Wireless communication system

Abstract

To obtain a wireless communication system which is easily operated by an operator and is used for safety control of the operator.SOLUTION: A mobile terminal 10 has functions such as originating a signal related to safety or the like of an operator other than a function of performing a telephone conversation with an external side and between operators. A base station 20 is connected to the mobile terminals 10 by a wireless LAN and arranged at a place communicable with all the mobile terminals 10. When an abnormality related to the operator and the mobile terminal 10 is recognized, the recognition of the abnormality is transmitted to a guard terminal 50 from the base station 20, an EPC 30, and an SIP server 40 via a network. The operator holds a smaller remote controller 70 having only a limited function other than the mobile terminal 10. The other party of communication of the remote controller 70 is only the mobile terminal 10 held by the operator who holds the remote controller 70 simultaneously.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a wireless communication system in which a portable mobile terminal capable of making a call, such as a smartphone, is used.

Background Art

[0002] Wireless communication systems are used for various applications. For example, as described in Patent Document 1, they may be used for the purpose of safety management of workers within a large factory or the like.

[0003] FIG. 8 shows an outline of the configuration of a wireless communication system 9 described in Patent Document 1. Here, the mobile terminal 110 is carried by each worker at the work site W, and the base station 120 is provided for each work site W and is installed in a state where it can perform wireless communication with all the mobile terminals 110 of the workers at this work site W. A control device 130 is connected to the base station 120 by a LAN. In FIG. 8, the number of work sites W and the number of mobile terminals 110 per work site W are set to two, but these numbers are arbitrary. In particular, the number of mobile terminals 110 per work site W may be larger. The control device 130 has a function of causing the mobile terminal 110 to communicate with the outside or between the mobile terminals 110, and a function of issuing an alarm based on information obtained from each mobile terminal 110. Further, for example, when a worker falls during work and the mobile terminal 110 physically recognizes this, it can transmit this fact to the external control device 130, and when the external control device 130 recognizes this, it can also issue an alarm.

[0004] In this case, in order to make the system inexpensive, it is preferable to use a commercially available portable terminal as the mobile terminal 110 instead of a specially designed device. For this reason, conventionally, for example, when constructing a private system, the PHS (Personal Handy-Phone System) method is used as a relatively easy system, and as the mobile terminal 110, a PHS terminal equipped with a mechanical push-button type operation unit is particularly preferably used because the system can be made inexpensive and high reliability can be obtained.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Disclosure of the Invention

Problems to be Solved by the Invention

[0006] Due to the recent progress of wireless communication technology, the communication system has shifted from the PHS system to the fourth-generation wireless communication system and the fifth-generation wireless communication system, making it possible to wirelessly communicate more data. Furthermore, the corresponding mobile terminals are being replaced by more high-functional smartphones. In addition, it is expected that the service of the PHS system will end and it will be difficult to obtain PHS terminals. Therefore, even when the above wireless communication system changes, it has been desired to use a smartphone instead of a mobile terminal such as a PHS terminal equipped with a conventional mechanical push-button type operation unit.

[0007] On the other hand, while smartphones are highly functional, when an operator handles them during work as described above, they may be more inconvenient than, for example, a mobile terminal equipped with a conventional mechanical push-button type operation unit such as a PHS terminal. For example, in a conventional mobile terminal, generally, a plurality of mechanical push-button type operation buttons for the telephone function are arranged on the surface, and the operation is performed by the operator selecting and pressing this operation button. In contrast, generally, the operation of a smartphone is performed by the operator touching a touch panel (touch panel display) that occupies most of the surface of the smartphone in order to realize more functions.

[0008] During work, workers often wear gloves for safety. While it is easy to press the operation buttons on a conventional mobile terminal with gloved fingers, it is often difficult to operate the touch panel display on a smartphone. Therefore, when operating a smartphone, the worker had to remove the gloves. In this case, if the conventional mobile terminal was simply replaced with a smartphone in the above wireless communication system, it might not be easy to perform operations, especially in case of emergency. For this reason, a wireless communication system that is easy for workers to operate and is used for worker safety management is desired.

[0009] The present invention has been made in view of such a situation, and an object thereof is to solve the above problems.

Means for Solving the Problems

[0010] The wireless communication system of the present invention includes a mobile terminal carried by a worker Having a call function and a base station connected to the mobile terminal by wireless communication, and is a wireless communication system that enables communication via the base station by the mobile terminal, and is separated from the mobile terminal, Accepting an operation only by being pressed and includes an operation unit provided with a plurality of operation buttons. Each of the operation buttons is associated with a function corresponding to an operation related to a call using the mobile terminal. When one of the operation buttons is operated, a remote control device is provided that transmits a signal for causing the operation in the mobile terminal corresponding to the operation button to be performed toward the mobile terminal by wireless communication The remote control device includes an acceleration sensor that detects an acceleration applied along a certain direction in itself, transmits a notification signal to the mobile terminal according to the detected acceleration, and the mobile terminal performs an operation according to the received notification signal. A plurality of the remote control devices can be connected to one mobile terminal by the wireless communication thereby. In the wireless communication system of the present invention, the wireless communication between the remote control device and the mobile terminal may be performed by BLE (BlueTooth Low Energy: registered trademark) 。 In the wireless communication system of the present invention, the remote control device is carried by the worker, the notification signal is a signal for notifying that an abnormality has occurred to the worker, and the mobile terminal may notify the management device that manages the worker via the base station that the notification signal has been received.

Advantages of the Invention

[0011] According to the present invention, a wireless communication system for the safety management of workers, which is easy for workers to operate, can be obtained.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0013] Next, embodiments for carrying out the present invention will be specifically described with reference to the drawings. FIG. 1 is a diagram showing the overall configuration of a wireless communication system 1 according to an embodiment of the present invention.

[0014] This wireless communication system 1 is used for the purpose of safety management of workers at the work site W inside a large factory or the like, similar to the wireless communication system 9 shown in FIG. 8 of Patent Document 1. For this reason, each worker holds a mobile terminal 10. This mobile terminal 10 is similar to the above-mentioned mobile terminal 110 in that, in addition to the functions of making calls to the outside and making calls between workers (mobile terminals 10), it also has functions such as transmitting signals related to the safety of workers. However, this mobile terminal 10 is a more highly functional smartphone, whereas the above-mentioned mobile terminal 110 was a mobile terminal having, for example, a conventional mechanical push-button type operation button. For this reason, no operation keys (operation buttons) are provided on the surface of the mobile terminal 10, and a touch panel display that occupies most of the surface is provided. In FIG. 1, only two mobile terminals 10 are provided, but in reality, since the mobile terminals 10 are individually held by workers, a large number of them are provided according to the number of workers.

[0015] The base station 20 is connected to the mobile terminal 10 by a wireless LAN (such as Wi-Fi (registered trademark)) and is installed at a location where it can communicate with all mobile terminals 10. The base station 20 has a function of relaying when the mobile terminal 10 performs the above operations, and in this regard, it is the same as the wireless communication system described in Patent Document 1. In FIG. 1, one work site W and one base station 20 are provided correspondingly, but similar to the case in FIG. 8, a plurality of work sites W may be provided, and a base station 20 may be provided for each of them.

[0016] The base station 20 is connected to an EPC (Evolved Packet Core) 30, which is a core network system for calls, via a LAN. The EPC 30 is further connected to a SIP server 40 via a LAN. The SIP server 40 is a call management server similar to that described in, for example, Japanese Patent Application Laid-Open No. 2019-134377. Note that while the position of the mobile terminal 10 may vary constantly with the operator, if the positions of the base station 20 and the SIP server 40 are fixed, a network connecting them can appropriately use a network corresponding to this situation, and it is not necessary to use the same method (wireless LAN) as that used between the mobile terminal 10 and the base station 20.

[0017] Particularly, when an abnormality is recognized regarding the operator or the mobile terminal 10, this fact is transmitted from the base station 20, the EPC 30, and the SIP server 40 to a security terminal (management device) 50 via the network. The security terminal 50 can obtain information and various signals from all connected mobile terminals 10 and issue an alarm or other messages accordingly. This alarm can be issued, for example, using a simultaneous broadcast within the work site W.

[0018] In the above configuration, except that a smartphone is used as the mobile terminal 10, there is no significant difference from the technology described in Patent Document 1. However, here, in addition to the mobile terminal 10 (smartphone), the operator also holds a remote control device 70 that is smaller and has only limited functions. FIG. 2(a) is an external view of this remote control device 70, and FIG. 2(b) is a block diagram showing its configuration. This remote control device 70 also has a communication function similar to that of the mobile terminal 10, but the communication partner of the remote control device 70 is only the mobile terminal 10 held by the operator who holds this remote control device 70 at the same time. For this reason, the communicable distance of the remote control device 70 is set short, and instead, it is preferably low power consumption. As a communication method used between the remote control device 70 and the mobile terminal 10 in this way, for example, BLE (BlueTooth Low Energy (registered trademark)) is preferably used as the wireless LAN.

[0019] In Fig. 2(b), a BLE communication unit 71 for performing communication (transmission and reception) by BLE as described above, and a storage unit 72 which is a non-volatile memory for storing various software and data are provided. Further, an operation unit 73 having seven operation buttons, a display unit 74 which is smaller than the mobile terminal 10 (smartphone) for displaying various information, a control unit 75 for controlling the entire remote control device 70, and a battery 76 which serves as the power source of the remote control device 70 are provided. Further, an acceleration sensor 77 for detecting abnormalities such as the operator's fall as will be described later is also provided. Since the functions of this remote control device 70 are fewer compared to the mobile terminal 10 (smartphone) or a conventional mobile terminal (PHS terminal, etc.) having, for example, mechanical push-button type operation buttons, the operation unit 73 is composed of only the seven operation buttons as described above. Also, the information displayed on the display unit 74 is less than that of the mobile terminal 10, and for example, it may be sufficient to display character information or the like that simply and clearly indicates the currently performed operation. For this reason, as shown in Fig. 2(a), if most of the surface of the remote control device 70 is occupied by the operation unit 73 and the display unit 74, the remote control device 70 can be made smaller than the mobile terminal 10.

[0020] When connected by BLE, the remote control device 70 is a peripheral (slave unit), and the mobile terminal 10 is a central (master unit). For this reason, the BLE communication unit 71 periodically transmits an advertisement packet, and when the mobile terminal 10 searches for and recognizes this, a connection request is transmitted to this remote control device 70, thereby establishing a BLE connection between them. In Fig. 1, it is assumed that the same operator holds the mobile terminal 10 and the remote control device 70 at the same time, and the mobile terminal 10 and the remote control device 70 correspond one-to-one. However, as will be described later, only one operator holds the mobile terminal 10, and a plurality of operators individually hold the remote control device 70, and there may be a case where a plurality of remote control devices 70 correspond to one mobile terminal 10. Even in this case, a BLE connection between the mobile terminal 10 and each individual remote control device 70 is established by the same operation, and the mobile terminal 10 can recognize each individual remote control device 70.

[0021] As will be described later, the control unit 75 transmits various signals to the mobile terminal 10 by the BLE communication unit 71 according to the operations by the operation unit 73 and the output of the acceleration sensor 77. Further, the control unit 75 can detect the output voltage and current of the battery 76, recognize the remaining amount of the battery by a well-known method, and also transmit a signal corresponding thereto to the mobile terminal 10.

[0022] Since the remote control device 70 is sufficiently smaller and lighter than the mobile terminal 10, it is easy for the operator to hold the mobile terminal 10 and the remote control device 70 simultaneously. FIG. 3 is a diagram schematically showing a form in which the operator H holds the mobile terminal 10 and the remote control device 70 simultaneously. The relatively large mobile terminal 10 can be accommodated in the large pocket P1 in the work clothes S worn by the operator H, and the small remote control device 70 can be accommodated in the small pocket P2. Since the operator H does not need to touch the mobile terminal 10 and the remote control device 70 during normal work, the state of FIG. 3 is maintained. At this time, if the remote control device 70 has an elongated shape as shown in FIG. 1 and the pocket P2 has a vertically long shape corresponding thereto, the posture of the remote control device 70 with respect to the operator H (the posture in which the up-down direction in FIG. 1 coincides with the actual up-down direction) is maintained constant.

[0023] The functions realized by this remote control device 70 will be described. These functions are roughly classified into (1) a function for calls by the operator H and (2) a function for the management of the operator H and the remote control device 70 itself.

[0024] First, the function for the operator H to make a call will be described. As described above, seven operation buttons (#1 to #7) are provided on the operation unit 73. In a mobile terminal (such as a PHS terminal) having a mechanical push-button type operation button that was conventionally used as a mobile terminal, more than 10 operation buttons corresponding to telephone numbers (numbers 0 to 9) and the like were used. In contrast, each of the seven operation buttons on this operation unit 73 corresponds to a unique function in the mobile terminal 10. FIG. 4 shows an example of the functions associated with the seven operation buttons. When each operation button is pressed, the control unit 75 issues a signal indicating that the operation button has been operated to the mobile terminal 10 side by the BLE communication unit 71.

[0025] In FIG. 4, when the operation button #1 is pressed, the mobile terminal 10 recognizes this and issues an emergency alert (a communication indicating that an emergency has occurred) to the security terminal 50 side.

[0026] The other operation buttons in FIG. 4 correspond to operations related to making a call using the operator H's mobile terminal 10 (smartphone). First, when the operation button #5 is pressed, the mobile terminal 10 starts a call as an emergency contact. As a result, in the form of FIG. 3, the operator H can start a call in this state without taking out the mobile terminal 10 from the pocket P1. Similarly, the operation button #3 corresponds to the response when a call comes in to the mobile terminal 10, the operation button #2 corresponds to off-hook (ending the call), the operation button #4 corresponds to mute (stopping voice input), and the operation button #6 corresponds to hold. When these operation buttons are pressed, the mobile terminal 10 causes these operations to be performed. Also, the operation button #7 is a button for starting a call to a specific destination (for example, the security terminal 50 side, etc.) that is not an emergency contact.

[0027] In particular, operation buttons #2 to #7 are operations related to calls using the mobile terminal 10. At this time, for such calls, it is not necessary to take out the mobile terminal 10 from the pocket 1 from the state shown in FIG. 3. Therefore, for dealing with such calls, the operator H can perform them only by taking out the remote control device 70 from the pocket P2 and operating it without touching the mobile terminal 10 at all.

[0028] The configuration of FIG. 4 is an example. However, by limiting the functions of the operation buttons of the operation unit 73 in this way, the number of operation buttons can be made smaller than that of conventional mobile terminals (such as PHS terminals). Therefore, the operation of the remote control device 70 becomes easier than the operation of conventional mobile terminals. Also, the operator can directly perform the same operation using the mobile terminal 10. However, in this case, since it is necessary to operate the touch panel display on the mobile terminal 10, when wearing gloves, it is necessary to remove them when performing this operation. On the other hand, in the above configuration, the operations related to calls as described above can be realized only by operating the small number of operation buttons on the operation unit 73 of the remote control device 70, and there is no need to touch the mobile terminal 10 at all.

[0029] Figure 5 is a sequence diagram of the operations in the wireless communication system 1 when the operation buttons #1 and #2 are pressed. When the operation button #1 is pressed in the remote control device 70 (S101), a corresponding signal (a signal indicating that the operation button #1 has been operated) is emitted from the remote control device 70 by the BLE communication unit 71, and the mobile terminal 10 receives this signal (S102). When the mobile terminal 10 recognizes this, it transmits an emergency notification signal to the SIP server 40 via the base station 20 and the EPC 30 in FIG. 1 (S103). The SIP server 40 relays this emergency notification signal and transmits it to the security terminal 50 (S104). The security terminal 50 or its administrator recognizes the emergency notification signal and the identification number of the mobile terminal 10 that issued this signal. When the security terminal 50 recognizes these, it establishes and maintains the connection (call) state between this mobile terminal 10 and the security terminal 50 or the telephone system connected to this (connection sequence: S105). As a result, the operator H holding this mobile terminal 10 can make a call or the like with the security terminal 10 side, and for example, can report details about the occurred emergency situation to the security terminal 50 side. At this time, since the first report of the occurrence of the emergency situation is quickly made only by pressing the operation button 1, the above operations can be performed quickly. The measures after the security terminal 50 receives the emergency notification signal are appropriately set, such as making this notification by in-building broadcast and contacting all the mobile terminals 10.

[0030] When the operator H finishes the call, by pressing the operation button #2 (S106), a signal indicating that the operation button #2 has been operated is emitted from the remote control device 70 by BLE, and the mobile terminal 10 receives this signal (S107). When the mobile terminal 10 recognizes this, it ends the call and transmits a signal corresponding to off-hook to the SIP server 40 via the EPC 30 (S108). The SIP server 40 relays this emergency notification signal and transmits it to the security terminal 50 (S109). The security terminal 50 recognizes this and releases the connection sequence (S105). As a result, the call in case of emergency ends.

[0031] In the above operation, the first report of an emergency is quickly made only by pressing the operation button #1. Therefore, the security terminal 50 can quickly recognize the emergency and can quickly perform the above operation. At this time, the operator does not need to touch the mobile terminal 10 at all, and can perform the above operation while wearing gloves, for example.

[0032] Next, the operation for the safety management of the operator (2) by the remote control device 70 and the management of the remote control device 70 itself will be described. The operation of (1) above was started by the operation of the operation unit 73 (operation button) by the operator H, whereas this operation is automatically performed by the control unit 75.

[0033] First, the operation related to the safety management of the operator will be described. This operation is mainly performed based on the value of the acceleration detected by the acceleration sensor 77. The states of the operator that should be recognized for this purpose include a state where the operator has fallen during work and a state where the operator has become immobile due to sudden illness or the like (immobile state).

[0034] Here, the acceleration sensor 77 detects the acceleration applied to itself along the longitudinal direction (vertical direction in the figure) of the remote control device 70 in FIGS. 1 to 3. Therefore, an acceleration of 1G is detected in the state of FIG. 3, and when the operator H lies down from this state, the value of the detected acceleration becomes smaller and approaches zero. Therefore, when the acceleration is recognized as small for a certain period of time, it can be estimated that the operator H has fallen. Similarly, when the operator performs some work, at least a part of the body moves, so the value of the acceleration detected by the acceleration sensor 77 changes over time. Therefore, when the state where no change in acceleration is recognized continues for a certain period of time, it can be estimated that the operator is in an immobile state. However, in practice, in addition to these conditions, various restrictions are added, and the determination of the fallen state and the immobile state can be made.

[0035] FIG. 6 is a flowchart showing an operation of detecting that an operator has fallen in this wireless communication system. Here, the subject performing each operation is described in parentheses in each step, and for steps without this, it is assumed to be by the remote control device 70 (control unit 75).

[0036] First, the control unit 75 recognizes the current acceleration value by the acceleration sensor 77 (S1). This operation can be performed at regular intervals. Next, the control unit 75 recognizes whether the recognized acceleration is equal to or less than a certain threshold value α1 (S2). Here, since the remote control device 70 lying on its side is recognized as a fallen state, this threshold value α1 can be set to a value smaller than, for example, 1G, for example, 0.7G. When the acceleration exceeds α1 (S2: No), it is recognized that there is no abnormality, so it waits until the next acceleration detection (S1). Even when the acceleration is equal to or less than α1 (S2: Yes), considering that the remote control device 70 may temporarily lie on its side during work but not fall, comparing with the previous measurement results (S1), even when the state where the acceleration has continuously been equal to or less than α1 has not reached a certain time T1 at this point (S3: No), similarly, it waits until the next acceleration detection (S1). T1 can be set to, for example, 30 sec.

[0037] When the state where the acceleration has continuously been equal to or less than α1 has exceeded a certain time T1 (S3: Yes), there is a high possibility that the operator has fallen. Therefore, the control unit 75 issues a signal (fall signal: notification signal) indicating that the operator has fallen to the mobile terminal 10 side by the BLE communication unit 71 (S4), and the mobile terminal 10 recognizes this.

[0038] In response to this, on the side of the mobile terminal 10, an alarm (for example, an alarm sound) is issued to the operator, and the operator's response thereto is recognized. This operation is performed a plurality of times with the preset number of retries N1 as the upper limit until there is a response by call from the operator and the recognized acceleration increases. Therefore, on the side of the mobile terminal 10, first, the number of times this operation has been performed is reset (S5). Next, the mobile terminal 10 issues an alarm (fall alarm) such as emitting an alarm sound (S6). In this case, the alarm may be continued for a time shorter than T2 described later, or the alarm may be continuously issued. Also, the mobile terminal 10 may display that fact on the touch panel display thereof. The operator H can thereby know that he / she is recognized as having fallen.

[0039] Thereafter, the mobile terminal 10 establishes a call connection between the security terminal 50 and the mobile terminal 10 in the same manner as S105 in FIG. 5 (S7). Thereby, the operator can make a call with the security terminal 50 side using the mobile terminal 10. At this time, similar to the above case, the operator H does not need to touch the remote control device 70 or the mobile terminal 10. Thereafter, the mobile terminal 10 waits to wait for this call for a time T2 as the time required for the operator to respond (S8). T2 can be set to, for example, 30 sec.

[0040] If the mobile terminal 10 can confirm a call during this period (S9: Yes), it recognizes the acceleration recognized on the remote control device 70 side at this time and compares it with the threshold value α1 again (S10). If there is no response from the operator (S9: No), or if the subsequent acceleration does not exceed α1 even if there is a response (S9: Yes, S10: No), it is highly likely that some abnormal situation has occurred to the operator. Therefore, the mobile terminal 10 issues an alarm (fall report) to the security terminal 50 indicating that the operator holding this remote control device 70 (mobile terminal 10) has fallen (S11), increments the retry count (S12), and as long as this retry count does not exceed N1 (S14: No), the alarm reporting (S6) to the acceleration comparison with the threshold value α1 (S10) in the mobile terminal 10 is repeated. The upper limit N1 of the retry count can be set to 10 times, for example.

[0041] If there is a response from the operator (S9: Yes) and the acceleration exceeds the threshold value α1 (S10: Yes), it is considered that the operator is safe and has recovered from the fallen state. Therefore, the remote control device 70 releases the fall signal to return to the initial state (S14), and the mobile terminal 10 transmits to the security terminal 50 that the operator has recovered from the fallen state (S15).

[0042] If the retry count exceeds N1 (S13: Yes), it is presumed that the operator has fallen and become unable to respond. Therefore, the mobile terminal 10 contacts the security terminal 50 to that effect, and the security terminal 50 takes emergency measures such as making an in-premises broadcast (S16).

[0043] On the one hand, FIG. 7 is a flowchart showing an operation for detecting that an operator is in a stationary state in this wireless communication system. First, similar to the case of FIG. 6, the control unit 75 recognizes the current acceleration value by the acceleration sensor 77 (S21). This operation can be performed, for example, at a fixed period. Next, the control unit 75 recognizes the difference (absolute value) between the acceleration recognized here and the acceleration value detected immediately before (S22), and recognizes whether this difference is equal to or less than a certain threshold α2 (S22). Here, this threshold α2 can be set as a value that is sufficiently close to zero, for example, 0.05G. If this difference exceeds α2 (S22: No), it is recognized that the operator has made some movement, so the system waits until the next acceleration detection (S21). When this difference is equal to or less than the threshold (S22: Yes), even if the state where this difference has been continuously equal to or less than the threshold α2 has not reached a certain time T3 at this point (S23: No), similarly, the system waits until the next acceleration detection (S21). The time T3 can be set to, for example, 30 sec, similar to the case of T1 described above.

[0044] When the state where the acceleration difference is equal to or less than α2 has exceeded a certain time T3 (S23: Yes), it is highly likely that the operator is in a stationary state. Therefore, the control unit 75 emits a signal (stationary signal: notification signal) indicating that the operator is stationary to the mobile terminal 10 side through the BLE communication unit 71 (S24), and the mobile terminal 10 recognizes this.

[0045] In response to this, similar to the operation in FIG. 6, on the side of the mobile terminal 10, an alarm (for example, an alarm sound) is issued to the operator, the response of the operator to this is recognized, and then the operation of confirming the difference in acceleration is performed a plurality of times with the retry count N2 as the upper limit. Similar to N1 described above, N2 can be set to, for example, 10 times. For this reason, on the side of the mobile terminal 10, first, the retry count of this operation is reset (S25). The operation of issuing an alarm (immobility alarm) in the mobile terminal 10 (S26), the establishment of a call connection between the security terminal 50 and the mobile terminal 10 (S27), the standby at time T4 for recognizing a call from the operator during time T4 (S28), the confirmation of the call (S29), and the confirmation of the difference in acceleration again (S30) are performed in the same manner as S6 to S10 in FIG. 6. The standby time T4 can be set to, for example, 30 sec, similar to the case of T2 described above.

[0046] If there is no response from the operator (S29: No), or even if there is a response (S29: Yes) but the subsequent difference in acceleration does not exceed α2 (S30: No), it is highly likely that some abnormal situation has occurred to the operator. After that, similar to the case of FIG. 6, the operation of issuing an alarm (immobility report) to the security terminal 50 indicating that the operator is in an immobile state (S31), the increment of the retry count (S32), and the determination of whether this retry count exceeds N2 (S33) are performed. As a result, the operations from the alarm report (S26) to the comparison of the difference in acceleration with the threshold α2 (S30) in the mobile terminal 10 are repeated with the retry count N2 as the upper limit.

[0047] If there is a response from the operator (S29: Yes) and the difference in acceleration exceeds the threshold α2 (S30: Yes), it is considered that the operator is safe. For this reason, the remote control device 70 stops the immobility signal (S34), and the mobile terminal 10 transmits to the security terminal 50 that the operator has returned from the immobile state (S35).

[0048] When the number of retries exceeds N2 (S33: Yes), since it is presumed that the operator is in an immobile state and unable to respond, the mobile terminal 10 notifies the security terminal 50 to that effect, and the security terminal 50 takes emergency measures such as making an in-premises announcement (S36).

[0049] In the above example, when the recognized acceleration decreases (S2: Yes), it is estimated that the operator H has fallen, and when there is no change in the time variation of the recognized acceleration (S22: Yes), it is estimated that the operator H is in an immobile state. However, in addition to these, abnormalities occurring to the operator H can be estimated using the acceleration sensor 77. For example, when the acceleration detected by the acceleration sensor 77 becomes a large value significantly exceeding 1G, it can be estimated that a large impact has been applied to the operator H or the remote control device 70. In such a case, a configuration may be adopted to issue an alarm in the same manner as described above. Also, in the remote control device 70, α1, T1, T2, N1, α2, T3, T4, and N2, which are parameters in the above operations, are stored in the storage unit 72.

[0050] Next, the operation for the management of the remote control device 70 itself will be described. As this operation, there is an operation for managing the remaining amount of the battery 76. As described above, although the functions of the remote control device 70 are limited and its communication method uses low-power BLE, the remaining amount management of the battery 76 is important even though the power consumption in the remote control device 70 is small.

[0051] As described above, the control unit 75 can detect the output voltage and current of the battery 76 to estimate the remaining amount of the battery. Therefore, the control unit 75 can transmit the estimated remaining amount (%) of the battery to the mobile terminal 10 side by BLE communication. This operation can be performed at regular intervals, similar to the detection of the above acceleration (S1, S21), but the time interval may be longer than this, for example, about once per hour.

[0052] In the mobile terminal 10 that has received the battery level, when this level drops below a certain value (for example, 30%), an alarm can be issued in the same manner as in the above cases (S6, S26). As a result, the operator can recognize that it is necessary to replace or charge the battery of the remote control device 70.

[0053] In this way, by using the remote control device 70, which has only limited functions and is small in size, together with the mobile terminal 10, various operations can be performed. In the above example, the mobile terminal 10 was assumed to be a smartphone. However, when a relatively large and high-function mobile terminal 10 is used, it is effective to also use the remote control device 70, which has only limited functions and is small in size, in the same manner as above.

[0054] In the above example, it was assumed that one operator holds the mobile terminal 10 and the remote control device 70 simultaneously. However, when the work is carried out in groups, it may be set that only the leader of the group holds the mobile terminal 10 (smartphone), and all members including the leader hold the remote control device 70. Even in such a case, as described above, these can be connected via BLE, and the mobile terminal 10 can identify each remote control device 70 (operator).

[0055] In this case, if the call of the operator in the above example is replaced with the call of this leader, the same operation is possible. In this case, by having only the leader hold the expensive mobile terminal 10 (smartphone), the wireless communication system can be made less expensive.

[0056] Also, in the above example, it was assumed that the mobile terminal 10 and the remote control device 70 communicate via BLE. However, similar to BLE, other standards used in wireless PAN (Personal Area Network) that have a short communication distance but low power consumption, such as Wi-Fi (registered trademark), can also be used. However, since this communication distance is shorter and sufficient compared to the communication distance between the mobile terminal 10 and the base station 20, BLE is particularly preferable.

[0057] Also, in the above example, the remote control device 70 is provided with an acceleration sensor 77, and it is assumed that an abnormality (falling, immobile state) occurring to the worker W is recognized by this. However, if the acceleration sensor 77 is provided in the mobile terminal 10, conversely, even when the remote control device 70 is not used, the same operation as above can be performed using only the mobile terminal 10.

[0058] As described above, the present invention has been described based on the embodiments. These embodiments are illustrative, and it is understood by those skilled in the art that various modifications are possible for the combination of each of these components, and such modifications are also within the scope of the present invention.

Explanation of Reference Numerals

[0059] 1, 9 Wireless communication system 10, 110 Mobile terminal 20, 120 Base station 30 EPC (Evolved Packet Core) 40 SIP server 50 Security terminal (management device) 70 Remote control device 71 BLE communication unit 72 Storage unit 73 Operation unit 74 Display unit 75 Control unit 76 Battery 77 Acceleration sensor H Worker P1, P2 Pocket S Worker W Work site

Claims

1. A wireless communication system comprising a mobile terminal carried by an operator and having a call function, and a base station connected to the mobile terminal by wireless communication, wherein communication through the base station by the mobile terminal is enabled, The system includes an operation unit that is separate from the mobile terminal and is provided with a plurality of operation buttons that accept operations only by being pressed. Each of the operation buttons is associated with a function corresponding to an operation related to a call using the mobile terminal. When one of the operation buttons is operated, a remote control device is provided that transmits a signal for causing the mobile terminal to perform the operation corresponding to the operation button by wireless communication toward the mobile terminal, The remote control device includes an acceleration sensor that detects an acceleration applied along a certain direction in the device itself, and transmits a notification signal to the mobile terminal according to the detected acceleration, The mobile terminal performs an operation corresponding to the received notification signal, A wireless communication system characterized in that a plurality of the remote control devices can be connected to one mobile terminal by the wireless communication.

2. The wireless communication system according to claim 1, wherein the wireless communication between the remote control device and the mobile terminal is performed by BLE (Bluetooth Low Energy: registered trademark).

3. The remote control device is carried by the operator, The notification signal is a signal for notifying the operator that an abnormality has occurred. The mobile terminal notifies a management device that manages the operator via the base station that the notification signal has been received. The wireless communication system according to claim 1 or 2.

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