JP2022185706A - Master unit, terminal, repeater, communication system, control method, and control program - Google Patents

Abstract

To provide a communication monitoring system, a communication monitoring method, and a communication monitoring program that can suppress power necessary to maintain a standby state until a terminal receives a dead-or-alive monitoring packet.SOLUTION: A master unit 1 includes a clock supply unit 11a and a transmission/reception unit 12a. The clock supply unit 11a measures time of a predetermined cycle, and outputs it to the transmission/reception unit 12a. The transmission/reception unit 12a transmits a dead-or-alive monitoring packet to a terminal 2 or a repeater 3 at timing of the predetermined cycle based on the time measured by the clock supply unit 11a. At this time, the transmission/reception unit 12a attaches information on the time measured by the clock supply unit 11a to the dead-or-alive monitoring packet and transmits the packet to the terminal 2 or the repeater 3.SELECTED DRAWING: Figure 6

Description

The present invention relates to a parent device, a terminal, a relay device, a communication system, a control method, and a control program.

In recent years, with the development of IoT (Internet of Things) technology, there is an increasing demand for services that collect and utilize information acquired by remote cameras and various sensors via wireless terminals. There is a growing need for technology that compensates for communication uncertainties in communication standards that cover a wide area with low power consumption, such as the Wireless Area.

As a technique for compensating for communication uncertainty in a communication standard such as LPWA, there is known a technique for monitoring a terminal by transmitting a life-and-death monitoring packet to the terminal from the base unit at a certain period. .

Also, as a related technique, Patent Document 1 is known. In Patent Document 1, in a network in which the base unit and the terminal periodically access, the base unit specifies the time for the terminal to transmit packets, and the terminal is put to sleep during other time periods, thereby reducing the power consumption of the terminal. is disclosed.

JP 2008-48027 A

As described above, a terminal can be monitored by a life-and-death monitoring packet. However, since the terminal needs to wait for and respond to life-and-death monitoring packets, it may be difficult to reduce power consumption. That is, the terminal cannot accurately grasp the timing of receiving the life-and-death monitoring packet from the parent device. Therefore, the terminal needs to maintain the standby state until it receives the life-and-death monitoring packet from the parent device, which causes the problem of consuming power corresponding to this.

In addition, in Patent Document 1, it is not possible to suppress the power consumption of a terminal while monitoring the terminal with a life-and-death monitoring packet.

The present disclosure has been made to solve the above-described problems, and provides a base unit, a terminal, a repeater, a communication system, a control method, and a control program capable of suppressing power consumption while performing life-and-death monitoring. It is intended to

The parent device according to the present disclosure is
a time measuring unit that measures the time of a predetermined cycle;
a communication unit configured to transmit a life-and-death monitoring packet including time information of the measured time to a terminal or a repeater at the timing of the predetermined period based on the measured time;
It is a parent device with

The terminal according to the present disclosure is
a time measuring unit that measures the time of a predetermined cycle;
a communication unit that wakes up from a sleep state at the timing of the predetermined cycle based on the measured time and receives a life-and-death monitoring packet containing time information from the parent device or the relay device;
a time synchronization unit for synchronizing the time of the time measurement unit with the time information included in the received life-and-death monitoring packet;
is a terminal with

The repeater according to the present disclosure is
a time measuring unit that measures the time of a predetermined cycle;
a communication unit that wakes up from a sleep state at the timing of the predetermined cycle based on the measured time, receives a life-and-death monitoring packet including time information from the parent device, and transmits the life-and-death monitoring packet to the terminal;
a time synchronization unit for synchronizing the time of the time measurement unit with the time information included in the received life-and-death monitoring packet;
It is a repeater with

A communication system according to the present disclosure includes:
A communication system comprising a base unit and a terminal,
The parent device
a first time measuring unit that measures a first time of a predetermined cycle;
a first communication unit configured to transmit, to the terminal, a life-and-death monitoring packet including time information of the measured first time at the timing of the predetermined period based on the measured first time;
with
The terminal is
a second time measuring unit that measures a second time of the predetermined period;
a second communication unit that wakes up from a sleep state at timing of the predetermined cycle based on the measured second time and receives a life-and-death monitoring packet including time information from the parent device;
a time synchronization unit for synchronizing the second time with the time information included in the received life-and-death monitoring packet;
A communication system comprising

The control method of the parent device according to the present disclosure includes:
Measure the time of a predetermined cycle,
transmitting a life-and-death monitoring packet including the time information of the measured time to the terminal or relay at the timing of the predetermined cycle based on the measured time;
This is the control method of the parent device.

A terminal control method according to the present disclosure includes:
Measure the time of a predetermined cycle,
waking up from the sleep state at the timing of the predetermined cycle based on the measured time, and receiving a life-and-death monitoring packet containing time information from the parent device or the relay device;
synchronizing the time with the time information included in the received life-and-death monitoring packet;
It is a terminal control method.

The control program of the parent device according to the present disclosure is
Measure the time of a predetermined cycle,
transmitting a life-and-death monitoring packet including the time information of the measured time to the terminal or relay at the timing of the predetermined cycle based on the measured time;
It is a parent device control program for causing a computer to execute processing.

The terminal control program according to the present disclosure is
Measure the time of a predetermined cycle,
waking up from the sleep state at the timing of the predetermined cycle based on the measured time, and receiving a life-and-death monitoring packet containing time information from the parent device or the relay device;
synchronizing the time with the time information included in the received life-and-death monitoring packet;
It is a terminal control program for causing a computer to execute processing.

According to the present disclosure, it is possible to provide a master device, a terminal, a repeater, a communication system, a control method, and a control program capable of suppressing power consumption while performing life-and-death monitoring.

It is a figure which shows life-and-death monitoring operation|movement in related technology. It is a figure which shows life-and-death monitoring operation|movement in related technology. FIG. 4 is a diagram showing an overview of life-and-death monitoring operation in the embodiment; FIG. 4 is a diagram showing an overview of life-and-death monitoring operation in the embodiment; 1 is a configuration diagram showing a configuration of a communication system according to Embodiment 1; FIG. 2 is a block diagram showing the configuration of a parent device according to the first exemplary embodiment; FIG. 2 is a block diagram showing a configuration of a terminal according to Embodiment 1; FIG. 2 is a configuration diagram showing another configuration of the communication system according to Embodiment 1; FIG. 2 is a block diagram showing a configuration of a repeater according to Embodiment 1; FIG. FIG. 2 is a configuration diagram showing the configuration of a communication system according to a second embodiment; FIG. FIG. 8 is a block diagram showing configurations of a master device and a terminal according to the second embodiment; FIG. 8 is a schematic diagram showing communication between a master device and a terminal according to the second embodiment; FIG. 11 is a block diagram showing configurations of a master device, a terminal, and a relay device according to a third exemplary embodiment; FIG. 11 is a schematic diagram showing communication among a master device, a terminal, and a relay device according to a third embodiment;

(Examination of related technology)
Life-and-death monitoring is indispensable for grasping the status of terminals in network services that consist of base units and terminals. Life-and-death monitoring is performed by the parent device transmitting a life-and-death monitoring packet to the terminal at a certain cycle, and the terminal returning an acknowledgment (hereinafter referred to as ACK) to the parent device to notify that it is alive. .

FIG. 1 shows a life-and-death monitoring operation between a parent device 901 and a terminal 902 in related technology. As shown in FIG. 1, the terminal 902 wakes up from the sleep state at a certain period 922 and tries to receive the life-and-death monitoring packet 911, but it can receive the life-and-death monitoring packet 911 from the parent device 901 at an exact time. Thus, it was necessary to wait for reception with a certain length of waiting period 921 . At this time, the actual processing itself when terminal 902 receives life-and-death monitoring packet 911 is to return ACK 912 to parent device 901 to notify that it is alive, and when this processing is completed, terminal 902 immediately shifts to the sleep state. We were able to. However, as described above, it is necessary to maintain the standby state until the life-and-death monitoring packet 911 is received. This unnecessary power consumption reduces the availability of terminals and prevents them from taking full advantage of the advantages of communication standards.

FIG. 2 shows a life-and-death monitoring operation in a related technology when a relay device 903 is interposed between a base device 901 and a terminal 902 . As shown in FIG. 2 , when a repeater 903 is used between a master device 901 and a terminal 902 , the relay device 903 returns from the sleep state at a constant period 924 and waits for a standby period 923 . receive the life-and-death monitoring packet 911 of When forwarding this to terminal 902, repeater 903 needs to retransmit repeatedly until terminal 902 receives this and returns ACK 912, and as a result, power consumption in repeater 903 is greater than that of terminal 2 described above. There was a problem that became big.

In addition, when relay device 903 is routed, master device 901 receives ACK 912 from terminal 902 via relay device 903 even after relay device 903 has successfully received life-and-death monitoring packet 911 of master device 901 . There is also a problem that the power consumption of the base unit 901 increases due to the need to continuously perform the standby operation in order to receive the .

(Overview of Embodiment)
Therefore, in the embodiment, in a network consisting of a terminal 2 and a base unit 1 that transmits and receives information between the terminal 2, the base unit 1 monitors the terminal 2 to compensate for communication uncertainty. Secondly, the terminal 2 uses this monitoring operation to synchronize the communication between the base unit 1 and the terminal 2, and by this synchronization, the unnecessary power consumption generated in the terminal 2 due to waiting for the monitoring from the base unit 1 can be reduced. It has the feature of reducing the number of terminals 2 and achieving both monitoring and longevity of the terminal 2 .

FIG. 3 shows an overview of the life-and-death monitoring operation between base unit 1 and terminal 2 in the embodiment. As shown in FIG. 3, terminal 2 wakes up from the sleep state at regular intervals 202, waits for life-and-death monitoring packet 101 during standby period 201, and returns ACK 102 upon receiving life-and-death monitoring packet 101 from master device 1. FIG. FIG. 4 shows an outline of the life-and-death monitoring operation in the case of passing through the repeater 3 between the base unit 1 and the terminal 2 in the embodiment. As shown in FIG. 4 , repeater 3 returns from the sleep state in cycle 204 and waits in standby period 203 to receive life-and-death monitoring packet 101 from base 1 and transfer it to terminal 2 .

The above-mentioned problem is to synchronize communication between the base unit 1 and the terminal 2 or between the base unit 1, the repeater 3 and the terminal 2, and determine the wake-up timing of the terminal 2 and the repeater 3, the repeater 3 and the base unit. When the relay device 3 receives the life-and-death monitoring packet 101 from the master device 1, the relay device 3 immediately returns an ACK 102 to the master device 1, and the ACK 102 from the terminal 2. can be solved by returning together with ACK 102 from the repeater 3 next time.

That is, base unit 1, repeater unit 3, and terminal 2 each have their own independent timers with constant cycles, and base unit 1 transmits life-and-death monitoring packet 101 including its own time information. Relay device 3 and terminal 2 predict the next reception timing according to their own time information at the timing of receiving the life-and-death monitoring packet for the first time from base device 1 and the time information of base device 1 included in life-and-death monitoring packet 101. In addition, by waiting for the next reception, the repeater 3 and the terminal 2 can optimize the wake-up time width for waiting for the reception of the next and subsequent times, and can reduce the power consumption associated with the monitoring operation. At this time, relay device 3 and terminal 2 output ACK 102 immediately after receiving the packet as described above, and relay device 3 outputs ACK 102 received from terminal 2 together with ACK 102 to base device 1 next time. By this processing, power consumption associated with the monitoring operation can be reduced even in the base unit 1 when the relay unit 3 is passed.

Embodiment 1.
Embodiment 1 will be described below with reference to the drawings.
FIG. 5 is a configuration diagram showing a configuration example of a communication system according to this embodiment. As shown in FIG. 5, a communication system 1001 includes a base unit 1 and a terminal 2 that wirelessly communicate with each other. Base unit 1 transmits a life-and-death monitoring packet to terminal 2, and terminal 2 returns an ACK corresponding to the life-and-death monitoring packet.

FIG. 6 is a block diagram showing a configuration example of the master device 1 according to this embodiment. As shown in FIG. 6, the base unit 1 includes a clock supply section 11a and a transmission/reception section 12a.

The clock supply unit 11a is a time measurement unit that measures the time of a predetermined cycle (life-and-death packet transmission cycle) (sometimes referred to as a first time measurement unit). The clock supply unit 11a outputs the information to the transmission/reception unit 12a at the timing when the time of the predetermined cycle has passed.

The transmitting/receiving unit 12a is a communication unit that transmits a life-and-death monitoring packet including time information of the current time measured by the clock supply unit 11a at predetermined intervals based on the time measured by the clock supply unit 11a. (Sometimes referred to as a first communication unit). Further, the transmitting/receiving unit 12a wakes up (resumes) from the sleep state at the timing of a predetermined cycle, waits for an ACK (response packet) from the terminal 2 (or the repeater 3) after transmitting the life-and-death monitoring packet, and Receive an ACK returned to the life-and-death monitoring packet.

FIG. 7 is a block diagram showing a configuration example of the terminal 2 according to this embodiment. As shown in FIG. 7, the terminal 2 includes a clock supply section 11b, a transmission/reception section 12b, and a reception timing check section 13b. The clock supply unit 11b is a time measurement unit that measures the time of the same predetermined cycle as the master device 1 (sometimes referred to as a second or third time measurement unit). The clock supplying unit 11b outputs the information to the transmitting/receiving unit 12b at the timing when the predetermined period of time has elapsed.

Based on the time measured by the clock supply unit 11b, the transmission/reception unit 12b wakes up from the sleep state at the timing of a predetermined period, and receives the time information of the clock supply unit 11a from the base unit 1 (or the repeater 3). A communication unit that receives monitoring packets (sometimes referred to as a second or third communication unit). Further, the transmitting/receiving unit 12b wakes up for a predetermined reception standby time from the timing of the predetermined cycle, waits for a life-and-death monitoring packet, and transmits an ACK corresponding to the received life-and-death monitoring packet to the base unit 1. FIG. The transmission/reception unit 12b outputs the received time information of the clock supply unit 11a to the reception timing check unit 13. FIG.

The reception timing check unit 13b corrects the time measured by the clock supply unit 11b based on the time information of the clock supply unit 11a input from the transmission/reception unit 12b. Specifically, the clock supply units 11a and 11b are corrected so as to measure the same time. The reception timing check unit 13b can be said to be a time synchronization unit that synchronizes the time of the clock supply unit 11b with the time information included in the life-and-death monitoring packet received (sometimes referred to as a first or second time synchronization unit). .

A processing flow of the communication monitoring method according to the present embodiment will be described. First, the transmitting/receiving unit 12a of the base unit 1 transmits a life-and-death monitoring packet including the time information of the time of the clock supplying unit 11a at predetermined intervals based on the time measured by the clock supplying unit 11a. When the transmitting/receiving unit 12b of the terminal 2 receives the life-and-death monitoring packet, the transmitting/receiving unit 12b transmits an ACK corresponding to the life-and-death monitoring packet to the transmitting/receiving unit 12a, and the time information of the clock supply unit 11a is received by the reception timing check unit 13. output to After transmitting ACK to the transmitting/receiving unit 12a, the transmitting/receiving unit 12b shifts to a sleep state. The reception timing check unit 13b corrects the time of the clock supply unit 11b based on the time information of the clock supply unit 11a input from the transmission/reception unit 12b so that the clock supply units 11a and 11b measure the same time. After that, the transmitting/receiving unit 12b wakes up from the sleep state at a timing of a predetermined cycle based on the corrected time, and waits for a life-and-death monitoring packet transmitted from the base unit 1. FIG.

Thus, by synchronizing the times of the clock supply units 11a and 11b of the base unit 1 and the terminal 2, respectively, and matching the timing at which the terminal 2 receives the life-and-death monitoring packet with the timing at which the terminal 2 enters the standby state, , the standby time of the terminal 2 can be suppressed, and as a result, power consumption of the terminal can be suppressed while performing life-and-death monitoring by the life-and-death monitoring packet.

Moreover, the communication system is not limited to the configuration of FIG. 5, and may further include a repeater. FIG. 8 is a configuration diagram showing another configuration example of the communication system according to this embodiment. In the example of FIG. 8 , communication system 1002 includes repeater 3 that relays wireless communication between master 1 and terminal 2 .

FIG. 9 is a block diagram showing a configuration example of the repeater 3 according to this embodiment. As shown in FIG. 9, the repeater 3 includes a clock supply section 11c, a transmission/reception section 12c, and a reception timing check section 13c. The clock supply unit 11c is a time measurement unit that measures the time of the same predetermined period as the master device 1 (sometimes referred to as a second or third time measurement unit). The clock supplying unit 11c outputs the information to the transmitting/receiving unit 12c at the timing when the predetermined period of time has elapsed.

Transmitting/receiving unit 12c wakes up from the sleep state at the timing of a predetermined cycle based on the time measured by clock supplying unit 11c, and receives a life-and-death monitoring packet including time information of clock supplying unit 11a from master device 1. , a communication unit that transmits life-and-death monitoring packets to the terminal 2 (sometimes referred to as a second or third communication unit). The transmitting/receiving unit 12c transmits a life-and-death monitoring packet including time information of the current time measured by the clock supplying unit 11c. Further, the transmitting/receiving unit 12c wakes up for a predetermined reception standby time from the timing of the predetermined cycle, waits for the life-and-death monitoring packet, and transmits an ACK corresponding to the received life-and-death monitoring packet to the base unit 1. FIG. Further, after transmitting the life-and-death monitoring packet, it waits for an ACK from the terminal 2, receives an ACK returned from the terminal 2 in response to the life-and-death monitoring packet, and next transmits an ACK to the base unit 1. The ACK and the ACK received from the terminal 2 are collectively transmitted. The transmission/reception unit 12c outputs the received time information of the clock supply unit 11a to the reception timing check unit 13c.

The reception timing check unit 13c corrects the time measured by the clock supply unit 11c based on the time information of the clock supply unit 11a input from the transmission/reception unit 12c. Specifically, the clock supply units 11a and 11c are corrected so as to measure the same time. The reception timing check unit 13c can be said to be a time synchronization unit that synchronizes the time of the clock supply unit 11c with the time information included in the received life-and-death monitoring packet (sometimes referred to as a first or second time synchronization unit). .

As described above, by synchronizing the times of the clock supply units 11a, 11b, and 11c of the base unit 1, the terminal 2, and the repeater 3, life-and-death monitoring is performed by the life-and-death monitoring packets while the terminal and the repeater are synchronized. Power consumption can be suppressed.

Embodiment 2.
Next, Embodiment 2 will be described with reference to FIGS. 10 to 12. FIG. FIG. 10 is a configuration diagram showing a configuration example of a communication system according to this embodiment. As shown in FIG. 10, a communication system 1003 according to this embodiment includes a master device 1, a terminal 2, a relay device 3, and a management center 4. FIG. For example, the base unit 1, the terminal 2, and the repeater 3 are capable of low power consumption wireless communication such as LPWA. Base unit 1 and management center 4 are connected by any wired or wireless communication line 5 . Although only two terminals 2 are shown in FIG. 10 for the sake of simplicity, the number of connectable terminals 2 is not limited to two. Similarly, the number of repeaters 3 is not limited.

Base unit 1 performs processing based on a request from management center 4 and periodically monitors terminal 2 and repeater 3 . When any request is generated from the management center 4 , the master device 1 interrupts life-and-death monitoring and transmits various instruction commands corresponding to the request to the terminal 2 directly or via the relay device 3 . Further, when the corresponding ACK is not received from the terminal 2 or relay device 3 that transmitted the life-and-death monitoring packet, the base device 1 may notify the management center 4 of a warning.

The terminal 2 is, for example, a remote camera or various sensors. Terminal 2 performs processing according to commands received from base unit 1, and periodically receives life-and-death monitoring packets from base unit 1 and responds to them. The relay device 3 relays communication including commands and life-and-death monitoring packets between the base device 1 and the terminal 2 .

The management center 4 is a management device that manages the operations and data of the terminal 2 via the master device 1 . The management center 4 issues a request for controlling the operation of the terminal 2 to the base unit 1 as necessary.

Base unit 1 and terminal 2 may communicate directly, or may communicate via relay device 3 . In this embodiment, a case where base unit 1 and terminal 2 communicate directly will be described in detail. A case where base unit 1 and terminal 2 communicate via relay unit 3 will be described in detail in a third embodiment.

FIG. 11 is a block diagram showing the configurations of the master device 1 and the terminal 2 according to this embodiment. Base unit 1 periodically transmits a life-and-death monitoring packet to terminal 2, and terminal 2 returns an ACK to the life-and-death monitoring packet. As shown in FIG. 11, the master device 1 includes a clock supply section 11a, a transmission/reception section 12a, and a packet communication control section 16a.

The clock supply unit 11a is a timer that counts the time of a predetermined period. In the present embodiment, the clock supply unit 11a counts time with a predetermined cycle of 60 seconds, but this can be adjusted as appropriate. Base device 1 treats the time measured by clock supply unit 11a as the internal time.

The transmission/reception unit 12a communicates with the terminal 2 under the control of the packet communication control unit 16a, which will be described later. The transmitting/receiving unit 12 a transmits the packet input from the packet communication control unit 16 a to the terminal 2 . Further, when receiving a packet from the terminal 2, the transmitting/receiving section 12a outputs it to the packet communication control section 16a.

The packet communication control unit 16a controls communication of the transmission/reception unit 12a. For example, the packet communication control unit 16a generates commands to be transmitted to the terminal 2, attaches and removes headers to packets exchanged with the transmission/reception unit 12a, and inputs/outputs information necessary for packet communication control. good. The packet communication control unit 16a controls the transmission/reception unit 12a and communicates with the terminal 2 based on the internal time input from the clock supply unit 11a. Specifically, the packet communication control unit 16a wakes up from the sleep state at a predetermined cycle timing based on the internal time, and waits for an ACK from the terminal 2 after transmitting the life-and-death monitoring packet. The packet communication control unit 16a attaches the internal time input from the clock supply unit 11a to the life-and-death monitoring packet. Further, the packet communication control unit 16a may shift the transmitting/receiving unit 12a to the sleep state at the timing when the ACK of the terminal 2 is input from the transmitting/receiving unit 12a.

Further, as shown in FIG. 11, the terminal 2 includes a clock supply section 11b, a transmission/reception section 12b, a reception timing check section 13b, a storage section 14b, a standby time setting section 15b, and a packet communication control section 16b. For example, the reception timing checking unit 13b, the storage unit 14b, the standby time setting unit 15b, and the packet communication control unit 16b may be provided in the CPU installed in the terminal 2. FIG. The clock supply unit 11b is a timer that counts the same period of time as the clock supply unit 11a. The clock supply unit 11b outputs the counting time information to the reception timing check unit 13b.

The transmitting/receiving section 12b communicates with the base unit 1 under the control of the packet communication control section 16b, which will be described later. Upon receiving a packet from base unit 1, transmitting/receiving section 12b outputs it to packet communication control section 16b. Also, it transmits the packet input from the packet communication control unit 16b to the base unit 1. FIG.

The reception timing check unit 13b inputs the time information of the clock supply unit 11a from the packet communication control unit 16b, and based on this, corrects the time information output by the clock supply unit 11b. Specifically, the reception timing check unit 13b corrects the time information output by the clock supply unit 11b so as to match the internal time of the base unit 1 output by the clock supply unit 11a. The terminal 2 treats this corrected time information as the internal time of the terminal 2 . In other words, the reception timing check unit 13b synchronizes the internal times of the base unit 1 and the terminal 2. FIG. The reception timing check section 13 outputs the synchronized internal time to the standby time setting section 15b.

The storage unit 14b is a memory that stores various parameters required for communication with the base unit 1. FIG. The storage unit 14b stores, as one of parameters, information on the length of time for which the terminal 2 is placed in a standby state (hereinafter referred to as standby time). In this embodiment, the standby time is set to 6 seconds until the first life-and-death monitoring packet is received, and to 1 second after the first life-and-death monitoring packet is received. Although this standby time can be adjusted as appropriate, it is preferable that the standby time after receiving the first life-and-death monitoring packet is shorter than the standby time until receiving the first life-and-death monitoring packet. In other words, when the terminal 2 synchronizes the internal time with the master device 1, it is preferable to set the standby time shorter than before the synchronization of the time.

The standby time setting unit 15b receives the internal time from the reception timing check unit 13b and inputs the standby time information from the storage unit 14b. The standby time setting unit 15b notifies the packet communication control unit 16b when the internal time reaches a predetermined time, and outputs information on the standby time.

The packet communication control unit 16b controls communication of the transmission/reception unit 12b. For example, the packet communication control unit 16b may add and remove headers of packets exchanged with the transmission/reception unit 12a, and input/output information necessary for packet communication control. The packet communication control unit 16b controls packet communication of the terminal 2 based on the notification from the standby time setting unit 15b. Specifically, at the timing when the notification is received from the standby time setting unit 15b, the transmitting/receiving unit 12b is shifted to the standby state, and the standby state of the terminal 2 is maintained during the set standby time. In other words, the terminal 2 wakes up for a predetermined reception waiting time from the timing of the predetermined cycle, and waits for the life-and-death monitoring packet. Further, when receiving the life-and-death monitoring packet of base unit 1 from transmitting/receiving unit 12b, packet communication control unit 16b outputs ACK to transmitting/receiving unit 12b.

11 and 12, the flow of life-and-death monitoring of base unit 1 and terminal 2 will be described in detail. FIG. 12 is a schematic diagram showing the relationship between the exchange of packets between base unit 1 and terminal 2 and the internal time. Arrows 101a to 101d directed from base unit 1 to terminal 2 represent life-and-death monitoring packets, and arrows 102a and b from terminal 2 to base unit 1 represent ACK. Periods 301a and 301b indicate periods in which there is no command input from the management center 4, and period 302 indicates periods in which there is no command input from the management center.

First, based on the base device 1 side internal time 401, the base device 1 transmits a life-and-death monitoring packet and the information of the base device 1 side internal time 401 to the terminal 2 at intervals of 1 second (corresponding to 101a to 101c). ). At this time, base unit 1 may repeat retransmission of the life-and-death monitoring packet until it receives ACK. Next, base unit 1 receives ACK 102 a corresponding to life-and-death monitoring packet 101 c from terminal 2 . Upon confirming reception of ACK 102a from terminal 2, base unit 1 shifts to a sleep state. After that, based on base unit 1 side internal time 401, base unit 1 shifts to the standby state at intervals of 60 seconds, which is a predetermined cycle, and transmits life-and-death monitoring packets to terminal 2 until an ACK from terminal 2 is received. Maintain standby time.

Next, the operation flow of the terminal 2 according to this embodiment will be described.
Terminal 2 uses the time counted by uncorrected clock supply unit 11b as terminal 2 internal time 402 until it receives the first life-and-death monitoring packet from base unit 1. It shifts to a standby state for a predetermined time. In the case of this embodiment, as described above, the terminal 2 shifts to the standby state at intervals of 60 seconds and maintains the standby state for 6 seconds. When the terminal 2 receives the first life-and-death monitoring packet 101c from the base device 1, the terminal 2 side internal time 402 is corrected based on the attached base device 1 side internal time 401 information. Specifically, the terminal 2 side internal time 402 is corrected so that the internal times of the base unit 1 and the terminal 2 are the same. For example, in the case of FIG. 12, since the life-and-death monitoring packet 101c is received at the timing of 3 seconds in the internal time of the base unit 1, the reception timing check unit 13b sets the timing of receiving the life-and-death monitoring packet 101c to 3 seconds as the internal time. The terminal 2 side internal time 402 of the terminal 2 is corrected. Next, terminal 2 transmits ACK 102a to base unit 1 and shifts to a sleep state. The standby time setting unit 15b notifies the packet communication control unit 16b each time the internal time 402 on the terminal 2 side becomes 0 seconds (that is, the timing when the clock supply unit 11b finishes counting a predetermined period of 60 seconds). out. The packet communication control unit 16b that has received the notification from the standby time setting unit 15b shifts the transmission/reception unit 12b to the standby state and maintains the standby state for one second. Terminal 2 receives a life-and-death monitoring packet from base unit 1 and returns an ACK during this standby state.

Base unit 1 and terminal 2 repeat these operations during periods 301a and 301b in which there is no command input from the management center. During a period 302 in which a command is input from the management center, communication of life-and-death monitoring packets is interrupted, and packets corresponding to the command are exchanged while maintaining the standby state.

To summarize the above, the reception timing check unit 13b corrects the internal time of the terminal 2 based on the internal time information of the base unit 1 transmitted with the life-and-death monitoring packet from the base unit 1, The internal time of the base unit 1 and the terminal 2 can be synchronized. As a result, it is possible to match the timing at which base unit 1 transmits the life-and-death monitoring packet with the timing at which terminal 2 shifts to the standby state, and terminal 2 can suppress the standby time.

Embodiment 3.
Next, Embodiment 3 will be described. In this embodiment, a case where base unit 1 and terminal 2 communicate via relay unit 3 in communication system 1003 of FIG. 10 will be described in detail using FIGS.

FIG. 13 is a block diagram showing the configurations of the parent device, terminals, and relay device according to the present embodiment. Base unit 1 and terminal 2 have the same configuration as in the second embodiment. The repeater 3 includes a clock supply unit 11c, a transmission/reception unit 12c, a reception timing check unit 13c, a storage unit 14c, a standby time setting unit 15c, and a packet communication control unit 16c, similarly to the terminal 2 in the second embodiment. there is

The clock supply unit 11c is a timer that counts the same period of time as the clock supply units 11a and 11b. The clock supply unit 11b outputs the counting time information to the reception timing check unit 13c.

The transmitting/receiving section 12b communicates with the base unit 1 under the control of the packet communication control section 16b, which will be described later. Upon receiving a packet from base unit 1, transmitting/receiving unit 12c outputs it to packet communication control unit 16c. Also, the packet input from the packet communication control unit 16c is transmitted to the base unit 1. FIG. Furthermore, the transmitting/receiving unit 12c communicates with the terminal 2 as well. That is, the packet input from the packet communication control unit 16c is transmitted to the terminal 2, and the packet received from the terminal 2 is output to the packet communication control unit 16c.

The reception timing check unit 13c receives the time information of the clock supply unit 11a from the packet communication control unit 16c, and based on this, corrects the time information output by the clock supply unit 11c. Specifically, the reception timing check unit 13c corrects the time information output by the clock supply unit 11c so as to match the internal time of the base unit 1 output by the clock supply unit 11a. The repeater 3 treats this corrected time information as the internal time of the repeater 3 . In other words, the reception timing check unit 13c synchronizes the internal times of the base unit 1 and the relay unit 3. FIG. The reception timing check unit 13c outputs the synchronized internal time to the standby time setting unit 15c.

The storage unit 14c is a memory that stores various parameters required for communication with the base unit 1. FIG. The storage unit 14c stores information on the standby time of the repeater 3 as one of parameters. In this embodiment, a standby time of 6 seconds is set until the first life-and-death monitoring packet is received, and after receiving the first life-and-death monitoring packet, the terminal 2 is set to shift to sleep as soon as ACK is received from terminal 2. is doing. Note that this standby time can be adjusted as appropriate. In addition, in this embodiment, after receiving the first life-and-death monitoring packet, it is set to shift to sleep as soon as ACK is received from terminal 2. May be set.

The standby time setting unit 15c receives the internal time from the reception timing check unit 13c and inputs the standby time information from the storage unit 14c. The standby time setting unit 15c notifies the packet communication control unit 16c when the internal time reaches a predetermined time, and outputs information on the standby time.

The packet communication control unit 16c controls communication of the transmission/reception unit 12c. For example, the packet communication control unit 16c may add or remove headers of packets exchanged between the transmitting/receiving units 12a and 12b, or input/output information necessary for packet communication control. The packet communication control unit 16c controls packet communication of the repeater 3 based on the notification from the standby time setting unit 15c. Specifically, at the timing when the notification is received from the standby time setting unit 15c, the transmitting/receiving unit 12c is shifted to the standby state, and the standby state of the repeater 3 is set based on the standby time information input from the standby time setting unit 15c. to maintain Further, when receiving the life-and-death monitoring packet for base unit 1 from transmission/reception unit 12c, packet communication control unit 16c outputs ACK for base unit 1 and a life-and-death monitoring packet for terminal 2 to transmission/reception unit 12c. At this time, the packet communication control unit 16c attaches the corrected internal time of the repeater 3 inputted from the reception timing check unit 13c to the life-and-death monitoring packet for the terminal 2. FIG. Further, when receiving the ACK from the terminal 2, the packet communication control unit 16c outputs the ACK from the terminal 2 to the transmitting/receiving unit 12c and causes the base unit 1 to transmit the ACK at the next timing of receiving the life-and-death monitoring packet from the base unit.

Hereinafter, with reference to FIGS. 13 and 14, the processing flow of base unit 1, terminal 2, and relay unit 3 according to the present embodiment will be described. FIG. 14 is a schematic diagram showing the relationship between the exchange of packets among the parent device 1, the terminal 2, and the relay device 3 and the internal time. Arrows 101a to 101h from base unit 1 to repeater 3 or from repeater 3 to terminal 2 represent life-and-death monitoring packets. Arrows 102a-d represent ACKs. Periods 301a and 301b indicate periods in which there is no command input from the management center 4, and period 302 indicates periods in which there is no command input from the management center.

First, based on the base device 1 side internal time 401, the base device 1 transmits a life-and-death monitoring packet and the information of the base device 1 side internal time 401 to the relay device 3 at intervals of 1 second (101a to 101c). Correspondence). Next, base device 1 receives ACK 102a corresponding to life-and-death monitoring packet 101c from relay device 3 . Upon confirming the reception of ACK 102a, base unit 1 transitions to a sleep state. After that, based on the base device 1 side internal time 401, the base device 1 shifts to the standby state at intervals of 60 seconds, which is a predetermined cycle, and transmits a life-and-death monitoring packet to the relay device 3. From the relay device 3, The standby time is maintained until ACKs from terminal 2 and repeater 3 arrive. At this time, if an ACK has not been received from the repeater 3 after a predetermined time has passed, or if the repeater 3 has not received an ACK from the terminal 2, the master 1 notifies the management center of a warning. may

Next, the operation flow of the repeater 3 according to this embodiment will be described. When relay device 3 receives the first life-and-death monitoring packet 101c from base device 1, relay device 3 performs the same processing as terminal 2 in the second embodiment, and synchronizes base device 1 side internal time 401 with relay device 3 side internal time 403. do. Further, relay device 3 transmits ACK 102a to base device 1 when receiving life-and-death monitoring packet 101c. Next, relay device 3 transmits to terminal 2 a life-and-death monitoring packet including information on relay device 3 side internal time 403 synchronized with base device 1 side internal time 401 . As with base unit 1, repeater 3 transmits life-and-death monitoring packets (corresponding to life-and-death monitoring packets from 101d to 101f) to terminal 2 at intervals of one second. At this time, the repeater 3 repeats retransmission of the life-and-death monitoring packet until it receives an ACK from the terminal 2 . After confirming the reception of ACK 102b from terminal 2, repeater 3 shifts to a sleep state. Repeater 3 that has transitioned to the sleep state transitions again to the standby state after a predetermined period of 60 seconds has elapsed, and receives life-and-death monitoring packet 101g from master device 1 . Upon receiving the life-and-death monitoring packet 101g from base unit 1, relay unit 3 returns ACK 102c. This ACK 102c includes information on the ACK of the terminal 2 corresponding to the life-and-death monitoring packet 101c (that is, ACK 102b) and information on the ACK of the repeater 3 itself corresponding to the life-and-death monitoring packet 101g. In other words, when relay device 3 receives an ACK from terminal 2 , relay device 3 transmits the ACK received from terminal 2 and its own ACK together when it next receives a life-and-death monitoring packet from base device 1 . Further, after receiving the life-and-death monitoring packet 101g, the repeater 3 transmits a life-and-death monitoring packet 101h corresponding to the life-and-death monitoring packet 101g to the terminal 2, and maintains the standby state until receiving the ACK 102d from the terminal 2. . With such a configuration, the standby time of the repeater 3 can be reduced more than the method shown in FIG.

The terminal 2 synchronizes the internal time 403 on the side of the relay device 3 with the internal time 402 on the side of the terminal 2 by the same processing as in the second embodiment, and synchronizes the timing of receiving the life-and-death monitoring packet from the relay device 3 with the timing of waking up itself. The timing is adjusted to exchange life and death monitoring packets with the repeater 3. - 特許庁

Base unit 1, terminal 2, and repeater 3 repeat these operations during periods 301a and 301b in which there is no command input from the management center. During a period 302 in which a command is input from the management center, communication of life-and-death monitoring packets is interrupted, and packets corresponding to the command are exchanged while maintaining the standby state.

In summary, the communication system according to the present disclosure can be applied even when the master device 1 and the terminal 2 communicate via the relay device 3, and the standby of the master device, the terminal, and the relay device The time to maintain the state can be reduced, and as a result, power consumption can be reduced.

Other embodiments.
The operations of base unit 1, terminal 2, and repeater 3 shown in Embodiments 2 and 3 may be executed by a communication monitoring program installed in these devices.

It should be noted that a program includes instructions (or software code) that, when read into a computer, cause the computer to perform one or more of the functions described in the embodiments. The program may be stored in a non-transitory computer-readable medium or tangible storage medium. By way of example, and not limitation, computer readable media or tangible storage media may include random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drives (SSD) or other memory technology, CDs -ROM, digital versatile disc (DVD), Blu-ray disc or other optical disc storage, magnetic cassette, magnetic tape, magnetic disc storage or other magnetic storage device. The program may be transmitted on a transitory computer-readable medium or communication medium. By way of example, and not limitation, transitory computer readable media or communication media include electrical, optical, acoustic, or other forms of propagated signals.

Some or all of the above-described embodiments can also be described in the following supplementary remarks, but are not limited to the following.
(Appendix 1)
a time measuring unit that measures the time of a predetermined cycle;
a communication unit configured to transmit a life-and-death monitoring packet including time information of the measured time to a terminal or a repeater at the timing of the predetermined period based on the measured time;
parent device.
(Appendix 2)
The communication unit wakes up from a sleep state at the timing of the predetermined cycle, and waits for a response packet from the terminal or relay device after transmitting the life-and-death monitoring packet.
A parent device as described in appendix 1.
(Appendix 3)
the communication unit transitions to a sleep state when receiving the response packet;
A parent device according to appendix 2.
(Appendix 4)
The communication unit repeats retransmission of the life-and-death monitoring packet until the response packet is received.
The parent device according to appendix 2 or 3.
(Appendix 5)
a time measuring unit that measures the time of a predetermined cycle;
a communication unit that wakes up from a sleep state at the timing of the predetermined cycle based on the measured time and receives a life-and-death monitoring packet containing time information from the parent device or the relay device;
a time synchronization unit for synchronizing the time of the time measurement unit with the time information included in the received life-and-death monitoring packet;
terminal with
(Appendix 6)
The communication unit wakes up for a predetermined reception waiting time from the timing of the predetermined cycle and waits for the life-and-death monitoring packet.
A terminal according to Appendix 5.
(Appendix 7)
When synchronizing the time, setting the reception standby time shorter than before synchronizing the time;
A terminal according to Appendix 6.
(Appendix 8)
a time measuring unit that measures the time of a predetermined cycle;
a communication unit that wakes up from a sleep state at the timing of the predetermined cycle based on the measured time, receives a life-and-death monitoring packet including time information from the parent device, and transmits the life-and-death monitoring packet to the terminal;
a time synchronization unit for synchronizing the time of the time measurement unit with the time information included in the received life-and-death monitoring packet;
A repeater with a
(Appendix 9)
wherein the communication unit transmits to the terminal a life-and-death monitoring packet including time information of the synchronized time;
The repeater according to appendix 8.
(Appendix 10)
the communication unit, when receiving the life-and-death monitoring packet, transmits its own response packet to the parent device;
10. The repeater according to appendix 8 or 9.
(Appendix 11)
The communication unit wakes up from a sleep state at the timing of the predetermined cycle, transmits the life-and-death monitoring packet to the terminal, and then waits for a response packet from the terminal.
11. The repeater according to appendix 10.
(Appendix 12)
The communication unit repeats retransmission of the life-and-death monitoring packet until it receives a response packet from the terminal.
The repeater according to appendix 11.
(Appendix 13)
When the communication unit receives a response packet from the terminal, the communication unit collectively transmits the response packets received from the terminal when transmitting its own response packet to the parent device next time.
13. The repeater according to appendix 11 or 12.
(Appendix 14)
A communication system comprising a base unit and a terminal,
The parent device
a first time measuring unit that measures a first time of a predetermined cycle;
a first communication unit configured to transmit, to the terminal, a life-and-death monitoring packet including time information of the measured first time at the timing of the predetermined period based on the measured first time;
with
The terminal is
a second time measuring unit that measures a second time of the predetermined period;
a second communication unit that wakes up from a sleep state at timing of the predetermined cycle based on the measured second time and receives a life-and-death monitoring packet including time information from the parent device;
a time synchronization unit for synchronizing the second time with the time information included in the received life-and-death monitoring packet;
communication system.
(Appendix 15)
A communication system comprising a base unit, a repeater and a terminal,
The parent device
a first time measuring unit that measures a first time of a predetermined cycle;
a first communication unit configured to transmit, to the terminal, a life-and-death monitoring packet including time information of the measured first time at the timing of the predetermined period based on the measured first time;
with
The repeater is
a second time measuring unit that measures a second time of the predetermined period;
A communication unit that wakes up from a sleep state at the timing of the predetermined cycle based on the measured second time, receives a life-and-death monitoring packet including time information from the parent device, and transmits the life-and-death monitoring packet to the terminal. When,
a first time synchronization unit for synchronizing the second time with the time information included in the received life-and-death monitoring packet;
said terminal comprising:
a third time measuring unit that measures a third time of the predetermined period;
a third communication unit that wakes up from a sleep state at timing of the predetermined cycle based on the measured third time and receives a life-and-death monitoring packet including time information from the repeater;
a second time synchronization unit for synchronizing the third time with the time information included in the received life-and-death monitoring packet;
communication system.
(Appendix 16)
Measure the time of a predetermined cycle,
transmitting a life-and-death monitoring packet including the time information of the measured time to the terminal or relay at the timing of the predetermined cycle based on the measured time;
Control method of parent machine.
(Appendix 17)
Measure the time of a predetermined cycle,
waking up from the sleep state at the timing of the predetermined cycle based on the measured time, and receiving a life-and-death monitoring packet containing time information from the parent device or the relay device;
synchronizing the time with the time information included in the received life-and-death monitoring packet;
Terminal control method.
(Appendix 18)
Measure the time of a predetermined cycle,
waking up from the sleep state at the timing of the predetermined cycle based on the measured time, receiving a life-and-death monitoring packet containing time information from the parent device, and transmitting the life-and-death monitoring packet to the terminal;
synchronizing the time with the time information included in the received life-and-death monitoring packet;
Control method of the repeater.
(Appendix 19)
Measure the time of a predetermined cycle,
transmitting a life-and-death monitoring packet including the time information of the measured time to the terminal or relay at the timing of the predetermined cycle based on the measured time;
A control program for the main unit that causes the computer to execute the processing.
(Appendix 20)
Measure the time of a predetermined cycle,
waking up from the sleep state at the timing of the predetermined cycle based on the measured time, and receiving a life-and-death monitoring packet containing time information from the parent device or the relay device;
synchronizing the time with the time information included in the received life-and-death monitoring packet;
A terminal control program that causes a computer to perform processing.
(Appendix 21)
Measure the time of a predetermined cycle,
waking up from the sleep state at the timing of the predetermined cycle based on the measured time, receiving a life-and-death monitoring packet containing time information from the parent device, and transmitting the life-and-death monitoring packet to the terminal;
synchronizing the time with the time information included in the received life-and-death monitoring packet;
A repeater control program that causes a computer to execute processing.

1, 901 base unit 2, 902 terminal 3, 903 repeater 4 management center 5 communication line 11a-c clock supply unit 12a-c transmission/reception unit 13b, 13c reception timing check unit 14b, 14c storage unit 15b, 15c standby time setting unit 16b, 16c Packet communication control units 101, 101a-h, 911 Life-and-death monitoring packets 102, 102a-d, 912 from the terminal to the terminal ACK from the terminal to the terminal
201, 921 Periods 202, 922 during which the terminal is in a standby state Cycles 203, 923 during which the terminal cancels the sleep state Periods 204, 924 during which the repeater is in a standby state Cycles 301a, 301b during which the repeater cancels the sleep state From the management center No command input period 302 Period with command input from the management center 401 Base unit 1 side internal time 402 Terminal 2 side internal time 403 Repeater 3 side internal time 1001, 1002, 1003 Communication system

Claims (12)

a time measuring unit that measures the time of a predetermined cycle;
a communication unit configured to transmit a life-and-death monitoring packet including time information of the measured time to a terminal or a repeater at the timing of the predetermined period based on the measured time;
parent device. The communication unit wakes up from a sleep state at the timing of the predetermined cycle, and waits for a response packet from the terminal or relay device after transmitting the life-and-death monitoring packet.
The master unit according to claim 1. a time measuring unit that measures the time of a predetermined cycle;
a communication unit that wakes up from a sleep state at the timing of the predetermined cycle based on the measured time and receives a life-and-death monitoring packet containing time information from the parent device or the relay device;
a time synchronization unit for synchronizing the time of the time measurement unit with the time information included in the received life-and-death monitoring packet;
terminal with The communication unit wakes up for a predetermined reception waiting time from the timing of the predetermined cycle and waits for the life-and-death monitoring packet.
A terminal according to claim 3. a time measuring unit that measures the time of a predetermined cycle;
wakes up from a sleep state at the timing of the predetermined cycle based on the measured time, receives a life-and-death monitoring packet including time information from the master device, and sends a response packet corresponding to the received life-and-death monitoring packet to the master device; a communication unit that transmits the life-and-death monitoring packet to the terminal;
a time synchronization unit for synchronizing the time of the time measurement unit with the time information included in the received life-and-death monitoring packet;
A repeater with a maintaining the awake state until the communication unit receives a response packet to the life-and-death monitoring packet from the terminal;
The repeater according to claim 5. When the communication unit receives the response packet from the terminal, the communication unit collectively transmits the response packets received from the terminal when transmitting its own response packet to the parent device next time.
The repeater according to claim 5 or 6. A communication system comprising a base unit and a terminal,
The parent device
a first time measuring unit that measures a first time of a predetermined cycle;
a first communication unit configured to transmit, to the terminal, a life-and-death monitoring packet including time information of the measured first time at the timing of the predetermined period based on the measured first time;
with
The terminal is
a second time measuring unit that measures a second time of the predetermined period;
a second communication unit that wakes up from a sleep state at timing of the predetermined cycle based on the measured second time and receives a life-and-death monitoring packet including time information from the parent device;
a time synchronization unit for synchronizing the second time with the time information included in the received life-and-death monitoring packet;
communication system. Measure the time of a predetermined cycle,
transmitting a life-and-death monitoring packet including the time information of the measured time to the terminal or relay at the timing of the predetermined cycle based on the measured time;
Control method of parent machine. Measure the time of a predetermined cycle,
waking up from the sleep state at the timing of the predetermined cycle based on the measured time, and receiving a life-and-death monitoring packet containing time information from the parent device or the relay device;
synchronizing the time with the time information included in the received life-and-death monitoring packet;
Terminal control method. Measure the time of a predetermined cycle,
transmitting a life-and-death monitoring packet including the time information of the measured time to the terminal or relay at the timing of the predetermined cycle based on the measured time;
A control program for the main unit that causes the computer to execute the processing. Measure the time of a predetermined cycle,
waking up from the sleep state at the timing of the predetermined cycle based on the measured time, and receiving a life-and-death monitoring packet containing time information from the parent device or the relay device;
synchronizing the time with the time information included in the received life-and-death monitoring packet;
A terminal control program that causes a computer to perform processing.

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