KR102296151B1 - Methods and systems for energy harvesting using power beacon in wireless network environment - Google Patents

Abstract

The present invention relates to a method and system for energy harvesting using a power beacon in a wireless network environment, and an energy harvesting method performed by a cellular base station in a wireless network environment according to an embodiment of the present invention, in a wireless network environment. Determining a sensor node from which status information is not received periodically as a power shortage sensor node, confirming the location information of a candidate power beacon located in an energy harvesting area around the determined power shortage sensor node, and sending a wireless power transmission request message transmitting, receiving an acknowledgment message including battery level information from the candidate power beacon, selecting an optimal power beacon based on the identified location information of the candidate power beacon and the received battery level information Scheduling transmission, and transmitting a scheduling message for wireless power transmission to the selected optimal power beacon.

Description

Energy harvesting method and system using power beacon in wireless network environment

The present invention relates to a method and system for energy harvesting using a power beacon in a wireless network environment.

The Internet of Things (IoT) is a paradigm that connects multiple sensors and devices to each other and is a solution to a large-scale connected network. In addition, IoT has features such as low power consumption and low data rate, and it is predicted that billions of sensor nodes will be deployed and used in the future. These sensor nodes have the purpose of traffic management and traffic information collection in a complex urban environment, and through this, enable an intelligent transportation system (ITS).

Sensor nodes have the advantage of reliability and no disconnection of communication, but have the disadvantage of limited battery capacity due to an independent power source. Also, sensor nodes require a lot of money to replace batteries. One of the key designs for extending the life of these batteries is to provide energy to them. Energy production methods such as solar and wind energy obtain energy from nature and then convert it into electrical energy. However, this energy production method revealed limitations in relying on the natural environment. However, the RF energy harvesting technology is a more convenient method of supplying energy to these sensor nodes than the energy production method described above.

Radio Frequency (RF) energy harvesting technology involves obtaining electrical energy from RF signals. In general, the range of energy harvesting (EH) is several tens of meters in radius. Accordingly, a sensor node located far away from the RF signal may not receive sufficient energy. This problem can be solved by deploying dedicated RF resources for charging sensor nodes such as power beacons, but it poses a problem in terms of cost.

The conventional sensor node is charged with energy by utilizing an RF signal transmitted from a device having a fixed location, such as a cellular base station (CBS), a Wi-Fi access point (AP), and a TV tower. However, there is a limit to scalability in using the energy charged from the RF signal. In addition, the EH region of the RF signal is generally several tens of meters in radius. Therefore, sensor nodes located at a distance may not obtain sufficient energy. One solution is to deploy a dedicated RF energy source, such as a power beacon. However, these solutions are expensive because they require additional infrastructure to be installed. Another solution is to use a mobile-specific RF energy source, such as a mobile charger. However, this solution also requires the additional efficient travel path planning of a dedicated RF energy source.

Embodiments of the present invention are a solution for supplying power to a sensor node having a limited battery capacity by an independent power source. A wireless network that can transmit power wirelessly to a sensor node through an optimal power beacon located around the sensor node. An object of the present invention is to provide a method and system for energy harvesting using a power beacon in an environment.

Embodiments of the present invention supply RF energy to the sensor node through a wireless power transmission function of a vehicle (eg, a mobile vehicle, etc.) serving as a mobile power beacon (MPB, Mobile Power Beacon), thereby providing a sensor node with insufficient power. An object of the present invention is to provide a method and system for energy harvesting using a power beacon in a wireless network environment, which can be conveniently charged. As such, embodiments of the present invention are intended to provide a method and system for energy harvesting using a power beacon in a wireless network environment, capable of supplying power to a sensor node while using a vehicle as an RF resource.

However, the problems to be solved by the present invention are not limited thereto, and may be variously expanded in an environment within the scope not departing from the spirit and scope of the present invention.

According to an embodiment of the present invention, in an energy harvesting method performed by a cellular base station in a wireless network environment, determining a sensor node from which status information is not periodically received in a wireless network environment as a power shortage sensor node ; transmitting a wireless power transmission request message by confirming location information of a candidate power beacon located in an energy harvesting area around the determined power shortage sensor node; receiving an acknowledgment message including battery level information from the candidate power beacon; scheduling wireless power transmission by selecting an optimal power beacon based on the identified candidate power beacon location information and the received battery level information; and transmitting a scheduling message for wireless power transmission to the selected optimal power beacon. An energy harvesting method in a cellular base station in a wireless network environment may be provided.

The candidate power beacon may be installed in a vehicle moving around a sensor node located in the wireless network environment to operate as a mobile power beacon.

In the determining of the power shortage sensor node, the sensor node that has transmitted the energy harvesting request message may be determined as the power shortage sensor node.

In the transmitting of the wireless power transmission request message, when there is no candidate power beacon located in the energy harvesting area around the determined power shortage sensor node, path information of the power beacon located outside the energy harvesting area is checked and wireless A power transmission request message may be transmitted.

In the scheduling of the wireless power transmission, the wireless power transmission request message may be transmitted by checking location information of a candidate power beacon having a battery level higher than or equal to a preset battery level among candidate power beacons located in the energy harvesting area.

Meanwhile, according to another embodiment of the present invention, there is provided an energy harvesting method performed by a power beacon in a wireless network environment, the method comprising: receiving a wireless power transmission request message from a cellular base station located in a wireless network environment; transmitting an acknowledgment message in response to the wireless power transmission request message to the cellular base station when the battery power level of the provided battery is equal to or greater than a preset threshold; receiving a scheduling message for wireless power transmission from the cellular base station; and performing wireless power transmission using the charging power of the battery to the selected insufficient power sensor node according to the received scheduling message. An energy harvesting method in a power beacon in a wireless network environment may be provided.

The power beacon may be installed in a vehicle moving around a sensor node located in the wireless network environment to operate as a mobile power beacon.

The method may further include periodically transmitting the location information of the power beacon to the cellular base station.

The transmitting of the acknowledgment message may include not transmitting the acknowledgment message to the cellular base station when the battery power level of the provided battery is less than a preset threshold.

The performing of the wireless power transmission may include converting the charging power of the battery into an RF signal for wireless power transmission, and transmitting the converted RF signal to the power shortage sensor node through an antenna connected through switching control. .

On the other hand, according to another embodiment of the present invention, a communication module for communicating with the sensor node and the power beacon in a wireless network environment; a node determination unit that determines a sensor node to which status information is not periodically received through the communication module as a power shortage sensor node; Through the communication module, the position information of the candidate power beacon located in the energy harvesting area around the determined power shortage sensor node is checked, the wireless power transmission request message is transmitted, and the acknowledgment response including the battery level information from the candidate power beacon a message management unit for receiving a message; and scheduling wireless power transmission by selecting an optimal power beacon based on the identified candidate power beacon location information and the received battery level information, and transmitting a scheduling message for wireless power transmission to the selected optimal power beacon. A cellular base station for energy harvesting in a wireless network environment may be provided, comprising:

The candidate power beacon may be installed in a vehicle moving around a sensor node located in the wireless network environment to operate as a mobile power beacon.

The node determining unit may determine the sensor node that has transmitted the energy harvesting request message as a power shortage sensor node.

If there is no candidate power beacon located in the energy harvesting area around the determined power shortage sensor node, the message management unit may check the path information of the power beacon located outside the energy harvesting area to transmit a wireless power transmission request message. have.

The scheduling unit may transmit a wireless power transmission request message by confirming location information of a candidate power beacon having a battery level higher than or equal to a preset battery level among candidate power beacons located in the energy harvesting area.

On the other hand, according to another embodiment of the present invention, a battery for storing charging power; a power converter converting the power charged in the battery into an RF signal; a transceiver for receiving a wireless power transmission request message from a cellular base station located in a wireless network environment; and a power transmission control unit configured to transmit an acknowledgment message for the wireless power transmission request message to the cellular base station through the transceiver if the battery power level of the provided battery is greater than or equal to a preset threshold, wherein the transceiver unit includes the cellular Receives a scheduling message for wireless power transmission from the base station, and the power transmission control unit performs wireless power transmission using charging power of the battery to a selected power shortage sensor node according to the received scheduling message, in a wireless network environment A power beacon may be provided for energy harvesting.

The power beacon may be installed in a vehicle moving around a sensor node located in the wireless network environment to operate as a mobile power beacon.

The power transmission control unit may periodically transmit the location information of the power beacon to the cellular base station through the transceiver.

The power transmission controller may not transmit the acknowledgment message to the cellular base station through the transceiver when the battery power level of the provided battery is less than a preset threshold.

The power transmission control unit may connect the power conversion unit to the antenna through switching control of the transceiver unit to transmit the converted RF signal to the power shortage sensor node.

The disclosed technology may have the following effects. However, this does not mean that a specific embodiment should include all of the following effects or only the following effects, so the scope of the disclosed technology should not be construed as being limited thereby.

Embodiments of the present invention are solutions for supplying power to a sensor node having a limited battery capacity by an independent power source, and may wirelessly transmit power to the sensor node through an optimal power beacon located around the sensor node.

Embodiments of the present invention supply RF energy to the sensor node through a wireless power transmission function of a vehicle (eg, a mobile vehicle, etc.) serving as a mobile power beacon (MPB, Mobile Power Beacon), thereby providing a sensor node with insufficient power. can be conveniently charged.

Embodiments of the present invention may reduce infrastructure construction costs because additional infrastructure such as a dedicated power beacon for charging a sensor node does not need to be installed.

Further, embodiments of the present invention may use a conventional mobile vehicle as a mobile power beacon to recharge the sensor node by scheduling the sensor node through a controller implemented in the cellular base station.

In addition, the embodiments of the present invention may reduce capital expenditure and operating costs because no more dedicated RF energy sources or dedicated RF resources used to plan vehicle routes are required.

1 is a diagram illustrating an example of a wireless network environment to which an energy harvesting system using a power beacon according to an embodiment of the present invention is applied.
2 is a configuration diagram for explaining the configuration of a power beacon in an energy harvesting system according to an embodiment of the present invention.
3 is a configuration diagram illustrating a configuration of a cellular base station in an energy harvesting system according to an embodiment of the present invention.
4 is a flowchart illustrating an energy harvesting method in a power beacon according to an embodiment of the present invention.
5 is a flowchart illustrating an energy harvesting method in a cellular base station according to an embodiment of the present invention.
6 is a flowchart illustrating an energy harvesting method in a sensor node according to an embodiment of the present invention.
7 is a diagram illustrating a wireless power transmission operation in an energy harvesting system according to an embodiment of the present invention.

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to a specific embodiment, it can be understood to include all transformations, equivalents or substitutes included in the spirit and scope of the present invention. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Terms such as first, second, etc. may be used to describe various elements, but the elements are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

The terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. The terms used in the present invention have been selected as currently widely used general terms as possible while considering the functions in the present invention, but these may vary depending on the intention of those skilled in the art, precedents, or emergence of new technology. In addition, in a specific case, there is a term arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the description of the corresponding invention. Therefore, the term used in the present invention should be defined based on the meaning of the term and the overall content of the present invention, rather than the name of a simple term.

The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present invention, terms such as "comprises" or "have" are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals, and the overlapping description thereof will be omitted. do.

1 is a diagram illustrating an example of a wireless network environment to which an energy harvesting system using a power beacon according to an embodiment of the present invention is applied.

As shown in FIG. 1 , an energy harvesting system using a power beacon in a wireless network environment according to an embodiment of the present invention is a cellular base station 110 , a power beacon installed in a vehicle 120 and a sensor node 130 . includes

As an example of the wireless network environment, consider a cellular network in which a sensor node 130 is disposed on a structure of a road in a dense urban environment within the area of the cellular base station 110 . It is assumed that the location of the sensor node 130 is being verified by the cellular base station 110 . The sensor node 130 periodically transmits a data packet including status information to the cellular base station 110 . The power shortage sensor node 131 transmits an energy harvesting request message to the cellular base station 110 or stops transmitting data packets. In the latter case, if the cellular base station 110 does not receive a data packet from the sensor node 130 for a specific time, it is considered that the battery of the corresponding sensor node 130 is exhausted.

The cellular base station 110 reserves resources for downlink transmission. A sensor node 130 that is within an energy harvesting area of the cellular base station 110 may obtain energy from a signal received during downlink transmission of the cellular base station 110 . However, the sensor node 130 may be disposed outside the energy charging area of the cellular base station 110 and may not obtain sufficient energy from the surrounding signal.

In order to charge the sensor node 130 , information on a vehicle to be registered for wireless power transmission is required, and information on the vehicle registered in the cellular base station 110 is stored. In one embodiment of the present invention, the registered vehicle 120 is called "Wireless Power Transfer (WPT) capable vehicle (Vehicles capable of WPT)". The vehicle registered in the cellular base station 110 is equipped with an Energy Transmit Unit (ETU) and functions as a mobile power beacon. In addition, the wireless power transmission capable vehicle 120 periodically communicates with the cellular base station 110 to notify its location. On the other hand, a vehicle in which a power beacon is not installed may be designated as the vehicle 121 incapable of wireless power transmission.

The cellular base station 110 selects an optimal vehicle for supplying power to the power shortage sensor node 131 . Here, an embodiment of the present invention may be implemented with the controller C located in the cellular base station 110 . Alternatively, the controller C may be implemented by being integrated with the cellular base station 110 . The cellular base station 110 transmits the state information of the sensor node 130 to the controller C. If information from the sensor node 130 is not received within a limited time, the controller C transmits the location information of the non-responsive sensor node and the location information of the “wireless power transmission capable vehicle” in the energy harvesting area to the cellular base station 110 . receive through Then, the controller C transmits a wireless power transmission request to the “wireless power transmission capable vehicle” through the cellular base station 110 .

To charge the sensor node 130 via the power in the vehicle battery, a vehicle near the energy harvesting area of the low power sensor node 131 responds by sending an acknowledgment message to the cellular base station 110 . The acknowledgment message includes vehicle battery status information. Using the battery level and location information, the controller selects an optimal vehicle from the candidate vehicles to power the low power sensor node 131 . The controller sends the selected vehicle information to the cellular base station 110 . The cellular base station 110 charges the sensor node 130 by sending a scheduling message to the power beacon of the selected vehicle.

For example, as shown in FIG. 1 , a sensor node 1 (Sensor Node: 1) lacking energy has two vehicles capable of wireless power transmission in the energy harvesting area, but another sensor node N (Sensor Node) lacking power. Node: N) does not have a vehicle capable of wireless power transmission in the energy harvesting area. The cellular base station 110 transmits a wireless power transfer request message to a vehicle close to the sensor node 1 (Sensor Node: 1) lacking power, and a candidate vehicle with sufficient vehicle battery responds by sending a confirmation message to the cellular base station 110 . do. The optimal vehicle is selected by the controller and receives a scheduling message. The optimal vehicle receiving the message transmits a high-power RF signal to charge the insufficient power sensor node 1 (Sensor Node: 1).

In order to solve the problems of the distance limit of the RF signal and the limited battery capacity of the sensor node 130, the controller in the cellular base station 110 through the mobile power beacon function vehicle near the power shortage sensor node 131 and When the power shortage sensor node 131 and the mobile power beacon function vehicle are within a defined distance by communicating, wireless power transmission is performed to the power shortage sensor node 131 .

2 is a configuration diagram for explaining the configuration of a power beacon in an energy harvesting system according to an embodiment of the present invention.

As shown in FIG. 2 , the power beacon 200 according to an embodiment of the present invention includes a battery 210 , a power converter 220 , a transceiver 230 , and a power transmission controller 240 . Here, the power beacon 200 may be installed in a vehicle moving around the sensor node 130 located in a wireless network environment to operate as a mobile power beacon. However, not all illustrated components are essential components. The power beacon 200 may be implemented by more components than the illustrated components, and the power beacon 200 may be implemented by fewer components than that.

Hereinafter, a detailed configuration and operation of each component of the power beacon 200 of FIG. 2 will be described.

The battery 210 stores charging power.

The power converter 220 converts the power charged in the battery 210 into an RF signal.

The transceiver 230 communicates with the cellular base station 110 and the sensor node 130 . The transceiver 230 receives a wireless power transmission request message from the cellular base station 110 located in a wireless network environment. In addition, the transceiver 230 receives a scheduling message for wireless power transmission from the cellular base station 110 . The power transmission controller 240 may periodically transmit location information of the power beacon 200 to the cellular base station 110 through the transceiver 230 .

When the battery power level of the provided battery 210 is greater than or equal to a preset threshold, the power transmission control unit 240 sends an acknowledgment message to the cellular base station 110 through the transceiver 230 in response to the wireless power transmission request message. to send On the other hand, when the battery power level of the provided battery 210 is less than a preset threshold, the power transmission control unit 240 may not transmit the acknowledgment message to the cellular base station 110 through the transceiver 230 . have.

The power transmission control unit 240 performs wireless power transmission using the charging power of the battery 210 to the selected insufficient power sensor node 131 according to the scheduling message received from the transceiver 230 . The power transmission control unit 240 may connect the power conversion unit 220 to the antenna 233 through the switching control of the transceiver unit 230 to transmit the converted RF signal to the power shortage sensor node 131 .

The mobile power beacon 200 according to an embodiment of the present invention may be installed in a vehicle and implemented as a wireless energy transmission unit (ETU). A wireless energy transmission unit (ETU) is installed in a vehicle capable of wireless power transmission (WPT). The power transmission control unit 240 may include a control unit 241 , an information processing unit 242 , and a signal processing unit 243 . The transceiver 230 may include switches 1 (SW1, 231), switches 2 (SW2, 232), and an antenna 233. Switch 1 (SW1, 231) switches the information transmission or information reception connection with the antenna. Switch 2 (SW2, 232) switches the information transmission/reception or power transmission connection with the antenna.

The wireless energy transmission unit operates in a half-duplex mode, ie, transmitting an RF signal or transmitting and receiving an information signal.

The control unit 241 of the wireless energy transmission unit includes digital logic for controlling the operation of the wireless energy transmission unit.

The information processing unit 242 decodes a message received from the cellular base station 110 , processes information, and encodes an acknowledgment message.

The signal processing unit 243 performs modulation/demodulation, AC/DC conversion, and the like.

The power converter 220 converts DC power into a high-power RF signal transmitted by the antenna 233 .

The power beacon 200 receives a wireless power transmission request message from the cellular base station 110 . In response to the wireless power transmission request message, the information processing unit 242 collects vehicle battery level information. When the vehicle battery 210 has sufficient power to transmit the RF signal, the information processing unit 242 encodes an acknowledgment message including the current state of the vehicle battery level. This information is processed by the signal processing unit 243 and transmitted to the cellular base station 110 through the antenna 233 of the transceiver 230 . The optimal vehicle among the candidate vehicles is scheduled by the controller to transmit the RF signal. The wireless energy transfer unit of the selected vehicle receives the scheduling message from the cellular base station 110 .

When a scheduling message is received from the cellular base station 110 , the control unit 241 sends a control signal to the switch and transmits DC power to the power converter 220 . Then, the connection is switched in the switch, and the power converter 220 is operated to convert the energy of the vehicle battery 210 into RF energy. This RF energy is transmitted to power the underpowered sensor node 131 .

3 is a configuration diagram illustrating a configuration of a cellular base station in an energy harvesting system according to an embodiment of the present invention.

As shown in FIG. 3 , the cellular base station 110 in the energy harvesting system according to an embodiment of the present invention includes a communication module 310 , a node determination unit 320 , a message management unit 330 , and a scheduling unit. (340). Here, the energy harvesting operation may be performed through a separate device called a controller within the cellular base station 110 . Alternatively, the controller may be implemented by integrating with the cellular base station 110 . However, not all illustrated components are essential components. The cellular base station 110 may be implemented by more components than the illustrated components, or the cellular base station 110 may be implemented by fewer components.

Hereinafter, a detailed configuration and operation of each component of the cellular base station 110 in the energy harvesting system of FIG. 3 will be described.

The communication module 310 communicates with the sensor node 130 and the power beacon 200 in a wireless network environment.

The node determination unit 320 determines the sensor node 130 to which the state information is not periodically received through the communication module 310 as the power shortage sensor node 131 . The node determining unit 320 may determine the sensor node 130 that has transmitted the energy harvesting request message as the power shortage sensor node 131 .

The message management unit 330 wirelessly transmits power by confirming the location information of the candidate power beacon located in the energy harvesting area around the power shortage sensor node 131 determined by the node determination unit 320 through the communication module 310 . It transmits a request message and receives an acknowledgment message including battery level information from the candidate power beacon. Here, when the message management unit 330 does not receive an acknowledgment message including the battery level information from the candidate power beacon, the position information of the candidate power beacon located in the energy harvesting area around the determined insufficient power sensor node 131 is By rechecking, the wireless power transmission request message can be transmitted. When there is no candidate power beacon located in the energy harvesting area around the determined power shortage sensor node 131, the message management unit 330 checks the path information of the power beacon located outside the energy harvesting area to send a wireless power transmission request message. can be transmitted

The scheduling unit 340 schedules wireless power transmission by selecting an optimal power beacon based on the received battery level information and the location information of the candidate power beacon confirmed by the message management unit 330 . The scheduling unit 340 transmits a scheduling message for wireless power transmission to the selected optimal power beacon. Here, the scheduling unit 340 may transmit a wireless power transmission request message by confirming location information of a candidate power beacon having a battery level higher than or equal to a preset battery level among candidate power beacons located in the energy harvesting area.

The candidate power beacon may be installed in a vehicle moving around the sensor node 130 located in a wireless network environment and may operate as a mobile power beacon.

4 is a flowchart illustrating an energy harvesting method in a power beacon according to an embodiment of the present invention.

4 illustrates a method of performing an energy harvesting operation through a mobile power beacon installed in a vehicle as an example. The power beacon 200 may periodically transmit location information of the power beacon 200 to the cellular base station 110 . For example, the cellular base station 110 may periodically receive location information of a vehicle in which the power beacon 200 is installed.

In step S101 , the power beacon 200 receives a request message from the cellular base station 110 . Alternatively, the vehicle in which the mobile power beacon is installed may receive a wireless power transmission request message from the cellular base station 110 .

In step S102, the power beacon 200 obtains battery level information from the battery.

In step S103 , the power beacon 200 checks whether the battery level exceeds a preset threshold.

In step S104 , when the battery level exceeds a preset threshold, the power beacon 200 transmits an acknowledgment message to the cellular base station 110 . On the other hand, if the battery level is less than or equal to the preset threshold, the power beacon 200 does not transmit an acknowledgment message to the cellular base station 110 . In this way, the power beacon 200 checks the battery level information of the battery installed in the vehicle and transmits an acknowledgment message to the cellular base station 110 if the battery level is sufficient than a preset threshold value. If the vehicle battery is not sufficient, the wireless power transmission scheduling message cannot be received from the cellular base station 110 .

In step S105 , the power beacon 200 checks whether a scheduling message is received from the cellular base station 110 for wireless power transmission.

In step S106 , when the power beacon 200 receives a scheduling message from the cellular base station 110 for wireless power transmission, the power beacon 200 performs wireless power transmission to the selected sensor node 130 according to the scheduling message. Here, the power beacon 200 converts the charging power of the battery into an RF signal for wireless power transmission, and transmits the converted RF signal through the antenna 233 connected through the switching control to the power shortage sensor node 131. have. On the other hand, the power beacon 200 does not start wireless power transmission unless it receives a scheduling message from the cellular base station 110 .

5 is a flowchart illustrating an energy harvesting method in the cellular base station 110 according to an embodiment of the present invention.

The energy harvesting operation of the cellular base station 110 illustrated in FIG. 5 may be performed by the cellular base station 110 or by a controller in the cellular base station 110 .

In step S201 , the cellular base station 110 receives status information of the sensor node 130 . The cellular base station 110 periodically receives status information of the sensor node 130 .

In step S202 , the cellular base station 110 checks whether status information is received from the sensor node 130 .

In step S203 , when the status information is not received from the sensor node 130 , the cellular base station 110 checks the sensor ID of the non-responsive sensor node 130 . As such, if the data packet of the sensor node 130 is not received, it is regarded as a non-responsive sensor, and the cellular base station 110 checks the ID of the non-responsive sensor node. The cellular base station 110 determines that the sensor node 130 from which status information is not periodically received in the wireless network environment is the insufficient power sensor node 131 . When the cellular base station 110 receives the state information from the sensor node 130 , the cellular base station 110 again performs step S201 of receiving the state information of the sensor node 130 .

In step S204 , the cellular base station 110 checks the location information of the wireless power transmission vehicle around the energy harvesting area of the non-responsive sensor node 130 . The cellular base station 110 may receive location information of a vehicle capable of wireless power transmission in the vicinity of an energy harvesting station of a non-responsive sensor node through a cellular network. Here, the location information becomes location information of a candidate power beacon located in the energy harvesting area around the power shortage sensor node 131 .

In step S205, the cellular base station 110 transmits a wireless power transmission request message to the wireless power transmission vehicle through the cellular network.

In step S206 , the cellular base station 110 determines whether an acknowledgment message is received from the wireless power transmission vehicle. That is, the cellular base station 110 receives an acknowledgment message including battery level information from the candidate power beacon.

In step S207, upon receiving the acknowledgment message from the wireless power transmission vehicle, the cellular base station 110 selects an optimal vehicle for wireless power transmission among candidate vehicles. If the cellular base station 110 receives the acknowledgment message, the vehicle becomes a candidate vehicle, and selects an optimal vehicle from among these candidate vehicles. If the cellular base station 110 does not receive an acknowledgment message from the wireless power transmission capable vehicle, it again receives location information of the wireless power transmission capable vehicle near the energy harvesting area.

In step S208 , the cellular base station 110 transmits a scheduling message to the optimal vehicle selected to the cellular base station 110 . As such, the cellular base station 110 may schedule wireless power transmission by selecting an optimal power beacon based on the identified candidate power beacon location information and received battery level information, and may transmit a scheduling message.

6 is a flowchart illustrating an energy harvesting method in a sensor node according to an embodiment of the present invention.

In step S301 , the sensor node 130 generates a data packet including state information of the sensor node 130 .

In step S302, the sensor node 130 checks the battery level. That is, the sensor node 130 checks the battery state of the sensor node 130 .

In step S303, the sensor node 130 checks whether the battery level is equal to or greater than a threshold.

In step S304 , if the battery level is greater than or equal to the threshold, the sensor node 130 transmits a data packet including status information to the cellular base station 110 .

In step S305, if the battery level is less than the threshold, the sensor node 130 switches to the sleep mode for the wireless power transmission vehicle and waits.

In step S306, the sensor node 130 receives an RF signal from the vehicle capable of wireless power transmission.

In step S307, the sensor node 130 performs energy harvesting.

In this way, the sensor node 130 transmits state information to the cellular base station 110 if the battery state is greater than the threshold value, and if the battery state is lower than the threshold value, waits for a wireless power transmission capable vehicle and receives an RF signal from the vehicle do. Accordingly, the sensor node 130 can charge the battery of the sensor node 130 .

7 is a diagram illustrating a wireless power transmission operation in an energy harvesting system according to an embodiment of the present invention.

As shown in FIG. 7 , the sensor node 130 generates sensor data packets including state information at regular intervals, that is, every time slot T. Also, it is assumed that a vehicle registered for wireless power transmission periodically transmits its location to the cellular base station 110 .

The sensor node 130 periodically transmits a sensor data packet including state information to the cellular base station 110 . If a message is not received from the sensor node 130 for a specific period of time, the cellular base station 110 assumes that the battery of the sensor node 130 is low. The cellular base station 110 transmits a WPT request message to a vehicle capable of wireless power transmission close to an energy depleted sensor 131 .

When the first wireless power transmission request message is transmitted, vehicles 1, 2, and 3 (Vehicles 1, 2, 3) are close to the power shortage sensor node 131 . These vehicles receive a WPT request message from the power beacon and decode the information signal including the wireless power transmission request message. When the vehicle has a high-power RF signal, that is, vehicles 1 and 3 have sufficient power to transmit to the sensor node 130 , the vehicle responds by sending an acknowledgment message including current battery level information (ACK message) do.

In FIG. 7 , vehicles 1 and 3 (Vehicles 1 and 3) are candidate vehicles for wireless power transmission. It is considered that vehicle 1 has more battery power than vehicle 3 and is closer to the low power sensor node 131 . Therefore, it is selected as an optimal vehicle for wireless power transmission, and the cellular base station 110 transmits a scheduling message to vehicle 1 . Vehicle 1 charges the power shortage sensor node 131 by transmitting high-power RF signals for the defined time slots, three time slots in FIG. 7 . When sufficiently charged, the sensor node 130 periodically starts transmitting data packets including state information.

When the energy of the sensor node 130 is depleted again, the vehicle 4 is close to the power shortage sensor node 131 . Assuming that vehicle 4 has sufficient battery power, it receives a scheduling message by the cellular base station 110 to recharge the sensor node 130 .

Meanwhile, according to an embodiment of the present invention, the various embodiments described above are implemented as software including instructions stored in a machine-readable storage media readable by a machine (eg, a computer). can be The device is a device capable of calling a stored command from a storage medium and operating according to the called command, and may include an electronic device (eg, the electronic device A) according to the disclosed embodiments. When the instruction is executed by the processor, the processor may perform a function corresponding to the instruction by using other components directly or under the control of the processor. Instructions may include code generated or executed by a compiler or interpreter. The device-readable storage medium may be provided in the form of a non-transitory storage medium. Here, 'non-transitory' means that the storage medium does not include a signal and is tangible, and does not distinguish that data is semi-permanently or temporarily stored in the storage medium.

In addition, according to an embodiment of the present invention, the methods according to the various embodiments described above may be provided by being included in a computer program product. Computer program products may be traded between sellers and buyers as commodities. The computer program product may be distributed in the form of a machine-readable storage medium (eg, compact disc read only memory (CD-ROM)) or online through an application store (eg, Play Store™). In the case of online distribution, at least a part of the computer program product may be temporarily stored or temporarily created in a storage medium such as a memory of a server of a manufacturer, a server of an application store, or a relay server.

In addition, according to an embodiment of the present invention, the various embodiments described above are stored in a recording medium readable by a computer or a similar device using software, hardware, or a combination thereof. can be implemented in In some cases, the embodiments described herein may be implemented by the processor itself. According to the software implementation, embodiments such as the procedures and functions described in this specification may be implemented as separate software modules. Each of the software modules may perform one or more functions and operations described herein.

Meanwhile, computer instructions for performing the processing operation of the device according to the above-described various embodiments may be stored in a non-transitory computer-readable medium. The computer instructions stored in the non-transitory computer-readable medium, when executed by the processor of the specific device, cause the specific device to perform the processing operation in the device according to the various embodiments described above. The non-transitory computer-readable medium refers to a medium that stores data semi-permanently, rather than a medium that stores data for a short moment, such as a register, cache, memory, etc., and can be read by a device. Specific examples of the non-transitory computer-readable medium may include a CD, DVD, hard disk, Blu-ray disk, USB, memory card, ROM, and the like.

In addition, each of the components (eg, a module or a program) according to the above-described various embodiments may be composed of a singular or a plurality of entities, and some sub-components of the above-described corresponding sub-components may be omitted, or other Sub-components may be further included in various embodiments. Alternatively or additionally, some components (eg, a module or a program) may be integrated into a single entity to perform the same or similar functions performed by each corresponding component prior to integration. According to various embodiments, operations performed by a module, program, or other component are executed sequentially, parallel, iteratively, or heuristically, or at least some operations are executed in a different order, are omitted, or other operations are added. can be

In the above, preferred embodiments of the present invention have been shown and described, but the present invention is not limited to the specific embodiments described above, and it is common in the technical field pertaining to the present disclosure without departing from the gist of the present invention as claimed in the claims. Various modifications may be made by those having the knowledge of, of course, and these modifications should not be individually understood from the technical spirit or perspective of the present invention.

110: cellular base station
120: vehicle capable of wireless power transmission
121: wireless power transmission impossible vehicle
130: sensor node
131: lack of power sensor node
200: power beacon
210: battery
220: power conversion unit
230: transceiver
231: switch 1
232: switch 2
233: antenna
240: power transmission control unit
241: control unit
242: information processing unit
243: signal processing unit
310: communication module
320: node determination unit
330: message management unit
340: scheduling unit

Claims (20)

An energy harvesting method performed by a cellular base station in a wireless network environment, the method comprising:
determining a sensor node to which status information is not periodically received in a wireless network environment as a power shortage sensor node;
transmitting a wireless power transmission request message by confirming location information of a candidate power beacon located in an energy harvesting area around the determined power shortage sensor node;
receiving an acknowledgment message including battery level information from the candidate power beacon;
scheduling wireless power transmission by selecting a power beacon based on the identified candidate power beacon location information and the received battery level information; and
and transmitting a scheduling message for wireless power transmission to the selected power beacon. According to claim 1,
The candidate power beacon is
An energy harvesting method in a cellular base station in a wireless network environment, which is installed in a vehicle moving around a sensor node located in the wireless network environment and operates as a mobile power beacon. According to claim 1,
The step of determining the power shortage sensor node is,
An energy harvesting method in a cellular base station in a wireless network environment, in which a sensor node that has transmitted an energy harvesting request message is determined as a power shortage sensor node. According to claim 1,
Transmitting the wireless power transmission request message comprises:
If there is no candidate power beacon located in the energy harvesting area around the determined power shortage sensor node, check the path information of the power beacon located outside the energy harvesting area and transmit a wireless power transmission request message in a wireless network environment A method of energy harvesting in a cellular base station. According to claim 1,
Scheduling the wireless power transmission comprises:
An energy harvesting method in a cellular base station in a wireless network environment for transmitting a wireless power transmission request message by confirming location information of a candidate power beacon having a battery level or higher among candidate power beacons located in the energy harvesting area. delete delete delete delete delete a communication module for communicating with the sensor node and the power beacon in a wireless network environment;
a node determination unit that determines a sensor node to which status information is not periodically received through the communication module as a power shortage sensor node;
Through the communication module, the position information of the candidate power beacon located in the energy harvesting area around the determined power shortage sensor node is checked, the wireless power transmission request message is transmitted, and the acknowledgment response including the battery level information from the candidate power beacon a message management unit for receiving a message; and
A scheduling unit configured to schedule wireless power transmission by selecting a power beacon based on the identified location information of the candidate power beacon and the received battery level information, and transmitting a scheduling message for wireless power transmission to the selected power beacon , a cellular base station for energy harvesting in a wireless network environment. 12. The method of claim 11,
The candidate power beacon is
A cellular base station for energy harvesting in a wireless network environment, which is installed in a vehicle moving around a sensor node located in the wireless network environment and operates as a mobile power beacon. 12. The method of claim 11,
The node determination unit,
A cellular base station for energy harvesting in a wireless network environment, which determines that a sensor node that has transmitted an energy harvesting request message is a sensor node lacking in power. 12. The method of claim 11,
The message management unit,
If there is no candidate power beacon located in the energy harvesting area around the determined power shortage sensor node, check the path information of the power beacon located outside the energy harvesting area and transmit a wireless power transmission request message in a wireless network environment Cellular base station for energy harvesting. 12. The method of claim 11,
The scheduling unit,
A cellular base station for energy harvesting in a wireless network environment, which transmits a wireless power transmission request message by confirming location information of a candidate power beacon having a battery level or higher among candidate power beacons located in the energy harvesting area. delete delete delete delete delete

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