JP2011205246A - Communications equipment and communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption of communication equipment which is used as a slave unit in a network.SOLUTION: The communication equipment includes a data communication part which transmits/receives a data signal to/from a master unit and suppresses the power consumption of the communication equipment, by stopping an operation in a period, when transmission and reception are not performed; a register which receives back-off time data received from the master unit from the data communication part to be stored; a wake-up signal reception determination part which generates a back-off time standby signal instructing back-off processing, when the wake-up signal is received from the master unit during operation stop of the data communication part; and a back-off time standby part which reads back-off time data stored in the register, when the back-off time standby signal is detected, generates a physical phenomenon by which variation with time can be observed with a scale according to back-off time, and starts the data communication part after observing the variation with time to stand by, until an elapse of the back-off time is detected.

Description

  The present invention relates to a communication network including a parent device and a plurality of child device terminals communicating with the parent device, and a communication device used in the network. The present invention also relates to a method for operating such a communication apparatus.

  In recent years, as seen in wireless sensor networks, etc., a sensing system that installs a plurality of battery-powered wireless terminals equipped with sensors in a service area and collects environmental data in the area collectively has been popular. Has been considered. In such a wireless communication network, the number of wireless terminals may be large depending on the service content. In addition, the wireless terminal may be installed in a place where maintenance is difficult. For this reason, it is necessary to reduce the power consumption of the wireless terminal and replace the battery as frequently as possible. In addition, as with home appliance linkage services, such wireless terminals are connected to home appliances in the home, and the home server collects and controls the operating status of each home appliance. Services have been proposed. In this case, the wireless terminal can eliminate the battery by receiving power supply from the installed home appliance. However, there is a high demand for reducing power consumption of home appliances, and reduction of power consumption of wireless terminals connected to home appliances is also required.

  Therefore, while not communicating, it waits in a state that consumes little power, while using only a small amount of power during that time, waits for a wake-up signal that is a communication request signal from the master unit, and wakes up the signal to its own station There has been proposed a low power consumption type wireless terminal that is activated when a signal is received.

  For example, Patent Literature 1 discloses a wireless activation device 1301 as illustrated in FIG. 13 as a conventional technique for reducing power consumption during standby. The wireless activation device 1301 drives the analog timer circuit according to the received electric field strength of the tone signal from the parent device that is regarded as a wake-up signal, and intermittently activates the electronic device 1353 that is a wireless terminal. In the wireless activation device 1301, the signal received by the antenna 1351 is input to the detection circuit 1322 via the tuning circuit 1352. The detection circuit 1322 detects the received signal and demodulates the tone signal, and the amplifier 1323 amplifies the demodulated tone signal. Here, the amplifier 1323 operates intermittently as described later. The tone resonance circuit 1324 removes noise included in the amplified tone signal. The rectifier circuit 1329 converts the tone signal from which the noise has been removed into a direct current component and takes it out as an activation signal. The activation signal is input to the electronic device 1353 and activates the electronic device 1353. The voltage controlled oscillator 1326 is connected to the output of the tone resonance circuit 1324 via the peak detection circuit 1325. The voltage-controlled oscillator 1326 includes a charging circuit 1330 and a discharge switch 1327, and discharges at a cycle corresponding to the voltage indicating the peak of the tone signal output from the peak detection circuit 1325. This discharge current is supplied to the amplifier 1323, and the amplifier 1323 operates intermittently according to the discharge cycle. With these configurations, the activation cycle of the electronic device 1353 is controlled according to the electric field strength of the tone signal from the parent device, and the power consumption of the electronic device 1353 that is a wireless terminal is reduced.

  However, the activated wireless terminal starts communication with the base unit and other wireless terminals. However, since a plurality of wireless terminals are activated simultaneously, a communication collision may occur. There is a need for wireless terminals that avoid such communication collisions while reducing power consumption.

  For example, Patent Document 2 discloses a carrier detection circuit 1402 shown in FIG. 14 as a conventional technique for reducing the power consumption of such a process for avoiding a communication collision. A carrier detection circuit 1402 provided in a cordless telephone 1401 which is a wireless terminal using a multi-channel access scheme is for shortening the detection time of an empty channel by advancing the detection cycle of the presence / absence of carrier at the time of carrier sense. The carrier detection circuit 1402 includes a carrier determination unit 1404 and a short-circuit discharge unit 1403. The carrier determination unit 1404 includes a CR time constant circuit, and stores a voltage corresponding to the reception intensity of the radio wave based on the detection output from the reception unit for each channel that is periodically switched. The carrier determination unit 1404 determines whether or not the channel is empty based on the amount of stored electricity. The control unit 1405 of the cordless telephone 1401 inputs a channel switching signal LE to the short-circuit discharge unit 1403 at the time of channel switching. When the channel switching signal LE is input, the short-circuit discharge unit 1403 short-circuits and discharges the charge stored by the carrier determination unit 1404. With these configurations, since the short-circuit discharge unit 1403 instantaneously discharges the electric charge stored by the carrier determination unit 1404 at the time of channel switching, the time until the completion of discharge can be shortened, and the detection cycle of the empty channel is accelerated accordingly, so communication collision The power consumption of avoidance processing is reduced.

JP 2007-243514 A Japanese Patent Laid-Open No. 7-59148

  In the wireless activation device of Patent Document 1, the received electric field strength of the tone signal is an index of activation timing. Since the reception electric field strength is approximately the same in neighboring wireless terminals, the neighboring wireless terminals are often activated simultaneously. For this reason, there are many situations in which a communication collision occurs but the communication cannot be performed, and it is difficult to obtain an effect of reducing power consumption.

  In addition, the carrier detection circuit of Patent Document 2 has a limited effect because power consumption is reduced only when a channel is switched to search for an empty channel in a multi-channel access wireless terminal. Further, in the case of a communication system that avoids communication collision while continuously using the same channel, no effect was obtained.

  Furthermore, in the wireless activation device in Patent Document 1, many elements such as the amplifier 1323 are always operating. Also, the control unit 1405 of the cordless telephone 1401 in Patent Document 2 is operating during the period of detecting an empty channel. Since these elements consume a large amount of power, any of the conventional techniques is insufficient in reducing power consumption.

  As a method for avoiding communication collision while continuously using the same channel, a CSMA / CA (Carrier Sense Multiple Access with Collision Aidance) method is generally used. In this method, the wireless terminal that is the slave unit performs processing (carrier sense) to check whether the channel is free, performs communication when the channel is free, and performs communication for a predetermined time (back) when the channel is not available. After waiting, the carrier sense process is performed again. Here, the length of the back-off time is set in advance to be different for each wireless terminal or is determined at random. In wireless terminals using this method, the power consumption for multiple times of carrier sensing and the power consumption of the random number generation circuit for determining the back-off time in the slave unit and the time-off circuit for the back-off time are reduced. It is important to do.

  SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a communication device with reduced power consumption, which is used in a communication network that performs communication using the CSMA / CA method or the like.

  The present invention is a communication device used as a slave device terminal in a communication network system composed of a master device and a plurality of slave devices communicating with the master device, and transmits and receives data signals with the master device, The data communication unit that suppresses the power consumption of the communication device by stopping operation during the period in which the transmission / reception is not performed, and the backoff time data that specifies the backoff time included in the data signal received from the master unit, When receiving the wake-up signal, the register for receiving and storing from the data communication unit, and waiting for a wake-up signal for requesting transmission / reception of the data signal from the base unit to the communication device while the operation of the data communication unit is stopped, A wake-up signal reception determination unit that generates a back-off time standby signal instructing back-off processing and a back-off time standby signal are detected. , Read back-off time data stored in the register, generate a physical phenomenon capable of observing a change with time on a scale corresponding to the back-off time, and observe the change with time to The communication apparatus includes a back-off time standby unit that activates the data communication unit after waiting until the progress is detected.

  In addition, the back-off time standby unit includes a capacitor, applies a voltage determined based on the back-off time to the capacitor, accumulates charge, and observes the subsequent discharge phenomenon to detect the back-off time. May be.

  Moreover, it is preferable that the back-off time represented by the back-off time data included in the data signal received from the parent device is a value unique to each communication terminal.

  Moreover, it is preferable to determine the timing to stop the operation based on the sleep command included in the data signal or wakeup signal received from the master unit.

  Further, the present invention provides a communication device used as a parent device in a communication network system including a parent device and a plurality of child device terminals communicating with the parent device, and an identifier for identifying a child device terminal serving as a communication partner A wake-up signal transmission unit that transmits a wake-up signal for requesting communication to the slave terminal, and a back-off time that is a standby time from when the slave terminal receives the wake-up signal until communication is started A back-off time generating unit for generating back-off time data, and a data communication unit for transmitting and receiving data signals to and from the handset terminal. The data signal transmitted by the data communication unit includes an identifier, back-off time data, and It is a communication apparatus containing.

  Moreover, it is preferable that the back-off time represented by the back-off time data is a value unique to each slave terminal. The backoff time represented by the backoff time data may be a random value.

  Further, the identifier may be a group identifier that identifies a plurality of handset terminals. Further, the identifier may be an identifier that identifies a single slave terminal.

  Further, it is preferable to transmit a data signal or a wake-up signal including a sleep command for designating operation stop timing to the slave terminal serving as a communication partner.

  The present invention is also directed to a method and a program for operating the communication apparatus as described above. The present invention is also directed to an integrated circuit in which the functions of the communication device as described above are integrated. Furthermore, the present invention is also directed to a communication network including the above-described communication devices.

  According to the present invention, it is possible to provide a communication device with reduced power consumption, which is used in a communication network that performs communication using the CSMA / CA method or the like.

The block diagram of the communication system which concerns on the 1st-3rd embodiment of this invention. Configuration diagram of a base unit according to the first embodiment of the present invention The block diagram of the communication terminal which concerns on the 1st-3rd embodiment of this invention. 1 is a configuration diagram of a data packet and a wake-up packet according to the first embodiment of the present invention. 1 is a configuration diagram of a data packet according to a first embodiment of the present invention. The flowchart which shows operation | movement of the communication terminal which concerns on the 1st Embodiment of this invention. The figure which shows the structure and operation | movement of the back-off time waiting part which concern on the 1st Embodiment of this invention. The sequence diagram of the comparative example for showing the effect of the present invention Sequence diagram showing the effect of the present invention The block diagram of the main | base station which concerns on the 2nd Embodiment of this invention The block diagram of the data packet which concerns on the 2nd Embodiment of this invention Configuration diagram of data packet and wake-up packet according to third embodiment of the present invention Configuration diagram of a conventional wireless activation device Configuration diagram of a conventional wireless terminal

(First embodiment)
FIG. 1 is a configuration diagram of a communication system 100 according to the present embodiment. The communication system 100 includes a parent device 101, a communication terminal that is a first child device 192, and a communication terminal that is a second child device 193. In this example, two communication terminals are used, but three or more communication terminals may be used. In the communication system 100, communication is performed between the parent device 101 and the child device 192 and between the parent device 101 and the child device 193. The wake-up signal Sig. 101 is transmitted. Thereafter, the data signal Sig. Is transmitted between the slave units 192 and 193 and the master unit 101, respectively. 102 and Sig. 103 is transmitted and received.

  FIG. 2 is a configuration diagram of base unit 101. The base unit includes an antenna 111, an RF switch 110, a data communication unit 104, a wakeup signal transmission unit 107, a backoff time generation unit 103, and a control unit 102. The data communication unit 104 includes a data transmission / reception device 106 that performs modulation / demodulation of a data signal transmitted / received to / from a communication terminal that is a child device, and a packet processing device 105 that performs packetization and inverse packetization of the data signal. The wakeup signal transmitter 107 includes a wakeup packet generator 108 that generates a wakeup packet, and a wakeup signal transmitter 109 that generates a wakeup signal by modulating the wakeup packet. Further, the back-off time generation unit 103 generates back-off time data included in data transmitted to the communication terminal. The control unit 102 controls the operation of these components of the parent device 101, and control lines (not shown) are appropriately connected from the control unit 102 to these components.

  FIG. 3 is a configuration diagram of the communication terminal 201 which is the slave units 192 and 193 shown in FIG. The communication terminal 201 includes an antenna 211, an RF switch 210, a data communication unit 204 including a control unit 202, a wakeup signal reception determination unit 207, a backoff time standby unit 203, and a register 214. The data communication unit 204 includes a data transmission / reception device 206 that performs modulation / demodulation of a data signal transmitted / received to / from the base unit 101, and a packet processing device 205 that performs packetization and depacketization of the data signal. The wakeup signal reception determination unit 207 also includes a wakeup signal reception device 209 that demodulates a wakeup signal from the parent device, and a wakeup signal determination that determines whether the wakeup signal is addressed to the own device. Device 208. The back-off time standby unit 203 includes a charging / discharging device 212 that performs charging and discharging, and a back-off voltage generating device 213 that charges the charging / discharging device. Note that the control unit 202 can control these components of the communication terminal 201 during its operation, and control lines (not shown) are appropriately connected from the control unit 202 to these components. In the present embodiment, the control unit 202 is included in the data communication unit 204, but may be provided separately from the data communication unit 204.

  Hereinafter, the operation in a state in which the parent device 101 is transmitting / receiving data to / from the communication terminal 201 as a child device will be described separately for reception and transmission.

(Data reception operation by the main unit)
When the base unit 101 receives a data signal from the communication terminal 201, the RF switch 110 is switched by the control unit 102 to connect the antenna 111 and the data transmitting / receiving device 106 in the data communication unit 104. The data signal received from the communication terminal 201 is received from the antenna 111 and demodulated into a data packet by the data transmitting / receiving device 106. The data packet is sent to the packet processing device 105, subjected to reverse packet processing, and separated into payload data and control data as user data. The configuration of the data packet created by the communication terminal 201 will be described later.

  Among these data, the payload data is output to the outside of the parent device 101 via the control unit 102. For example, the parent device 101 may include a display device and display payload data. Alternatively, the control unit 102 may perform processing based on the payload data without outputting the payload data to the outside. The control data is sent to the control unit 102 and used for various controls of the parent device 101. Further, the parent device ID, the child device ID, and the code error detection code included in the header are sent to the control unit 102 and used for verifying the reliability of the communication content.

(Data transmission operation by the main unit)
When the base unit 101 transmits a data signal to the communication terminal 201, the RF switch 110 is switched by the control unit 102 to connect the antenna 111 and the data transmission / reception device 106 in the data communication unit 104. FIG. 4A is a diagram showing a configuration of a data packet 401 created by the parent device. The data packet 401 includes a preamble 402, a synchronization code 403, a header 404, payload data 405, and a code error detection code 406. The preamble 402 is a regular code string provided for drawing the free-running frequency of a demodulation PLL circuit (Phase Locked Loop phase synchronization circuit, not shown) built in the data transmitting / receiving device 206 of the communication terminal 201. The synchronization code 403 is an indicator that indicates the beginning of byte alignment of data, and a unique word such as a code that violates the code modulation method or a PN code can be used. The payload data 405 is user data that can be used by the user, and can include an error detection and correction code for the user data. The code error detection code 406 is a check code for detecting a transmission error of the data packet. For example, a CRC code (Cyclic Redundancy Check cyclic redundancy check code) can be used. The header 404 includes a child device ID 407, a parent device ID 408, backoff time data 409, control data 410, and a code error detection code 411. The slave unit ID 407 is a code indicating a communication terminal serving as a slave unit of a communication partner, and the master unit ID 408 is a code indicating a master unit that is its own station. Since the communication source and the communication destination are specified by the child device ID 407 and the parent device ID 408, highly reliable communication can be performed. The back-off time data 409 is time data for designating the back-off time for the communication terminal 201. The control data 410 is a flag group for controlling the operation of the communication terminal 201. The code error detection code 411 is a check code for detecting a transmission error of the header 404, and for example, a CRC code can be used. Since each data in the header is highly important in the transmission procedure, the reliability can be improved by adding a dedicated code error detection code 411. As the control data, for example, a first sleep command that requests the communication terminal 201 to stop the operation of the data communication unit 204, an ACK (Acknowledgement) response that responds that the communication from the communication terminal 201 has been normally received, and the like. There is.

  The control unit 102 generates a preamble 402, a synchronization code 403, a header 404, payload data 405, and a code error detection code 406. Payload data 405 is user data, and is input from the outside of parent device 101. For example, the parent device 101 may include an input device, and user data may be input to the control unit 102 via the input device. Alternatively, the control unit 102 may create user data. The back-off time generation unit 103 generates a unique value for each child device as the back-off time data. A unique value for each slave unit may be determined in advance. The packet processing device 105 packetizes the back-off time data 409, the preamble 402 generated by the control unit 102, the synchronization code 403, the header 404, the payload data 405, and the code error detection code 406, and performs data packet processing. 401 is generated. The data packet 401 is modulated by the data transmitting / receiving device 106. The modulated data packet 401 is transmitted from the antenna 111 via the RF switch 110.

  Next, a wake-up signal transmission operation, which is an operation when the base unit 101 starts data transmission / reception with the communication terminal 201 in a state where data transmission / reception is not performed, will be described.

(Wake-up signal transmission operation by the main unit)
When base unit 101 transmits a wakeup signal, RF switch 110 is switched by control unit 102 to connect antenna 111 and wakeup signal transmission device 109 in wakeup signal transmission unit 107. Here, the configuration of the wake-up packet 420 included in the wake-up signal will be described with reference to FIG. The wake-up packet 420 includes a preamble 421, a synchronization code 422, wake-up information 423, and a code error detection code 424. Preamble 421 is a regular code string provided for drawing a free-running frequency of a demodulation PLL circuit (not shown) built in the wake-up signal receiver of the communication terminal. The synchronization code 422 is an indicator that indicates the beginning of byte alignment of data, and a unique word such as a code that violates the code modulation method or a PN code can be used. The code error detection code 424 is a check code for detecting a transmission error of the wakeup packet. For example, a CRC code can be used. The wake-up information 423 includes control information 425 and a wake-up ID 426. The control information 425 is an operation parameter related to the wake-up operation, and the wake-up ID 426 is an ID that identifies the communication terminal 201 that is a slave device to be activated, but is a group ID that targets a plurality of slave devices. There may be. Further, it may be a simultaneous activation ID for all the slave units. The control unit 102 generates a preamble 421, a synchronization code 422, wakeup information 423, and a code error detection code 424. The wakeup packet creation device 108 packetizes these data generated by the control unit 102 and generates a wakeup packet 420. Wake-up packet 420 is modulated by wake-up signal transmitter 109. The modulated wakeup packet 420 is transmitted from the antenna 111 as a wakeup signal via the RF switch 110.

  Hereinafter, the operation of the communication terminal 201 in the normal operation mode in which the communication terminal 201 is transmitting / receiving data to / from the base unit 101 will be described separately for reception and transmission.

(Data reception operation by communication terminal)
When the communication terminal 201 transmits / receives data to / from the base unit 101, the RF switch 210 is switched by the control unit 202 to connect the antenna 211 and the data transmission / reception device 206 in the data communication unit 204. The data signal received from the antenna 211 is demodulated into a data packet 401 by the data transmission / reception device 206. The data packet 401 is sent to the packet processing device 205, subjected to reverse packet processing, and separated into payload data 405, control data 410, and the like, which are user data.

  Among these data, payload data 405 is output to the outside of the communication terminal 201 via the control unit 202. For example, the communication terminal 201 may be provided with a display device or the like and display the payload data 405. Alternatively, the control unit 202 may perform processing based on the payload data 405 without outputting the payload data 405 to the outside. The control data 410 is sent to the control unit 202 and used for various controls of the communication terminal 201. In addition, the parent device ID 408, the child device ID 407, and the code error detection codes 406 and 411 included in the header are sent to the control unit 202 and used for verifying the reliability of the communication contents.

  The packet processing device 205 transmits back-off time data 409 included in the data packet 401 to the register 214. Further, the packet processing device 205 transmits a latch signal to the register 214 in synchronization with the timing at which the back-off time data 409 is transmitted to the register 214. When the register 214 detects the latch signal, the register 214 stores the transmitted back-off time data 409. The register 214 is composed of flip-flop circuits as many as the bit length of the back-off time data 409, and requires an operating current at the moment of storage, but the period during which the stored back-off time data 409 is held is almost Does not require operating current. Therefore, the register 214 is equivalent to a memory circuit with low power consumption. Each time the data packet 401 indicating that the child device ID 407 is addressed to the own device arrives, the packet processing device 205 transmits the back-off time data 409 included in the data packet 401 to the register 214 and overwrites it. The stored contents of the register 214 are updated. Therefore, the output state of the register 214 always maintains the latest back-off time data 409.

(Data transmission operation by communication terminal)
FIG. 5 is a diagram showing the configuration of the data packet 501 created by the communication terminal. The data packet has substantially the same configuration as the data packet 401 created by the parent device, but differs in that it does not include the back-off time data 409. The data packet 501 includes a preamble 502, a synchronization code 503, a header 504, payload data 505, and a code error detection code 506. Preamble 502 is a regular code string provided to pull in a free-running frequency of a demodulation PLL circuit (not shown) built in data transmitting / receiving apparatus 106 of base unit 101. The synchronization code 503 is an indicator that indicates the beginning of byte alignment of data, and a unique word such as a code that violates the code modulation method or a PN code can be used. The payload data 505 is user data that can be used by the user, and can include an error detection and correction code for the user data. The code error detection code 506 is a check code for detecting a transmission error of the data packet. For example, a CRC code can be used. The header 504 includes a child device ID 507, a parent device ID 508, control data 510, and a code error detection code 511. The slave unit ID 507 is a code indicating the communication terminal which is the local station, and the master unit ID 508 is a code indicating the master unit which is the communication partner. Since the communication source and the communication destination are specified by the child device ID 507 and the parent device ID 508, highly reliable communication can be performed. The arrangement order of the child device ID 507 and the parent device ID 508 may be reversed. The control data 510 is a flag group for controlling the operation of the parent device 101. The code error detection code 511 is a check code for detecting a transmission error of the header 504, and for example, a CRC code can be used. Since each data in the header is highly important in the transmission procedure, the reliability can be improved by adding a dedicated code error detection code 511. The control data includes, for example, an ACK response that responds that the communication from the parent device 101 has been normally received.

  The control unit 202 generates a preamble 502, a synchronization code 503, a header 504, payload data 505, and a code error detection code 506. Payload data 505 is user data and is input from the outside of the communication terminal 201. For example, the communication terminal 201 may include an input device, and user data may be input to the control unit 202 via the input device. Alternatively, the control unit 202 may create user data. The packet processing device 205 packetizes the preamble 502, the synchronization code 503, the header 504, the payload data 505, and the code error detection code 506 generated by the control unit 202, and generates a data packet 501. The data packet 501 is modulated by the data transmitting / receiving device 206. The modulated data packet 501 is transmitted from the antenna 211 via the RF switch 210.

  Thus, when the data transmission / reception with the parent device 101 is completed, the data communication unit 204 stops its operation. Since the control unit 202 and the data transmission / reception device 206 with large power consumption are stopped, the power consumption in this state is small. Such a state of the communication terminal 201 is referred to as a low power consumption operation mode. The operation from the state in which the data communication unit 204 is transmitting / receiving data to / from the base unit 101 to the transition to the low power consumption operation mode will be described below with reference to FIG.

  FIG. 6 is a flowchart showing the operation of the communication terminal 201. First, in step S <b> 601, the communication terminal 201 performs data transmission / reception with the parent device 101 by the operation of the data communication unit 204. In step S 602, backoff time data 409 included in data packet 401 from base unit 101 is stored in register 214. In step S603, the control unit 202 confirms whether or not the first sleep instruction is included in the data packet 401. If not included, the control unit 202 returns to step S601 to continue data transmission and reception. If so, the process proceeds to step S604. In step S604, the control unit 202 transmits a data packet 501 including an ACK response to the base unit, and switches the RF switch 210 to connect to the wakeup signal reception device 209 in the wakeup signal reception determination unit 207. Further, the operation of the data communication unit 204 is stopped including the control unit 202 itself. The process in step S604 is referred to as a sleep process.

  Here, the data transmission / reception completion condition is the time when the data packet 401 including the first sleep command is received from the parent device 101 as shown in step S603, but the data packet 501 to be transmitted by the communication terminal 201 is used. May be transmitted or when a predetermined communication sequence with the parent device 101 is completed.

  When the communication terminal 201 shifts to a state where the operations of the control unit 202 and the data communication unit 204 are stopped, the wakeup signal reception device 209 waits for a wakeup signal that is a communication request signal from the parent device 101 in step S605. . Operations from when the communication terminal 201 stops the operations of the control unit 202 and the data communication unit 204 to when communication with the parent device 101 is started again will be described with reference to FIG. In step S <b> 605, the wakeup signal reception device 209 is waiting for a wakeup signal from the parent device 101. Since the wake-up signal receiving device 209 starts subsequent processing with the input of radio waves of a predetermined channel as a trigger, the power consumption during standby is very small.

  When receiving the wakeup signal, the wakeup signal reception device 209 demodulates the wakeup signal 420 and transmits the wakeup signal 420 to the wakeup signal determination device 208. The wakeup signal determination apparatus 208 verifies the reliability of the wakeup signal based on the code error detection code 424 included in the wakeup packet 420. Also, the wakeup signal determination device 208 performs various controls based on the control information 425 when the slave unit specified by the wakeup ID 426 included in the wakeup information 423 is included in the slave unit. If the slave unit specified by the wakeup ID 426 does not include the own device, the process remains in step S605 until the wakeup signal is received again.

  In step S606, the wake-up signal determination device 208 transmits a back-off time standby signal to the charging / discharging device 212 in the back-off time standby unit 203. The back-off voltage generator 213 in the back-off time standby unit 203 calculates a voltage value based on the back-off time data held by the register 214 and transmits the voltage value to the charge / discharge device 212. When the charging / discharging device 212 receives the back-off time standby signal, the charging / discharging device 212 starts charging a capacitor, which will be described later, by this voltage value, and accumulates the electric charge. When a certain time sufficient for charging elapses, it is determined that charging is completed, and discharging is started.

  Next, in step S607, when the charging / discharging device 212 detects that the voltage between the terminals of the capacitor has dropped to a predetermined value due to the discharge, the charging / discharging device 212 determines that the discharging has been completed, and notifies the control unit 202 of the control unit start signal. Send. The time required for discharge becomes longer when the voltage is higher, and shorter when the voltage is lower. The back-off voltage generator 213 calculates the voltage value so that the time required for discharging is equal to the back-off time represented by the back-off time data.

  Next, in step S608, the control unit 202 is activated by a control unit start signal. Next, in step S609, the control unit 202 activates the data communication unit 204. In addition, the control unit 202 switches the RF switch 210 so as to connect the antenna 211 and the data transmission / reception device 206 in the data communication unit 204. In this way, the communication terminal 201 returns to step S601, which is in a state of transmitting / receiving data to / from the parent device.

  Here, the configuration and operation of the back-off time standby unit will be described in detail. FIG. 7A is a diagram illustrating an internal configuration of the back-off time waiting unit 203.

  The back-off voltage generator 213 includes a DA (digital-analog) converter 701. The DA converter 701 includes back-off time data Sig. 791 is DA-converted, and the back-off voltage Sig. 751 is generated. In the DA conversion performed by the DA converter 701, as described above, the time required for the charge / discharge performed by the charge / discharge device 212 is the back-off time data Sig. 791 is equal to the back-off time represented by 791. A voltage value of 751 is determined.

  The charge / discharge device 212 includes a first pulse generator 709, a transistor 702, a capacitor 703, a transistor 704, a resistor 705, an inverter 706, a resistor 707, a second pulse generator 708, and an inverter 710. The first pulse generation device 709 is a pulse generation circuit that generates a single pulse signal by detecting a rising edge of an input signal. Here, the first pulse generator 709 is connected to the back-off time standby signal Sig. A single pulse signal is generated by the rising edge of 792.

  The transistor 702 has a first gate signal Sig. In accordance with 752, the switching operation of the transistor 702 is controlled. Further, the first gate signal Sig. 752 is inverted in logic by the inverter 710, and the second gate signal Sig. 754 is input to the gate to the transistor 704 to control the switching operation of the transistor 704. Therefore, the transistor 702 and the transistor 704 perform complementary operations. Here, the pulse signal generated by the first pulse generator 709 is the first gate signal Sig. 752.

  One terminal of the capacitor 703 is connected to the source of the transistor 702 and the drain of the transistor 704, and the other terminal is grounded. The resistor 705 has one terminal connected to the source of the transistor 704 and the other terminal grounded. Back-off time standby signal Sig. 792 causes the first pulse generator to output a pulse signal, and the first gate signal Sig. When the transistor 752 is high, the transistor 702 is turned on and at the same time the transistor 704 is turned off. Therefore, the back-off voltage Sig. A voltage according to 751 is applied and the charge is rapidly charged.

  Thereafter, the first gate signal Sig. When 752 goes low, the transistor 702 is turned off and at the same time the transistor 704 is turned on, so that the charge charged in the capacitor 703 is discharged through the resistor 705. Therefore, the source signal Sig. The voltage 755 drops as the capacitor 703 is discharged. Source signal Sig. 755 is input to the inverter 706. The inverter 706 is equivalent to a comparator with hysteresis because its input and output are connected via a resistor 707. Source signal Sig. While the voltage of 755 is higher than the threshold voltage of the inverter 706, the inverter signal Sig. 756 goes low. As the discharge proceeds, the source signal Sig. When the voltage of 755 falls below the threshold voltage of the inverter 706, the inverter signal Sig. 756 goes high.

  When the threshold voltage of the inverter 706 is changed, the timing for determining that the discharge has been completed changes. Therefore, the threshold voltage of inverter 706 is determined so that the time from the start of charging to the completion of discharging is equal to the back-off time represented by the back-off time data, as in the above-described DA conversion.

  The second pulse generator 708 is a pulse generator that generates a single pulse signal by detecting the rising edge of the input signal. Here, the second pulse generator 708 is connected to the inverter signal Sig. With the rising edge of 756, the control unit start signal Sig. 793 is generated. The control unit start signal is transmitted to the control unit 202 as an output of the back-off time standby unit 203.

  Next, back-off time data Sig. 791 and a back-off time waiting signal Sig. 792 and the control unit start signal Sig. 793, and the first gate signal Sig. 752, inverter signal Sig. 756 and the voltage Sig. A state of time change 753 will be described. FIG. 7B is a timing chart showing temporal changes of these signals.

  At time T70, the back-off time standby signal Sig. 792 rises, the first pulse generator 709 causes the first gate signal Sig. Having the pulse width Tc at time T71. 752 is generated. The pulse width Tc has a constant pulse width sufficient to quickly charge the capacitor 703. The first gate signal Sig. 752 turns on the transistor 702 at time T71, and as a result, the capacitor 703 starts to be charged and the amount of charge starts to increase.

  At time T72 when the time Tc has elapsed from time T71, a sufficient time has elapsed for the capacitor 703 to be charged, and charging can be considered complete. At this time, the voltage Sig. 753 is a back-off voltage Sig. It is approximately equal to the voltage of 751.

  At time T72, the first gate signal Sig. 752 goes low, turning off the transistor 702 and the first gate signal Sig. The second gate signal Sig. Since 754 becomes Hi and the transistor 704 is turned on, discharging starts from the capacitor 703 toward the resistor 705, and the charge amount starts to decrease. At this time, the voltage Sig. 753 and the source signal Sig. 755 is substantially the same potential. Immediately after time T72, the source signal Sig. Since the potential of 755 is high, the inverter signal Sig. 756 goes low.

  After that, at time T73, the inter-terminal voltage Sig. Assume that 753 falls below the threshold voltage of the inverter 706. As a result, it is determined that the discharge of the capacitor 703 has been completed. At this time, the inverter signal Sig. 756 goes high. The second pulse generator 708 receives the inverter signal Sig. 756 rising edge is detected, and at time T74, the control unit activation signal Sig. 793 is generated.

  In this way, the back-off time standby unit 203 performs the back-off time standby signal Sig. 792 is input, after the back-off time has elapsed, the control unit activation signal Sig. 793 can be generated.

  The chart at time T75 to T79 shown in FIG. 7B shows the back-off voltage Sig. The case where 751 is higher than the case in T70 to T74 is shown. In this case, the capacitor terminal voltage Sig. The time until 753 falls below the threshold voltage of the inverter 706 due to discharge is longer. That is, the time from time T77 to time T78 is longer than the time from time T72 to time T73. Thus, the back-off voltage Sig. The backoff time can be controlled by a value of 751.

  In order to explain the effect of the present invention, consider the operation of a conventional communication terminal in which such a back-off time standby unit is not provided and the control unit 202 is immediately activated by a wake-up signal. FIG. 8 is a diagram illustrating an example of operation when two such communication terminals communicate with the parent device 801 as the first child device 802 and the second child device 803, respectively.

  Until time T80, both the first slave unit 802 and the second slave unit 803 are in the low power consumption operation mode. At time T80, the base unit 801 transmits a wake-up signal 851 in order to start all the slave units simultaneously.

  At time T80, the first slave unit 802 and the second slave unit 803 receive the wake-up signal 851, and transition from the low power consumption operation mode to the normal operation mode. Thereafter, both slave units perform carrier sense (denoted as CS in the figure). As a result of carrier sense, first slave unit 802 and second slave unit 803 determine that the channel is free, and transmit data signal 852 and data signal 853, respectively, but at time T81, transmissions overlap. , Communication conflicts.

  Since the base unit 801 cannot normally receive the data signal 852 and the data signal 853 due to a communication collision at the time T81 and does not return a response, both the slave units enter a reception waiting state and time out at the time T82.

  The first handset 802 starts the first back-off immediately after the timeout, and the second handset 803 starts the second back-off. The first handset 802 terminates the first backoff at time T83, confirms that the channel is free by carrier sense, and at time T84, transmits the data signal 854 as a retransmission of the data signal 852. To 801. Since the data signal 854 does not collide with the transmission signal of the second slave unit 803, it is normally received by the master unit 801. After receiving data signal 854, base unit 801 transmits sleep signal 855, which is a data signal including the first sleep command, to first slave unit 802 at time T85. Receiving sleep signal 855, first slave unit 802 transmits an ACK signal 856, which is a data signal including an ACK response, to master unit 801 at time T86 and ends the communication session. Thereafter, the data communication unit and the control unit are stopped again.

  The second slave unit 803 terminates the second back-off at time T86, and thereafter communicates with the master unit 801 in the same procedure as the first slave unit 802, and then terminates the communication session and performs data communication again. And the control unit are stopped.

  Since the communication terminals that operate as the first slave unit 802 and the second slave unit 803 do not have a back-off time standby unit, the control unit that is immediately activated by the wake-up signal determines the carrier sense and the back-off time. In order to control the random number generation operation for the user and the time counting operation using a digital counter, etc., power consumption in the control unit is required. Further, when the control unit is activated by receiving the wake-up signal at the same time, since communication is started at the same time, a communication collision is likely to occur in the first transmission of the transmission data signal. Therefore, another carrier sense is required, and a long waiting time is generated in a state where the control unit is activated, so that the total communication time becomes long and more power consumption is required.

  Next, the operation when two communication terminals 201 according to the present embodiment communicate with the parent device 101 as the first child device 192 and the second child device 193 will be described. FIG. 9 is a diagram illustrating an example of an operation when the first slave unit 192 and the second slave unit 193 communicate with the master unit 101.

  Until time T90, the first handset 192 and the second handset 193 are waiting for a wake-up signal in the low power consumption operation mode. At time T90, the base unit 101 transmits a wake-up signal 951 to activate all the slave units at the same time.

  At time T90, the first handset 192 and the second handset 193 receive the wake-up signal 951. Immediately thereafter, the first slave unit 192 starts the first back-off while remaining in the low power consumption operation mode, and the second slave unit 193 also starts the second back-off while maintaining the low power consumption. .

  The first handset 192 completes the first backoff at time T91, transitions from the low power consumption operation mode to the normal operation mode, and transmits the data signal 952 to the parent device 101 at time T91. Since the second handset 193 does not transmit a data signal at this time, the data signal 952 is normally received by the base unit 101 without a communication collision.

  After receiving data signal 952, base unit 101 transmits sleep signal 953 to first slave unit 192 at time T92. The first slave unit 192 that has received the sleep signal 953 transmits an ACK signal 954 to the master unit 101 at time T93 and ends the communication session. Thereafter, the low power consumption operation mode is entered again.

  The second slave unit 193 transitions from the low power consumption operation mode to the normal operation mode after completing the second back-off at time T94, and thereafter, the second slave unit 193 and the master unit 101 in the same procedure as the first slave unit 192. After communication, at time T95, the communication session is terminated and the low power consumption operation mode is entered again.

  Note that the first handset 192 and the second handset 193 store the backoff time data in a register when the received data signal received from the base unit 101 includes backoff time data.

  As described above, in the communication terminal according to the present embodiment, the back-off time is received from the parent device 101, so that a random number generation circuit or the like is not necessary. Moreover, a digital counter etc. become unnecessary by a charging / discharging apparatus. Therefore, it is not necessary for the control unit to perform control such as a random number generation operation for determining the back-off time, a time counting operation using a digital counter, or the like, and it is not necessary to start up until immediately before actually communicating with the parent device. Furthermore, after receiving the wake-up signal, the base unit uses the back-off time determined as a unique value for each communication terminal, and then back-off and then the transmission of the first transmission data signal causes a communication collision. It reduces the possibility of doing so and makes carrier sense unnecessary. Therefore, the overall communication time can be shortened. As a result, power consumption can be reduced. Therefore, when the communication terminal is battery-driven, the battery life is extended.

  In addition, capacitors, transistors, resistors, inverters, and the like that constitute the back-off standby unit can be easily configured as semiconductor elements, and thus are easily integrated. Further, since most of the back-off standby unit is a low power consumption type passive circuit, almost no power consumption occurs during operation, and power consumption during operation can be kept small.

  In addition, in order to improve the reliability of communication, the communication terminal may perform carrier sense immediately before transmitting a data signal. The carrier sense process is performed, for example, by the data transmitter / receiver measuring the received radio wave intensity and the control unit comparing the intensity with a threshold value. As a result of the carrier sense, if the received radio wave intensity is greater than the threshold due to other communication terminals communicating or interference from other communication systems, it is determined that the channel cannot be used. In this case, the communication terminal waits again for the back-off time. The standby process in this case may be performed by the back-off time standby unit as described above.

  When the communication terminal first participates in the communication system or restarts due to battery replacement or the like, there may be a case where the register does not hold the back-off time data. For such a case, for example, the back-off time standby unit holds the back-off time initial value, and the back-off time initial value is stored until the back-off time data received from the parent device is stored in the register. May be used as the back-off time.

(Second Embodiment)
The second embodiment of the present invention is obtained by replacing the back-off time generation unit of the parent device with a random number generation unit in the first embodiment. The communication terminal is the same as the communication terminal 201 of the first embodiment. FIG. 10 is a configuration diagram of the parent device 1001 according to the present embodiment. In FIG. 10, the same components as those in FIG. The random number generation unit 1003 generates random number data as a back-off time to be transmitted to the communication terminal. As shown in FIG. 11, the packet processing device 105 creates a data packet 1101 in which random number data 1109 is packetized instead of backoff time data in the data packet 401 in the first embodiment. Thereby, a random back-off time is given to each slave unit, the possibility of a communication collision is reduced, and the efficiency of CSMA / CA communication can be improved.

  The random number generation unit 1003 may use the slave device ID of a communication terminal as a communication partner as a seed for random number generation. In this case, since the uniqueness of the random number sequence is given to each slave unit, the randomness is improved and the efficiency of CSMA / CA communication can be further improved. The random number generator may include an electronic component such as a diode, detect thermal noise thereof, and generate a random number based on the detected thermal noise. In this case, since the random number generator generates a true random number, the efficiency of CSMA / CA communication can be further improved.

(Embodiment 3)
In the third embodiment of the present invention, in the first or second embodiment, the communication terminal receives from the base unit 101 or 1001 and demodulates as control data included in the data packet or in the wake-up packet. The control information includes a second sleep command. A configuration example of such a data packet 1201 and a wake-up packet 1220 is shown in FIG. In FIG. 12, in the data packet 1201, the second sleep instruction 1202 is stored as the control data 410 in the data packet 401 according to the first embodiment. In the wake-up packet 1220, a second sleep command 1203 is stored as the control information 425 in the wake-up packet 420 according to the first embodiment.

  When the communication terminal 201 decodes the data signal or wakeup signal received from the parent device 101 or 1001, if the second sleep command is included, the second sleep command is transmitted to the control unit 202. . The control unit 202 shifts to the sleep process even if the communication with the parent device is not completed after a predetermined time from activation by receiving the wakeup signal. As a result, it is possible to prevent the communication terminal from falling into a protocol deadlock state due to a communication error or the like, and the control unit 202 and the data communication unit 204 to continue to be activated to increase power consumption and accelerate battery consumption. When the control unit receives the first sleep command, even if the second sleep command is received before or after the first sleep command, it is not necessary to wait for a predetermined time, and the sleep processing may be performed immediately.

  In each of the above embodiments, the back-off time standby unit discharges the capacitor and observes the potential to detect the passage of the back-off time. However, the means for detecting the passage of the back-off time is limited to this. In other words, another phenomenon having a certain temporal variation characteristic and reproducible may be used. For example, a current may be observed by passing a pulse current through the inductance. Alternatively, photons may be confined in a nanostructure cavity and leakage of the photons may be observed. Alternatively, the electrolyte may be ionized and the ionic current may be observed. When such a physical phenomenon is generated, predetermined energy is required, but only energy is released in the subsequent aging. Moreover, what is necessary is just to use the energy discharge | released for observation. Therefore, when the time is measured by such a physical phenomenon, the power consumption can be made smaller than when the time is measured using a digital counter or the like that always requires power supply during the time measurement.

  The configuration excluding the antenna 211 of the communication terminal 201 according to each embodiment and the configuration excluding the antenna 111 of the parent device 101 and 1001 may be realized as an LSI that is an integrated circuit. These configurations may be made into one chip, or may be made into a chip so as to include a part thereof. The term “LSI” here may be referred to as “IC”, “system LSI”, “super LSI”, or “ultra LSI” depending on the degree of integration. Further, the method of circuit integration is not limited to LSI, and circuit integration may be performed with a dedicated circuit or a general-purpose processor. Alternatively, a field programmable gate array (FPGA) that can be programmed after manufacturing the LSI, or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used. Alternatively, the calculation of these functional blocks can be performed using, for example, a DSP or a CPU. Furthermore, these processing steps may be processed by being recorded on a recording medium as a program and executed. Further, the antenna 211 and the antenna 111 may be formed as an LSI so as to be configured in a phased array type or the like.

  The present invention is also directed to a method and program for realizing the functions of the communication terminal and the parent device as described above. Furthermore, the present invention is also directed to a communication network system including the communication terminal and the parent device as described above.

  The present invention is useful for communication terminals, and is particularly useful for battery-driven wireless communication terminals that require low power consumption, as seen in wireless sensor networks and wireless remote controllers.

DESCRIPTION OF SYMBOLS 100 Communication system 101,801,1001 Base unit 102 Control part 103 Backoff time production | generation part 104 Data communication part 105 Packet processing apparatus 106 Data transmission / reception apparatus 107 Wakeup signal transmission part 108 Wakeup packet production apparatus 109 Wakeup signal transmission apparatus 110 , 210 RF switch 111, 211 Antenna 192, 802 First slave unit 193, 803 Second slave unit 201 Communication terminal 202 Control unit 203 Back-off time waiting unit 204 Data communication unit 205 Packet processing unit 206 Data transmission / reception unit 207 Wake Up signal reception determination unit 208 Wake-up signal determination device 209 Wake-up signal reception device 212 Charging / discharging device 213 Back-off voltage generator 214 Register 401, 501, 110 1, 1201 Data packet 402, 502 Preamble 403, 503 Synchronization code 404, 504 Header 405, 505 Payload data 406, 411, 506, 511 Code error detection code 407, 507 Slave unit ID
408, 508 Base unit ID
409 Backoff time data 410, 510 Control data 420, 1220 Wakeup packet 421 Preamble 422 Synchronization code 423 Wakeup information 424 Code error detection code 425 Control information 426 Wakeup ID
701 DA converter 702, 704 Transistor 703 Capacitor 705, 707 Resistor 706, 710 Inverter 708 Second pulse generator 709 First pulse generator 851 Wake-up signal 852, 853, 952 Data signal 855, 953 Sleep signal 856, 954 ACK signal 951 Wake-up signal 1003 Random number generator 1109 Random number data 1202, 1203 Second sleep command 1301 Wireless activation device 1322 Detection circuit 1323 Amplifier 1324 Tone resonance circuit 1325 Peak detection circuit 1327 Discharge switch 1329 Rectification circuit 1330 Charging circuit 1351 Antenna 1352 Tuning Circuit 1353 Electronic Device 1401 Cordless Telephone 1402 Carrier Detection Circuit 1403 Short-Circuit Discharge Unit 1404 Key Rear determination unit 1405 control unit

Claims (15)

In a communication network system composed of a parent device and a plurality of child device terminals communicating with the parent device, a communication device used as the child device terminal,
A data communication unit that transmits and receives data signals to and from the base unit, and stops operation during a period in which the transmission and reception are not performed, thereby suppressing power consumption of the communication device;
A register that is included in the data signal received from the base unit and receives back-off time data specifying a back-off time from the data communication unit;
While the operation of the data communication unit is stopped, the master unit waits for a wake-up signal requesting the communication device to transmit / receive the data signal, and when the wake-up signal is received, a back-off process is instructed. A wake-up signal reception determination unit that generates an off-time standby signal;
When the back-off time standby signal is detected, the back-off time data stored in the register is read, and a physical phenomenon capable of observing a change with time on a scale according to the back-off time is generated. A communication device comprising: a back-off time standby unit that activates the data communication unit after observing the change over time and detecting the elapse of the back-off time.   The back-off time standby unit includes a capacitor, applies a voltage determined based on the back-off time to the capacitor, accumulates electric charge, and observes a subsequent discharge phenomenon, thereby measuring the lapse of the back-off time. The communication device according to claim 1, wherein the communication device is detected.   The communication apparatus according to claim 1 or 2, wherein a back-off time represented by back-off time data included in the data signal received from the base unit is a value unique to each communication terminal.   The communication device according to claim 1, wherein the communication unit determines a timing to stop the operation based on a sleep command included in the data signal or the wake-up signal received from the parent device. In a communication network system composed of a parent device and a plurality of child device terminals communicating with the parent device, a communication device used as the parent device,
A wakeup signal transmission unit that includes an identifier that identifies a slave terminal that is a communication partner, and that transmits a wakeup signal that requests communication to the slave terminal;
A back-off time generating unit for generating back-off time data specifying a back-off time, which is a waiting time from when the slave terminal receives the wake-up signal until communication is started;
A data communication unit that transmits and receives data signals to and from the slave terminal;
The data signal transmitted by the data communication unit includes the identifier and the back-off time data.   The communication apparatus according to claim 5, wherein the back-off time represented by the back-off time data is a value unique to each slave terminal.   The communication apparatus according to claim 6, wherein the back-off time represented by the back-off time data is a random value.   The communication apparatus according to claim 5, wherein the identifier is a group identifier that specifies a plurality of handset terminals.   The communication device according to any one of claims 5 to 7, wherein the identifier is an identifier that identifies a single handset terminal.   The communication device according to any one of claims 5 to 9, wherein the data signal or the wake-up signal including a sleep command for designating operation stop timing is transmitted to the slave terminal serving as the communication partner. A communication network comprising a data communication unit including a control unit, a register, a wake-up signal reception determination unit, and a back-off time standby unit, and comprising a parent device and a plurality of child device terminals communicating with the parent device In the system, an operation method for functioning as the slave terminal,
The data communication unit transmits and receives data signals to and from the master unit, and suppresses power consumption of the communication device by stopping operation during a period in which the data communication is not performed;
The data communication unit is included in the data signal received from the master unit, and stores back-off time data specifying a back-off time in the register;
The wake-up signal reception determination unit waits for a wake-up signal for requesting transmission / reception of the data signal from the base unit to the communication device while the operation of the data communication unit is stopped, and receives the wake-up signal. Generating a back-off time standby signal instructing back-off processing;
When the back-off time standby unit detects the back-off time standby signal, the back-off time data stored in the register is read, and a change with time is observed on a scale corresponding to the back-off time. Generating a possible physical phenomenon, observing the change over time and waiting until the back-off time is detected, and then activating the data communication unit. A communication network comprising a data communication unit including a control unit, a register, a wake-up signal reception determination unit, and a back-off time standby unit, and comprising a parent device and a plurality of child device terminals communicating with the parent device In the system, a program executed by the control unit to function as the child device terminal,
The control unit causes the data communication unit to transmit / receive a data signal to / from the base unit, and during a period when the transmission / reception is not performed, stops the operation including the control unit itself, thereby consuming the communication device. Suppressing power, and
The control unit includes the step of causing the data communication unit to store back-off time data for specifying a back-off time in the register, which is included in the data signal received from the master unit,
The wake-up signal reception determination unit waits for a wake-up signal for requesting transmission / reception of the data signal from the base unit to the communication device while the operation of the data communication unit is stopped, and receives the wake-up signal. A back-off time standby signal for instructing back-off processing,
When the back-off time standby unit detects the back-off time standby signal, the back-off time data stored in the register is read, and a change with time is observed on a scale corresponding to the back-off time. A program that is executed again by activating the data communication unit after generating a possible physical phenomenon, observing the change over time, and waiting until the elapse of the back-off time is detected. In a communication network system composed of a parent device and a plurality of child device terminals communicating with the parent device, an integrated circuit in which functions of a communication device used as the child device terminal are integrated,
A data communication unit that transmits and receives data signals to and from the base unit, and stops operation during a period in which the transmission and reception are not performed, thereby suppressing power consumption of the communication device;
A register that is included in the data signal received from the base unit and receives back-off time data specifying a back-off time from the data communication unit;
While the operation of the data communication unit is stopped, the master unit waits for a wake-up signal requesting the communication device to transmit / receive the data signal, and when the wake-up signal is received, a back-off process is instructed. A wake-up signal reception determination unit that generates an off-time standby signal;
When the back-off time standby signal is detected, the back-off time data stored in the register is read, and a physical phenomenon capable of observing a change with time on a scale according to the back-off time is generated. An integrated circuit in which a function with a back-off time standby unit that activates the data communication unit is integrated after waiting for the back-off time to be detected by observing the change over time. A communication network system comprising a parent device and a plurality of child device terminals communicating with the parent device,
The base unit is
A wakeup signal transmission unit that includes an identifier that identifies a slave terminal that is a communication partner, and that transmits a wakeup signal that requests communication to the slave terminal;
A back-off time generating unit for generating back-off time data specifying a back-off time, which is a waiting time from when the slave terminal receives the wake-up signal until communication is started;
A master side data communication unit that transmits and receives data signals to and from the slave terminal,
The data signal transmitted by the base-side data communication unit includes the identifier and the back-off time data,
The slave terminal is
A slave side data communication unit that suppresses power consumption of the communication device by transmitting and receiving data signals to and from the base unit and stopping operation during a period in which the transmission and reception is not performed;
A register that is included in the data signal received from the base unit and receives back-off time data specifying a back-off time from the data communication unit;
While the operation of the data communication unit on the slave side is stopped, the master unit waits for a wakeup signal requesting the communication device to transmit / receive the data signal, and when the wakeup signal is received, backoff processing is performed. A wake-up signal reception determination unit that generates a back-off time standby signal to be instructed;
When the back-off time standby signal is detected, the back-off time data stored in the register is read, and a physical phenomenon capable of observing a change with time on a scale according to the back-off time is generated. A communication network system, comprising: a back-off time standby unit that activates the data communication unit on the slave unit after observing the change over time and detecting the elapse of the back-off time.   The back-off time standby unit of the slave terminal includes a capacitor, stores a charge by applying a voltage determined based on the back-off time data to the capacitor, and observing a subsequent discharge phenomenon. The communication network system according to claim 14, wherein the passage of off time is detected.

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