 14-1 and the radio reception repeater 12-1, a node ID for specifying a transmission source as a child node that receives a message based on the parent-child relationship is registered in advance. That is, node IDs of the wireless sensors 16-13 and 16-14 and the radio relay 14-1 that are child nodes are registered in advance in the wireless reception repeater 12-1. Also, node IDs of the wireless sensors 16-11 and 16-12 that are child nodes are registered in advance in the radio wave repeater 14-1.

  The same applies to the 2F and 3F wireless reception repeaters 12-2 and 12-3 and the radio wave repeaters 14-2 and 14-3, and the wireless reception repeater 12-2 includes the wireless sensor 16-. 23, 16-24 and the node IDs of the radio repeaters 14-2 are registered in advance, and the radio repeater 14-2 registers the node IDs of the wireless sensors 16-21 and 16-22, and the radio reception repeaters 12-3 registers the node IDs of the wireless sensors 16-33 and 16-34 and the radio relay 14-3, and the radio relay 14-3 stores the node IDs of the wireless sensors 16-31 and 16-32. Is registered.

  When a telegram is received by registering the node ID for the radio reception repeater 12-1 and the radio repeater 14-1, the transmission source ID included in the telegram is compared with the node ID registered in advance. For example, when both match, it is processed as a valid message.

  Furthermore, in the present embodiment, the wireless reception repeater 12-1 receives directly from the wireless sensors 16-11 and 16-12 that are not in a parent-child relationship without going through the radio wave repeater 14-1. In order to enable processing as a valid electronic message, the registered node ID is transferred from the radio wave repeater 14-1 to the wireless reception repeater 12-1, and is additionally registered. Even when a message is received directly from the wireless sensors 16-11 and 16-12 that are not assigned as child nodes in the device 12-1, a match with the additionally registered node ID is determined and a valid message is received. Can be processed as.

  The radio repeater 14-1 performs intermittent reception. In this intermittent reception, the presence or absence of a telegram carrier transmitted from the wireless sensors 16-11 and 16-12 is detected every predetermined carrier sense period Tcs, and when a carrier is detected, a reception operation is performed. The carrier sense period Tsc is determined so that a message can be received effectively in one of two transmission times T1, for example, with a transmission pause time T2 transmitted from the wireless sensors 16-11 and 16-12 in between. ing. The details of this carrier sense period Tcs will be clarified in later explanation.

  When the radio wave repeater 14-1 receives a message from the wireless sensors 16-11 and 16-12 by intermittent reception, the radio wave repeater 14-1 compares the transmission source ID of the message with the registered node ID. When they match, they are relayed and transmitted to the wireless reception repeater 12-1 as an effective message. The transmission of the relay message from the radio wave repeater 14-1 repeats the transmission operation of transmitting the same message data, for example, four times continuously over a predetermined transmission time, three times with a predetermined transmission pause time.

  The wireless reception repeater 12-1 is always in a receiving state, and when receiving a message from the wireless sensors 16-13 and 16-14 assigned as child nodes, The registered node ID is compared, and when both match, the received message is processed as valid, and the processing result is transmitted to the P-type receiver 10.

  When the received electronic message is a message indicating a fire from the wireless sensor, the wireless reception repeater 12-1 sends a notification current as a contact output to the sensor line 18-1 to the P-type receiver 10. A fire alarm signal is transmitted by flowing.

  The wireless reception repeater 12-1 is registered in advance with the transmission source ID included in the electronic message even when the electronic message is received from the wireless sensors 16-11 and 16-12 via the radio wave repeater 14-1. The received message is received as a valid message by matching the received node ID, and the reception result is transmitted to the P-type receiver 10.

  Further, the wireless reception repeater 12-1 is additionally registered with the transmission source ID of the received message even when the message is directly received from the wireless sensors 16-11 and 16-12 which are not assigned. Compared with the node ID, if both match, the message is processed as a valid message, and the processing result is transmitted to the P-type receiver 10.

  In the present embodiment, it is monitored that the radio wave repeater 14-1 and the wireless sensors 16-11 to 16-14 are operating normally, i.e., no carry-out or battery exhaustion has occurred. Therefore, each of the nodes periodically transmits a periodic notification message.

  In response to the transmission of the periodic notification message from the wireless sensors 16-11 to 16-14 and the radio wave repeater 14-1, the wireless reception repeater 12-1 matches the node ID registered with the transmission source ID of the message. When the message is received as a valid message, the periodic notification timer provided for each registered node ID is reset and started. However, if the periodic notification timer expires after a predetermined period of time without receiving a periodic notification message, it is determined that the node is not operating properly and the periodic notification is abnormal. Notify the receiver 10 of the occurrence of a failure.

  For example, the failure occurrence notification notifies the occurrence of a failure due to abnormal periodic notification by disconnecting the terminal resistor connected to the sensor line 18-1 from the P-type receiver 10 to create a pseudo disconnection state.

  FIG. 2 is an explanatory diagram showing a message format of a message transmitted and received by the wireless disaster prevention system of FIG.

  FIG. 2 is an explanatory view showing a message transmitted and received by the wireless disaster prevention system of FIG. In FIG. 2, the message format 90 includes a phase correction signal 92, a serial number 94, a transmission source ID 96, a message content 98, and an error check code 100. The phase correction signal 92 is a preamble signal that repeats with a predetermined bit length of “101010... 10”, whereby preparation for reception by phase synchronization of a reception PLL provided in the wireless communication unit can be performed.

  The serial number 94 stores a value that changes in order in the range of 0 to 255 for each transmission of the message, and the receiving side can know the order of the message transmission. In the transmission source ID 95, the node ID of the device that is the transmission source is set, and in the present embodiment, for example, it is 32-byte data. In the message content 98, fire information, failure information, and the like are set.

  In FIG. 3, a wireless sensor 16-11 as a sensor node includes a processor 20, a wireless communication unit 22, an antenna 24, a sensor unit 26, an operation unit 28 using a dip switch, and a battery 30. The sensor unit 26 is a temperature detection unit using, for example, a photoelectric smoke sensing unit or a thermistor.

  The processor 20 is provided with a sensor processing unit 74 and an intermittent transmission processing unit 76 as functions realized by executing the program. The sensor processing unit 74 compares, for example, a smoke concentration detection signal output from the sensor unit 26 with a predetermined threshold value, determines that a fire has occurred when the threshold value is exceeded, and sends a message indicating the fire from the antenna 24 from the wireless communication unit 22. Wireless transmission.

  Further, when the registration mode is set by the dip switch or the like of the operation unit 28, the sensor processing unit 74 transmits an activation message or a test message in which the node ID known as the device ID is set as the transmission source ID, and the radio wave repeater 14-1 To register the node ID.

  The intermittent transmission processing unit 76 performs intermittent transmission of a transmission message when a transmission event such as fire detection or periodic notification occurs. As shown in FIG. 5, this intermittent transmission includes a transmission operation of transmitting transmission telegrams 110-1 to 110-3 including, for example, 18 pieces of identical telegram data 112-1 to 112-18 over a predetermined transmission time T1. , Repeated three times with a predetermined transmission pause time T2, and then a random pause time T6 unique to the wireless sensor is provided, and similarly, transmission messages 110-4 to 110-6 including 18 identical message data are The transmission operation for transmitting over the transmission time T1 is repeated three times with a predetermined transmission pause time T2, and this is set as one set of transmission operation. The random pause time T6 is randomly determined based on the transmission source ID and the like, for example, in a range of 3 to 7 seconds.

  Referring to FIG. 3 again, the wireless communication unit 22 is provided with a transmission circuit 22a, and in the case of Japan, for example, performs wireless communication in accordance with the standard of a specific low power wireless station in the 400 MHz band. Note that the wireless sensor 16 only transmits a telegram to the receiver side, and therefore no receiving circuit is provided in this embodiment.

  Further, the channel frequency of the wireless communication unit 22 uses any one of four channel frequencies f1 to f4 that can be used in the specific low power wireless station standard of the 400 MHz band. The channel frequencies may be the same on each floor in FIG. 1, or different channel frequencies may be used on adjacent floors, for example, to avoid interference.

  Next, the radio repeater 14-1 will be described. The radio wave repeater 14-1 includes a processor 32, a wireless communication unit 34 including a reception circuit 34a and a transmission circuit 34b, an antenna 35, an operation unit 36, a display unit 37, a memory 38, and a power supply unit 40. The processor 32 is provided with a carrier sense cycle setting unit 78, an intermittent reception processing unit 80, and a relay processing unit 82 as functions realized by executing the program.

  When the relay processing unit 82 starts using the radio wave repeater 14-1 by operating a registration switch provided in the operation unit 36, the relay processing unit 82 is assigned to the relay control table 84 of the memory 38 as shown in FIG. The node IDs of the wireless sensors 16-11 and 16-12 shown are registered.

  Also, each time the relay processing unit 82 registers the assigned node IDs of the wireless sensors 16-11 and 16-12 in the relay control table 84 in FIG. It is transferred to the device 16-1 by a registration message, and additional registration is performed on the wireless reception repeater 16-1.

  Further, in the monitoring state after the registration of the node ID to the relay control table 66 is completed, the relay processing unit 82 transmits the fire message, the periodic notification message, etc. transmitted from the wireless sensor by the wireless communication unit 34 to the intermittent reception processing unit 80. When the message is received, the transmission source ID included in each message is acquired and compared with the node ID registered in the relay control table 66. When the two match, the received message is relayed and transmitted. In this case, relay transmission is not performed.

  When the transmission message 110-1 to 110-6 shown in FIG. 5 is transmitted from the wireless sensor 16-11, the carrier sense period setting unit 78, for example, performs two consecutive times with the message suspension time T2 interposed therebetween. The carrier sense cycle Tcs is set so that at least one of the message transmission times T1 of the transmission messages 110-1 and 110-2 overlaps with the minimum required carrier sense time T5 required for the reception operation.

  The intermittent reception processing unit 80 detects the presence / absence of a carrier by a transmission message for each carrier sense cycle Tcs, and processes the received message when the carrier detection state continues for the carrier sense required transmission time T5 or more.

  The power supply unit 40 uses a battery power supply in principle, but may be supplied with power from the P-type receiver 10.

  FIG. 6 is a time chart showing the intermittent reception processing by the radio wave repeater of FIG. 3 that effectively receives two transmission telegrams in the wireless sensor 16-11 of FIG.

  FIG. 6A shows a transmission message, which shows transmission messages 110-1 and 110-2 at the beginning of one set of transmission messages, and the transmission messages 110-1 and 110-2 are the transmission time T1. There is a pause time T2 in between.

  In the present embodiment, the carrier sense period Tcs is set so that a message can be effectively received once by N = 2 times of carrier sense with respect to N = 2 times of transmitted messages 110-1 and 110-2. ing.

  The calculation method of such a carrier sense period is as follows. First, the minimum required time from the start of carrier sense until the message can be received successfully is set as a carrier sense essential time T5. The required carrier sense time T5 includes the setting time of the receiving IC that is performed after it is understood that there is a radio wave by carrier sensing, and the time required for reception of the wireless message, and depends on the specification of the receiving IC to be used and the message length. For example, T5 = 0.5 sec.

Here, if the carrier sense is not started within the time (T1-T5) obtained by subtracting the carrier sense essential time T5 from the transmission time T1 of the transmission telegrams 110-1 and 110-2, the reception cannot be performed. The time is defined as a receivable time T3. That is, the receivable time T3 is
T1-T5 = T3
It becomes.

On the other hand, since a message cannot be received in the time zone obtained by adding the transmission suspension time T4 to the carrier sense essential time T5, this is referred to as a reception impossible time T4. Unreceivable time T4 is
T2 + T5 = T4
It becomes.

  FIG. 6B shows a receivable state 114-1, 114-2 determined by the receivable time T3 for the transmission signals 110-1, 110-2 in FIG. 6A, and a receivable impossible determined by the unreceivable time T4. States 116-1 and 116-2 are shown as reception enable / disable states.

First, in order to reduce the power consumption by the carrier sense operation, the carrier sense cycle Tcs is set longer than the transmission time T1 of the transmission message,
Tcs> T1 (1)
It is necessary to decide to become.

Next, if the carrier sense period Tcs is not equal to or longer than the unreceivable time T4, it cannot be received with at least two carrier senses.
Tcs ≧ T4 (2)
It becomes.

This is because, if it Tcs <T4, because the carrier sense timing in the received impossible time T4 will be entered more than once, because can not be received by the carrier sense twice.

Subsequently, in order to have at least two carrier sense timings before two receivable times T3,
Tcs ≦ (T3 × 2 + T4) / 2 (3)
It is necessary to.

However, when receiving with carrier sense twice,
{T3 × 2 / (T3 × 2 + T4)} ≧ (1/2) (4)
It must be. The (4) of the condition, because once out carrier sense two must be performed on the received available time T3, two sandwiching the transmission impossible time T4 containing two ready time T3 This is because ½ or more of the time (T3 × 2 + T4) over the communication telegrams 110-1 and 110-2 must be the receivable time.

That is, when formulas (2) and (3) are put together, the carrier sense period Tcs is
T4 ≦ Tcs ≦ (T3 × 2 + T4) / 2 (5)
It becomes.

  The carrier sense period Tcs can be determined based on the above equations (1) to (5).

As a specific example, transmission time T1 = 2 sec
Transmission pause time T2 = 2sec
Carrier sense required time T5 = 0.5 sec
Receivable time T3 = T1-T5 = 1.5 sec
Unreceivable time T4 = T2 + T5 = 2.5 sec
In this case, it is calculated as follows.
From Equation (1), Tcs> 2 sec
From equation (2) Tcs ≧ 2.5 sec
From Equation (3), Tcs ≧ (1.5 × 2 +2.5) / 2
Tcs ≦ 2.75sec
From equation (4), 0.55 ≧ 0.5, which is also satisfied.

The carrier sense period Tcs satisfying the expressions (1), (2), and (3) is 2.5 sec ≦ Tcs ≦ 2.75 sec.
It becomes. Here, since the longer carrier sense period Tcs can reduce power consumption, it is preferable to take a longer one. For example, T = 2.7 sec.

  FIG. 6C shows carrier sense timings 118-1 to 118-4 with the carrier sense period Tcs = 2.7 sec determined as described above, and the carrier sense timing 118-1 is the transmission telegram 110-1. The case where it coincides with the start timing is taken as an example.

  In this case, as shown in the message reception in FIG. 6D, since the message can be received by the carrier sense based on the carrier sense timing 118-1 for the time longer than the carrier sense essential time T5, the reception can be completed.

  FIG. 7 shows a case where the same carrier sense period Tcs = 2.7 sec as in FIG. 6 is set. However, as shown in FIG. 7C, the carrier sense timing 118- is set for the first transmission telegram 110-1. 1 shows a state in which the message cannot be received because the carrier sense timing 118-2 is appropriate for the second transmission message 110-2 and the message is received.

  In this case, the reception preparation operation is started at the carrier sense timing 118-1 for the first transmission telegram 110-1, but the reception operation is effectively performed because the reception for the carrier sense essential time T5 cannot be performed. Absent. However, at the next carrier sense timing 118-2, the message can be received for a time equal to or longer than the carrier sense essential time T5, so that the reception can be completed.

  Such determination of the carrier sense period Tcs is a method of determining the carrier sense period Tcs so that a message can be effectively received once by N times of carrier sense with respect to N transmission messages 110-1 and 110-2. Can be generalized as:

  Generalizing equations (1) to (5) gives the following.

Formula (1) is directly Tcs> T1 (6)
Equation (2) is expressed as Tcs × (N−1) ≧ T4 (7)
It becomes.

Equation (3) is expressed as Tcs ≦ {T3 × N + T4 × (N−1)} / N (8)
It becomes.

Furthermore, conditional expression (4) is
(T3 × N) / {T3 × N + T4 × (N−1)} ≧ 1 / N (9)
It becomes.

And the expression (5) that summarizes the expressions (7) and (8) is
{T3 × N + T4 × (N−1)} / N ≧ Tcs ≧ T4 / (N−1) (10)
It becomes.

  FIG. 8 is a time chart showing intermittent reception with a carrier sense period Tcs for always receiving a message with N = 3 carrier senses for N = 3 message transmissions.

The carrier sense period Tcs when N = 3 is given by substituting N = 3 into the general formulas (6) to (10).
Tcs> T1 (11)
Tcs × 2 ≧ T4 (12)
Tcs ≦ (T3 × 3 + T4 × 2) / 3 (13)
T3 × 3 / (T3 × 3 + T4 × 2) ≧ 1/3 (14)
(T3 × 3 + T4 × 2) / 3 ≧ Tcs ≧ T4 / 2 (15)

As a specific example, transmission time T1 = 2 sec
Transmission pause time T2 = 2sec
Carrier sense required time T5 = 0.5 sec
Receivable time T3 = T1-T5 = 1.5 sec
Unreceivable time T4 = T2 + T5 = 2.5 sec
In this case, it is calculated as follows.

First, Tcs> 2.0 sec from equation (11)
From Equation (12), Tcs ≧ 1.25 sec
From formula (13), Tcs ≦ (1.5 × 3 + 2.5 × 2) / 3
Tcs ≦ 3.17
Expression (14) satisfies 0.47 ≧ 0.33, which is also satisfied.

Therefore, the carrier sense period Tcs is 2.0 sec ≦ Tcs ≧ ≦ 3.17 sec from the equations (11), (12), and (13).
For example, Tcs = 3.0 sec is determined.

  In the case of receiving with two carrier senses for two transmission messages with N = 2 shown in FIGS. 6 and 7, the longest carrier sense period was 2.75 sec, but N = 3 In the case of receiving with one of the three carrier senses for the three transmitted telegrams, the longest carrier sense period is 3.17 sec, which can reduce the power consumption and extend the battery life. Since reception is performed by the third carrier sense at the longest, the average time until reception becomes long. Therefore, when priority is given to reducing power consumption, the carrier sense period is determined with N = 3, and when priority is given to shortening the reception average time, the carrier sense period may be determined with N = 2.

  FIG. 8C shows carrier sense timings 132-1 to 132-4 with the carrier sense period Tcs = 3.0 sec determined as N = 3, and the carrier sense timing 132-1 is the start of the transmission telegram 110-1. The case where it coincides with the timing is taken as an example.

  In this case, as shown in the message reception in FIG. 8D, the message can be received by the carrier sense based on the carrier sense timing 132-1, so that the message can be received for the time longer than the carrier sense essential time T5.

  FIG. 9 shows the same carrier sense cycle Tcs = 3.0 sec as in FIG. 8, but for the first and second transmission telegrams 110-1 and 110-2 as shown in FIG. 9C. Although the carrier sense timings 132-1 and 132-2 are shifted and cannot be received, the carrier sense timing 132-3 is appropriate for the third transmission telegram 110-3 and the message reception is performed.

  In this case, the reception preparation operation 142 is started at the carrier sense timing 132-2 for the second transmission telegram 110-2, but the reception operation is effective because the reception for the carrier sense essential time T5 cannot be performed. Not done. However, at the next carrier sense timing 132-3, the message can be received for a time equal to or longer than the carrier sense essential time T5, so that the reception can be completed.

  Next, the P-type receiver 10 of FIG. 4 will be described. In FIG. 4, a P-type receiver 10 includes a processor 58 functioning as a control unit, line receiving units 60-1 to 60-3, a power supply unit 62, a display unit 64, an acoustic alarm unit 66, an operation unit 68, a transfer report. Unit 70 and nonvolatile memory 72. In addition, the operation power supply uses the commercial power supply appropriately backed up (not shown).

  As shown in FIG. 1, sensor lines 18-1 to 18-3 are drawn from the line receiving units 60-1 to 60-3, respectively, and the wireless reception repeater 16-1 is connected to the sensor line 18-1. Is connected.

  The line receiving unit 60-1 detects the alarm current that flows through the contact operation by the wired communication unit 48 provided in the wireless reception repeater 16-1, and outputs a fire detection signal to the processor 58. Further, disconnection of the terminating resistor in the wired communication unit 48 of the wireless reception repeater 16-1 is detected as an interruption of the monitoring current when the actual sensor line is disconnected, and a failure detection signal is output to the processor 58.

  The processor 58 includes a CPU, a ROM, a RAM, an AD conversion port, and various input / output ports, and realizes the function of the fire monitoring unit 88 by executing a program by the CPU.

  The fire monitoring unit 88 determines that the fire detection signal of the corresponding sensor line is generated when the reception output of the fire alarm signal is obtained by detecting the alarm current by any of the line reception units 60-1 to 60-3, A representative fire display is displayed on the display unit 64, and a district display is performed for each line. An acoustic fire alarm is output from the acoustic alarm unit 66.

  In addition, when the line monitoring units 60-1 to 60-3 detect the disconnection of the sensor lines 18-1 to 18-3, the fire monitoring unit 88 displays a representative failure on the display unit 64 and generates a failure. The district is displayed for each line, and an acoustic failure warning is output from the acoustic warning unit 84.

  FIG. 10 is a flowchart showing sensor processing by the wireless sensor 16-11 of FIG. 2, and is realized by execution of a program by the processor 20. In FIG. 10, after initialization and self-diagnosis are performed in step S1, the sensor process proceeds to step S2 if normal, and determines the presence or absence of fire detection. At this time, if, for example, a smoke detection signal from the sensor unit 26 exceeds a predetermined threshold value, a fire is determined, and a fire telegram is intermittently transmitted in step S3 as shown in FIG.

  Subsequently, in step S4, it is determined whether or not the periodic notification timer has expired. If it is determined that the periodic notification timer has expired, the periodic notification message is intermittently transmitted in step S5, and then the periodic notification timer is reset in step S6. Start.

  In sensor processing, in addition to fire and periodic notifications, a message such as a failure or recovery is transmitted, but this is omitted.

  FIG. 11 is a flowchart showing the radio wave relay process by the radio wave repeater 14-1 in FIG. 2, which is a process realized by executing a program by the processor 32.

  In FIG. 11, in the radio wave relay process, after performing initialization and self-diagnosis upon power-on in step S11, if there is no abnormality, registration process of the relay control table 84 is executed in step S12.

  When the registration process in step S12 is completed, the monitoring state is entered, and the intermittent reception process based on the carrier sense period Tcs set in step S13 is performed. Details of this intermittent reception processing are shown in FIG.

  Subsequently, in step 14, it is determined whether or not the message has been received effectively. If the message has been received, the process proceeds to step S15 where the received message is analyzed, and the transmission source ID and relay control table obtained from the message in step S16. If the node ID of the table registration registered in 84 is compared to determine a match, the process proceeds to step S17 as a valid received message, and the received message is relayed and transmitted.

  Subsequently, in step S18, it is determined whether or not the periodic notification timer has timed up. If it is determined that the time has expired, a periodic notification message is transmitted in step S19, then the periodic notification timer is reset and started in step S20, and step S13. Return to.

  FIG. 12 is a flowchart showing details of the intermittent reception process in step S13 of FIG. In FIG. 12, in the intermittent reception process, the arrival at the carrier sense period Tcs is determined at step S21. When the arrival at the carrier sense period Tcs is determined, the process proceeds to step S22 to determine presence / absence of carrier sense.

  When the carrier sense is determined in step S22, the process proceeds to step S23 to start the reception preparation operation. If the reception preparation operation is in progress, no carrier sense is detected in step S25 until completion of the reception preparation operation is determined in step S24. It is determined whether or not. If the transmission telegram ends before the completion of the reception preparation operation and it is determined in step S25 that there is no carrier sense, the process proceeds to step S32 to determine the telegram reception failure.

  If it is determined in step S24 that the reception preparation operation is completed without receiving the carrier sense during the reception preparation operation, the first message data is received in step S26, and then the second message data is received in step 27. In step S28, the received data is collated for the first time and the second time. If the message match is determined in step S29, the message reception is successful in step S30, and the message data received in step S31 is held. If the message data does not match in step S29, the process proceeds to step S32 and it is determined that the message reception has failed.

  FIG. 13 is a flowchart showing the wireless reception relay process by the wireless reception repeater 16-1 of FIG. In FIG. 13, when the radio reception repeater 12-1 is turned on, initialization and self-diagnosis are executed in step S41. If there is no abnormality, registration processing of the relay control table 87 is executed in step S42. .

  When the registration process ends, the monitoring state is entered, and in step S43, it is determined whether or not there is a valid message reception in which the transmission source ID of the received message matches the node ID of the table registration. If it is determined in step S43 that a valid message has been received, the message is analyzed in step S44, and if a fire alarm is determined in step S47, a notification current is passed through the contact output to the sensor line 18 in step S46. A fire alarm signal is transmitted to the machine 10 to output a fire alarm.

  If it is determined in step S47 that the message is a periodic notification message, the process proceeds to step S48 to reset and start the periodic notification timer of the corresponding node specified by the transmission source ID.

  Subsequently, in step S49, it is checked whether or not there is a periodic notification timer that has timed up. If there is a periodic notification timer that has timed out, it is determined in step S50 that the periodic notification is abnormal, and the sensor line 18 is set in a pseudo disconnection state. Thus, a failure signal is sent to the P-type receiver 10 to output a failure alarm.

  In the above embodiment, the intermittent reception of the radio wave repeater with respect to the intermittent transmission from the wireless sensor is taken as an example, but it is the same as the reception operation with the radio reception repeater for the intermittent transmission for relaying from the radio wave repeater. Intermittent reception may be applied.

  Moreover, although this invention took the radio | wireless disaster prevention system as an example, it is not limited to this, It can apply to the intermittent transmission of the transmission node in the appropriate radio | wireless system, and the intermittent reception of a reception node.

  In the above embodiment, a wireless reception repeater is connected to a sensor line from a P-type receiver as a fire receiver, but a wireless reception repeater is connected to an R-type receiver having a data transmission function. It may be.

  In addition, the flowcharts in the above-described embodiments have described a schematic example of processing, and the order of processing is not limited to this. Further, it is possible to provide a delay time between each process or between processes, insert another determination, or the like.

  The failure alarm output method shown in the above embodiment is merely an example, and other methods may be adopted.

The present invention includes appropriate modifications that do not impair the objects and advantages thereof, and is not limited by the numerical values shown in the above embodiments.

10: P-type receivers 12-1 to 12-3: Radio reception repeaters 14-1 to 14-3: Radio wave repeaters 15: Power supply lines 16-11 to 16-34: Wireless sensors 18-1 to 18-1 18-3: Sensor lines 20, 32, 42, 58: Processors 22, 34, 44: Wireless communication units 24, 35, 46: Antenna 26: Sensor units 28, 36, 50, 68: Operation unit 30: Battery 38 , 54: Memory 40, 56, 62: Power supply unit 48: Wired communication unit 52, 64: Display unit 60-1 to 60-3: Sensor line 66: Acoustic alarm unit 70: Transfer unit 72: Non-volatile memory 74: Sensor processing unit 76: intermittent reception processing unit 78: carrier sense cycle setting unit 80: intermittent reception processing unit 82: relay processing unit 84, 87: relay control table 86: reception processing unit 88: fire processing unit 90: message format 110- 1-110- : Send message 112-1～112-18: data telegram 114-1～114-4: carrier sense timing 120: Receive a preparation operation 122: message receiving operation

Claims (8)

The radio disaster prevention node includes a sensor node, a radio relay node, a radio disaster prevention node, and a receiver, and receives a telegram signal transmitted from the sensor node or a telegram signal transmitted from the sensor node via the radio relay node. In the wireless disaster prevention system that transmits the processing result to the receiver connected by a signal line,
The sensor node includes an intermittent transmission unit that transmits intermittently by repeating a predetermined message transmission time for continuously transmitting the same message signal and a message suspension time for stopping message transmission,
The radio wave relay node is
Carrier sense for setting a carrier sense cycle when performing carrier sense N times so that a predetermined carrier sense essential time overlaps at least one of N times of message transmission times that are consecutive multiple times across the message pause time. A cycle setting unit;
An intermittent receiving unit that detects the presence or absence of a carrier of the telegram signal for each carrier sense period, and processes a telegram received when a carrier detection state continues for the carrier sense essential time or more ,
The carrier sense cycle setting unit
The message transmission time is T1, the message suspension time is T2, the receivable time obtained by subtracting the minimum carrier sense required time T5 required for the reception operation from the message transmission time T1 is T3, and the message suspension required time is set to the message suspension time T2. When the reception impossible time including T5 is T4,
Receivable time T3 and unreceivable time T4
(T3 × N) / {T3 × N + T4 × (N−1)} ≧ 1 / N
On the condition that the carrier sense period Tcs is satisfied.
{T3 × N + T4 × (N−1)} / N ≧ Tcs ≧ T4 / (N−1)
A wireless disaster prevention system characterized in that it is set to a value in the range .
In the wireless disaster prevention system according to claim 1 ,
In the case where N = 2 times, the carrier sense cycle setting unit sets (T3 × 2) / (T3 × 2 + T4) ≧ 1/2 for the receivable time T3 and the unreceivable time T4.
If the above condition is satisfied, the carrier sense period Tcs is set to (T3 × 2 + T4) / 2 ≧ Tcs ≧ T4
A wireless disaster prevention system characterized in that it is set to a value in the range.
In the wireless disaster prevention system according to claim 1 ,
When N = 3 times, the carrier sense cycle setting unit sets the receivable time as T3 and the unreceivable time T4. As the receivable time as T3 and the unreceivable time T4, (T3 × 3) / (T3 × 3 + T4). × 2) ≧ 1/3
If the above condition is satisfied, the carrier sense period Tcs is set to (T3 × 3 + T4 × 2) / 3 ≧ Tcs ≧ T4 / 2
A wireless disaster prevention system characterized in that it is set to a value in the range.
The wireless disaster prevention system according to any one of claims 1 to 3 , wherein the carrier sense essential time is a minimum necessary time until a message can be effectively received after detecting the carrier. Wireless disaster prevention system.
A radio relay node that receives a message signal transmitted intermittently by repeating a predetermined message transmission time for continuously transmitting the same message signal and a message suspension time for stopping the message transmission from the sensor node and relays them to the radio disaster prevention node. In
Carrier sense for setting a carrier sense cycle when performing carrier sense N times so that a predetermined carrier sense essential time overlaps at least one of N times of message transmission times that are consecutive multiple times across the message pause time. A cycle setting unit;
Wherein detecting the presence or absence of a carrier of the message signal, and a discontinuous reception unit carrier detection state to process message received when continuing the carrier sense essential hours or more for each of the carrier sensing period,
The carrier sense cycle setting unit
The message transmission time is T1, the message suspension time is T2, the receivable time obtained by subtracting the minimum carrier sense required time T5 required for the reception operation from the message transmission time T1 is T3, and the message suspension required time is set to the message suspension time T2. When the reception impossible time including T5 is T4,
Receivable time T3 and unreceivable time T4
(T3 × N) / {T3 × N + T4 × (N−1)} ≧ 1 / N
On the condition that the carrier sense period Tcs is satisfied.
{T3 × N + T4 × (N−1)} / N ≧ Tcs ≧ T4 / (N−1)
A radio relay node characterized by being set to a value in the range of .
In the radio relay node according to claim 5 ,
In the case where N = 2 times, the carrier sense cycle setting unit sets (T3 × 2) / (T3 × 2 + T4) ≧ 1/2 for the receivable time T3 and the unreceivable time T4.
If the above condition is satisfied, the carrier sense period Tcs is set to (T3 × 2 + T4) / 2 ≧ Tcs ≧ T4
A radio relay node characterized by being set to a value in the range of.
In the radio relay node according to claim 5 ,
When N = 3 times, the carrier sense cycle setting unit sets the receivable time as T3 and the unreceivable time T4. As the receivable time as T3 and the unreceivable time T4, (T3 × 3) / (T3 × 3 + T4). × 2) ≧ 1/3
If the above condition is satisfied, the carrier sense period Tcs is set to (T3 × 3 + T4 × 2) / 3 ≧ Tcs ≧ T4 / 2
A radio relay node characterized by being set to a value in the range of.
The radio relay node according to any one of claims 5 to 7 , wherein the required carrier sense time is a minimum necessary time from when a carrier is detected until a message can be received effectively. A radio relay node to be used.

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