JP6202747B2 - Communication terminal - Google Patents

Description

  The present invention relates to a communication terminal, and more particularly to a communication terminal that periodically transmits data from a communication terminal to a computer via a base station.

  A communication system comprising: a communication terminal; a base station capable of wireless communication with the communication terminal; and a computer connected to the base station via a network or the like, and a communication system that transmits data from the communication terminal to the computer via the base station. It has been put into practical use. In recent years, a sensor network system has been proposed in which a communication terminal of such a communication system is connected to a sensor that detects data such as temperature and humidity, and data detected by the sensor is transmitted to a computer via a base station. Yes.

  Communication terminals of such communication systems are often driven by batteries in consideration of ease of arrangement, mobility, miniaturization, and the like. In that case, it is better that the frequency of battery replacement is low from the viewpoint of ease of maintenance. Therefore, a communication terminal that can suppress power consumption is demanded. As such a communication terminal, a sensor (communication terminal) according to Patent Document 1 has been proposed. FIG. 9 is an explanatory diagram showing the configuration of the sensor 203 according to Patent Document 1. As shown in FIG.

  The sensor 203 is a sensor module having a sensing function and a wireless communication function. As illustrated in FIG. 9, the sensor 203 includes a timer unit 211, an activation unit 212, a measurement unit 213, a communication unit 214, a sleep setting unit 215, and a storage unit 216.

  The timer unit 211 outputs a signal to the activation unit 212 at a predetermined time. In response to the signal from the timer unit 211, the activation unit 212 shifts the sensor 203 from the sleep state to the active state. The active state is a state where communication is possible (a state where the communication function is activated). The sleep state is a state where communication is impossible and current consumption is smaller than that of the active state (a state where at least a part of the communication function is stopped).

  The measurement unit 213 measures temperature, humidity, and the like, and outputs measurement data including measurement values and measurement times to the communication unit 214. The communication unit 214 is in communication connection with an external base station or relay station, and transmits measurement data to the computer via a base station or relay station (not shown). The sleep setting unit 215 determines a sleep period during which the sensor 203 is in the sleep state. When the activation unit 212 receives the signal from the sleep setting unit 215, the activation unit 212 shifts the sensor 203 from the active state to the sleep state.

  In this way, the sensor 203 periodically measures temperature, humidity, and the like, and transmits measurement data to the computer via the base station or the relay station. The sensor 203 is in the sleep state between the time when the measurement data is transmitted and the time when the response from the base station or the relay station is received, and the time for the active state is reduced to suppress power consumption.

JP 2012-23668 A

  When such a communication terminal waits while maintaining a communication connection with the base station, a beacon reception function for receiving a beacon signal periodically transmitted from the base station and information for communication connection with the base station are provided. It is necessary to activate some communication functions including the information storage function to be stored.

  When waiting with some of these communication functions activated, the power consumption during standby is lower than when the communication connection between the communication terminal and the base station is disconnected and all communication functions are stopped. The amount (total of the power used multiplied by time) increases. On the other hand, when the communication connection with the base station is disconnected and waiting, it is necessary to perform communication connection between the communication terminal and the base station and disconnection of the communication connection every time data transmission is performed. In that case, compared with the case where the communication connection of a communication terminal and a base station is maintained, the power consumption at the time of data transmission increases. For this reason, when the transmission cycle for transmitting data is short, it is easier to suppress the power consumption of the communication terminal by maintaining the communication connection with the base station, and when the transmission cycle is long, Disconnecting the communication connection and waiting makes it easier to suppress the power consumption of the communication terminal.

  In addition, during data transmission, all communication functions are activated and radio signals are frequently transmitted and received between the communication terminal and the base station. Therefore, the longer the time required for data transmission, the more power is consumed during data transmission. Will increase. The time required for data transmission becomes longer as the time required for communication connection between the communication terminal and the base station and disconnection of the communication connection becomes longer. The time required for the communication connection between the communication terminal and the base station or the disconnection of the communication connection is likely to change depending on the communication environment between the communication terminal and the base station due to the radio wave environment near the communication terminal.

  For these reasons, the optimum operating condition during standby for suppressing the power consumption of the communication terminal may differ depending on the communication environment such as the transmission cycle of data transmission and the radio wave environment near the communication terminal. On the other hand, if the operating conditions of the communication terminal during standby are constant, the operating conditions during standby cannot be optimized according to the transmission cycle and communication environment, and as a result, the power consumption of the communication terminal is efficiently suppressed. Can not do.

  The present invention has been made in view of such a state of the art, and an object thereof is to provide a communication terminal capable of efficiently suppressing power consumption in accordance with a transmission cycle and a communication environment.

  In order to solve this problem, the communication terminal according to claim 1 is capable of communication connection by wireless communication with a base station and communication connection with a computer connected to the base station, A communication terminal that periodically transmits data to the computer via the base station, wherein a standby mode in standby mode in which the data is not transmitted is set in a first standby mode in which the communication connection with the base station is disconnected and waited. A first step of measuring a first required time required for communication connection with the base station, and a second standby mode for maintaining the communication connection with the base station and waiting, A second step of measuring a second required time required for communication connection with the computer; a third step of measuring a third required time required for transmitting the data to the computer; A fourth step of measuring a fourth required time required for disconnecting the communication connection with the computer, a fifth step of measuring a fifth required time required for disconnecting the communication connection with the base station, and transmitting the data The first standby mode, the second required time, the second required time, the third required time, the fourth required time, and the fifth required time. The standby mode is selected according to a procedure including a sixth step of selecting one of the standby modes.

  The communication terminal of this configuration includes a standby mode in standby mode, a first standby mode in which the communication connection with the base station is disconnected and waits, a second standby mode in which the communication connection with the base station is maintained and standby, Can be switched to. Therefore, the operating condition during standby can be optimized by switching between the first standby mode and the second standby mode.

  Moreover, the communication terminal of this configuration, according to the procedure from the first step to the fifth step, the first required time required for communication connection with the base station, the second required time required for communication connection with the computer, A third required time required for transmitting data to the computer, a fourth required time required for disconnecting the communication connection with the computer, and a fifth required time required for disconnecting the communication connection with the base station are measured. . Then, the communication terminal performs the first standby mode and the second standby based on the transmission cycle for transmitting data, the first required time, the second required time, the third required time, the fourth required time, and the fifth required time. One of the modes is selected. Therefore, even when the transmission cycle and the communication environment are different, the operating conditions during standby are determined based on the transmission cycle, the first required time, the second required time, the third required time, the fourth required time, and the fifth required time. Can be optimized. As a result, the communication terminal having this configuration can efficiently suppress the power consumption of the communication terminal in accordance with the transmission cycle and communication environment.

  The communication terminal according to claim 2 has a beacon receiving function for receiving a beacon signal transmitted from the base station, and an information storage function for storing information for communication connection with the base station, In the first standby mode, the beacon reception function and the information storage function are stopped, and in the second standby mode, the beacon reception function and the information storage function are activated.

  When waiting while maintaining the communication connection between the communication terminal and the base station, the communication terminal can receive a beacon reception function for receiving a beacon signal transmitted from the base station and information for communication connection with the base station even during standby. It is necessary to activate some communication functions including the information storage function to be stored. On the other hand, when the communication connection with the base station is disconnected and waiting, the beacon reception function and the information storage function become unnecessary. Therefore, if these functions are activated during standby, useless power is consumed.

  On the other hand, in the first standby mode in which the communication terminal with this configuration disconnects and waits for the communication connection with the base station, the beacon reception function and the information storage function are stopped and the communication connection with the base station is maintained. In the second standby mode, the beacon reception function and the information storage function are activated. Therefore, the power consumption during standby can be optimized in accordance with the communication connection state with the base station. As a result, the power consumption of the communication terminal can be more efficiently suppressed.

  The communication terminal according to claim 3 is characterized in that in the second standby mode, the communication connection with the computer is disconnected.

  When the communication connection between the communication terminal and the computer is maintained for a long time, communication between the communication terminal and the computer is performed even during standby in order to determine whether or not to maintain the communication connection between the communication terminal and the computer. Is often performed regularly. For this reason, when the transmission cycle is long, maintaining the communication connection between the communication terminal and the computer and waiting will cause the power consumption during standby to increase. On the other hand, in an environment where the time required for the communication connection between the communication terminal and the computer and the disconnection of the communication connection is short, the communication connection between the communication terminal and the computer and the disconnection of the communication connection are repeated each time data transmission is performed. Time to use power can be shortened, and power consumption during data transmission can be easily suppressed. Therefore, in an environment where the transmission cycle is long and the time required for the communication connection between the communication terminal and the computer and the disconnection of the communication connection is short, the communication terminal and the communication terminal Disconnecting the communication connection with the computer makes it easier to suppress the power consumption of the communication terminal than maintaining the communication connection between the communication terminal and the computer.

  On the other hand, the communication terminal with this configuration disconnects the communication connection with the computer in the second standby mode in which the communication connection with the base station is maintained and waits. Therefore, power consumption of the communication terminal can be more efficiently suppressed in an environment where the transmission cycle is long and the time required for communication connection and disconnection between the communication terminal and the computer is short.

  According to a fourth aspect of the present invention, the communication terminal maintains a communication connection with the computer in the second standby mode.

  When the transmission cycle is short, even if the communication connection between the communication terminal and the computer is kept on standby, the influence of standby power consumption on the overall power consumption of the communication terminal can be reduced. On the other hand, in an environment where the time required for the communication connection between the communication terminal and the computer and the disconnection of the communication connection is long, the communication connection between the communication terminal and the computer and the disconnection of the communication connection are repeated every time data transmission is performed. A large amount of time is used, and the power consumption of the communication terminal tends to increase. Therefore, if the transmission cycle is short and the time required for communication connection between the communication terminal and the computer and the time required for disconnecting the communication connection is long, the communication connection with the base station is maintained and the communication is performed. If the communication connection between the terminal and the computer is also maintained, it is easier to suppress the power consumption of the communication terminal than repeating the communication connection between the communication terminal and the computer and the disconnection of the communication connection each time data transmission is performed.

  On the other hand, the communication terminal having this configuration maintains the communication connection with the computer in the second standby mode in which the communication connection with the base station is maintained and waits. Therefore, in an environment where the transmission cycle is short and the time required for communication connection between the communication terminal and the computer and disconnection of the communication connection is long, the power consumption of the communication terminal can be more efficiently suppressed.

  The communication terminal according to claim 5 periodically performs communication connection with the base station and disconnection of the communication connection, and reviews the standby mode according to the procedure from the first step to the sixth step. It is characterized by performing.

  In an environment where the communication environment between the communication terminal and the base station is likely to change with time, the optimum operating condition of the communication terminal also changes with time. On the other hand, the communication terminal of this configuration periodically performs communication connection with the base station and disconnection of the communication connection, and reviews the standby mode according to the procedure from the first step to the sixth step. Yes. Therefore, even if the communication environment changes with time, the operating conditions during standby can be optimized accordingly. As a result, in the communication terminal having this configuration, the power consumption of the communication terminal can be more efficiently suppressed in an environment where the communication environment easily changes with time.

  The communication terminal according to claim 6 is connected to a sensor that detects the data, and periodically transmits the data detected by the sensor to the computer.

  The communication terminal having this configuration is connected to a sensor that detects data, and periodically transmits data detected by the sensor to a computer. In this way, by combining the communication terminal and the sensor, it is possible to construct a sensor network in which the power consumption of the communication terminal is small.

  ADVANTAGE OF THE INVENTION According to this invention, the communication terminal which can suppress power consumption efficiently according to a transmission period and communication environment can be provided.

It is explanatory drawing which shows the structure of the communication terminal 20 which concerns on 1st Embodiment of this invention. It is the 1st explanatory view about operation of communication terminal 20 shown in FIG. FIG. 6 is a second explanatory diagram regarding the operation of the communication terminal 20 shown in FIG. 1. It is a flowchart which shows the selection procedure of the standby mode of the communication terminal 20 shown in FIG. It is a flowchart which shows the procedure of the data transmission of the communication terminal 20 shown in FIG. It is explanatory drawing which shows the structure of the communication terminal 120 which concerns on 2nd Embodiment of this invention. It is explanatory drawing regarding operation | movement of the communication terminal 120 shown in FIG. It is a flowchart which shows the procedure of the data transmission of the communication terminal 120 shown in FIG. It is explanatory drawing which shows the structure of the sensor 203 which concerns on patent document 1. FIG.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. First, the configuration of the communication terminal 20 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is an explanatory diagram showing the configuration of the communication terminal 20 according to the first embodiment of the present invention. FIG. 1A shows a configuration of the communication system 1 using the communication terminal 20, and FIG. 1B shows a configuration of the communication terminal 20.

  The communication system 1 according to the embodiment of the present invention is used for a sensor network that manages data such as temperature and humidity transmitted from a sensor. The communication system 1 includes a sensor 10, a communication terminal 20, a base station 40, and a computer 50 as shown in FIG. The sensor 10 and the communication terminal 20 are connected to each other to form a sensor module 30. Communication terminal 20 and base station 40 can be communicatively connected by wireless communication. The base station 40 and the computer 50 are communicatively connected via a wired or wireless network. The communication terminal 20 and the computer 50 can be connected for communication via the base station 40.

  The sensor 10 is a detection device having a temperature sensor, a humidity sensor, and the like, and detects data such as temperature and humidity around the communication terminal 20. Data detected by the sensor 10 is transmitted to the communication terminal 20.

  The communication terminal 20 is a communication terminal compatible with a communication standard such as a wireless LAN. The communication terminal 20 periodically transmits data detected by the sensor 10 to the computer 50 via the base station 40. As illustrated in FIG. 1, the communication terminal 20 includes a communication unit 21, a storage unit 22, a timer unit 23, and a control unit 24.

  The communication unit 21 is a communication circuit corresponding to a communication standard such as a wireless LAN. The communication unit 21 receives a radio signal transmitted from the base station 40 and transmits a radio signal to the base station 40 using the communication antenna 21 a connected to the communication unit 21. As a radio signal transmitted and received by the communication unit 21, a radio signal having a frequency of 2.4 GHz band or 5 GHz band is used. Data detected by the sensor 10 is transmitted from the communication unit 21 as a modulation component of a radio signal.

  The storage unit 22 is a circuit having a storage semiconductor such as a RAM. The storage unit 22 stores information for communication connection with the base station 40, information for communication connection with the computer 50, encryption information for authentication, and the like. The information for communication connection with the base station 40 includes unique information and communication protocol of the base station 40 to be connected for communication. The information for communication connection with the computer 50 includes information specific to the computer 50 to be connected for communication, a communication protocol, and the like.

  The timer unit 23 is a circuit having a timer function. The timer 23 is used for measuring and managing various times.

  The control unit 24 is a circuit having a control semiconductor such as a CPU. The control unit 24 controls the communication unit 21, the storage unit 22, and the time measuring unit 23. Moreover, the control part 24 acquires the information regarding various time from the time measuring part 23, and makes various judgments based on the acquired information.

  The base station 40 is a base station called an access point corresponding to a communication standard such as a wireless LAN. As described above, the communication terminal 20 and the base station 40 can be connected by wireless communication. Although not shown, a plurality of base stations 40 are arranged in a predetermined area. Of the plurality of base stations 40, the base station 40 having the best communication environment with the communication terminal 20 is connected to the communication terminal 20 for communication.

  The computer 50 is a personal computer (PC) for data management. As described above, the base station 40 and the computer 50 are communicatively connected via a wired or wireless network. The communication terminal 20 and the computer 50 can be connected for communication via the base station 40. Then, the computer 50 obtains data periodically transmitted from the communication terminal 20 via the base station 40.

  Next, operation | movement of the communication terminal 20 is demonstrated using FIG.2 and FIG.3. FIG. 2 is a first explanatory diagram regarding the operation of the communication terminal 20 shown in FIG. FIG. 2A schematically shows the relationship between the operation timing of the communication terminal 20 and the power required by the communication terminal 20 when the standby mode is the first standby mode. FIG. 2B shows in more detail the operation timing at the time of data transmission in FIG. In FIG. 2, the horizontal axis is time, and the vertical axis is power. FIG. 3 is a second explanatory diagram relating to the operation of the communication terminal 20 shown in FIG. FIG. 3A schematically shows the relationship between the operation timing of the communication terminal 20 and the power required by the communication terminal 20 when the standby mode is the second standby mode. FIG. 3B shows in more detail the operation timing at the time of data transmission in FIG. In FIG. 3, the horizontal axis is time, and the vertical axis is power.

  The communication terminal 20 can be switched to three operation modes: a data transmission mode, a first standby mode, and a second standby mode. The data transmission mode is an operation mode at the time of data transmission for performing data transmission. The first standby mode and the second standby mode are standby operation modes in which data transmission is not performed (hereinafter, abbreviated as standby mode). The first standby mode is a standby mode in a case where the communication connection with the base station 40 is cut off and the standby is performed. The second standby mode is a standby mode in which the communication connection with the base station 40 is maintained for standby.

  In the data transmission mode, the communication terminal 20 operates all communication functions. The communication terminal 20 is in communication with the base station 40 and in communication with the computer 50. When switching from the first standby mode to the data transmission mode, the communication terminal 20 performs communication connection with the computer 50 after performing communication connection with the base station 40. When switching from the second standby mode to the data transmission mode, the communication terminal 20 performs only communication connection with the computer 50.

  At the time of data transmission, since all communication functions are operated and radio signals are frequently transmitted and received, large power is required. The power required at the time of data transmission varies depending on the circuit configuration of the communication terminal 20, the communication environment between the communication terminal 20 and the base station 40, etc., but an average power of about several hundred mW is required. Hereinafter, the description will be made assuming that the average power necessary for data transmission is the transmission power Pa.

  In the first standby mode, the communication terminal 20 is disconnected from the communication connection with the base station 40 and the communication connection with the computer 50. Then, the communication terminal 20 stops all communication functions and stands by. When the data transmission mode is switched to the first standby mode, the communication connection with the computer 50 is disconnected and the communication connection with the base station 40 is also disconnected. Then, all communication functions are stopped and waited. When waiting in the first standby mode, all communication functions are stopped, so that the power required for standby (hereinafter abbreviated as standby power) is almost zero.

  In the second standby mode, the communication terminal 20 disconnects the communication connection with the computer 50 and maintains the communication connection with the base station 40. When the data transmission mode is switched to the second standby mode, the communication connection with the computer 50 is disconnected, but the communication connection with the base station 40 is maintained. Then, a part of communication functions for maintaining the communication connection with the base station 40 is activated to stand by.

  Some communication functions operated in the second standby mode include a beacon reception function and an information storage function. The beacon reception function is a function for receiving a beacon signal periodically transmitted from the base station 40. The beacon signal is a signal including information for communication connection such as unique information of the base station 40 and a communication protocol. The information storage function or the like is a function for storing information for communication connection such as unique information of the base station 40 or a communication protocol. In order to operate some of these communication functions, standby power of about several mW is required. Hereinafter, description will be given assuming that standby power in the case of standby in the second standby mode is Ps.

  As shown in FIGS. 2 and 3, the communication terminal 20 periodically switches from the standby mode to the data transmission mode, transmits data to the computer 50, and after the data transmission is completed, again from the data transmission mode to the standby mode. And wait until the next data transmission.

  Hereinafter, the transmission period T is the period at which the communication terminal 20 performs data transmission, and the time required for the communication terminal 20 to switch from the standby mode to the data transmission mode to transmit data to the computer and return to the standby mode is the data transmission time ta. The description will be given assuming that the time that the communication terminal 20 waits without transmitting data is the waiting time ts. Further, the time required for communication connection between the communication terminal 20 and the base station 40 is the first required time ta1, the time required for communication connection between the communication terminal 20 and the computer 50 is the second required time ta2, and the communication terminal 20 to the computer 50. The time required for data transmission is the third required time ta3, the time required for disconnecting the communication connection between the communication terminal 20 and the computer 50 is the fourth required time ta4, and the communication connection between the communication terminal 20 and the base station 40 is required to be disconnected. The description will be given assuming that the time is the fifth required time ta5.

  The transmission period T is appropriately set according to the usage conditions of the communication terminal 20. For example, when the temperature and humidity are finely managed in a short period, the transmission period T is set to about several tens of seconds. When the temperature and humidity are managed in a long period, the transmission period T is several minutes to several hours. Set to degree. In the present embodiment, the communication terminal 20 is a communication terminal that assumes a case where the transmission cycle T is relatively long.

  The data transmission time ta differs depending on whether the standby mode is the first standby mode or the second standby mode. When the standby mode is the first standby mode, the data transmission time ta is, as shown in FIG. 2, the first required time ta1, the second required time ta2, the third required time ta3, the fourth required time ta4, and the fifth It is a time obtained by adding the required time ta5. When the standby mode is the second standby mode, the data transmission time ta is a time obtained by adding the second required time ta2, the third required time ta3, and the fourth required time ta4 as shown in FIG. The standby time ts is a time obtained by subtracting the data transmission time ta from the transmission cycle T.

  The power consumption per transmission cycle T of the communication terminal 20 (the sum of values obtained by multiplying the power by time) is the value obtained by multiplying the transmission power Pa by the data transmission time ta and the standby power (0 or Ps) by the standby time ts. This is the sum of the multiplied values. The power per transmission cycle T of the communication terminal 20 depends on the length of the data transmission time ta, the length of the standby time ts, and the operating conditions such as whether the standby mode is the first standby mode or the second standby mode. Consumption will vary.

  For this reason, it is necessary to select one of the first standby mode and the second standby mode based on the data transmission time ta and the standby time ts, and to optimize the operating conditions during standby. Hereinafter, the power consumption per transmission cycle T of the communication terminal 20 is abbreviated as the power consumption of the communication terminal 20, and reducing the power consumption per transmission cycle T of the communication terminal 20 refers to the power consumption of the communication terminal 20. It is abbreviated to suppress.

  Next, a method for selecting the standby mode of the communication terminal 20 will be described with reference to FIG. FIG. 4 is a flowchart showing a standby mode selection procedure of the communication terminal 20 shown in FIG.

  As shown in FIG. 4, first, in step Sa <b> 1 that is the first step, the communication terminal 20 establishes communication connection with the base station 40 and measures the first required time required for communication connection with the base station 40. Next, in step Sa2 as the second step, the communication terminal 20 is connected to the computer 50 and measures a second required time ta2 required for communication connection with the computer 50.

  Next, in step Sa3, which is the third step, the communication terminal 20 transmits test data for measurement to the computer 50, and measures a third required time ta3 required for data transmission to the computer 50. Next, in step Sa4 which is the fourth step, the communication terminal 20 disconnects the communication connection with the computer 50, and measures the fourth required time ta4 required to disconnect the communication connection with the computer 50.

  Next, in step Sa5 which is the fifth step, the communication terminal 20 disconnects the communication connection with the base station 40, and measures the fifth required time ta5 required for disconnecting the communication connection with the base station 40.

  Next, in step Sa6, which is the sixth step, the communication terminal 20 causes the transmission cycle T, the first required time ta1, the second required time ta2, the third required time ta3, the fourth required time ta4, and the fifth required time. Based on ta5, one of the first standby mode and the second standby mode is selected.

  In step Sa6, the communication terminal 20 determines the data transmission time ta from the transmission cycle T, the first required time ta1, the second required time ta2, the third required time ta3, the fourth required time ta4, and the fifth required time ta5. The waiting time ts is calculated. The communication terminal 20 determines whether the standby mode is the first standby mode and the standby mode is the second standby mode based on the calculated data transmission time ta and standby time ts. The predicted value of power consumption is calculated respectively.

  When the standby mode is the first standby mode, the predicted value of the power consumption of the communication terminal 20 is transmission power Pa × data transmission time ta. The predicted value of the data transmission time ta is the first required time ta1 + the second required time ta2 + the third required time ta3 + the fourth required time ta4 + the fifth required time ta5. The predicted value of the standby time ts is the transmission cycle T-data transmission time ta.

  When the standby mode is the second standby mode, the predicted value of the power consumption of the communication terminal 20 is transmission power Pa × data transmission time ta + standby power Ps × standby time ts. The predicted value of the data transmission time ta is second required time ta2 + third required time ta3 + fourth required time ta4, which is shorter than when the standby mode is the first standby mode. The predicted value of the standby time ts is the transmission cycle T-data transmission time ta, and is longer than when the standby mode is the first standby mode.

  Then, the communication terminal 20 determines which of the power of the communication terminal 20 is the case where the standby mode is the first standby mode and the case where the standby mode is the second standby mode based on the calculated predicted power consumption. It is determined whether the consumption can be suppressed, that is, which can reduce the power consumption of the communication terminal 20. And the communication terminal 20 has selected the direction which can suppress the power consumption of the communication terminal 20 as standby mode from 1st standby mode and 2nd standby mode.

  Next, in step Sa7, the communication terminal 20 sets its own operation mode to the standby mode selected in step Sa6. When the selected standby mode is the first standby mode, the communication terminal 20 sets the communication connection with the base station 40 to be disconnected and stops all communication functions. When the selected standby mode is the second standby mode, the communication terminal 20 sets the communication connection with the base station 40 and activates some of the communication functions described above.

  The communication terminal 20 thus performs the first required time ta1, the second required time ta2, the third required time ta3, the fourth required time ta4, and the fifth according to the procedure shown from the first step to the fifth step. The required time ta5 is measured, and the standby mode is selected according to the procedure shown in the sixth step.

  Next, a data transmission procedure from the communication terminal 20 to the computer 50 will be described with reference to FIG. FIG. 5 is a flowchart showing a data transmission procedure of the communication terminal 20 shown in FIG.

  As shown in FIG. 5, first, in step Sb1, the communication terminal 20 selects a standby mode according to a predetermined procedure. The communication terminal 20 performs the first required time ta1, the second required time ta2, the third required time ta3, the fourth required time ta4, and the fifth according to the procedure shown from the first step to the fifth step shown in FIG. The required time ta5 is measured, and the standby mode is selected according to the procedure shown in the sixth step. Then, the communication terminal 20 sets its operation state to the selected standby mode state.

  Next, in step Sb2, the communication terminal 20 waits for a predetermined time. When the standby mode is the first standby mode, the communication terminal 20 disconnects the communication connection with the base station 40, stops all communication functions, and waits. When the standby mode is the second standby mode, the communication terminal 20 maintains a communication connection with the base station 40, operates a part of communication functions, and stands by. And it moves to step Sb3.

  Next, in step Sb3, the communication terminal 20 determines whether the selected standby mode is the first standby mode or the second standby mode. If the selected standby mode is the first standby mode, the process moves to step Sb4. When the selected standby mode is the second standby mode, the process moves to step Sb6.

  In step Sb4, the communication terminal 20 switches from the first standby mode to the data transmission mode, and activates all communication functions. Next, in step Sb5, communication connection with the base station 40 is performed. And it moves to step Sb7.

  In step Sb6, the communication terminal 20 switches from the second standby mode to the data transmission mode, and activates all communication functions. And it moves to step Sb7. In the second standby mode, since the communication connection with the base station 40 is maintained, it is not necessary to perform the communication connection with the base station 40 again.

  Next, in step Sb7, the communication terminal 20 establishes communication connection with the computer 50. Next, in step Sb8, the communication terminal 20 transmits predetermined data to the computer 50. Next, in step Sb9, the communication terminal 20 disconnects the communication connection with the computer 50.

  Next, in step Sb10, the communication terminal 20 determines whether the selected standby mode is the first standby mode or the second standby mode. If the selected standby mode is the first standby mode, the process moves to step Sb11. If the selected standby mode is the second standby mode, the process moves to step Sb13.

  In step Sb11, the communication terminal 20 disconnects the communication connection with the base station 40. Next, in step Sb12, the communication terminal 20 stops all communication functions. And it moves to step Sb15.

In step Sb13, the communication terminal 20 maintains a communication connection with the base station 40. Next, in step Sb14, the communication terminal 20 activates some of the communication functions described above and stops other communication functions. And it moves to step Sb15.

Next, in step Sb15, the communication terminal 20 makes a determination based on whether or not the standby mode needs to be reviewed. When it is determined that the review of the standby mode is unnecessary, the process returns to step Sb2 and the procedure from step Sb2 is repeated. If it is determined that the standby mode needs to be reviewed, the process returns to step Sb1 and the procedure from step Sb1 is repeated. The communication terminal 20 performs data transmission to the computer 50 according to such a procedure.

As described above, in step Sb1, the communication terminal 20 measures various required times and selects a standby mode according to the procedure shown in FIG. Therefore, the standby mode can be periodically reviewed by returning to step Sb1 every time data transmission is performed a plurality of times.

  Next, the effect of this embodiment will be described. The communication terminal 20 according to the present embodiment is configured to wait for a standby mode of the first standby mode in which the communication connection with the base station 40 is disconnected and the second standby mode in which the communication connection with the base station 40 is maintained. Switching to standby mode is possible. Therefore, the operating condition during standby can be optimized by switching between the first standby mode and the second standby mode.

  Moreover, the communication terminal 20 performs the first required time ta1 required for communication connection with the base station 40 and the first time required for communication connection with the computer 50 according to the procedure from the first step to the fifth step shown in FIG. 2 required time ta2, third required time ta3 required for data transmission to the computer 50, fourth required time ta4 required for disconnecting the communication connection with the computer 50, and required for disconnecting the communication connection with the base station 40 The fifth required time ta5 is measured. Then, based on the transmission cycle T for transmitting data, the first required time ta1, the second required time ta2, the third required time ta3, the fourth required time ta4, and the fifth required time ta5, One of the two standby modes is selected.

  Therefore, even when the transmission cycle T and the communication environment are different, based on the transmission cycle T, the first required time ta1, the second required time ta2, the third required time ta3, the fourth required time ta4, and the fifth required time ta5. The operating conditions during standby can be optimized. As a result, the communication terminal 20 can efficiently suppress the power consumption of the communication terminal 20 according to the transmission cycle T and the communication environment.

  Moreover, in the communication terminal 20 of this embodiment, when maintaining a communication connection with the base station 40 and waiting, a beacon receiving function for receiving a beacon signal periodically transmitted from the base station 40, It is necessary to activate some communication functions including an information storage function for storing information for communication connection. On the other hand, when the communication connection with the base station 40 is cut off to stand by, the beacon reception function and the information storage function become unnecessary. Therefore, if these functions are activated during standby, useless power is consumed.

  In contrast, in the first standby mode in which the communication terminal 20 of the present embodiment disconnects and waits for the communication connection with the base station 40, the communication terminal 20 stops the beacon reception function and the information storage function, and communicates with the base station 40. In the second standby mode for maintaining the connection and waiting, the beacon reception function and the information storage function are activated. Therefore, the power consumption during standby can be optimized according to the communication connection state with the base station 40. As a result, the power consumption of the communication terminal 20 can be more efficiently suppressed.

  Further, in the communication terminal 20 of the present embodiment, when the communication connection between the communication terminal 20 and the computer 50 is maintained and the communication terminal 20 waits for a long time, it is determined whether or not the communication connection between the communication terminal 20 and the computer 50 is maintained. Therefore, in many cases, communication between the communication terminal 20 and the computer 50 is periodically performed even during standby. Therefore, when the transmission cycle T is long, if the communication connection between the communication terminal 20 and the computer 50 is maintained and waits, it becomes a factor of increasing power consumption during standby. On the other hand, in an environment where the time required for the communication connection between the communication terminal 20 and the computer 50 and the disconnection of the communication connection is short, the communication connection between the communication terminal 20 and the computer 50 and the disconnection of the communication connection are repeated each time data transmission is performed. However, it is possible to shorten the time for using a large amount of power, and to easily suppress the power consumption during data transmission. Therefore, in an environment where the transmission cycle T is long and the time required for the communication connection between the communication terminal 20 and the computer 50 and the disconnection of the communication connection is short, even if the communication connection with the base station 40 is maintained and waiting is performed. If the communication connection between the communication terminal 20 and the computer 50 is disconnected, it is easier to suppress the power consumption of the communication terminal 20 than maintaining the communication connection between the communication terminal 20 and the computer 50.

  On the other hand, the communication terminal 20 of the present embodiment disconnects the communication connection with the computer 50 in the second standby mode in which the communication connection with the base station 40 is maintained and waits. Therefore, the power consumption of the communication terminal 20 can be more efficiently suppressed in an environment where the transmission cycle T is long and the time required for the communication connection between the communication terminal 20 and the computer 50 and the disconnection of the communication connection is short.

  Further, in the communication terminal 20 of the present embodiment, in an environment where the communication environment between the communication terminal 20 and the base station 40 is likely to change with time, the optimum operating condition of the communication terminal 20 also changes with time. On the other hand, the communication terminal 20 of the present embodiment periodically performs communication connection with the base station 40 and disconnection of the communication connection, and reviews the standby mode according to the procedure from the first step to the sixth step. It is carried out. Therefore, even if the communication environment changes with time, the operating conditions during standby can be optimized accordingly. As a result, the communication terminal 20 can more efficiently suppress the power consumption of the communication terminal 20 in an environment where the communication environment is likely to change with time.

  In addition, the communication terminal 20 according to the present embodiment is connected to the sensor 10 that detects data, and periodically transmits data detected by the sensor 10 to the computer 50. In this manner, by combining the communication terminal 20 and the sensor 10, a sensor network with a small amount of power consumption of the communication terminal 20 can be constructed.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. In addition, in this embodiment, when it is the same structure as 1st Embodiment mentioned above, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  First, the configuration of the communication terminal 120 according to the second embodiment of the present invention will be described using FIG. FIG. 6 is an explanatory diagram showing the configuration of the communication terminal 120 according to the second embodiment of the present invention. FIG. 6A shows the configuration of the communication system 101 using the communication terminal 120, and FIG. 6B shows the configuration of the communication terminal 120.

  As shown in FIG. 6, the communication system 101 according to the embodiment of the present invention is obtained by replacing the communication terminal 20 of the communication system 1 according to the first embodiment with a communication terminal 120. The configuration of the communication terminal 120 is the same as that of the communication terminal 20 according to the first embodiment. However, the communication terminal 120 is a communication terminal that assumes a case where the transmission cycle T is relatively short, and the operation state during standby is slightly different from that of the communication terminal 20.

  Next, the operation of the communication terminal 120 will be described with reference to FIG. FIG. 7 is a second explanatory diagram regarding the operation of the communication terminal 120 shown in FIG. FIG. 7A schematically shows the relationship between the operation timing of the communication terminal 120 and the power required by the communication terminal 120 when the standby mode is the second standby mode. FIG. 7B shows in more detail the operation timing at the time of data transmission in FIG.

  Similar to the communication terminal 20, the communication terminal 120 can be switched to three operation modes: a data transmission mode, a first standby mode, and a second standby mode. The data transmission mode is an operation mode at the time of data transmission for performing data transmission. The first standby mode is a standby mode in a case where the communication connection with the base station 40 is cut off and the standby is performed. The second standby mode is a standby mode in which the communication connection with the base station 40 is maintained for standby.

  However, as shown in FIG. 7, in the second standby mode, the communication terminal 120 not only maintains the communication connection with the base station 40 but also maintains the communication connection with the computer 50 and stands by. Some communication functions that the communication terminal 120 operates in the second standby mode include a function for receiving a signal transmitted from the computer 50 via the base station 40 in addition to a beacon reception function and an information storage function. A function of transmitting a response signal corresponding to the signal transmitted from the computer 50 to the computer 50 via the base station 40 is also included.

When the standby mode is the second standby mode, the data transmission time ta is the same as the third required time ta3 as shown in FIG. In comparison, the data transmission time ta is further shortened.

When the standby mode is the second standby mode, the predicted value of the power consumption of the communication terminal 120 is
As in the first embodiment, transmission power Pa × data transmission time ta + standby power Ps × standby time ts, but the predicted value of the data transmission time ta is further shorter than the predicted value in the first embodiment. On the other hand, the predicted value of the waiting time ts is further longer than the predicted value in the first embodiment.

  Next, the data transmission procedure from the communication terminal 20 to the computer 50 will be described with reference to FIG. FIG. 8 is a flowchart showing a data transmission procedure of communication terminal 120 shown in FIG.

  As shown in FIG. 8, first, in step Sc1, the communication terminal 120 selects a standby mode according to a predetermined procedure. Similar to the communication terminal 20 of the first embodiment, the communication terminal 120 measures various required times and selects a standby mode according to the procedure shown in FIG. However, as described above, in the present embodiment, the predicted value of the data transmission time ta is further shortened and the predicted value of the standby time ts is further increased as compared with the first embodiment. Therefore, the optimum operating condition during standby is different from that in the first embodiment.

  Next, in step Sc2, the communication terminal 120 waits for a predetermined time. When the standby mode is the first standby mode, the communication terminal 120 disconnects the communication connection with the base station 40, stops all communication functions, and waits. When the standby mode is the second standby mode, the communication terminal 120 maintains a communication connection with the base station 40 and activates some communication functions to stand by. And it moves to step Sc3.

  Next, in step Sc3, the communication terminal 120 determines whether the selected standby mode is the first standby mode or the second standby mode. When the selected standby mode is the first standby mode, the process moves to step Sc4. When the selected standby mode is the second standby mode, the process moves to step Sc7.

  In step Sc4, the communication terminal 120 switches from the first standby mode to the data transmission mode, and activates all communication functions. Next, in step Sc5, the communication terminal 120 performs communication connection with the base station 40. Next, in step Sc <b> 6, the communication terminal 120 performs communication connection with the computer 50. Then, the process proceeds to step Sc8.

  In step Sc7, the communication terminal 120 switches from the second standby mode to the data transmission mode, and activates all communication functions. Then, the process proceeds to step Sc8. In the second standby mode, since the communication connection with the base station 40 and the communication connection with the computer 50 are maintained, there is no need to perform a communication connection with the base station 40 or a communication connection with the computer 50 again. .

  Next, in step Sc8, the communication terminal 120 transmits predetermined data to the computer 50. Next, in step Sc9, the communication terminal 120 makes a determination based on whether the selected standby mode is the first standby mode or the second standby mode. When the selected standby mode is the first standby mode, the process moves to step Sc10. If the selected standby mode is the second standby mode, the process moves to step Sc13.

  In step Sc10, the communication terminal 120 disconnects the communication connection with the computer 50. Next, in step Sc11, the communication terminal 120 disconnects the communication connection with the base station 40. Next, in step Sc12, the communication terminal 120 stops all communication functions. And it moves to Step Sc16.

In step Sc <b> 13, the communication terminal 120 maintains a communication connection with the computer 50. Next, in step Sc14, the communication terminal 120 maintains a communication connection with the base station 40. Next, in step Sc15, the communication terminal 120 activates some communication functions and stops other communication functions. And it moves to Step Sc16.

Next, in step Sc16, the communication terminal 120 makes a determination based on whether or not the standby mode needs to be reviewed. When it is determined that the review of the standby mode is unnecessary, the process returns to step Sc2 and the procedure from step Sc2 is repeated. If it is determined that the standby mode needs to be reviewed, the process returns to step Sc1 and the procedure from step Sc1 is repeated. The communication terminal 120 performs data transmission to the computer 50 according to such a procedure.

As described above, in step Sc1, the communication terminal 120 measures various required times and selects a standby mode according to the procedure shown in FIG. Therefore, the standby mode can be periodically reviewed by returning to step Sc1 every time data transmission is performed a plurality of times.

  Next, the effect of this embodiment will be described. In the present embodiment, only effects different from those of the first embodiment will be described.

  In the communication terminal 120 of the present embodiment, when the transmission cycle T is short, even when the communication connection between the communication terminal 120 and the computer 50 is maintained and standby, the standby power with respect to the entire power consumption of the communication terminal 120 is maintained. Consumption can be reduced. On the other hand, in an environment where the time required for the communication connection between the communication terminal 120 and the computer 50 and the disconnection of the communication connection is long, the communication connection between the communication terminal 120 and the computer 50 and the disconnection of the communication connection are performed each time data transmission is performed. If it repeats, it will use large power for a long time, and the power consumption at the time of data transmission will increase easily. Therefore, when the communication cycle with the base station 40 is maintained and waiting in an environment where the transmission cycle T is short and the time required for the communication connection between the communication terminal 120 and the computer 50 and the disconnection of the communication connection is long. If the communication connection between the communication terminal 120 and the computer 50 is maintained, the communication terminal 120 is connected to the communication terminal 120 and the computer 50 each time data transmission is performed. Easy to suppress power consumption.

  On the other hand, the communication terminal 120 of this embodiment maintains the communication connection with the computer 50 in the second standby mode in which the communication connection with the base station 40 is maintained and waits. Therefore, the power consumption of the communication terminal 20 can be more efficiently suppressed in an environment where the transmission cycle T is short and the time required for the communication connection between the communication terminal 120 and the computer 50 and the disconnection of the communication connection is long.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to said embodiment, In the range which does not deviate from the objective of this invention, it can change suitably.

  For example, in the embodiment of the present invention, the data detected by the sensor 10 may be data other than temperature and humidity. The communication terminal 20 may transmit data other than the data transmitted from the sensor 10 to the computer 50.

  In the embodiment of the present invention, the communication terminal 20 and the communication terminal 120 may be communication terminals compatible with standards other than the wireless LAN. The radio signal to be transmitted / received may be a radio signal having a frequency other than those described above. In addition, the standard supported by the base station 40 may be appropriately changed according to the standard supported by the communication terminal 20.

  In the embodiment of the present invention, the computer 50 may be an apparatus other than a personal computer. For example, the computer 50 may be a portable information terminal, a tablet PC, a large computer, or the like. Further, the computer 50 may be a dedicated measuring instrument having a function as a computer.

  In the embodiment of the present invention, when the communication terminal 20 or the communication terminal 120 is used in an environment where the transmission cycle T is relatively short or the communication environment does not change with time, the communication terminal 20 or the communication terminal 120 is It is not necessary to periodically review the standby mode. Conversely, when the communication terminal 20 or the communication terminal 120 is used in a case where the transmission cycle T is relatively long or the communication environment is likely to change with time, the communication terminal 20 or the communication terminal 120 performs data transmission. You may review the standby mode each time.

DESCRIPTION OF SYMBOLS 1 Communication system 10 Sensor 20 Communication terminal 21 Communication part 21a Communication antenna 22 Memory | storage part 23 Timing part 24 Control part 30 Sensor module 40 Base station 50 Computer 101 Communication system 120 Communication terminal

Claims (6)

Communication connection by wireless communication with the base station is possible,
A communication connection is also possible with a computer connected to the base station,
A communication terminal that periodically transmits data to the computer via the base station,
The standby mode when not transmitting the data,
A first standby mode in which the communication connection with the base station is disconnected and waits;
A second standby mode for maintaining a communication connection with the base station and waiting;
Can be switched to
A first step of measuring a first required time required for communication connection with the base station;
A second step of measuring a second required time required for communication connection with the computer;
A third step of measuring a third required time required to transmit the data to the computer;
A fourth step of measuring a fourth time required for disconnecting the communication connection with the computer;
A fifth step of measuring a fifth required time required to disconnect the communication connection with the base station;
Based on the transmission period for transmitting the data, the first required time, the second required time, the third required time, the fourth required time, and the fifth required time, the first standby mode and the first required time A sixth step of selecting one of the two standby modes;
Follow the steps including
A communication terminal that selects the standby mode. A beacon receiving function for receiving a beacon signal transmitted from the base station;
An information storage function for storing information for communication connection with the base station,
In the first standby mode,
Stop the beacon reception function and the information storage function,
In the second standby mode,
Activating the beacon receiving function and the information storage function,
The communication terminal according to claim 1. In the second standby mode,
The communication connection with the computer is cut off,
The communication terminal according to claim 1 or 2. In the second standby mode,
Maintaining a communication connection with the computer,
The communication terminal according to claim 1 or 2. Periodically performing communication connection with the base station and disconnection of the communication connection,
According to the procedure from the first step to the sixth step,
The standby mode is reviewed,
The communication terminal according to any one of claims 1 to 4. Connected to a sensor for detecting the data,
The data detected by the sensor is
Periodically sending to the computer,
The communication terminal according to any one of claims 1 to 5.