Device and method for power control in wireless power transmission system

Abstract

To provide a device and a method for performing authentication in a wireless power transmission system.SOLUTION: An authentication method in a wireless power transfer system according to the present specification includes a stage of receiving, from a target device, a first packet including instruction information regarding whether the target device supports an authentication function, a stage of sending an authentication request message to the target device when the target device supports the authentication function, a step of receiving an authentication response message including a certificate regarding wireless charging from the target device as a response to the authentication request message, and a stage of confirming the authentication of the target device on the basis of the authentication response message.SELECTED DRAWING: Figure 79

Description

Technical Field

[0001] The present invention relates to wireless power transmission, and more particularly, to an apparatus and method for performing power control in a wireless power transmission system.

Background Art

[0002] Wireless power transmission technology is a technology for wirelessly transmitting power between a power source and an electronic device. As an example, wireless power transmission technology enables charging of the battery of a wireless terminal such as a smartphone or a tablet by simply placing the wireless terminal on a wireless charging pad, providing better mobility, convenience, and safety compared to a wired charging environment that uses an existing wired charging connector. In addition to wireless charging of wireless terminals, wireless power transmission technology is attracting attention for replacing the existing wired power transmission environment in various fields such as electric vehicles, various wearable devices such as Bluetooth (registered trademark) earphones and 3D glasses, household appliances, furniture, underground facilities, buildings, medical devices, robots, and leisure.

[0003] The wireless power transmission method is also referred to as a non-contact power transmission method, a no point of contact power transmission method, or a wireless charging method. A wireless power transmission system includes a wireless power transmission device that supplies electrical energy by a wireless power transmission method, and a wireless power reception device that receives the electrical energy wirelessly supplied from the wireless power transmission device and supplies power to a power reception device such as a battery cell.

[0004] Wireless power transmission technologies are diverse, such as those that transmit power through magnetic coupling, radio frequency (RF), microwave, ultrasonic waves, etc. The method based on magnetic coupling is further classified into a magnetic induction method and a magnetic resonance method. The magnetic induction method is a way to transmit energy by utilizing the current induced in the receiving coil by the magnetic field generated from the transmitting coil battery cell through electromagnetic coupling between the transmitting coil and the receiving coil. The magnetic resonance method is similar to the magnetic induction method in that it uses a magnetic field. However, the magnetic resonance method is different from magnetic induction in that resonance occurs when a specific resonance frequency is applied to the transmitting coil and the receiving coil, and energy is transmitted due to the phenomenon that the magnetic field is concentrated at both ends of the transmitting side and the receiving side.

[0005] A wireless power system realized to comply with a specific standard technology can solve safety problems when overheated by foreign objects or the like. By the way, uncertified products that have not received product certification regarding technical standards or specifications are being circulated in the market, which may expose users to risks. Therefore, it is necessary to ensure stability and reliability by mutually authenticating that the wireless power transmission device and the wireless power reception device are genuine products during the process before and after wireless charging. 〔Prior Art Documents〕 〔Patent Documents〕 〔Patent Document 1〕Japanese Patent Application Laid-Open No. 2017-229112

Summary of the Invention

Problems to be Solved by the Invention

[0006] The technical problem of the present invention is to provide an apparatus and method for performing power control in a wireless power transmission system.

Means for Solving the Problems

[0007] According to one aspect of the present invention, a wireless power transmission device is provided. The device includes a power conversion unit configured to form a magnetic coupling with a wireless power receiving device to transmit wireless power to the wireless power receiving device, and a communication / control unit configured to perform transmission control of the wireless power and transmission or reception of data based on communication with the wireless power receiving device.

[0008] Here, the communication / control unit receives a received power packet (RPP) indicating a power value received by the wireless power receiving device from the wireless power receiving device. When there is data that the communication / control unit transmits to the wireless power receiving device, the communication / control unit transmits a bit pattern requesting communication by the wireless power transmission device as a response to the RPP to the wireless power receiving device, and can receive a packet for polling the data to be transmitted as a response to the bit pattern from the wireless power receiving device.

[0009] On one side, the data to be transmitted can include power-related information for increasing or decreasing the level of the wireless power.

[0010] On another side, the RPP can indicate that the wireless power receiving device is in mode 0.

[0011] On still another side, when the RPP indicates the remaining modes except mode 4, the communication / control unit can transmit the bit pattern.

[0012] On still another side, the bit pattern and the polling packet can each be 8 bits.

[0013] According to another aspect of the present invention, there is provided a power control method by a wireless power transmission device. The method includes forming a magnetic coupling with a wireless power receiving device to transmit wireless power to the wireless power receiving device, and performing transmission control of the wireless power and transmission or reception of data based on communication with the wireless power receiving device.

[0014] Here, the step of performing transmission or reception of the data may include receiving a received power packet (RPP) indicating a power value received by the wireless power receiving device from the wireless power receiving device, and when there is data to be transmitted by the wireless power transmission device to the wireless power receiving device, transmitting a bit pattern for requesting communication by the wireless power transmission device as a response to the RPP to the wireless power receiving device, and receiving a packet for polling the data to be transmitted as a response to the bit pattern from the wireless power receiving device.

[0015] In one aspect, the data to be transmitted may include power-related information for increasing or decreasing the level of the wireless power.

[0016] In another aspect, the RPP may indicate that the wireless power receiving device is in mode 0.

[0017] In still another aspect, when the RPP indicates the remaining modes except mode 4, the communication / control unit may transmit the bit pattern.

[0018] In still another aspect, the bit pattern and the polling packet may each be 8 bits.

[0019] According to still another aspect of the present invention, there is provided a wireless power receiving device. The device includes a power pickup unit configured to form a magnetic coupling with a wireless power transmitting device to receive wireless power from the wireless power transmitting device, and a communication / control unit configured to perform transmission control of the wireless power and transmission or reception of data based on communication with the wireless power transmitting device.

[0020] Here, the communication / control unit transmits a received power packet (RPP) indicating a power value received by the wireless power receiving device to the wireless power transmitting device. When there is data transmitted by the wireless power transmitting device, the communication / control unit receives a bit pattern from the wireless power transmitting device that requests communication by the wireless power transmitting device as a response to the RPP, and can transmit a packet to the wireless power transmitting device that polls the data to be transmitted as a response to the bit pattern.

[0021] In one aspect, the data to be transmitted can include power-related information for increasing or decreasing the level of the wireless power.

[0022] In another aspect, the RPP can indicate that the wireless power receiving device is in mode 0.

[0023] In still another aspect, when the RPP indicates the remaining modes except mode 4, the communication / control unit can receive the bit pattern.

[0024] In still another aspect, the bit pattern and the polling packet can each be 8 bits.

[0025] According to still another aspect of the present invention, there is provided a power control method by a wireless power receiving device. The method includes: forming a magnetic coupling with a wireless power transmitting device to receive wireless power from the wireless power transmitting device; and performing transmission control of the wireless power and transmission or reception of data based on communication with the wireless power transmitting device.

[0026] Here, the step of performing transmission or reception of the data may include: transmitting a received power packet (RPP) indicating a power value received by the wireless power receiving device to the wireless power transmitting device; when there is data that the wireless power transmitting device transmits to the wireless power receiving device, receiving, from the wireless power transmitting device, a bit pattern for requesting communication by the wireless power transmitting device as a response to the RPP; and transmitting, to the wireless power transmitting device, a packet for polling the data to be transmitted as a response to the bit pattern.

[0027] In one aspect, the data to be transmitted may include power-related information for increasing or decreasing the level of the wireless power.

[0028] In another aspect, the RPP may indicate that the wireless power receiving device is in mode 0.

[0029] In still another aspect, when the RPP indicates the remaining modes except mode 4, the communication / control unit may receive the bit pattern.

[0030] In still another aspect, the bit pattern and the polling packet may each be 8 bits.

Advantages of the Invention

[0031] Essential elements for authentication between a wireless power transmission device and a receiving device, such as the format of a wireless charging certificate, instruction information regarding support for authentication functions, the timing between authentication-related procedures and wireless charging phases, authentication procedures and messages, and lower-level protocols that support authentication procedures, are clearly provided by the present invention, enabling stability and reliability to be ensured even during high-power wireless charging.

Brief Description of the Drawings

[0032]

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Embodiments for Carrying Out the Invention

[0033] As used hereinafter, the term "wireless power" is used to mean any form of energy related to an electric field, a magnetic field, an electromagnetic field, etc. that is transmitted from a wireless power transmitter to a wireless power receiver without using a physical electromagnetic conductor. Wireless power may also be referred to as a wireless power signal, and may also mean an oscillating magnetic flux enclosed by a primary coil and a secondary coil. For example, power conversion in a system for wirelessly charging devices including mobile phones, cordless phones, iPods (registered trademark), MP3 players, headsets, etc. is described herein. Generally, the basic principle of wireless power transmission includes, for example, all methods of transmitting power by magnetic-coupling, methods of transmitting power by radio frequency (RF), methods of transmitting power by microwave, and methods of transmitting power by ultrasonic waves.

[0034] FIG. 1 is a block diagram of a wireless power system 10 according to an embodiment.

[0035] As shown in FIG. 1, the wireless power system 10 includes a wireless power transmitter 100 and a wireless power receiver 200.

[0036] The wireless power transmitter 100 generates a magnetic field when power is applied from an external power source (S). The wireless power receiver 200 uses the generated magnetic field to generate a current and wirelessly receive power.

[0037] In the wireless power system 10, the wireless power transmitter 100 and the wireless power receiver 200 can transmit and receive various information necessary for wireless power transmission. Here, the communication between the wireless power transmitter 100 and the wireless power receiver 200 is performed by either in-band communication that uses the magnetic field utilized for wireless power transmission or out-band communication that uses a separate communication carrier.

[0038] Here, the wireless power transmitter 100 is provided in a fixed type or a mobile type. Examples of the fixed type include a form embedded in furniture such as an indoor ceiling, wall surface, or table, a form implanted in an outdoor parking lot, bus stop, subway station, etc., and a form installed in a means of transportation such as a vehicle or a train. The mobile wireless power transmitter 100 can be realized as a part of a mobile device with a movable weight and size or another device such as a cover of a notebook computer.

[0039] Also, the wireless power receiver 200 must be interpreted as a comprehensive concept including various electronic devices equipped with a battery and various home appliances that are wirelessly powered and driven instead of a power cable. Representative examples of the wireless power receiver 200 include a portable terminal, a cellular phone, a smart phone, a personal digital assistant (PDA), a portable media player (PMP), a Wibro terminal, a tablet, a pablet, a notebook, a digital camera, a navigation terminal, a television, and an electric vehicle (EV).

[0040] In the wireless power system 100, there can be one or more wireless power receiving devices 200. In FIG. 1, it is shown that the wireless power transmitting device 100 and the wireless power receiving device 200 exchange power on a one-to-one basis. However, as shown in FIG. 2, it is also possible for one wireless power transmitting device 100 to transmit power to a plurality of wireless power receiving devices 200-1, 200-2,..., 200-M. In particular, when wireless power transmission is performed by the magnetic resonance method, one wireless power transmitting device 100 can apply the simultaneous transmission method or the time-division transmission method to transmit power to a plurality of wireless power receiving devices 200-1, 200-2,..., 200-M simultaneously.

[0041] Also, in FIG. 1, it shows the state where the wireless power transmitting device 100 immediately transmits power to the wireless power receiving device 200. However, a separate wireless power transmitting and receiving device such as a relay or a repeater can also be provided between the wireless power transmitting device 100 and the wireless power receiving device 200 to increase the wireless power transmission distance. In this case, power is transmitted from the wireless power transmitting device 100 to the wireless power transmitting and receiving device, and the wireless power transmitting and receiving device can transmit power to the wireless power receiving device 200 again.

[0042] Hereinafter, the wireless power receiver, power receiver, and receiver mentioned in this specification indicate the wireless power receiving device 200. Also, the wireless power transmitter, power transmitter, and transmitter mentioned in this specification indicate the wireless power receiving and transmitting device 100.

[0043] FIG. 3 shows embodiments of various electronic devices in which a wireless power transmission system is introduced.

[0044] Figure 3 classifies and shows electronic devices according to the amount of electric power transmitted and received in a wireless power transmission system. As shown in Figure 3, for wearable devices such as smart watches, smart glasses, head-mounted displays (HMDs), and smart rings, and mobile electronic devices (or portable electronic devices) such as earphones, remote controls, smartphones, PDAs, and tablet computers, a low-power (about 5 W or less or about 20 W or less) wireless charging method can be applied.

[0045] For medium / small household electrical appliances such as notebook computers, robot vacuum cleaners, TVs, audio equipment, vacuum cleaners, and monitors, a medium-power (about 50 W or less or about 200 W or less) wireless charging method can be applied. For kitchen household electrical appliances such as mixers, microwave ovens, and electric rice cookers, and personal mobility devices (or electronic devices / mobility means) such as wheelchairs, electric kick scooters, electric bicycles, and electric vehicles, a high-power (about 2 kW or less or 22 kW or less) wireless charging method can be applied.

[0046] The electronic devices / mobility means described above (or shown in Figure 1) can each include a wireless power receiver to be described later. Therefore, the electronic devices / mobility means described above can be wirelessly charged by receiving power from a wireless power transmitter.

[0047] Hereinafter, the description will focus on mobile devices to which the wireless power charging method is applied, but this is merely an embodiment, and the wireless charging method according to the present invention can be applied to various electronic devices described above.

[0048] Standards for wireless power transmission include the Wireless Power Consortium (WPC), the Air Fuel Alliance (AFA), and the Power Matters Alliance (PMA).

[0049] The WPC standard defines a baseline power profile (BPP) and an extended power profile (EPP). The BPP relates to wireless power transmitters and receivers that support 5W power transmission, and the EPP relates to wireless power transmitters and receivers that support power transmission in the range greater than 5W and less than 30W.

[0050] Various wireless power transmitters and receivers using different power levels are covered by each standard and classified into different power classes (PCs) or categories.

[0051] For example, WPC classifies wireless power transmitters and receivers into power class (PC)-1, PC0, PC1, and PC2 and provides standard documents for each PC. The PC-1 standard relates to wireless power transmitters and receivers that provide guaranteed power of less than 5W. Applications of PC-1 include wearable devices such as smartwatches.

[0052] The PC0 standard relates to wireless power transmitting and receiving devices that provide guaranteed power of 5W. The PC0 standard includes EPP where the guaranteed power is up to 30W. In-band (IB) communication is the mandatory communication protocol for PC0, but out-of-band (OBB) communication, which is used as an optional backup channel, can also be used. The wireless power receiving device can be identified by setting the OBB flag in the configuration packet to indicate whether OOB is supported or not. The wireless power transmitting device that supports OOB can enter the OOB handover phase by transmitting a bit-pattern for OOB handover as a response to the configuration packet. The response to the configuration packet can be NAK, ND, or a newly defined 8-bit pattern. Applications of PC0 include smartphones.

[0053] The PC1 standard relates to wireless power transmitting and receiving devices that provide guaranteed power from 30W to 150W. OOB is the mandatory communication channel for PC1, and IB is used for initializing and establishing a link to OOB. The wireless power transmitting device can enter the OOB handover phase by transmitting a bit-pattern for OOB handover as a response to the configuration packet. Applications of PC1 include laptops and power tools.

[0054] The PC2 standard relates to wireless power transmitting and receiving devices that provide guaranteed power from 200W to 2kW, and its applications include kitchen appliances.

[0055] In this way, the PCs are differentiated by power levels, and whether to support the compatibility between the same PCs is a matter of choice or requirement. Here, the compatibility between the same PCs means that power can be transmitted and received between the same PCs. For example, when a wireless power transmission device that is PCx can charge a wireless power reception device that has the same PCx, it can be regarded that the compatibility between the same PCs is maintained. Similarly, the compatibility between different PCs can also be supported. Here, the compatibility between different PCs means that power can be transmitted and received between different PCs. For example, when a wireless power transmission device that is PCx can charge a wireless power reception device that has PCy, it can be regarded that the compatibility between different PCs is maintained.

[0056] Supporting the compatibility between PCs is a very important issue in terms of user experience and infrastructure construction. However, there are various technical problems as follows for maintaining the compatibility between PCs.

[0057] In the case of the compatibility between the same PCs, for example, a wireless power reception device with a lap-top charging method that can be stably charged only when power is continuously transmitted may have a problem in stably receiving power from a wireless power transmission device of an electric tool method that transmits power discontinuously, even if it is a wireless power transmission device of the same PC. Also, in the case of the compatibility between different PCs, for example, when a wireless power transmission device with a minimum guaranteed power of 200W transmits power to a wireless power reception device with a maximum guaranteed power of 5W, the wireless power reception device may be damaged due to overvoltage. As a result, it is difficult for the PCs to serve as indicators / criteria representing / indicating compatibility.

[0058] Hereinafter, a "profile" is newly defined as an indicator / criterion representing / indicating compatibility. That is, compatibility is maintained between wireless power transmission and reception devices having the same "profile", and it can be interpreted that power transmission and reception are not possible between wireless power transmission and reception devices having different "profiles". The profile can be defined by whether or not it is compatible (or independently) regardless of the power class and / or by the application.

[0059] For example, the profile is roughly divided into four categories: i) mobile, ii) power tool, iii) kitchen, and iv) wearable.

[0060] In the case of the "mobile" profile, the PC can be defined as PC0 and / or PC1, the communication protocol / method can be IB and OOB, the operating frequency can be defined as 87 to 205 kHz, and examples of applications include smartphones, laptops, etc.

[0061] In the case of the "power tool" profile, the PC can be defined as PC1, the communication protocol / method can be IB, the operating frequency can be defined as 87 to 145 kHz, and examples of applications include power tools, etc.

[0062] In the case of the "kitchen" profile, the PC can be defined as PC2, the communication protocol / method can be NFC-based, the operating frequency can be defined as less than 100 kHz, and examples of applications include kitchen / home appliances, etc.

[0063] In the case of the "wearable" profile, the PC can be defined as PC-1, the communication protocol / method can be IB, the operating frequency can be defined as 87 to 205 kHz, and examples of applications include wearable devices worn on the user's body, etc.

[0064] Maintaining compatibility between the same profiles is an essential matter, and maintaining compatibility between other profiles may be an optional matter.

[0065] The aforementioned profiles (mobile profile, power tool profile, kitchen profile, and wearable profile) can be generalized to represent the first through nth profiles, and new profiles can be added / replaced according to the WPC standard and embodiments.

[0066] When the profile is defined in this way, the wireless power transmitter can selectively transmit power only to the wireless power receiver with the same profile as itself, enabling more stable power transmission. Also, the burden on the wireless power transmitter is reduced, and since it no longer attempts to transmit power to an incompatible wireless power receiver, the risk of damage to the wireless power receiver is reduced.

[0067] PC1 in the "mobile" profile can be defined by borrowing selective extensions such as OOB based on PC0. In the case of the "power tool" profile, PC1 can be defined as a simply modified version of the "mobile" profile. Also, although it has been defined for the purpose of maintaining compatibility between the same profiles, in the future, technology can be developed in the direction of maintaining compatibility between different profiles. The wireless power transmitter or wireless power receiver can notify its profile to the other party in various ways.

[0068] The AFA standard refers to the wireless power transmitter as a PTU (power transmitting unit) and the wireless power receiver as a PRU (power receiving unit). The PTU is classified into multiple classes as shown in Table 1, and the PRU is classified into multiple categories as shown in Table 2.

[0069]

Table 1

[0070]

Table 2

[0071] As shown in Table 1, the maximum output power capability of class n PTU is greater than or equal to the P value of that class. PRU cannot draw more power than the power specified in that category. TX_IN_MAX Figure 4 is a block diagram of a wireless power transmission system according to another embodiment.

[0072] As shown in FIG. 4, the wireless power transmission system 10 includes a mobile device 450 that receives power wirelessly and a base station 400 that transmits power wirelessly.

[0073] The base station 400 is a device that provides inductive power or resonant power, and can include at least one wireless power transmitter 100 and a system unit 405. The wireless power transmitter 100 can transmit inductive power or resonant power and control the transmission. The wireless power transmitter 100 can include a power conversion unit 110 that converts electrical energy into a power signal by generating a magnetic field with a primary coil(s), and a communications & control unit 120 that controls communication and power transmission with the wireless power receiver 200 to transmit power at an appropriate level. The system unit 405 can perform other operation controls of the base station 100, such as input power provisioning, control of multiple wireless power transmitters, and user interface control.

[0074]

[0075] ​The primary coil can generate an electromagnetic field by using alternating current power (or voltage or current). When an alternating current power (or voltage or current) of a specific frequency output from the power conversion unit 110 is applied to the primary coil, a magnetic field of the specific frequency can be generated thereby. The magnetic field can be generated in a non-radiative or radiative manner, but the wireless power receiving device 200 receives this and generates an electric current. In other words, the primary coil wirelessly transmits power.

[0076] In the magnetic induction method, the primary coil and the secondary coil can have any suitable form, for example, it can be a copper wire wound around a formation of high magnetic permeability such as ferrite or amorphous metal. The primary coil can also be called a primary core, a primary winding, a primary loop antenna, etc. On the other hand, the secondary coil can also be called a secondary core, a secondary winding, a secondary loop antenna, a pickup antenna, etc.

[0077] When using the magnetic resonance method, the primary coil and the secondary coil are each provided in the form of a primary resonance antenna and a secondary resonance antenna. The resonance antenna can have a resonance structure including a coil and a capacitor. At this time, the resonance frequency of the resonance antenna is determined by the inductance of the coil and the capacitance of the capacitor. Here, the coil can be formed in the shape of a loop. Also, a core can be arranged inside the loop. The core can include a physical core such as a ferrite core or an air core.

[0078] Energy transmission between the primary resonance antenna and the secondary resonance antenna can be achieved by means of the resonance phenomenon of the magnetic field. The resonance phenomenon means that when a near field corresponding to the resonance frequency is generated by one resonance antenna and there are other resonance antennas located around it, the two resonance antennas are coupled to each other and high-efficiency energy transfer occurs between the resonance antennas. When a magnetic field corresponding to the resonance frequency is generated between the primary resonance antenna and the secondary resonance antenna, a phenomenon occurs in which the primary resonance antenna and the secondary resonance antenna resonate with each other. As a result, compared with the general case where the magnetic field generated by the primary resonance antenna is radiated into free space, the magnetic field is focused toward the secondary resonance antenna with higher efficiency. Therefore, energy can be transmitted from the primary resonance antenna to the secondary resonance antenna with high efficiency. The magnetic induction method is realized similarly to the magnetic resonance method, but at this time the frequency of the magnetic field does not need to be the resonance frequency. Instead, in the magnetic induction method, matching between the loops constituting the primary coil and the secondary coil is required, and the distance between the loops must be very close.

[0079] Although not shown in the figure, the wireless power transmission device 1100 may further include a communication antenna. The communication antenna can transmit and receive communication signals using a communication carrier other than magnetic field communication. For example, the communication antenna can transmit and receive communication signals such as Wi-Fi, Bluetooth (registered trademark), Bluetooth LE, ZigBee (registered trademark), and NFC.

[0080] The communication / control unit 120 can transmit and receive information with the wireless power receiving device 200. The communication / control unit 120 can include at least one of an IB communication module or an OOB communication module.

[0081] The IB communication module can transmit and receive information by using magnetic waves with a specific frequency as the center frequency. For example, the communication / control unit 120 can perform in-band communication by loading information onto the magnetic waves and transmitting them via the primary coil, or by receiving the magnetic waves containing information via the primary coil. At this time, modulation methods such as binary phase shift keying (BPSK) or amplitude shift keying (ASK) and coding methods such as Manchester coding or non-return-to-zero level (NZR-L) coding can be used to put information into the magnetic waves or analyze the magnetic waves containing information. By using such IB communication, the communication / control unit 120 can transmit and receive information at a data transmission rate of several kbps over a distance of several meters.

[0082] The OOB communication module can also perform out-of-band communication via a communication antenna. For example, the communication / control unit 120 can be provided as a short-range communication module. Examples of short-range communication modules include communication modules such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, and NFC.

[0083] The communication / control unit 120 can control the overall operation of the wireless power transmission device 100. The communication / control unit 120 can perform calculations and processing of various information and control each component of the wireless power transmission device 100.

[0084] The communication / control unit 120 can be implemented by a computer or a similar device using hardware, software, or a combination thereof. Hardware-wise, the communication / control unit 120 is provided in the form of an electronic circuit that processes electrical signals to perform control functions, and software-wise, it can be provided in the form of a program that drives the hardware-based communication / control unit 120.

[0085] The communication / control unit 120 can control the transmission power by controlling the operating point. The operating point to be controlled can correspond to a combination of frequency (or phase), duty cycle, duty ratio, and voltage amplitude. The communication / control unit 120 can control the transmission power by adjusting at least one of the frequency (or phase), duty cycle, duty ratio, and voltage amplitude. Also, the wireless power transmission device 100 can supply a constant power, and the wireless power reception device 200 can control the received power by controlling the resonance frequency.

[0086] The mobile device 450 includes a wireless power receiver 200 that receives wireless power via a secondary coil, and a load 455 that receives and stores the power received by the wireless power receiver 200 and supplies it to the device.

[0087] The wireless power receiver 200 can include a power pick-up unit 210 and a communications & control unit 220. The power pick-up unit 210 receives wireless power via the secondary coil and converts it into electrical energy. The power pick-up unit 210 rectifies the AC signal obtained via the secondary coil and converts it into a DC signal. The communications / control unit 220 controls the transmission and reception of wireless power (power transfer and reception).

[0088] The secondary coil can receive the wireless power transmitted from the wireless power transmission device 100. The secondary coil can receive power by using the magnetic field generated by the primary coil. Here, when a specific frequency is the resonance frequency, a magnetic resonance phenomenon can occur between the primary coil and the secondary coil, and power can be received more efficiently.

[0089] Although not shown in FIG. 4, the communication / control unit 220 may further include a communication antenna. The communication antenna can transmit and receive communication signals using a communication carrier other than magnetic field communication. For example, the communication antenna can transmit and receive communication signals such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, NFC, etc.

[0090] The communication / control unit 220 transmits and receives information to and from the wireless power transmission device 100. The communication / control unit 220 may include at least one of an IB communication module or an OOB communication module.

[0091] The IB communication module can transmit and receive information using a magnetic wave having a specific frequency as a center frequency. For example, the communication / control unit 220 can perform IB communication by loading information on a magnetic wave and transmitting it through a secondary coil or receiving a magnetic wave containing information through a secondary coil. At this time, modulation methods such as binary phase shift keying (BPSK) or amplitude shift keying (ASK), and coding methods such as Manchester coding or non-return-to-zero level (NZR-L) coding can be used to put information into the magnetic wave or analyze the magnetic wave containing information. By using such IB communication, the communication / control unit 220 can transmit and receive information at a data transmission rate of several kbps over a distance of up to several meters.

[0092] The OOB module can also perform out-of-band communication via a communication antenna. For example, the communication / control unit 220 can be provided as a short-range communication module.

[0093] Examples of the short-range communication module include communication modules such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, NFC, etc.

[0094] The communication / control unit 220 can control the overall operation of the wireless power receiving device 200. The communication / control unit 220 can perform calculations and processing of various types of information and control each component of the wireless power receiving device 200.

[0095] The communication / control unit 220 can be implemented by a computer or a similar device using hardware, software, or a combination thereof. Hardware-wise, the communication / control unit 220 is provided in the form of an electronic circuit that processes electrical signals to perform control functions, and software-wise, it can be provided in the form of a program that drives the hardware communication / control unit 220.

[0096] The load 455 can be a battery. The battery can store energy using the power output from the power pickup unit 210. On the other hand, the mobile device 450 does not necessarily have to include a battery. For example, the battery can be provided as an external configuration in a detachable form. As another example, the wireless power receiving device 200 can include driving means for driving various operations of the electronic device instead of a battery.

[0097] The mobile device 450 is illustrated as including the wireless power receiving device 200, and the base station 400 is illustrated as including the wireless power transmitting device 100. However, in a broad sense, the wireless power receiving device 200 can be regarded as the same as the mobile device 450, and the wireless power transmitting device 100 can also be regarded as the same as the base station 400.

[0098] Hereinafter, a coil or a coil part can also be referred to as a coil assembly, a coil cell, or a cell, including the coil and at least one element adjacent to the coil.

[0099] FIG. 5 is a state transition diagram for explaining the wireless power transmission procedure.

[0100] As shown in FIG. 5, the transmission of power from the wireless power transmitter to the receiver according to an embodiment of the present invention is roughly classified into a selection phase 510, a ping phase 520, an identification and configuration phase 530, a negotiation phase 540, a calibration phase 550, a power transfer phase 560, and a renegotiation phase 570.

[0101] The selection phase 510 can be a phase that is transitioned when a specific error or a specific event is detected while starting or maintaining power transmission - for example, including reference numerals S502, S504, S508, S510, and S512. Here, the specific error and the specific event will become clear from the following description. Also, in the selection phase 510, the wireless power transmitter can monitor whether an object exists on the surface of the interface. If the wireless power transmitter senses that an object exists on the surface of the interface, it can transition to the ping phase 520. In the selection phase 510, the wireless power transmitter can transmit a very short pulse of an Analog Ping signal and sense whether an object exists in the Active Area on the surface of the interface based on the current change in the transmission coil or the Primary Coil.

[0102] When an object is detected in the selection phase 510, the wireless power transmitter can measure the quality factor of a wireless power resonance circuit (e.g., a power transmission coil and / or a resonance capacitor). In one embodiment of the present invention, when an object is detected in the selection phase 510, the quality factor can be measured to determine whether a wireless power receiver is placed in the charging area together with a foreign object. The coil provided in the wireless power transmitter can have its inductance and / or the series resistance component in the coil decreased due to environmental changes, thereby causing the quality factor value to decrease. In order to determine whether a foreign object is present by using the measured quality factor value, the wireless power transmitter can receive from the wireless power receiver a reference quality factor value measured in advance when no foreign object is placed in the charging area. The reference quality factor value received in the negotiation phase S540 can be compared with the measured quality factor value to determine whether a foreign object is present. However, in the case of a wireless power receiver with a low reference quality factor value - for example, a specific wireless power receiver can have a low reference quality factor value depending on the type, use, and characteristics of the wireless power receiver - there is a problem that the difference between the quality factor value measured when a foreign object is present and the reference quality factor value is not large, making it difficult to determine whether a foreign object is present. Therefore, other judgment elements need to be further considered, or other methods need to be used to determine whether a foreign object is present.

[0103] In another embodiment of the present invention, when an object is detected in the selection phase 510, the quality factor value within a specific frequency range (e.g., the operating frequency range) can be measured to determine whether a wireless power receiver is placed in the charging area together with a foreign object. The coil of the wireless power transmitter can have its inductance and / or the series resistance component in the coil decreased due to environmental changes, thereby enabling the resonance frequency of the coil of the wireless power transmitter to be changed (shifted). That is, the quality factor peak frequency, which is the frequency at which the maximum quality factor value within the operating frequency band is measured, may be shifted.

[0104] In phase 520, when the wireless power transmitter senses an object, it wakes up the receiver and transmits a Digital Ping to identify whether the sensed object is a wireless power receiver. In the ping phase 520, if the wireless power transmitter does not receive a response signal to the digital ping - for example, a signal strength packet - from the receiver, it transitions back to the selection phase 510. Also, in the ping phase 520, when the wireless power transmitter receives a signal indicating that power transmission to the receiver is complete - that is, a charge completion packet - it can also transition to the selection phase 510.

[0105] When the ping phase 520 is completed, the wireless power transmitter identifies the receiver and transitions to the identification and configuration phase 530 to collect the configuration and status information of the receiver.

[0106] In the identification and configuration phase 530, the wireless power transmitter can transition to the selection phase 510 if an unexpected packet is received, no desired packet is received for a predefined time (time out), there is a packet transmission error, or no power transfer contract is set.

[0107] The wireless power transmitter can check whether it is necessary to enter the negotiation phase 540 based on the value of the negotiation field in the configuration packet received in the identification and configuration phase 530. If the result of the check indicates that negotiation is necessary, the wireless power transmitter can enter the negotiation phase 540 to perform a predetermined FOD detection procedure. On the contrary, if the result of the check indicates that negotiation is not necessary, the wireless power transmitter can immediately enter the power transmission phase 560.

[0108] In the negotiation phase 540, the wireless power transmission device can receive an FOD (Foreign Object Detection) status packet including a reference quality factor value. Or, it can receive an FOD status packet including a reference peak frequency value. Or, it can receive a status packet including both the reference quality factor value and the reference peak frequency value. At this time, the wireless power transmission device can determine a quality factor threshold for FO detection based on the reference quality factor value. The wireless power transmission device can determine a peak frequency threshold for FO detection based on the reference peak frequency value.

[0109] The wireless power transmission device can detect whether there is an FO in the charging area by using the determined quality factor threshold for FO detection and the currently measured quality factor value (the quality factor value measured before the ping phase), and can control power transmission according to the FO detection result. As an example, when an FO is detected, power transmission may be interrupted, but it is not limited to this.

[0110] The wireless power transmission device can detect whether there is an FO in the charging area by using the determined peak frequency threshold for FO detection and the currently measured peak frequency value (the peak frequency value measured before the ping phase), and can control power transmission according to the FO detection result. As an example, when an FO is detected, power transmission may be interrupted, but it is not limited to this.

[0111] When FO is detected, the wireless power transmitter can return to the selection phase 510. On the contrary, when FO is not detected, the wireless power transmitter can also enter the power transmission phase 560 through the correction phase 550. Specifically, when FO is not detected, the wireless power transmitter can determine the intensity of the power received at the receiving end in the correction phase 550 and measure the power loss at the receiving end and the transmitting end to determine the intensity of the power transmitted at the transmitting end. That is, the wireless power transmitter can predict the power loss based on the difference between the transmission power at the transmitting end and the reception power at the receiving end in the correction phase 550. The wireless power transmitter according to one embodiment can also correct the threshold for FOD detection by reflecting the predicted power loss.

[0112] In the power transmission phase 560, the wireless power transmitter can transition to the selection phase 510 if an unexpected packet is received, no desired packet is received for a predefined time (time out), a violation of the set power transfer contract occurs, or charging is completed.

[0113] Also, in the power transmission phase 560, the wireless power transmitter can transition to the renegotiation phase 570 if it is necessary to reconfigure the power transfer contract due to a change in the state of the wireless power transmitter or the like. At this time, when the renegotiation is completed normally, the wireless power transmitter can return to the power transmission phase 560.

[0114] The above-mentioned power transfer contract can be set based on the state and characteristic information of the wireless power transmitter and the receiver. As an example, the state information of the wireless power transmitter can include information about the maximum amount of power that can be transmitted, information about the maximum number of receivers that can be accommodated, etc., and the state information of the receiver can include information about the required power, etc.

[0115] FIG. 6 shows a power control method according to an embodiment.

[0116] In FIG. 6, in the power transmission phase 560, the wireless power transmitter 100 and the wireless power receiver 200 can control the amount of power transmitted by performing communication in parallel with the power transmission and reception. The wireless power transmitter and the wireless power receiver operate at a specific control point. The control point indicates a combination of voltage and current provided at the output of the wireless power receiver when power transmission is performed.

[0117] More specifically, the wireless power receiver selects a desired control point - desired output current / voltage, temperature at a specific location of the mobile device, etc., and further determines the actual control point at which it is currently operating. The wireless power receiver can calculate a control error value using the desired control point and the actual control point, and transmit this as a control error packet to the wireless power transmitter.

[0118] Then, the wireless power transmitter can use the received control error packet to set / control a new operating point - amplitude, frequency, and duty cycle - to control power transmission. Therefore, the control error packet is transmitted / received at regular time intervals during the power transmission stage. As an embodiment, when the wireless power receiver attempts to reduce the current of the wireless power transmitter, it can set the control error value to a negative number, and when attempting to increase the current, it can set the control error value to a positive number and transmit it. In this way, in the inductive mode, the wireless power receiver can control power transmission by transmitting a control error packet to the wireless power transmitter.

[0119] In the resonance mode described below, it can operate in a different manner from the inductive mode. In the resonance mode, one wireless power transmission device must be able to serve multiple wireless power reception devices simultaneously. However, when controlling power transmission as in the inductive mode described above, since the transmitted power is controlled by communication with one wireless power reception device, power transmission to additional wireless power reception devices may become difficult to control. Therefore, in the resonance mode of the present invention, the wireless power transmission device attempts to use a method in which it commonly transmits basic power and the wireless power reception device controls the amount of power received by controlling its own resonance frequency. However, even in such an operation of the resonance mode, the method described in FIG. 6 is not completely excluded, and additional transmitted power can also be controlled by the method of FIG. 6.

[0120] FIG. 7 is a block diagram of a wireless power transmission device according to another embodiment. This can belong to a wireless power transmission system in a magnetic resonance method or a shared mode. The shared mode refers to a mode in which one-to-many communication and charging are performed between a wireless power transmission device and a wireless power reception device. The shared mode is realized by a magnetic induction method or a resonance method.

[0121] As shown in FIG. 7, the wireless power transmission device 700 can include at least one of a cover 720 covering the coil assembly, a power adapter 730 that supplies power to a power transmitting unit 740, a power transmitting unit 740 that transmits wireless power, or a user interface 750 that provides power transmission progress and other related information. In particular, the user interface 750 can be optionally included or included as another user interface 750 of the wireless power transmission device 700.

[0122] The power transmitting unit 740 can include at least one of a coil assembly 760, an impedance matching circuit 770, an inverter 780, a communication unit 790, or a control unit 710.

[0123] The coil assembly 760 includes at least one primary coil that generates a magnetic field and can also be called a coil cell.

[0124] The impedance matching circuit 770 can provide impedance matching between the inverter and the primary coil(s). The impedance matching circuit 770 can generate resonance at a frequency suitable for boosting the primary coil current. In the multi - coil power transmitter 740, the impedance matching circuit can additionally include a multiplexer that routes signals from the inverter to a subset of the primary coils. The impedance matching circuit can also be called a "tank circuit".

[0125] The impedance matching circuit 770 can include a capacitor, an inductor, and a switching element that switches their connections. The impedance matching is performed by detecting the reflected wave of the wireless power transmitted through the coil assembly 760 and switching the switching element based on the detected reflected wave to adjust the connection state of the capacitor or inductor, or to adjust the capacitance of the capacitor or the inductance of the inductor. In some cases, the impedance matching circuit 770 can be omitted and implemented, and this specification also includes embodiments of the wireless power transmission device 700 in which the impedance matching circuit 770 is omitted.

[0126] The inverter 780 can convert a DC input into an AC signal. The inverter 780 can be driven by a half - bridge or full - bridge to generate a pulse wave and duty cycle of adjustable frequency. Also, the inverter can include multiple stages to adjust the input voltage level.

[0127] The communication unit 790 can communicate with the power receiver. The power receiver performs load modulation to communicate requests and information to the power transmitter. Accordingly, the power transmitter 740 can monitor the current and / or voltage amplitude and / or phase of the primary coil to demodulate the data transmitted by the power receiver using the communication unit 790.

[0128] Also, the power transmitter 740 can control the output power to transmit data using a method such as FSK (Frequency Shift Keying) via the communication unit 790.

[0129] The control unit 710 can control the communication and power transmission of the power transmitter 740. The control unit 710 can control power transmission by adjusting the aforementioned operating point. The operating point can be determined by at least one of, for example, the operating frequency, duty cycle, and input voltage.

[0130] The communication unit 790 and the control unit 710 can be provided as separate units / elements / chip sets or as one unit / element / chip set.

[0131] FIG. 8 shows a wireless power receiving device according to another embodiment. This belongs to a wireless power transmission system in a magnetic resonance method or a shared mode.

[0132] In FIG. 8, the wireless power receiving device 800 can include at least one of a user interface 820 that provides power transmission progress and other related information, a power receiving unit 830 that receives wireless power, a load circuit 840, or a base 850 that supports and covers a coil assembly. In particular, the user interface 820 can be optionally included or included as another user interface 82 of the power receiving equipment.

[0133] The power receiver 830 can include at least one of a power converter 860, an impedance matching circuit 870, a coil assembly 880, a communication unit 890, or a control unit 810.

[0134] The power converter 860 can convert the AC power received from the secondary coil into a voltage and current suitable for the load circuit. As an embodiment, the power converter 860 includes a rectifier. The rectifier can rectify the received wireless power to convert it from AC to DC. The rectifier can use diodes or transistors to convert AC to DC and use capacitors and resistors to smooth it. As the rectifier, a full-wave rectifier, a half-wave rectifier, a voltage multiplier, etc. realized by a bridge circuit or the like are used. Further, the power converter can also apply the reflected impedance of the power receiver.

[0135] The impedance matching circuit 870 can provide impedance matching between the combination of the power converter 860 and the load circuit 870 and the secondary coil. As an embodiment, the impedance matching circuit can generate a resonance near 100 kHz that can enhance power transmission. The impedance matching circuit 870 can be composed of capacitors, inductors, and switching elements that switch combinations thereof. Impedance matching can be performed by controlling the switching elements of the circuits constituting the impedance matching circuit 870 based on voltage values, current values, power values, frequency values, etc. of the received wireless power. In some cases, the impedance matching circuit 870 can be omitted, and this specification also includes embodiments of the wireless power receiving device 200 in which the impedance matching circuit 870 is omitted.

[0136] The coil assembly 880 includes at least one secondary coil and can optionally further include an element for shielding the metal parts of the receiver from the magnetic field.

[0137] The communication unit 890 can perform load modulation to communicate requests and other information to the power transmitter.

[0138] For this purpose, the power receiver 830 can also switch a resistor or a capacitor to change the reflection impedance.

[0139] The control unit 810 can control the received power. For this purpose, the control unit 810 can determine / calculate the difference between the actual operating point and the desired operating point of the power receiver 830. Then, the control unit 810 adjusts / reduces the difference between the actual operating point and the desired operating point by adjusting the reflection impedance of the power transmitter and / or making a request to adjust the operating point of the power transmitter. When this difference is minimized, optimal power reception can be achieved.

[0140] The communication unit 890 and the control unit 810 can be provided as separate elements / chip sets or can also be provided as one element / chip set.

[0141] Figure 9 shows a communication frame structure according to an embodiment. This can be a communication frame structure in the shared mode.

[0142] As shown in FIG. 9, in the shared mode, frames of different forms can be used together. For example, in the shared mode, a slotted frame having a plurality of slots as shown in (A) and a free format frame having no specific form as shown in (B) can be used. More specifically, the slotted frame is a frame for transmitting a short data packet from the wireless power receiving device 200 to the wireless power transmitting device 100, and since the free format frame does not include a plurality of slots, it can be a frame capable of transmitting a long data packet.

[0143] On the other hand, the slotted frame and the free format frame can be changed to various names by those skilled in the art. For example, the slotted frame can be changed to a channel frame, and the free format frame can be named by changing it to a message frame or the like.

[0144] More specifically, the slotted frame can include a sync pattern indicating the start of a slot, a measurement slot, nine slots, and an additional sync pattern having the same time interval before each of the nine slots.

[0145] Here, the additional sync pattern is a sync pattern different from the sync pattern indicating the start of the frame described above. More specifically, the additional sync pattern does not indicate the start of the frame, but can indicate information regarding adjacent slots (that is, two consecutive slot lures located on both sides of the sync pattern).

[0146] A sync pattern can be located between two consecutive slots among the nine slots. In this case, the sync pattern provides information regarding the two consecutive slots.

[0147] In addition, the nine slots and the sync patterns provided in front of each of the nine slots can each have the same time interval. For example, the nine slots can have a time interval of 50 ms. Also, the nine sync patterns can also have a time length of 50 ms.

[0148] On the other hand, a free-format frame such as (B) may not have a specific form other than the sync pattern indicating the start of the frame and the measurement slots. That is, the free-format frame is for performing a role different from that of the slot frame. For example, it can be used to communicate a long data packet (such as an additional owner information packet) between the wireless power transmission device and the wireless power reception device, or in a wireless power transmission device composed of a plurality of coils, it can also be used for the role of selecting any one of the plurality of coils.

[0149] Hereinafter, the sync pattern included in each frame will be described more specifically with reference to the drawings.

[0150] FIG. 10 shows the structure of a sync pattern according to an embodiment.

[0151] As shown in FIG. 10, the sync pattern is composed of a preamble, a start bit, a response field, a type field, an info field, and a parity bit. In FIG. 10, the start bit is shown as ZERO.

[0152] More specifically, the preamble is composed of consecutive bits and can be set to all 0s. That is, the preamble is a bit for adjusting the time length of the sync pattern.

[0153] The number of bits constituting the preamble can be made dependent on the operating frequency such that the length of the sync pattern is closest to 50 ms, but does not exceed 50 ms. For example, when the operating frequency is 100 kHz, the sync pattern is composed of two preamble bits, and when the operating frequency is 105 kHz, the sync pattern is composed of three preamble bits.

[0154] The start bit is the bit following the preamble and means zero (ZERO). The zero (ZERO) can be a bit indicating the type of the sync pattern. Here, the types of sync patterns include a frame sync containing information about the frame and a slot sync containing information about the slot. That is, the sync pattern can be a frame sync located between consecutive frames and indicating the start of a frame, or a slot sync located between consecutive slots among a plurality of slots constituting a frame and containing information about the consecutive slots.

[0155] For example, when the zero is 0, it means that the corresponding slot is a slot sync located between slots, and when it is 1, it means that the sync pattern is a frame sync located between frames.

[0156] The parity bit is the last bit of the sync pattern and indicates the number of bits constituting the data field (i.e., the response field, type field, information field) of the sync pattern. For example, the parity bit can be 1 when the number of bits constituting the data field of the sync pattern is even, and 0 in other cases (i.e., when it is odd).

[0157] The response field can include response information of the wireless power transmitter for communication with the wireless power receiver within the slot before the sync pattern. For example, the response field can have "00" when the execution of communication with the wireless power receiver is not detected. Also, the response field can have "01" when a communication error is detected in the communication with the wireless power receiver. The communication error can occur when two or more wireless power receivers attempt to approach one slot and a collision occurs between two or more wireless power receivers.

[0158] Also, the response field can include information indicating whether the data packet is accurately received from the wireless power receiver. More specifically, the response field can be "10" (10 - not acknowledge, NAK) when the wireless power transmitter denies the data packet, and "11" (11 - acknowledge, ACK) when the wireless power transmitter confirms the data packet.

[0159] The type field indicates the type of the sync pattern. More specifically, the type field can have "1" indicating a frame sync when the sync pattern is the first sync pattern of the frame (i.e., the pattern of the first sync of the frame located before the measurement slot).

[0160] Also, the type field can have "0" indicating a slot sync when the sync pattern is not the first sync pattern of the frame in the slot frame.

[0161] Also, the meaning of the value of the information field is determined by the type of sink pattern indicated by the type field. For example, when the type field is 1 (i.e., indicating a frame sink), the meaning of the information field can indicate the type of frame. That is, the information field indicates whether the current frame is a slotted frame or a free-format frame. For example, when the information field is "00", it indicates a slotted frame, and when the information field is "01", it indicates a free-format frame.

[0162] In contrast, when the type field is 0 (i.e., a slot sink), the information field can indicate the state of the next slot located behind the sink pattern. More specifically, the information field can have "00" when the next slot is an allocated slot for a specific radio power receiver, "01" when it is a locked slot for temporary use by a specific radio power receiver, or "10" when it is a slot that can be freely used by any radio power receiver.

[0163] FIG. 11 shows the operating states of a radio power transmitter and a radio power receiver in a shared mode according to an embodiment.

[0164] As shown in FIG. 11, a radio power receiver operating in the shared mode can operate in any one of a selection phase 1100, an introduction phase 1110, a configuration phase 1120, a negotiation phase 1130, and a power transfer phase 1140.

[0165] First, a wireless power transmission device according to an embodiment can transmit a wireless power signal to sense a wireless power reception device. That is, the process of sensing a wireless power reception device using a wireless power signal can be called Analog ping.

[0166] On the other hand, a wireless power reception device that has received a wireless power signal can enter the selection phase 1100. The wireless power reception device that has entered the selection phase 1100 can sense the presence of an FSK signal on the wireless power signal as described above.

[0167] That is, the wireless power reception device can communicate in either an exclusive mode or a shared mode depending on the presence or absence of an FSK signal.

[0168] More specifically, the wireless power reception device can operate in the shared mode when an FSK signal is included in the wireless power signal, and can operate in the exclusive mode otherwise.

[0169] When the wireless power reception device operates in the shared mode, the wireless power reception device can enter the introduction phase 1110. In the introduction phase 1110, the wireless power reception device can transmit a control information packet to the wireless power transmission device to transmit a control information packet in a setting phase, a negotiation phase, and a power transmission phase. The control information packet can have a header and information related to control. For example, the header of the control information packet can be 0X53.

[0170] In the introduction phase 1110, the wireless power receiving device attempts to request a free slot to transmit a control information (CI) packet over the following configuration phase, negotiation phase, and power transmission phase. At this time, the wireless power receiving device selects a free slot and transmits the first CI packet. If the wireless power transmitting device responds with an ACK to the CI packet, the wireless power transmitting device enters the configuration phase. If the wireless power transmitting device responds with a NACK, it means that another wireless power receiving device is in the process of the configuration and negotiation phases. In this case, the wireless power receiving device attempts to request a free slot again.

[0171] If the wireless power receiving device receives an ACK as a response to the CI packet, the wireless power receiving device determines the position of the private slot within the frame by counting the remaining slot syncs up to the first frame sync. In all subsequent slot-based frames, the wireless power receiving device transmits the CI packet via the slot.

[0172] If the wireless power transmitting device permits the wireless power receiving device to proceed to the configuration phase, the wireless power transmitting device provides a series of locked slots for exclusive use by the wireless power receiving device. This ensures that the wireless power receiving device can proceed with the configuration phase without collisions.

[0173] The wireless power receiving device transmits a sequence of data packets, such as two identification data packets (IDHI and IDLO), using the locked slots. When this phase is completed, the wireless power receiving device enters the negotiation phase. In the negotiation phase, the wireless power transmitting device continues to provide locked slots for exclusive use by the wireless power receiving device. This ensures that the wireless power receiving device can proceed with the negotiation phase without collisions.

[0174] The wireless power receiving device uses the lock slot to transmit one or more negotiation data packets, which may be mixed with proprietary data packets. Eventually, the sequence ends with a specific request (SRQ) packet. When the sequence is completed, the wireless power receiving device enters the power transmission phase and the wireless power transmitting device interrupts the provision of the lock slot.

[0175] In the power transmission state, the wireless power receiving device transmits CI packets using the assigned slot and receives power. The wireless power receiving device can include a regulator circuit. The regulator circuit can be included in the communication / control unit. The wireless power receiving device can self-regulate the reflected impedance of the wireless power receiving device via the regulator circuit. In other words, the wireless power receiving device can adjust the impedance to be reflected to transmit the amount of power required by the external load. This can prevent excessive power reception and overheating.

[0176] In the shared mode, since the wireless power transmitting device may not adjust the power in response to the received CI packet (depending on the operating mode), control is required to prevent overvoltage in this case.

[0177] The following discloses authentication between a wireless power transmission device and a wireless power reception device. The wireless power transmission device and the wireless power reception device can be mutually compatible and power transmission can be performed normally only when realized by the same pre-agreed power transmission interface and communication interface. Even if the wireless power transmission device and the reception device are not manufactured by the same manufacturer, they can be mutually compatible if they are manufactured based on the same technical standard or specification. However, even if they follow the same technical standard, the realized quality may vary from manufacturer to manufacturer. Also, if the standard is not followed honestly and accurately, wireless charging will not proceed smoothly. In particular, in the case of products with problems in foreign object detection (FOD) and overheat prevention functions, there is a risk of safety accidents such as explosions. Therefore, the standardization body operating the technical standard provides a service to test whether the wireless power transmission device or the wireless power reception device of each manufacturer accurately follows the standard technology (compliance) and whether the device interoperability is maintained by a recognized certification authority, and to authenticate genuine products.

[0178] Nevertheless, since it is realistically difficult to fundamentally block the circulation of uncertified products in the market, it is necessary to ensure stability and reliability by mutually authenticating that the wireless power transmission device and the wireless power reception device already in circulation in the market are normal with respect to each other during the pre- and post-wireless charging processes. That is, if the pre-authentication procedure is said to be that a recognized certification authority grants a genuine product certification before the product is launched, then the post-authentication procedure is said to be that the authentication procedure is performed between products during the operation of wireless charging after the product is launched. For example, mutual authentication between products can be performed via an in-band communication channel and is compatible with USB-C authentication. If the authentication fails, the wireless power reception device can warn the user and charge in low power mode or remove the power signal.

[0179] In this specification, the Qi standard of WPC is exemplified as a standard technology. However, the technical idea of the present invention includes not only the Qi standard but also implementation forms of authentication based on other standards.

[0180] When introducing USB-C authentication into a wireless power transmission system using in-band communication, performance indicators as shown in the following table are derived. That is, USB-C becomes one model for wireless charging authentication.

[0181]

Table 3

[0182] In Table 3, PRx means a wireless power receiving device, and PTx means a wireless power transmitting device. Authentication includes authentication of a wireless power transmitting device by a wireless power receiving device and authentication of a wireless power receiving device by a wireless power transmitting device.

[0183] When authenticating a wireless power transmitting device using full authentication, a long time of up to about 3 minutes may be required. This is because of the large size of the USB-C certificate and the low bit rate communication protocol adopted by the wireless power transmission system. In particular, in a public venue where a user frequently changes wireless charging spots, such a situation where full authentication occurs every time may cause inconvenience to the user. Therefore, it is necessary to define the size of the chain or packet related to authentication in a compact or simplified manner. Of course, it is preferable to maintain the 128-bit security level (security level, ECDSA with SHA256) in USB-C authentication while reducing the full authentication time to a reasonable time (within 60 seconds). Of course, the time required for authentication may also increase due to repeated transmission of data due to traffic errors.

[0184] The following discloses specific embodiments related to the certificate, authentication procedure, authentication message used for the authentication of the standard technology, and the lower-level communication protocol for performing the authentication procedure. All communications, protocols, messages, packets, etc. related to the authentication described below can be generated, processed, stored, transmitted, and processed by the communication and control units 120 and 220 and the communication units 790 and 890 described in the specification of this application.

[0185] 1. Wireless charging certificate

[0186] On the aspect of the chain level of the certificate, the level of the certificate chain may be restricted. For example, the level of the certificate chain can be 3. Even if the minimum chain level is applied, the manufacturer can still issue its own certificate for the product, and the burden on the manufacturer and the certificate authority (CA) can also be reduced. A certificate chain is a series of two or more certificates, and each certificate is signed by a preceding certificate within the chain.

[0187] On the aspect of the type of certificate, it can be stipulated that two types of certificates are transmitted between the wireless power transmitter and the receiver. Here, the two types of certificates can include an intermediate certificate and a leaf certificate. The root certificate is the same between both parties where mutual authentication is supported. The root certificate is self-signed as the first certificate within the certificate chain. The leaf certificate is the last certificate in the certificate chain, and the intermediate certificate is a certificate that is neither the root certificate nor the leaf certificate within the certificate chain.

[0188] In terms of the format of the certificate, the format of the certificate can be defined as a reduced or simplified format. Here, the "reduced" or "simplified" format can mean a format that is reduced or simplified for wireless charging compared to the USB-C certificate format (X509v3 format). For example, a certificate format simplified for intermediate and leaf certificates can be less than 100 bytes (e.g., 80 bytes). At this time, the root certificate may still follow the USB-C certificate format. Hereinafter, the simplified certificate format can be referred to as the wireless charging certificate format or the Qi certificate format. In the case of a wireless power transmission system that supports out-of-band (OOB) communication such as PC1, since a wider bandwidth can be used, it goes without saying that a wireless charging certificate in the USB-C format can be provided.

[0189] Figure 12 is a block diagram showing a wireless charging certificate format according to an embodiment.

[0190] As shown in Figure 12, the wireless charging certificate format includes a certificate type, a certificate length, an identification information (ID), reserved bits, a public key, and a signature.

[0191] The certificate type is, for example, 1 byte, which can indicate that the corresponding certificate is one of the root certificate / intermediate certificate / leaf certificate, can also indicate that it is a certificate related to the wireless power transmission device or a certificate related to the wireless power reception device, and can also indicate both pieces of information. For example, when the bit string b3~b0 of the certificate type is '0000'b, it indicates an intermediate certificate, and when it is '0001'b, it indicates a leaf certificate. And when the bit string b7~b4 of the certificate type is '0001'b, it indicates a certificate related to the wireless power transmission device, and when it is '0000'b, it indicates a certificate related to the wireless power reception device. Therefore, when the bit string of the certificate type reaches a specific value, the corresponding certificate can indicate that it is related to the wireless power transmission device and is a leaf certificate.

[0192] The length of the certificate is, for example, 2 bytes, and can indicate the length of the corresponding certificate in byte units.

[0193] The identification information is, for example, 6 bytes, and can indicate the manufacturer code of the wireless power transmission device or the manufacturer code of the wireless power reception device, or can also indicate the WPID (wireless power ID).

[0194] The spare bits can be, for example, 7 bytes. The public key can be, for example, 32 bytes. The signature can be, for example, 32 bytes or 64 bytes.

[0195] When performing authentication through in-band communication based on the wireless charging certificate format as shown in FIG. 12, the full authentication between each other can be completed within 1 minute as shown in Table 4.

[0196]

Table 4

[0197] FIG. 12 illustrates the case where the size of the certificate format is 80 bytes, but this is merely an illustration, and embodiments in which each field is defined with a different number of bits also fall within the technical idea of the present invention as a matter of course for those skilled in the art.

[0198] FIG. 13A is a block diagram showing a wireless charging certificate format according to another embodiment.

[0199] As shown in FIG. 13A, the wireless charging certificate format includes a certificate type, PTx and Leaf indicators (PTx, Leaf), a certificate length, identification information (ID), reserved bits, a public key, and a signature.

[0200] Within the wireless charging certificate format of FIG. 13A, the PTx and Leaf indicators are assigned to bits different from the certificate type within the same byte (B0) separated from the certificate type.

[0201] The certificate type is, for example, 6 bits and can indicate whether the corresponding certificate is one of a root certificate / intermediate certificate / leaf certificate, can indicate whether it is a certificate related to a wireless power transmission device or a certificate related to a wireless power reception device, or can indicate both pieces of information.

[0202] The PTx and Leaf indicators indicate whether the corresponding certificate is a leaf certificate regardless of whether it is related to a wireless power transmission device. That is, the PTx and Leaf indicators can indicate whether the corresponding certificate is a leaf certificate related to a wireless power transmission device.

[0203] The PTx and leaf indicators are, for example, 2 bits and are configured in a form including a 1-bit PTx indicator and a 1-bit leaf indicator. In this case, the PTx indicator indicates 1 if the corresponding certificate relates to a wireless power transmission device and indicates 0 if it relates to a wireless power reception device. Also, the leaf indicator is 1 bit, and its value can be set to 1 if the corresponding certificate corresponds to a leaf certificate, and can be set to 0 if it does not correspond to a leaf certificate. Since each bit in FIG. 13A is set to 1, it indicates that the corresponding certificate is a PTx leaf certificate.

[0204] The PTx and leaf indicators are included in the same byte (B0) as the certificate type, are configured in the bit sequence immediately adjacent to the certificate type, and are assigned to bits different from the certificate type.

[0205] The certificate length is, for example, 1 byte and can indicate the length of the corresponding certificate in byte units.

[0206] The identification information is, for example, 6 bytes and can indicate the manufacturer code of the wireless power transmission device or the manufacturer code of the wireless power reception device (PRx manufacturer code: PRMC), or can also indicate the WPID (wireless power ID). Alternatively, when the certificate type = intermediate certificate, the identification information indicates the manufacturer code of the wireless power transmission device or the manufacturer code of the wireless power reception device, and when the certificate type = leaf certificate, the identification information can also indicate the WPID.

[0207] The spare bits can be, for example, 4 bytes. The public key can be, for example, 32 bytes. The signature can be, for example, 64 bytes.

[0208] When FIG. 13A performs authentication in in-band communication based on the same wireless charging certificate format, full authentication between each other can be completed within 60 seconds as shown in Table 5.

[0209]

Table 5

[0210] FIG. 13A illustrates the case where the size of the certificate format is 108 bytes, but this is merely an illustration, and embodiments in which each field is defined with a different number of bits also fall within the technical idea of the present invention as a matter of course to those skilled in the art.

[0211] As a commercial performance requirement, it is preferable that the authentication procedure complete the authentication by the initiator of the responder within 60 seconds in an environment using in-band communication. Further, it is preferable that the authentication procedure provide a mechanism for secure recognition of a previously authenticated responder within 20 seconds in an environment using in-band communication.

[0212] FIG. 13B is a block diagram showing a wireless charging certificate format according to another embodiment.

[0213] As shown in FIG. 13B, the wireless charging certificate format includes a wireless charging standard certificate structure version (Qi Authentication Certificate Structure Version), spare bits, PTx and leaf indicator (PTx Leaf), certificate type, signature offset, serial number, issuer ID, subject ID, public key, and signature.

[0214] Within the wireless charging certificate format, PTx and the leaf indicator are assigned to bits different from the certificate type within the same byte (B0) separated from the certificate type.

[0215] The PTx and leaf indicator indicate whether the corresponding certificate is related to a wireless power transmission device and whether it is a leaf certificate. That is, the PTx and leaf indicator can indicate whether the corresponding certificate is a leaf certificate related to a wireless power transmission device.

[0216] The PTx and leaf indicator can be 1 bit, different from that in FIG. 13A. If the PTx and leaf indicator is 0, it can indicate that the corresponding certificate is not a leaf certificate or is a leaf certificate of a wireless power receiving device. On the contrary, if the PTx and leaf indicator is 1, it can indicate that the corresponding certificate is a leaf certificate of a wireless power transmission device.

[0217] The certificate type can be, for example, 2 bits, which can indicate that the corresponding certificate is any one of a root certificate / intermediate certificate / leaf certificate, or can also indicate all of them.

[0218] 2. Instruction information regarding support for authentication function

[0219] If neither the wireless power transmission device nor the wireless power receiving device supports the authentication function (for example, legacy products that have already been released may not support the new authentication function), ultimately, the authentication procedure cannot be executed between them. That is, for the authentication procedure to be executed, both the wireless power transmission device and the wireless power receiving device need to support the authentication function. By the way, since the authentication function may or may not be supported by the manufacturer depending on the product version, a procedure to confirm this and the messages used in this procedure are required. Consequently, when only one of the wireless power transmission device and the receiving device supports the authentication function and the other device is a legacy product, backward compatibility for the minimum charging function must be satisfied. Devices that do not support authentication according to the system policy must also support 5W (or the minimum power below that, for example, 3W).

[0220] The wireless power transmission device can notify whether it supports an authentication function to the wireless power reception device by using a capability packet (in the case of authentication of PTx by PRx). On the other hand, the wireless power reception device can notify whether it supports an authentication function to the wireless power transmission device by using a configuration packet (in the case of authentication of PRx by PTx). Hereinafter, the structure of the instruction information (capability packet and configuration packet) regarding whether to support the authentication function will be disclosed in more detail.

[0221] FIG. 14 shows the structure of a capability packet of a wireless power transmission device according to an embodiment.

[0222] As shown in FIG. 14, a capability packet whose corresponding header value is 0X31 is 3 bytes. The first byte (B0) includes a power class and a guaranteed power value. The second byte (B1) is reserved and includes a potential power value. The third byte (B2) is reserved and includes Auth, NFCPP, NFCD, WPID, and Not REs Sens. Specifically, Auth is 1 bit. For example, when its value is 0, it indicates that the wireless power transmission device does not support the authentication function. When its value is 1, it can indicate that the wireless power transmission device supports the authentication function.

[0223] FIG. 15 shows the structure of a capability packet of a wireless power transmission device according to another embodiment.

[0224] As shown in FIG. 15, the performance packet with the corresponding header value of 0X31 is 3 bytes. The first byte (B0) includes the power class and the guaranteed power value. The second byte (B1) is reserved and includes the potential power value. The third byte (B2) includes the Authentication Initiator (AI), Authentication Responder (AR), reserved, WPID, and Not REs Sens. Specifically, the Authentication Initiator is 1 bit. For example, when its value is '1b', it indicates that the wireless power transmission device can operate as an Authentication Initiator. Also, the Authentication Responder is 1 bit. For example, when its value is '1b', it indicates that the wireless power transmission device can operate as an Authentication Responder.

[0225] FIG. 16 shows the structure of the configuration packet of the wireless power receiving device according to an embodiment.

[0226] As shown in FIG. 16, the configuration packet with the corresponding header value of 0X51 is 5 bytes. The first byte (B0) includes the power class and the maximum power value. The second byte (B1) includes reserved. The third byte (B2) includes Prop, reserved, ZERO, and Count. The fourth byte (B3) includes the Window size and the Window offset. The fifth byte (B4) includes Neg, polarity, Depth, Auth, and reserved. Specifically, Auth is 1 bit. For example, when its value is 0, it indicates that the wireless power receiving device does not support the authentication function. When its value is 1, it can indicate that the wireless power receiving device supports the authentication function.

[0227] FIG. 17 shows the structure of the configuration packet of the wireless power receiving device according to another embodiment.

[0228] As shown in FIG. 17, a configuration packet whose corresponding header value is 0X51 is 5 bytes. The first byte (B0) includes a power class and a maximum power value. The second byte (B1) includes AI, AR, and reserve. The third byte (B2) includes Prop, reserve, ZERO, and Count. The fourth byte (B3) includes a window size and a window offset. The fifth byte (B4) includes Neg, polarity, depth, authentication (Auth), and reserve. Specifically, the authentication initiator is 1 bit. For example, when its value is '1'b, it indicates that the wireless power receiving device can operate as an authentication initiator. Also, the authentication responder is 1 bit. For example, when its value is '1b', it indicates that the wireless power receiving device can operate as an authentication responder.

[0229] 3. Timing between authentication-related procedures and wireless charging phases

[0230] The procedure for confirming whether to support the authentication function and the authentication procedure can be performed over at least one or a plurality of phases among the identification and configuration phase, negotiation phase, calibration phase, power transmission phase, renegotiation phase, and introduction phase.

[0231] As an example, the authentication procedure can be performed in the negotiation phase. By the way, when performing quick authentication in the negotiation phase, the process of reading and confirming DIGESTS in in-band communication may take about 4 seconds. Therefore, from the aspect of user convenience, rather than starting charging after authentication is completed, it can be considered to provide wireless charging with basic power even before authentication, regardless of the presence or absence of authentication. This is also preferable from the aspect of backward compatibility with devices without an authentication function.

[0232] As another example, the authentication procedure can be performed over a negotiation phase and a power transmission phase. During the identification and configuration phase, the packet sequence is strictly controlled and only unidirectional communication from the wireless power receiving device to the transmitting device is allowed, while bidirectional communication is allowed during the negotiation and power transmission phases. Therefore, the authentication procedure can be performed during the negotiation and power transmission phases where bidirectional communication is allowed. During the negotiation phase, quick authentication is performed by the wireless power transmitting or receiving device that exchanges {GET_DIGESTS,CHALLENGE} messages. And a power contract can be concluded based on the established trust. When the wireless power transmitting and receiving devices first meet by checking the DIGESTS, an initial power contract based on the system policy is established and the power transmission phase is entered to provide the default low power to the wireless power receiving device as soon as possible. During the power transmission phase, full authentication is performed by the wireless power transmitting or receiving device that exchanges {GET_CERTIFICATE,CHALLENGE} messages. When the full authentication is successfully completed, the wireless power transmitting device and / or the receiving device updates the power contract.

[0233] As yet another example, the wireless power transmitting and receiving devices can enter the power transmission phase immediately without authentication first and then perform the authentication procedure during the power transmission phase. If the authentication is successful during the power transmission phase, the power contract is updated through a re-negotiation phase or the wireless power transmitting device can support the target power or full power at the level desired by the wireless power transmitting / receiving device. Therefore, the convenience of the user is increased.

[0234] As another example, in the case of authentication of a wireless power transmitter (PTx) by a wireless power receiver (PRx), the wireless power receiver can perform a procedure to confirm whether the wireless power transmitter supports an authentication function in a negotiation phase. In this case, power transmission may already be in progress based on an initial power contract prior to the negotiation phase. In the negotiation phase, the wireless power receiver can confirm whether the wireless power transmitter supports the authentication function according to the procedure by transmitting a query packet and checking its response. On one aspect, the query packet can be a general request packet (0x07). In this case, when the wireless power receiver transmits the general request packet to the wireless power transmitter, the wireless power transmitter transmits a performance packet including authentication (auth) as shown in FIG. 14 or FIG. 15 to the wireless power receiver as a response. On another aspect, the query packet can be a specific request packet (0x20). In this case, when the wireless power receiver transmits the specific request packet to the wireless power transmitter, the wireless power transmitter responds with an ACK (if it supports the authentication function) or a NACK (if it does not support the authentication function). When it is confirmed in the negotiation phase that the wireless power transmitter supports the authentication function, the wireless power receiver can establish a power contract of 5 W or more with the wireless power transmitter (PC0).

[0235] The authentication procedure can be started only when the wireless power receiving device confirms the support of the authentication function of the wireless power transmitting device. More specifically, after the wireless power receiving device reaches a normal or stable operation point where it transmits a control error packet (CEP) at a period of about 250 ms, the wireless power receiving device can perform an authentication procedure with the wireless power transmitting device. During the power transmission phase, the authentication procedure can be used to renew an existing power contract. That is, the wireless power receiving device can renegotiate the power contract to increase the power level according to the existing power contract based on the result of the authentication procedure. In this case, the wireless power receiving device can update the power contract according to the power management policy by transmitting a renegotiation packet (0x09). For example, when the authentication procedure (along with DIGEST) is successful, the wireless power receiving device can update the power contract to the increased power or maintain the current power contract. On the contrary, when the authentication procedure fails, the wireless power receiving device can update the power contract to the decreased power or remove the power signal.

[0236] As another example, in the case of authentication of the wireless power receiving device (PRx) by the wireless power transmitting device (PTx), the wireless power transmitting device can perform a procedure to confirm whether the wireless power receiving device supports the authentication function in the initialization phase. Here, the initialization phase can be any one of the phases before the negotiation phase, for example, the selection phase, the ping phase, the identification and setting phase. In the initialization phase, the wireless power transmitting device receives a configuration packet including authentication (auth) as shown in FIG. 16 or FIG. 17 from the wireless power receiving device to confirm whether the wireless power receiving device supports the authentication function.

[0237] When the wireless power transmission device confirms support for the authentication function of the wireless power reception device, the authentication procedure can be started in the negotiation phase. At this time, an initial power contract is concluded. More specifically, the wireless power transmission device waits for the reception of DIGESTS from the wireless power reception device. If the wireless power transmission device recognizes that the wireless power reception device has already been authenticated before, the authentication procedure is successful. If the wireless power transmission device fails to acknowledge the DIGESTS, the wireless power transmission device continues the authentication procedure during the power transmission phase. Depending on the power management policy, the wireless power transmission device establishes a power contract with the wireless power reception device. At this time, the wireless power transmission device can establish a power contract of 5W or more with the wireless power reception device (PC0) that has passed authentication as DIGESTS. When the authentication procedure is completed during the power transmission phase, the wireless power transmission device can renegotiate the power contract to increase the power level.

[0238] After the wireless power reception device reaches a normal or stable operation point where it transmits a control error packet (CEP, 0x03) at a cycle of approximately 250 ms in the power transmission phase, the wireless power transmission device can perform an authentication procedure with the wireless power reception device. The authentication procedure can be used to renew an existing power contract during the power transmission phase. That is, the wireless power reception device can renegotiate the power contract to increase the power level according to the existing power contract based on the result of the authentication procedure. In this case, the wireless power reception device can update the power contract according to the power management policy by transmitting a renegotiation packet (0x09). For example, when the authentication procedure (along with the DIGEST) is successful, the wireless power reception device can update the power contract to the increased power or maintain the current power contract. On the contrary, when the authentication procedure fails, the wireless power reception device can update the power contract to the decreased power or remove the power signal.

[0239] 4. Authentication procedures and authentication messages

[0240] The following discloses an authentication procedure and various messages used in the authentication procedure.

[0241] A message used in the authentication procedure is called an authentication message. An authentication message is used to carry information related to authentication. There are two types of authentication messages. One is an authentication request, and the other is an authentication response. The authentication request is sent by an authentication initiator, and the authentication response is sent by an authentication responder. Both the wireless power transmitter and the receiver can be an authentication initiator and an authentication responder. For example, when the wireless power transmitter is the authentication initiator, the wireless power receiver becomes the authentication responder, and when the wireless power receiver is the authentication initiator, the wireless power transmitter becomes the authentication responder.

[0242] The authentication request message includes GET_DIGESTS (e.g., 4 bytes), GET_CERTIFICATE (e.g., 8 bytes), CHALLENGE (e.g., 36 bytes).

[0243] The authentication response message includes DIGESTS (e.g., 4 + 32 bytes), CERTIFICATE (e.g., 4 + certificate chain (3 × 512 bytes) = 1540 bytes), CHALLENGE_AUTH (e.g., 168 bytes), ERROR (e.g., 4 bytes).

[0244] The authentication message can also be called an authentication packet and can also be called authentication data and authentication control information. Also, messages such as GET_DIGEST and DIGESTS can also be called GET_DIGEST packets, DIGEST packets, etc.

[0245] The following describes the procedure for the wireless power receiving device to authenticate the wireless power transmitting device based on such an authentication message.

[0246] (1) Authentication of PTx by PRx (Authentication of the wireless power transmitter by the wireless power receiver)

[0247] When the authentication of the wireless power transmitting device by the wireless power receiving device (authentication of PTx by PRx) operates based on in-band communication, the required time for each stage is as shown in Table 6 or Table 7.

[0248] [Table 6]

[0249] Table 6 shows an example of the required time for each authentication message when the power contract is based on the result of GET_DIGESTS during the negotiation phase. If the wireless power receiving device already knows the DIGEST regarding the wireless power transmitting device, the transmission / reception stages of GET_CERTIFICATE and CERTIFICATE can be omitted. Also, the power contract can be updated in the re-negotiation phase depending on the authentication result.

[0250] [Table 7]

[0251] Table 7 shows another example of the required time for each authentication message when the power contract is based on the result of GET_DIGESTS during the negotiation phase. If the wireless power receiving device already knows the DIGEST regarding the wireless power transmitting device, the transmission / reception stages of GET_CERTIFICATE and CERTIFICATE can be omitted. Also, the power contract can be updated in the re-negotiation phase depending on the authentication result. The following discloses the authentication procedure for satisfying the required time.

[0252] Figure 18 is a flowchart showing the sequence of packets transmitted and received when a wireless power receiving device performs authentication of a wireless power transmitting device (authentication of PTx by PRx).

[0253] As shown in FIG. 18, the wireless power receiving device transmits GET_DIGESTS to the wireless power transmitting device in order to obtain or retrieve the authentication certificate chain DIGESTS of the wireless power transmitting device (S1800). Here, REQUEST is set to PTx’s DIGEST. The prerequisite operation for step S1800 can include an operation of confirming the support of the authentication function with the performance packet received by the wireless power receiving device from the wireless power transmitting device. The wireless power receiving device can transmit GET_DIGESTS to the wireless power transmitting device using a general request packet during the negotiation phase or the renegotiation phase. That is, GET_DIGESTS can be transmitted loaded on the general request packet.

[0254] FIG. 19 is an example of the message structure of GET_DIGESTS. As shown in FIG. 19, GET_DIGESTS is, for example, 1 byte and includes a request field. The request field can indicate, for example, the header of the DIGEST of the wireless power transmitting device.

[0255] FIG. 20 is another example of the message structure of GET_DIGESTS. As shown in FIG. 20, GET_DIGESTS is, for example, 1 byte and includes a reserved and a slot number. The slot number identifies the slot in which the requested authentication certificate chain is stored and can be, for example, 3 bits.

[0256] Referring again to FIG. 18, the wireless power transmission device transmits DIGESTS to the wireless power reception device as a response to GET_DIGESTS (S1805). DIGESTS is used to send a report regarding the certificate chain digest (digests) of the authentication responder and which slots contain the valid certificate chain digest (digests). The parameter of DIGESTS can be 32 bytes of the hash value of the certificate chain.

[0257] FIG. 21 shows the physical packet structure in which DIGESTS is transmitted and the method of transmitting it. As shown in FIG. 21, the DIGESTS packet includes a 32-byte DIGESTS payload, a 1-byte header indicating that the corresponding packet is related to DIGESTS, and a 2-byte header indicating the length of the packet. On the other hand, the wireless power transmission device divides such a DIGESTS packet into a plurality of small packets (for example, 3 bytes) of a specific length, adds a checksum to the end of the small packet, and transmits it as a sequence of 4-byte DIGESTS small packets. The size of the last small packet in such a sequence may be smaller than 4 bytes. The small packet can also be called a segment. The illustration in FIG. 21 limits the size of the transmission packet of the wireless power transmission device so that one authentication response is composed of a maximum of 4 bytes. Dividing one response message into a series of small packets in this way allows the wireless power reception device to transmit (extended) control error packets (CEP) and (extended) received power packets (RPP) to the transmission device periodically (about 250 ms), thereby enabling efficient management of the operating point and foreign object sensing for power transmission of the wireless power transmission device.

[0258] Again, in FIG. 18, if it is confirmed that the wireless power transmission device has already been previously authenticated (acknowledge), the authentication is successful. If the wireless power reception device does not check the DIGESTS, the wireless power reception device continues the authentication during the power transmission phase. Steps S1800 and S1805 can be performed in the negotiation or renegotiation phase. Alternatively, steps S1800 and S1805 can be performed in the power transmission phase.

[0259] Next, the wireless power reception device transmits GET_CERTIFICATE to the wireless power transmission device to obtain the certificate chain of the wireless power transmission device (S1810). Here, GET_CERTIFICATE is set by an offset and a length. GET_CERTIFICATE is used to read a segment of the target certificate chain.

[0260] FIG. 22 is an example of the message structure of GET_CERTIFICATE. As shown in FIG. 22, GET_CERTIFICATE can be, for example, 2 bytes and can include an offset and a length field. Here, the offset is the offset from the start position of the certificate chain to the position where the read request starts, and the indication unit is a byte (Offset in bytes from the start of the Certificate Chain to where the read request begins). The length is the length of the read request, and the indication unit is a byte (Length in bytes of the read request). For example, in order to read 4 bytes from the start position of the certificate chain, the offset of GET_CERTIFICATE [11...0]=00b and the length can have a value of 11b.

[0261] Again referring to FIG. 18, the wireless power transmission device transmits at least a part of the certificate chain to the wireless power reception device as a response to GET_CERTIFICATE (S1815). At this time, a part of the certificate chain may start from a point after the offset by the length in bytes.

[0262] FIG. 23 is an example of a physical packet structure in which a certificate is transmitted and a method of transmitting the same. As shown in FIG. 23, when transmitting a 1536-byte certificate packet, the wireless power transmission device extracts a certificate for a length of 4 bytes from the offset point of the certificate packet, adds a header indicating that it is a certificate at the front end, and adds a checksum at the rear end to generate and transmit a certificate segment with a total length of 6 bytes.

[0263] FIG. 24 is an example of a physical packet structure in which an authentication response message of a wireless power transmission device is transmitted and a method of transmitting the same. As shown in FIG. 24, an authentication certificate packet (e.g., 1543 bytes) can include an authentication certificate chain (e.g., 1540 bytes), a header (e.g., 1 byte) indicating that it is an authentication certificate, and a header (e.g., 2 bytes) indicating the length of the authentication certificate packet. On the other hand, the wireless power transmission device divides such an authentication certificate packet into a plurality of small packets (e.g., 3 bytes) of a specific length, adds a checksum to the end of the small packet, and transmits it as a sequence of 4-byte authentication certificate small packets. In this case, a total of 515 chunks of data are each transmitted. The size of the last small packet in the sequence can be smaller than 4 bytes. The small packet can also be called a segment. The illustration in FIG. 24 limits the size of the transmission packet of the wireless power transmission device so that one authentication response is configured with a maximum of 4 bytes. Dividing one response message into a series of small packets in this way allows the wireless power receiving device to transmit (extended) control error packets (CEPs) and (extended) received power packets (RPPs) to the transmitting device periodically (about 250 ms), thereby enabling efficient management of the operating point and foreign object sensing for power transmission of the wireless power transmission device.

[0264] Again, in FIG. 18, if necessary, the wireless power receiving device can transmit a control error (CE) packet and / or a received power packet (RPP) to the wireless power transmission device (S1820). Steps S1810 and S1820 can be performed, for example, in a power transfer phase.

[0265] Thereafter, the wireless power receiving device can repeat steps S1810 to S1820 until it reads out all the authentication certificate chains.

[0266] The wireless power receiving device transmits CHALLENGE to the wireless power transmitting device (S1825). CHALLENGE is used to initiate product authentication.

[0267] Figure 25 is an example of the CHALLENGE message structure. As shown in Figure 25, CHALLENGE can be, for example, 32 bits (4 bytes) and can include four Nonce fields. A Nonce is a binary random number selected by the authentication initiator.

[0268] Again referring to Figure 18, the wireless power receiving device transmits GET_CHALLENGE_AUTH to the wireless power transmitting device to obtain CHALLENGE_AUTH (S1830). Here, GET_CHALLENGE_AUTH can be set by an offset and a length.

[0269] The wireless power transmitting device transmits a part of CHALLENGE_AUTH to the wireless power receiving device as a response to GET_CHALLENGE_AUTH (S1835). At this time, a part of CHALLENGE_AUTH may start from the point where it starts in byte units and start after the offset.

[0270] FIG. 26 is an example of a physical packet structure in which CHALLENGE_AUTH is transmitted and a method of transmitting the same. As shown in FIG. 26, a CHALLENGE_AUTH packet (for example, 1600 bytes) can include a certificate chain hash (for example, 32 bytes), a Salt (for example, 32 bytes), a context hash (for example, 32 bytes), and a signature (for example, 64 bytes). On the other hand, the wireless power transmission device extracts such a CHALLENGE_AUTH packet from an offset by a specific length (for example, 4 bytes) based on the offset and length instructed by GET_CHALLENGE_AUTH, adds a header indicating that it is a CHALLENGE_AUTH packet to the front end, and adds a checksum to the rear end to generate and transmit an authentication certificate segment with a total length of 6 bytes.

[0271] Again, in FIG. 18, if necessary, the wireless power receiving device can transmit a control error (CE) packet and / or a received power packet (RPP) to the wireless power transmission device (S1840).

[0272] Thereafter, the wireless power receiving device can repeat steps S1830 to S1840 until all certificate chains are read out.

[0273] Next, a procedure for the wireless power transmission device to authenticate the wireless power receiving device based on an authentication message will be described.

[0274] (2) Authentication of PRx by PTx (Authentication of the wireless power receiver by the wireless power transmitter)

[0275] When the authentication of the wireless power receiving device by the wireless power transmission device (authentication of PRx by PTx) operates based on in-band communication, the required time for each step is as shown in Table 8 or Table 9.

[0276]

Table 8

[0277] Table 8 shows an example of the required time for each authentication message when the power contract is based on the result of GET_DIGESTS during the negotiation phase. If the wireless power transmitter already knows the DIGEST regarding the wireless power receiver, the transmission / reception stages of GET_CERTIFICATE and CERTIFICATE can be omitted. Also, the power contract can be updated in the re-negotiation phase depending on the authentication result.

[0278]

Table 9

[0279] Table 9 shows an example of the required time for each authentication message when the power contract is based on the result of GET_DIGESTS during the negotiation phase. If the wireless power transmitter already knows the DIGEST regarding the wireless power receiver, the control error packet transmission stage, communication request stage, and transmission / reception stages of GET_CERTIFICATE and CERTIFICATE can be omitted. Also, the power contract can be updated in the re-negotiation phase depending on the authentication result. Hereinafter, the authentication procedure for satisfying the required time will be disclosed.

[0280] FIG. 27 is a flowchart showing the sequence of packets transmitted and received when a wireless power transmitter authenticates a wireless power receiver (authentication of PRx by PTx) according to an embodiment.

[0281] As shown in FIG. 27, the wireless power transmission device receives DIGESTS transmitted from the wireless power reception device (S2700). DIGESTS is used for the authentication responder to transmit a report regarding the certificate chain digest (digests) and which slots contain the valid certificate chain digest. The parameter of DIGESTS can be 32 bytes of the hash value of the certificate chain. The prerequisite operations for step S2700 can include the operation of the wireless power reception device to confirm the support of the authentication function with the capability packet received from the wireless power transmission device, and the operation of the wireless power transmission device to transmit GET_DIGESTS to the wireless power reception device. Step S2700 can be performed in the negotiation or renegotiation phase or the power transmission phase.

[0282] FIG. 28 is an example of the message structure of GET_DIGESTS transmitted by the wireless power transmission device. As shown in FIG. 28, GET_DIGESTS is, for example, 1 byte and includes a request field. It includes reserved and a slot number. The slot number identifies the slot in which the requested certificate chain is stored and can be, for example, 3 bits.

[0283] Again referring to FIG. 27, during the power transmission phase, the wireless power reception device transmits a control error packet or a received power packet to the wireless power transmission device (S2705).

[0284] The wireless power transmission device transmits a request for communication as a response to the control error packet or the received power packet (S2710). The request for communication can be, for example, a bit pattern response.

[0285] When the wireless power receiving device responds with an ACK to a request for communication (S2715), the wireless power transmitting device transmits GET_CERTIFICATE to the wireless power receiving device to obtain the certificate chain or CHALLENGE_AUTH response of the wireless power receiving device (S2720). Here, GET_CERTIFICATE is set by an offset and a length. GET_CERTIFICATE is used to read a segment of the target certificate chain.

[0286] Figure 29 is an example of the GET_CERTIFICATE message structure transmitted by the wireless power transmitting device. As shown in Figure 29, GET_CERTIFICATE can be, for example, 2 bytes and can include an offset and a length field. Here, the offset is the offset from the start position of the certificate chain to the position where the read request starts, and its indication unit is a byte (Offset in bytes from the start of the Certificate Chain to where the read request begins). The length is the length of the read request, and its indication unit is a byte (Length in bytes of the read request). For example, in order to read 40 bytes from the start position of the certificate chain, the offset of GET_CERTIFICATE [7...0] = 00b and the length can have a value of 110000b.

[0287] Again referring to Figure 27, the wireless power receiving device transmits at least a part of the certificate chain to the wireless power transmitting device as a response to GET_CERTIFICATE (S2725). At this time, a part of the certificate chain may start after the offset from the point where it starts with the length in bytes.

[0288] Figure 30 shows an example of the physical packet structure in which the certificate of the wireless power receiving device is transmitted and the method of transmitting the same. As shown in Figure 30, when the wireless power receiving device transmits a 1536-byte certificate packet, it extracts the certificate for a length of 40 bytes from the offset point of the certificate packet, adds a header (for example, 1 byte) indicating that it is a certificate at the front end, and adds a checksum (for example, 1 byte) at the rear end to generate and transmit a certificate segment with a total length of 42 bytes.

[0289] Again, in Figure 27, the wireless power transmitting device can repeat steps S2710 to S2725 until all the certificate chains are read out.

[0290] If necessary, the wireless power receiving device can transmit a control error (CE) packet and / or a received power packet (RPP) to the wireless power transmitting device (S2730).

[0291] In response to the control error packet or the received power packet, the wireless power transmitting device transmits a request for communication (S2735). The request for communication can be, for example, a bit pattern response.

[0292] When the wireless power receiving device responds with an ACK to the request for communication (S2740), the wireless power transmitting device transmits CHALLENGE[n] to the wireless power receiving device (S2745). CHALLENGE is used to initiate the authentication of the product.

[0293] Figure 31 shows an example of the CHALLENGE message structure transmitted by the wireless power transmission device. As shown in Figure 31, CHALLENGE can be, for example, 32 bits (4 bytes) and can include four Nonce fields. A Nonce is a binary random number selected by the authentication initiator. The wireless power transmission device can provide a total of 32 bytes of Nonce to the wireless power reception device by transmitting eight CHALLENGE packets.

[0294] Referring again to Figure 27, after receiving the ACK from the wireless power reception device, the wireless power transmission device can repeat steps S2735 to S2750 until all CHALLENGEs are transmitted.

[0295] The wireless power reception device can transmit a control error packet and / or a received power packet to the wireless power transmission device (S2755). The wireless power transmission device transmits a request for communication as a response to the control error packet or the received power packet (S2760). The request for communication can be, for example, a bit pattern response.

[0296] When the wireless power reception device responds with an ACK to the request for communication (S2765), the wireless power transmission device transmits GET_CHALLENGE_AUTH to the wireless power reception device to obtain CHALLENGE_AUTH (S2770). Here, GET_CHALLENGE_AUTH can be set by an offset and a length.

[0297] The wireless power reception device transmits at least a part of CHALLENGE_AUTH to the wireless power transmission device as a response to GET_CHALLENGE_AUTH (S2775). At this time, at least a part of CHALLENGE_AUTH can start from the time when it starts with the length in bytes and start after the offset.

[0298] FIG. 32 is an example of a physical packet structure in which CHALLENGE_AUTH of a wireless power receiving device is transmitted and a method of transmitting the same. As shown in FIG. 32, a CHALLENGE_AUTH packet (for example, 160 bytes) can include a certificate chain hash (for example, 32 bytes), a Salt (for example, 32 bytes), a context hash (for example, 32 bytes), and a signature (for example, 64 bytes). On the other hand, the wireless power transmitting device extracts such a CHALLENGE_AUTH packet from an offset by a specific length (for example, 40 bytes) based on the offset and length indicated by GET_CHALLENGE_AUTH, adds a header (for example, 1 byte) indicating that it is a CHALLENGE_AUTH packet to the front end, and adds a checksum (for example, 1 byte) to the rear end to generate and transmit an authentication certificate segment with a total length of 42 bytes.

[0299] Thereafter, the wireless power transmitting device can repeat steps S2760 to S2775 until all CHALLENGE_AUTHs are read.

[0300] FIG. 33 is an example of a physical packet structure in which an authentication response message of a wireless power receiving device is transmitted and a method of transmitting the same. As shown in FIG. 33, for example, a certificate packet (e.g., N bytes) can include a certificate chain, a header indicating that it is a certificate (e.g., 1 byte), and a header indicating the length of the certificate packet (e.g., 2 bytes). On the other hand, the wireless power receiving device divides such a certificate packet into a plurality of small packets (e.g., M - 1 bytes) of a specific length, adds a 1 - byte checksum to the end of the small packet, and transmits it as a sequence of M - byte certificate small packets. The size of the last small packet in the sequence can be smaller than M bytes. The small packet can also be called a segment. The illustration of FIG. 33 limits the size of the transmission packet of the wireless power receiving device so that one authentication response is composed of M bytes. Thus, dividing one response message into a series of small packets allows the timing for the wireless power receiving device to transmit (extended) control error packets (CEPs) and (extended) received power packets (RPPs) periodically (about 250 ms) to the transmitting device, whereby the operating point for power transmission and foreign object sensing of the wireless power transmitting device can be efficiently managed.

[0301] FIG. 34 is another example of a physical packet structure in which an authentication response message of a wireless power receiving device is transmitted and a method of transmitting the same. As shown in FIG. 34, for example, a certificate packet (e.g., 1543 bytes) can include a certificate chain (e.g., 1540 bytes), a header indicating that it is a certificate (e.g., 1 byte), and a header indicating the length of the certificate packet (e.g., 2 bytes). On the other hand, the wireless power receiving device divides such a certificate packet into a plurality of small packets (e.g., 38 bytes) of a specific length, adds a preamble (e.g., 1 byte) to the front end of the small packet, and adds a checksum (e.g., 1 byte) to the rear end (add) and transmits it as a sequence of 40-byte certificate small packets. In this case, a total of 41 data chunks are each transmitted. The size of the last small packet in the sequence can be smaller than 40 bytes. The small packet can also be called a segment. The illustration of FIG. 34 limits the size of the transmission packet of the wireless power receiving device so that one authentication response is composed of 40 bytes. In this way, dividing one response message into a series of small packets allows the wireless power receiving device to transmit (extended) control error packets (CEPs) and (extended) received power packets (RPPs) periodically (about 250 ms) to the transmitting device, thereby enabling efficient management of the operating point for power transmission and foreign object sensing of the wireless power transmitting device.

[0302] FIG. 35 is a flowchart showing a sequence of packets transmitted and received when a wireless power transmitting device authenticates a wireless power receiving device (authentication of PRx by PTx) according to another embodiment.

[0303] As shown in FIG. 35, the wireless power transmission device receives DIGESTS transmitted from the wireless power reception device (S3500). Prerequisite operations for step S3500 may include an operation in which the wireless power reception device confirms support for the authentication function from the capability packet received from the wireless power transmission device, and an operation in which the wireless power transmission device transmits GET_DIGESTS to the wireless power reception device. Step S3500 can be performed in the negotiation phase or the power transmission phase.

[0304] During the power transmission phase, the wireless power reception device transmits a control error packet or a received power packet to the wireless power transmission device (S3505).

[0305] In response to the control error packet or the received power packet, the wireless power transmission device transmits a request for multiple communication (S3510). The request for multiple communication can be, for example, a bit pattern response.

[0306] When the wireless power reception device responds with an ACK to the request for multiple communication (S3515), the wireless power transmission device transmits GET_CERTIFICATE to the wireless power reception device to obtain the certificate chain or CHALLENGE_AUTH response of the wireless power reception device (S3520). Here, GET_CERTIFICATE is set by an offset and a length. GET_CERTIFICATE is used to read a segment of the target certificate chain.

[0307] In response to GET_CERTIFICATE, the wireless power reception device transmits at least a part of the certificate chain to the wireless power transmission device (S3525). At this time, a part of the certificate chain may start after the offset from the time when it starts with the length in bytes.

[0308] The wireless power transmission device can repeat steps S3520 to S3525 until it reads all the certificate chains.

[0309] If necessary, the wireless power receiving device can send a control error (CE) packet and / or a received power packet (RPP) to the wireless power transmission device (S3530).

[0310] The wireless power transmission device sends a request for multiple communications as a response to the control error packet or the received power packet (S3535). The request for multiple communications can be, for example, a bit pattern response.

[0311] When the wireless power receiving device responds with an ACK to the request for multiple communications (S3540), the wireless power transmission device sends CHALLENGE[n] to the wireless power receiving device (S3545). CHALLENGE is used to initiate product authentication.

[0312] After receiving an ACK from the wireless power receiving device (S3550), the wireless power transmission device can repeat steps S3545 to S3550 until it has sent all the CHALLENGEs.

[0313] The wireless power receiving device can send a control error packet and / or a received power packet to the wireless power transmission device (S3555). The wireless power transmission device sends a request for multiple communications as a response to the control error packet or the received power packet (S3560). The request for multiple communications can be, for example, a bit pattern response.

[0314] When the wireless power receiving device responds with an ACK to requests for multiple communications (S3565), the wireless power transmitting device transmits GET_CHALLENGE_AUTH to the wireless power receiving device to obtain CHALLENGE_AUTH (S3570). Here, GET_CHALLENGE_AUTH can be set by an offset and a length.

[0315] As a response to GET_CHALLENGE_AUTH, the wireless power receiving device transmits at least a part of CHALLENGE_AUTH to the wireless power transmitting device (S3575). At this time, at least a part of CHALLENGE_AUTH may start after the offset from the time when it starts with the length in bytes.

[0316] Thereafter, the wireless power transmitting device can repeat steps S3570 to S3575 until all of CHALLENGE_AUTH is read out.

[0317] 5. Lower-level protocol supporting authentication procedures

[0318] Since the low-level packet transmission protocol that supports the authentication procedure may be based on in-band communication, it is necessary to configure the packet structure used in in-band communication to conform to the authentication procedure and authentication messages.

[0319] FIG. 36 is a diagram showing the structure of a packet transmitted from the wireless power receiving device to the wireless power transmitting device in in-band communication. The packet according to FIG. 36 can be modulated by the ASK method.

[0320] As shown in FIG. 36, the bit rate is 2 Kbps, and the packet includes a preamble, a header, a message, and a checksum. For example, the preamble is set to 11 bits, the header is set to 1 B, and the checksum is set to 1 B (1 B → 11 bits).

[0321] FIG. 37 is a diagram showing the structure of a packet that a wireless power transmission device transmits to a wireless power reception device in in-band communication. The packet according to FIG. 37 can be modulated by an FSK method.

[0322] As shown in FIG. 37, the bit rate at an operating frequency of 100 kHz is 200 bps, and the packet includes a header, a message, and a checksum. For example, the header is set to 1B and the checksum is set to 1B (1B → 11 bits).

[0323] (1) Lower-level authentication sequence

[0324] 1) Authentication of PTx by PRx (Authentication of the wireless power transmitter by the wireless power receiver)

[0325] When the wireless power reception device is an authentication initiator, the wireless power transmission device becomes an authentication responder. Or, the wireless power transmission device can also be represented as an (authentication) target device. As an authentication initiator, the wireless power reception device transmits a message (or packet) that requests a message (or packet) necessary for authenticating the wireless power transmission device to the wireless power transmission device. As an authentication responder, the wireless power transmission device transmits an authentication response message composed of a sequence of various packets to the wireless power reception device. Such a series of message transmission and reception processes can be defined by a lower-level packet transmission protocol.

[0326] FIG. 38 is a diagram showing the packet transmission and reception sequence between a wireless power reception device and a transmission device from the perspective of a lower level according to an embodiment. FIG. 38 is a diagram showing the process in which the wireless power transmission device transmits an authentication response packet (DIGESTS) to the wireless power reception device in response to the wireless power reception device transmitting GET_DIGESTS to the wireless power transmission device.

[0327] As shown in FIG. 38, the wireless power transmission device waits for an ACK / NACK or continue / stop to be transmitted from the wireless power reception device after transmitting each packet of the sequence. The ACK / NACK or continue / stop is transmitted included in an extended control error packet (CEP) as shown in FIG. 39. The wireless power transmission device and / or reception device repeats the following procedure until all packets of the sequence are transmitted.

[0328] > If the wireless power transmission device receives "ACK and continue", the wireless power transmission device transmits the next packet.

[0329] > If the wireless power transmission device receives "ACK and stop", the wireless power transmission device waits until it receives the next extended CEP including "ACK and continue".

[0330] > If the wireless power transmission device receives "NACK and continue", the wireless power transmission device retransmits the previous packet.

[0331] > If the wireless power transmission device receives "NACK and stop", the wireless power transmission device waits until it receives the next extended CEP including "ACK and continue".

[0332] FIG. 39 is a diagram showing a packet transmission / reception sequence between a wireless power reception device and a transmission device from a lower-level perspective according to another embodiment. FIG. 39 is a diagram showing a process in which the wireless power transmission device transmits an authentication response packet (CERTIFICATE) to the wireless power reception device in response to the wireless power reception device transmitting GET_CERTIFICATE to the wireless power transmission device.

[0333] As shown in FIG. 39, the wireless power transmission device waits for an ACK / NACK or continue / stop to be transmitted from the wireless power reception device after transmitting each packet of the sequence. The ACK / NACK or continue / stop is transmitted included in an extended control error packet (CEP) as shown in FIG. 39. The wireless power transmission device and / or the reception device repeats the following procedure until all packets of the sequence are transmitted.

[0334] > If the wireless power transmission device receives "ACK and continue", the wireless power transmission device transmits the next packet. For example, for packet (1), "ACK and continue" can be received by an extended control error packet (CEP), and for packet (m), "ACK and continue" can be received by an extended received power packet (Extended RPP) as shown in FIG. 42.

[0335] > If the wireless power transmission device receives "ACK and stop", the wireless power transmission device waits until it receives the next extended CEP including "ACK and continue". For example, for packet (n), "ACK and stop" is received by an extended CEP.

[0336] > If the wireless power transmission device receives "NACK and continue", the wireless power transmission device retransmits the previous packet.

[0337] > If the wireless power transmission device receives "NACK and stop", the wireless power transmission device waits until it receives the next extended CEP including "ACK and continue".

[0338] FIG. 40 shows the structure of an extended control error packet according to an embodiment.

[0339] As shown in FIG. 40, the wireless power receiving device transmits an extended control error packet as a response to the packet of the wireless power transmitting device. At this time, the extended control error packet includes not only a control error value for adjusting the operating point of the wireless power transmitting device, but also at least one of ACK / NACK or continue / stop.

[0340] For example, the stop is 1 bit, and when its value is '1'b, it indicates that the wireless power transmitting device interrupts the transmission of the packet, and when its value is '0'b, it indicates that the wireless power transmitting device transmits the next packet of the sequence (i.e., continues the transmission). Here, when the wireless power receiving device needs to transmit the CEP in a short period to quickly adjust the operating point of the wireless power transmitting device, or when all response packets have been received, the wireless power receiving device can enforce the suspension of the wireless power transmitting device from transmitting packets in the next sequence by setting the stop to '1'.

[0341] The ACK / NACK is, for example, 4 bits, and when its value is '0000'b, it indicates ACK, and when its value is '1111'b, it indicates NACK. ACK indicates that the wireless power receiving device has successfully received the packet without error conditions, and NACK indicates that the wireless power receiving device requests the wireless power transmitting device to retransmit the packet due to the occurrence of a packet reception error.

[0342] FIG. 41 shows the structure of an end power transfer (EPT) packet according to an embodiment.

[0343] As shown in FIG. 41, the power transmission end packet corresponding to the header value 0x02 can indicate the code value required for the authentication procedure. For example, when the authentication of the wireless power transmission device fails, the wireless power reception device can set the EPT code value to a code value different from the conventional EPT code, such as 0x0E. By transmitting the new EPT code value, the wireless power reception device can remove the power transmission.

[0344] FIG. 42 is the structure of an extended received power packet according to an embodiment.

[0345] As shown in FIG. 42, the extended received power packet is 24 bits and can include a first reserved bit, a mode, a received power value, a second reserved bit, a stop, and an ACK / NACK. That is, the extended received power packet includes not only the received power value related to the FOD of the wireless power transmission device but also at least one of ACK / NACK or continue / stop.

[0346] For example, the stop is 1 bit. When its value is '1'b, the wireless power transmission device interrupts the transmission of the packet. When its value is '0'b, the wireless power transmission device transmits the next packet of the sequence (i.e., continues the transmission). Here, when the wireless power reception device needs to transmit the CEP in a short period to quickly adjust the operating point of the wireless power transmission device, or when all response packets have been received, the wireless power reception device can force the wireless power transmission device to suspend transmitting the packet in the next sequence by setting the stop to '1'.

[0347] ACK / NACK is, for example, 4 bits, where a value of '0000'b indicates ACK and a value of '1111'b indicates NACK. ACK indicates that the wireless power receiving device has successfully received the packet without error conditions, and NACK indicates that the wireless power receiving device requests the wireless power transmitting device to retransmit the packet due to the occurrence of a packet reception error.

[0348] 2) Authentication of PRx by PTx (Authentication of the wireless power receiver by the wireless power transmitter)

[0349] When the wireless power transmitting device is the authentication initiator, the wireless power receiving device becomes the authentication responder. Or, the wireless power receiving device can also be represented as the (authentication) target device. As the authentication initiator, the wireless power transmitting device transmits a message (or packet) that requests the wireless power receiving device for the message (or packet) necessary for the authentication of the wireless power receiving device. As the authentication responder, the wireless power receiving device transmits an authentication response message composed of a sequence of various packets to the wireless power transmitting device. The process of such a series of message transmissions and receptions can be defined by a lower-level packet transmission protocol.

[0350] FIG. 43 is a diagram showing a packet transmission and reception sequence between a wireless power receiving device and a transmitting device from a lower-level perspective according to an embodiment. FIG. 43 shows the process in which the wireless power receiving device receives an authentication response packet (CERTIFICATE) from the wireless power transmitting device in response to the wireless power transmitting device transmitting GET_CERTIFICATE to the wireless power transmitting device.

[0351] As shown in FIG. 43, the wireless power receiving device waits for an ACK / NACK (bit pattern response) to be transmitted from the wireless power transmitting device after transmitting each packet of the sequence. The bit response time can be, for example, 40 ms. The wireless power transmitting device and / or the receiving device can repeat the following procedure until all packets of the sequence are transmitted. In between the authentication response packets, the wireless power receiving device can also transmit CEP and / or RPP.

[0352] >If the wireless power receiving device receives an "ACK", the wireless power receiving device transmits the next packet. For example, when receiving an ACK for packet (1), the wireless power receiving device transmits packet (2) at the next transmission timing.

[0353] >If the wireless power receiving device receives a "NACK", the wireless power receiving device retransmits the previous packet.

[0354] (2) Lower-level data exchange protocol

[0355] The following discloses a data transaction protocol. This embodiment considers four rules for lower-level data exchange.

[0356] Rule 1 is that the wireless power receiving device operates as a master. When the wireless power receiving device operates as a master and the wireless power transmitting device operates as a slave, the wireless power receiving device determines when the communication of the wireless power transmitting device is permitted.

[0357] The wireless power receiving device can transmit a start of data stream (SOD) ADT_CTRL packet to question whether there is a data stream transmitted by the wireless power transmitting device. Or, the wireless power receiving device can transmit a general request packet (GRP) with the request set to "0xFF" to poll the wireless power transmitting device about whether there is a packet to be sent by the wireless power transmitting device.

[0358] Rule 2 is communication error control. The wireless power receiving device or transmitting device can re-write the ADT packet until it receives an ACK. Also, when no communication error occurs, an "ACK" ADT_CTRL packet is transmitted, and when a communication error is detected, a "NACK" ADT_CTRL packet is transmitted.

[0359] Rule 3 is the synchronization of the data stream. For synchronization, the header of the ADT data packet can be toggled each time a new ADT data packet is transmitted.

[0360] Rule 4 is to mark the end of the data stream or mark both the end and the start. Specifically, a start of data stream (SOD) ADT_CTRL packet can be added at the start of the data stream. Or, an end of data stream (EOD) ADT_CTRL packet can be added at the end of the data stream. Here, SOD and EOD are added when the length of the data stream is greater than one packet.

[0361] Based on the above rules, the data transport and packet structure can be defined as follows.

[0362] 1) Lower-level data transport and packet structure for authentication

[0363] The following provides a detailed description of the lower-level data transport and packet structure for authentication. The design methods of the lower-level data transport are broadly classified into two methods: a dedicated mapping method and a generic bit pipe method. The generic bit pipe method provides application-agnostic data transmission and has the advantage that it can be used not only for authentication but also for other applications in the future.

[0364] The design requirements for the lower-level data transport based on the generic bit pipe are: i) minimizing the interaction between the high level and the lower level, and ii) ensuring error-recovery and synchronized lower-level data transport. In relation to i), the high level encodes the data stream and pushes (writes) it to the lower level, and decodes (reads) the data stream provided by the lower level. Also, the lower level records or reads (writes / read) the data stream using a plurality of auxiliary data transport (ADT) data packets. In relation to ii), a simple and robust communication error-recovery mechanism includes the operation of re-writing the ADT packet until the radio power transmitter or receiver receives an ACK, and the operation of re-reading the ADT packet until there is no communication error. Also, simple synchronization of the data stream between the radio power transmitter and the receiver includes the operation of toggling the header of the data packet when transporting a new ADT data packet.

[0365] FIG. 44 is a diagram showing data transport according to an embodiment. FIG. 44 is an update data transport (UDT).

[0366] As shown in FIG. 44, the update data transport is used to carry update data. The update data includes several data packets. For example, the update data can selectively include a control error packet (CEP), a received power packet (RPP) that selectively includes an ACK or NACK, an auxiliary data transport (ADT), a charge status packet (CSP), a proprietary packet, a renegotiation (RNG) packet that selectively includes an ACK or NACK, and a spare packet (the wireless power transmitter must be resilient to spare bits).

[0367] The ADT is a lower-level data packet or transport for a higher-level application and includes the same logical layer packet as the performance packet of the wireless power transmitter.

[0368] FIG. 45 is a diagram showing data transport according to another embodiment. FIG. 45 is an auxiliary data transport (ADT).

[0369] As shown in FIG. 45, the ADT includes an ADT related to the wireless power receiver (ADT_PRx) and an ADT related to the wireless power transmitter (ADT_PTx).

[0370] The ADT related to the wireless power receiver carries data or response (e.g., ACK, NACK, RFA) packets or control packets from the wireless power receiver.

[0371] The ADT related to the wireless power transmission device carries data or response (e.g., ACK, NACK, RFA) packets or control packets or ACK / NACK / RFA bit pattern responses from the wireless power transmission device.

[0372] As an example, the header of the ADT packet can indicate a lower-level data packet for a higher-level application (e.g., a lower-level data packet of a wireless power receiving device or a lower-level data packet of a wireless power transmission device). The higher-level application can include, for example, authentication procedures, proprietary information exchange, firmware updates, and capabilities control of the wireless power transmission device.

[0373] As another example, the header of the ADT packet can indicate a logical layer data packet (e.g., a packet of a wireless power receiving device or a packet of a wireless power transmission device). As still another example, the header of the ADT packet can include a control packet.

[0374] As yet another example, the header of the ADT packet can indicate an ADT data packet. In this case, the header of the ADT data packet can include multiple types of headers (e.g., header A and header B, two types of headers like this). By toggling the header of the ADT data packet between A→B or B→A each time a new ADT data packet is transmitted, synchronization of the data stream can be achieved.

[0375] As still another example, the header of the ADT packet can indicate an ADT control packet. In this case, the header of the ADT packet can include a single type of header.

[0376] The following discloses the ADT packet structure as a lower-level data transport. As described above, ADT is composed of a pair of ADT related to the wireless power receiving device (ADT_PRx) and ADT related to the wireless power transmitting device (ADT_PTx), and it starts with the ADT related to the wireless power receiving device (ADT_PRx).

[0377] Figure 46 shows the structure of an ADT data packet (ADT_PRx Data Packet) related to a wireless power receiving device according to an embodiment.

[0378] As shown in Figure 46, the ADT data packet includes, for example, a (n + 1)-byte payload, and each payload can correspond to any one of a plurality of header types. Table 10 shows the correspondence between the payload size (up to 16 bytes when n = 15) of the ADT data packet and the header.

[0379] [Table 10]

[0380] Referring to Table 10, when the payload of a specific byte is included in the ADT data packet and transmitted, either Header A or Header B can be used. The size of the payload can range from 1 byte to 16 bytes. The wireless power receiving device and the wireless power transmitting device can synchronize with each other by agreeing to specify the pattern of the header values when transmitting a new ADT data packet and when retransmitting the previous ADT data packet. For example, in a situation where the wireless power receiving device transmits a 1-byte payload in an ADT data packet, when transmitting a new ADT data packet, the wireless power receiving device can toggle the header value from Header A (=0x1C) to B (=0x1D), or from B (=0x1D) to A (=0x1C), and when retransmitting the previous ADT data packet, it can maintain the previous header value as it is. The situation of retransmitting the previous ADT data packet can be when the wireless power receiving device receives a NACK response from the wireless power transmitting device, or when the wireless power receiving device discovers a decoding error in the wireless power transmitting device.

[0381] FIG. 47 is a structure of an ADT response packet (ADT_PRx Response Packet) related to a wireless power receiving device according to an embodiment.

[0382] As shown in FIG. 47, the ADT response packet related to the wireless power receiving device is, for example, 1 byte, and its value can indicate ACK, NACK, or RFA. Table 11 shows the correspondence between the payload values of the ADT response packet and their indicated contents.

[0383]

Table 11

[0384] In Table 11, when the payload value is '11111111'b, it indicates that the wireless power receiving device has successfully received and decoded the ADT data packet transmitted by the wireless power transmitting device in the previous ADT (ACK). When the payload value is '00000000'b, it indicates that the wireless power receiving device has not been able to successfully receive or decode the ADT data packet transmitted by the wireless power transmitting device in the previous ADT (NACK). In this case, the wireless power transmitting device re-transmits the previous ADT data packet in the current ADT. At this time, the header of the ADT data packet has a value corresponding to the re-transmission of the previous data packet (for example, 0x1C). When the payload value is '00110011'b, it indicates that the wireless power receiving device has requested the wireless power transmitting device to transmit response data. In Table 11, the payload value and its indication content are merely examples, and different values can be used for the payload values corresponding to each indication content, and these also fall within the technical scope of the present invention.

[0385] On the other hand, the structure of the ADT control packet for the wireless power receiving device can be the same as the ADT packet structure shown in FIG. 47.

[0386] FIG. 48 shows the structure of an ADT control packet (ADT_PRx Control Packet) for a wireless power receiving device according to an embodiment.

[0387] As shown in FIG. 48, the ADT control packet for the wireless power receiving device is, for example, 1 byte, and its value can indicate ACK, NACK, SOD, and EOD. Table 12 shows the correspondence between the payload values of the ADT control packet and their indication contents.

[0388]

Table 12

[0389] In Table 12, when the payload value is '11111111'b, it indicates that the wireless power receiving device has successfully received and decoded the ADT data packet transmitted by the wireless power transmitting device in the previous ADT (ACK). When the payload value is '00000000'b, it indicates that the wireless power receiving device has not been able to successfully receive or decode the ADT data packet transmitted by the wireless power transmitting device in the previous ADT (NACK). In this case, the wireless power transmitting device retransmits the previous ADT data packet in the current ADT. At this time, the header of the ADT data packet has a value corresponding to the retransmission of the previous data packet (for example, 0x1C). When the payload value is '00110011'b, it indicates a request to start the ADT data stream (SOD). When the payload value is '11001100'b, it indicates the end of the ADT data stream (EOD).

[0390] In Table 12, the payload value and its indicated content are merely examples, and different values can be used for the payload values corresponding to each indicated content, and these also fall within the technical scope of the present invention.

[0391] Hereinafter, the ADT (ADT_PTx) related to the wireless power transmitting device is disclosed.

[0392] FIG. 49 is a structure of an ADT data packet (ADT_PTx Data Packet) related to a wireless power transmitting device according to an embodiment.

[0393] As shown in FIG. 49, the ADT data packet includes, for example, a payload of (n + 1) bytes, and each payload can correspond to any one of a plurality of header types. Table 13 shows the correspondence between the payload size of the ADT data packet (when n = 3, a maximum of 4 bytes) and the header.

[0394]

Table 13

[0395] Referring to Table 13, when the payload of a specific byte is included in the ADT data packet and transmitted, either Header A or Header B can be used. The size of the payload can be from 1 byte to 4 bytes. The wireless power transmitter and the wireless power receiver can synchronize with each other by agreeing to specify the pattern of the header values when transmitting a new ADT data packet and when retransmitting the immediately previous ADT data packet. For example, in a situation where the wireless power transmitter transmits a 1-byte payload in an ADT data packet, when transmitting a new ADT data packet, the wireless power transmitter can toggle the header value from Header A (=0x1C) to B (=0x1D), or from B (=0x1D) to A (=0x1C), and when retransmitting the immediately previous ADT data packet, the wireless power transmitter can maintain the immediately previous header value as it is. The situation of retransmitting the immediately previous ADT data packet can be when the wireless power transmitter receives a NACK response from the wireless power receiver or when the wireless power transmitter discovers a decoding error in the wireless power receiver.

[0396] FIG. 50 is a structure of an ADT response packet (ADT_PTx Response Packet) related to a wireless power transmitter according to an embodiment.

[0397] As shown in FIG. 50, the ADT response packet related to the wireless power transmitter is, for example, 1 byte, and its value can indicate ACK, NACK, or RFA. Table 14 shows the correspondence between the payload values of the ADT response packet and their indicated contents.

[0398]

Table 14

[0399] In Table 14, when the payload value is '11111111'b, it indicates that the wireless power transmitter has successfully received and decoded the ADT data packet transmitted by the wireless power receiver in the previous ADT (ACK). When the payload value is '00000000'b, it indicates that the wireless power transmitter has not been able to successfully receive or decode the ADT data packet transmitted by the wireless power receiver in the previous ADT (NACK). In this case, the wireless power receiver retransmits the previous ADT data packet in the current ADT. At this time, the header of the ADT data packet has a value corresponding to the retransmission of the previous data packet (for example, 0x1C). When the payload value is '00110011'b, it indicates that the wireless power transmitter has requested the wireless power receiver to transmit response data (RFA). In Table 14, the payload value and its indication content are only examples, and different values can be used for the payload values corresponding to each indication content, and these also fall within the technical scope of the present invention.

[0400] FIG. 51 is a structure of an ADT response / control packet (ADT_PTx Response / Control Packet) related to a wireless power transmitter according to an embodiment.

[0401] As shown in FIG. 51, the ADT response packet related to the wireless power transmitter is, for example, 1 byte, and its value can indicate ACK and RFA. Table 15 shows the correspondence between the payload values of the ADT response packet and their indication contents.

[0402]

Table 15

[0403] In Table 15, when the payload value is '11111111'b, it indicates that the wireless power transmission device has successfully received and decoded the ADT data packet transmitted by the wireless power reception device in the previous ADT (ACK). When the payload value is '00110011'b, it indicates that the wireless power transmission device has requested to transmit response data to the wireless power reception device (RFA). According to this embodiment, if the wireless power transmission device fails to successfully receive or decode the ADT data packet transmitted by the wireless power reception device in the previous ADT, the wireless power transmission device does not separately transmit a communication error signal (NACK). In Table 15, the payload value and its indication content are merely examples, and different values can be used for the payload values corresponding to each indication content, and these also fall within the technical scope of the present invention.

[0404] FIG. 52 is a structure of an ADT control packet (ADT_PTx Control Packet) related to a wireless power transmission device according to an embodiment.

[0405] As shown in FIG. 52, the ADT control packet related to the wireless power transmission device is, for example, 1 byte, and its value can indicate ACK, NACK, SOD, and EOD. Table 16 shows the correspondence between the payload values of the ADT control packet and their indication contents.

[0406]

Table 16

[0407] In Table 16, when the payload value is '11111111'b, it indicates that the wireless power transmission device has successfully received and decoded the ADT data packet transmitted by the wireless power reception device in the previous ADT (ACK). When the payload value is '00000000'b, it indicates that the wireless power transmission device has not been able to successfully receive or decode the ADT data packet transmitted by the wireless power reception device in the previous ADT (NACK). In this case, the wireless power reception device re-transmits the previous ADT data packet in the current ADT. At this time, the header of the ADT data packet has a value corresponding to the re-transmission of the previous data packet (for example, 0x1C). When the payload value is '00110011'b, it indicates a request to start the ADT data stream (SOD). When the payload value is '11001100'b, it indicates the end of the ADT data stream (EOD). In Table 16, the payload value and its indication content are merely examples, and different values can be used for the payload values corresponding to each indication content, and these also fall within the technical scope of the present invention.

[0408] Hereinafter, an embodiment for realizing an authentication sequence based on the lower-level data transport and packet structure such as the aforementioned ADT is disclosed.

[0409] 2) Lower-level data exchange sequence for authentication (ADT-based)

[0410] FIG. 53 is a diagram showing a state machine related to ADT data packet write according to an embodiment.

[0411] As shown in FIG. 53, the transmitting side and / or the receiving side synchronize the data stream according to Rule 3 as shown in FIG. 53. That is, each time a new ADT data packet [n] is transmitted for synchronization, the header of the ADT data packet [n] can be toggled. The header of the ADT packet can indicate the ADT data packet. In this case, the header of the ADT data packet can include a plurality of types of headers (for example, header A and header B, two types of headers like this). Each time a new ADT data packet is successfully transmitted (ACK), the synchronization of the data stream can be achieved by toggling the header of the ADT data packet between A→B or B→A. When the wireless power receiving device receives a NACK response from the wireless power transmitting device or when the wireless power receiving device discovers a decoding error of the wireless power transmitting device, the immediately preceding ADT data packet is retransmitted, and in this case, the immediately preceding header value is maintained as it is.

[0412] 2-1) Authentication of PTx by PRx (Authentication of the wireless power transmitter by the wireless power receiver)

[0413] As a lower-level authentication sequence of the ADT infrastructure, first, the authentication of the wireless power transmitting device by the wireless power receiving device is described (PRx = Initiator / PTx = Responder)

[0414] FIG. 54 is a diagram for explaining the upper-level and high-level transmission sequences of the wireless power receiving device and the wireless power transmitting device when exchanging ADT data packets according to an embodiment.

[0415] As shown in FIG. 54, H_A indicates the A-type header, and H_b indicates the B-type header. When the top-level first data is transmitted to the lower level in the wireless power receiving device (sender) and transmitted to the wireless power transmitting device together with the header A, the lower level of the wireless power transmitting device transmits the first data to the upper level. When the reception of the first data is successful, the wireless power transmitting device transmits an ACK for the first data to the wireless power receiving device. After the wireless power receiving device transmits the new second data from the upper level to the lower level, it transmits it to the wireless power transmitting device together with the header B. At this time, if the wireless power transmitting device fails to receive the second data, it transmits a NACK to the wireless power receiving device. Since the wireless power receiving device receives the NACK, it retransmits the second data together with the previous header B in response to this. In such a manner, the wireless power receiving device and the wireless power transmitting device can ensure synchronization and realize a simple and robust error recovery and synchronization mechanism.

[0416] FIG. 55 is a diagram for explaining the upper-level and high-level transmission sequences of the wireless power receiving device and the wireless power transmitting device when exchanging ADT data packets according to another embodiment. Here, the wireless power receiving device is the authentication initiator, and the wireless power transmitting device is the authentication responder. The ADT data packet exchange between the wireless power receiving device and the transmitting device is performed according to the aforementioned "(1) lower-level authentication sequence" and "(2) lower-level data exchange protocol".

[0417] As shown in FIG. 55, the wireless power receiving device generates an M-byte CHALLENGE message at the upper level and transmits it to the lower level, and the lower level places this on an ADT data packet (or transport) and transmits it to the wireless power transmitting device.

[0418] According to the lower-level authentication sequence, the ADT data packet regarding the CHALLENGE message can be transmitted several times. While the ADT data packet is transmitted several times according to rule 2, the wireless power transmitter transmits the ACK / NACK regarding each next ADT data packet from the lower level to the wireless power receiver and transmits the ADT data packet to the upper level. After such a series of processes, when the transmission of the CHALLENGE message (from the upper-level perspective) or the ADT data packet regarding the CHALLENGE message (from the lower-level perspective) is completed, the wireless power receiver adds an EOD to the end of the ADT data packet regarding the CHALLENGE message and transmits it to notify the completion of the transmission according to rule 4.

[0419] On the other hand, the wireless power receiver questions according to rule 1 whether there is a data stream transmitted by the slave wireless power transmitter. For this purpose, the wireless power receiver can transmit an SOD. In this case, the wireless power receiver can repeatedly transmit the SOD until the wireless power transmitter responds with a data packet or until a timeout occurs. When the wireless power transmitter receives the SOD, the wireless power transmitter generates an N-byte CHALLENGE_AUTH_RESPONSE at the upper level and transmits it to the lower level, and the lower level loads this onto an ADT data packet (or transport) and transmits it to the wireless power receiver.

[0420] According to the lower-level authentication sequence, the ADT data packet regarding the CHALLENGE_AUTH_RESPONSE message can be transmitted several times. While the ADT data packet is transmitted several times according to rule 2, the wireless power receiving device transmits an ACK / NACK regarding each next ADT data packet from the lower level to the wireless power transmitting device and transmits the ADT data packet to the upper level. After such a series of processes, when the transmission of the CHALLENGE_AUTH_RESPONSE message (from the upper-level perspective) or the ADT data packet regarding the CHALLENGE_AUTH_RESPONSE message (from the lower-level perspective) is completed, the wireless power transmitting device adds an EOD to the end of the ADT data packet regarding the CHALLENGE_AUTH_RESPONSE message according to rule 4 to notify the completion of the transmission.

[0421] FIG. 56 is a diagram illustrating the upper-level and high-level transmission sequences of the wireless power receiving device and the wireless power transmitting device during the exchange of ADT data packets according to another embodiment.

[0422] The embodiment of FIG. 56 is different from the embodiment of FIG. 55 in that a general request packet (GRP) is used instead of the SOD for interrogation (or polling) according to rule 1 while strictly observing the addition of the SOD and EOD according to rule 4 each time an ADT data packet is transmitted.

[0423] FIG. 57 is a diagram illustrating the exchange sequence of the ADT data packet regarding the authentication request message according to an embodiment.

[0424] As shown in FIG. 57, when a bit stream (e.g., 35 bytes) for the authentication message is prepared, the wireless power receiving device transmits an ADT data packet composed of a header (e.g., 1 byte) and a payload (e.g., 34 bytes) to the lower level. Here, the authentication message can be, for example, a CHALLENGE message transmitted from the wireless power receiving device to the transmitting device.

[0425] Since the ADT data packet can be transmitted up to 16 bytes, the 35 - byte authentication message is split into a 16 - byte 0th ADT data packet (ADT_PRx(0)), a 16 - byte 1st ADT data packet (ADT_PRx(1)), and a 3 - byte 2nd ADT data packet (ADT_PRx(2)) and then transmitted.

[0426] First, on the first line, the wireless power receiving device successfully transmits the 0th ADT data packet (ADT_PRx(0)) and then receives an ACK, but fails to transmit the 1st ADT data packet (ADT_PRx(1)) and receives a NACK. Thereafter, on the second line, the wireless power receiving device re - transmits the 1st ADT data packet (ADT_PRx(1)), but fails to receive a response (ACK or NACK) thereto and transmits a NACK. In response, when the wireless power transmitting device responds with an ACK, it is confirmed that the re - transmission of the 1st ADT data packet (ADT_PRx(1)) is successful. So, the wireless power receiving device successfully transmits the remaining 3 - byte 2nd ADT data packet (ADT_PRx(2))) and then receives an ACK. In response, the wireless power receiving device successfully transmits the EOD and receives an ACK, thereby ending the transmission of the authentication message.

[0427] FIG. 58 is a diagram for explaining the exchange sequence of ADT data packets regarding an authentication request message according to another embodiment. The embodiment of FIG. 58 simplifies synchronization by toggling (header A <-> header B) the header of each ADT data packet according to rule 3 when the wireless power receiving device splits and transmits a total 35 - byte authentication message into a 16 - byte 0th ADT data packet (ADT_PRx(0)), a 16 - byte 1st ADT data packet (ADT_PRx(1)), and a 3 - byte 2nd ADT data packet (ADT_PRx(2))), and using the same header (header B in FIG. 58) as previously used when re - transmitting the ADT data packet, which is different from the embodiment of FIG. 57 in terms of indicating re - transmission.

[0428] FIG. 59 is a diagram illustrating an exchange sequence of ADT data packets for an authentication request message according to another embodiment. The embodiment of FIG. 59 is the same as the embodiment of FIG. 58 in that the wireless power receiving device divides a total 35-byte authentication message into a 16-byte 0th ADT data packet (ADT_PRx(0)), a 16-byte 1st ADT data packet (ADT_PRx(1)), and a 3-byte 2nd ADT data packet (ADT_PRx(2))) and transmits them, and toggles (header A <-> header B) the header of each ADT data packet according to Rule 3, but is different from the embodiment of FIG. 58 in that an SOD is added at the start of transmission of the ADT data packets.

[0429] FIG. 60 is a diagram illustrating an exchange sequence of ADT data packets for an authentication request message according to another embodiment. The embodiment of FIG. 60 is different from the embodiment of FIG. 58 in that when the transmission of the 2nd ADT data packet (ADT_PRx(2))) fails, although the header should not be toggled, a retransmission of the 2nd ADT data packet (ADT_PRx(2))) occurs with the header toggled, in the case where the wireless power receiving device divides a total 35-byte authentication message into a 16-byte 0th ADT data packet (ADT_PRx(0)), a 16-byte 1st ADT data packet (ADT_PRx(1)), and a 3-byte 2nd ADT data packet (ADT_PRx(2))) and transmits them. Here, a bit pattern response can be used instead of the ADT response packet of the wireless power transmitting device, whereby the ADT exchange time can be reduced.

[0430] FIG. 61 is a diagram illustrating an exchange sequence of ADT data packets related to an authentication request message according to another embodiment. The embodiment of FIG. 61 describes a scenario in which a wireless power receiving device divides a total 35-byte authentication message into a 16-byte 0th ADT data packet (ADT_PRx(0)), a 16-byte 1st ADT data packet (ADT_PRx(1)), and a 3-byte 2nd ADT data packet (ADT_PRx(2)) and transmits them. The transmission of the 0th ADT data packet (ADT_PRx(0)) and the 16-byte 1st ADT data packet (ADT_PRx(1)) is successful, but there is no response to the 2nd ADT data packet (ADT_PRx(2)), and the transmission fails.

[0431] FIG. 62 is a diagram illustrating an exchange sequence of ADT data packets related to an authentication response message according to an embodiment.

[0432] As shown in FIG. 62, a bit stream (e.g., 99 bytes) for an authentication response message is prepared. The authentication response message can be, for example, a CHALLENGE_AUTH_RESPONSE message transmitted from a wireless power transmitting device to a receiving device.

[0433] When using a communication protocol in the PTx→PRx direction (e.g., FSK), since an ADT data packet can be transmitted up to 4 bytes, the 99-byte authentication response message is divided into a 4-byte 0th ADT data packet (ADT_PTx(0)), a 4-byte 1st ADT data packet (ADT_PTx(1)),..., a 4-byte 23rd ADT data packet (ADT_PTx(23)), and a 3-byte 24th ADT data packet (ADT_PTx(24)) and transmitted.

[0434] First, when the wireless power receiving device transmits the SOD to the wireless power transmitting device for bowling, the wireless power transmitting device successfully transmits the 0th ADT data packet (ADT_PTx(0)) and then receives an ACK. However, the wireless power transmitting device fails to transmit the 1st ADT data packet (ADT_PTx(1)) and receives a NACK. Thereafter, the wireless power transmitting device re-transmits the 1st ADT data packet (ADT_PTx(1)), but fails to receive an ACK for this and receives a NACK. In contrast, when the wireless power receiving device responds with an ACK, it is confirmed that the re-transmission of the 1st ADT data packet (ADT_PTx(1)) has succeeded, so the wireless power transmitting device transmits the 2nd ADT data packet (ADT_PTx(2)). After repeating such a transmission sequence of ADT packets, the wireless power transmitting device successfully transmits the last remaining 3-byte 24th ADT data packet (ADT_PTx(24)) and then receives an ACK. In contrast, the wireless power transmitting device successfully transmits the EOD and receives an ACK, thereby ending the transmission of the authentication response message.

[0435] FIG. 63 is a diagram for explaining an exchange sequence of ADT data packets regarding an authentication response message according to another embodiment. The embodiment of FIG. 63 simplifies synchronization by toggling (header A <-> header B) the header of each ADT data packet according to rule 3 when the wireless power transmitting device divides and transmits a 99-byte authentication response message into a 4-byte 0th ADT data packet (ADT_PTx(0)), a 4-byte 1st ADT data packet (ADT_PTx(1)),..., a 4-byte 23rd ADT data packet (ADT_PTx(23)), and a 3-byte 24th ADT data packet (ADT_PTx(24)), and using the same header as previously used (header B in FIG. 62) when re-transmitting the 1st ADT data packet, which is different from the embodiment of FIG. 62 in terms of indicating re-transmission.

[0436] FIG. 64 is a diagram illustrating an exchange sequence of ADT data packets regarding an authentication response message according to another embodiment. The embodiment of FIG. 64 is the same as the embodiment of FIG. 63 in that the wireless power transmitter divides a total 99-byte authentication response message into 4-byte 0th ADT data packet (ADT_PTx(0)), 4-byte 1st ADT data packet (ADT_PTx(1)),..., 4-byte 23rd ADT data packet (ADT_PTx(23)), and 3-byte 24th ADT data packet (ADT_PTx(24)) and transmits them, and toggles (header A <-> header B) the header of each ADT data packet according to Rule 3. However, it is different from the embodiment of FIG. 63 in that the wireless power receiver uses GRP to poll the wireless power transmitter, and in response to this, the wireless power transmitter starts transmitting ADT data packets by responding with SOD.

[0437] FIG. 65 is a diagram illustrating an exchange sequence of ADT data packets regarding an authentication response message according to another embodiment. The embodiment of FIG. 65 is different from the embodiment of FIG. 64 in that when the transmission of the 1st ADT data packet (ADT_PTx(1)) fails, the retransmission of the 1st ADT data packet (ADT_PTx(1)) occurs with the header toggled, although the header should not be toggled.

[0438] FIG. 66 is a diagram for explaining an exchange sequence of ADT data packets for an authentication response message according to another embodiment. The embodiment of FIG. 66 illustrates a scenario where a wireless power transmission device divides a total 99-byte authentication response message into 4-byte 0th ADT data packet (ADT_PTx(0)), 4-byte 1st ADT data packet (ADT_PTx(1)),..., 4-byte 23rd ADT data packet (ADT_PTx(23)), and 3-byte 24th ADT data packet (ADT_PTx(24)) for transmission. The transmission of the 0th ADT data packet (ADT_PTx(0)) is successful, but there is no response to the 1st ADT data packet (ADT_PTx(1)) and the transmission fails.

[0439] 2-2) Authentication of PRx by PTx (Authentication of the wireless power receiver by the wireless power transmitter)

[0440] As a lower-level authentication sequence of the ADT infrastructure, the authentication of a wireless power receiving device by a wireless power transmission device is described (PTx = Initiator / PRx = Responder). When following Rule 1, since the wireless power transmission device is a slave, the wireless power receiving device must provide the ADT to the wireless power transmission device when it is confirmed that the wireless power transmission device operates as an authentication initiator based on the AI bit in the performance packet of the wireless power transmission device.

[0441] FIG. 67 is a diagram for explaining the upper-level and high-level transmission sequences of a wireless power transmission device and a wireless power receiving device during the exchange of ADT data packets according to an embodiment. Here, the wireless power transmission device is an authentication initiator, and the wireless power receiving device is an authentication responder. The exchange of ADT data packets between the wireless power transmission device and the receiving device is performed according to the aforementioned "(1) lower-level authentication sequence" and "(2) lower-level data exchange protocol".

[0442] As shown in FIG. 67, the wireless power transmission device is pulled by the SOD provided by the wireless power reception device to generate an M-byte CHALLENGE message at the upper level and transmit it to the lower level. The lower level places this on an ADT data packet (or transport) and transmits it to the wireless power reception device. In this case, the wireless power reception device can repeatedly transmit the SOD until the wireless power transmission device responds with an ADT data packet or until a timeout occurs.

[0443] According to the lower-level authentication sequence, the ADT data packet regarding the CHALLENGE message can be transmitted several times. While the ADT data packet is transmitted several times according to rule 2, the wireless power reception device transmits an ACK / NACK regarding each subsequent ADT data packet from the lower level to the wireless power transmission device and transmits the ADT data packet to the upper level. After such a series of processes, when the transmission of the CHALLENGE message (from the upper-level perspective) or the ADT data packet regarding the CHALLENGE message (from the lower-level perspective) is completed, the wireless power transmission device adds an EOD to the end of the ADT data packet regarding the CHALLENGE message and transmits it to indicate the completion of the transmission according to rule 4.

[0444] On the other hand, since the wireless power reception device operates as a master according to rule 1, it generates an N-byte CHALLENGE message at the upper level and transmits it to the lower level without separate polling for the CHALLENGE_AUTH_RESPONSE message it transmits. The lower level places this on an ADT data packet (or transport) and transmits it to the wireless power transmission device.

[0445] According to the lower-level authentication sequence, the ADT data packet regarding the CHALLENGE_AUTH_RESPONSE message can be transmitted several times. While the ADT data packet is being transmitted several times according to rule 2, the wireless power transmitter transmits an ACK / NACK regarding each next ADT data packet from the lower level to the wireless power receiver and transmits the ADT data packet to the upper level. After such a series of processes, when the transmission of the CHALLENGE_AUTH_RESPONSE message (from the upper-level perspective) or the ADT data packet regarding the CHALLENGE_AUTH_RESPONSE message (from the lower-level perspective) is completed, the wireless power receiver adds an EOD to the end of the ADT data packet regarding the CHALLENGE_AUTH_RESPONSE message according to rule 4 to notify the completion of the transmission.

[0446] Figure 68 is a diagram illustrating the upper-level and high-level transmission sequences of the wireless power transmitter and the wireless power receiver during the exchange of ADT data packets according to another embodiment.

[0447] The embodiment of Figure 68 is different from the embodiment of Figure 67 in that, while strictly adhering to the addition of SOD and EOD according to rule 4 each time an ADT data packet is transmitted, the wireless power receiver uses a general request packet (GRP) instead of SOD for the interrogation (or polling) according to rule 1.

[0448] Figure 69 is a diagram illustrating the exchange sequence of the ADT data packet regarding the authentication request message according to an embodiment.

[0449] As shown in Figure 69, when a bit stream (e.g., 35 bytes) for the authentication request message is prepared, the wireless power transmitter waits to transmit an ADT data packet composed of a header (e.g., 1 byte) and a payload (e.g., 34 bytes) from the lower level. Here, the authentication request message can be, for example, a CHALLENGE message.

[0450] At this time, the wireless power receiving device performs a polling operation to check whether there is data transmitted from the wireless power transmitting device. As part of this, the wireless power receiving device repeatedly transmits the SOD until the wireless power transmitting device responds or a timeout occurs.

[0451] When the SOD gives the wireless power transmitting device an opportunity to transmit an authentication request message, the wireless power transmitting device starts transmitting the ADT data packet. When using the communication protocol (FSK) in the PTx→PRx direction, since the ADT data packet can be transmitted up to 4 bytes, the 35-byte authentication message is divided and transmitted into a 4-byte 0th ADT data packet (ADT_PRx(0)), a 4-byte 1st ADT data packet (ADT_PTx(1)),..., a 4-byte 7th ADT data packet (ADT_PTx(7)), and a 3-byte 8th ADT eater packet (ADT_PTx(8)).

[0452] First, the wireless power transmitting device successfully transmits the 0th ADT data packet (ADT_PTx(0)) and then receives an ACK, but fails to transmit the 1st ADT data packet (ADT_PTx(1)) and receives a NACK. Thereafter, the wireless power transmitting device re-transmits the 1st ADT data packet (ADT_PTx(1)), but fails to receive an ACK response for this and a NACK is transmitted. In response, when the wireless power receiving device responds with an ACK, it is confirmed that the re-transmission of the 1st ADT data packet (ADT_PTx(1)) has been successful, so the wireless power transmitting device transmits the next 2nd ADT data packet (ADT_PTx(2)). When all transmissions are completed up to the last ADT data packet, in response to this, the wireless power transmitting device successfully transmits the EOD and receives an ACK, thereby ending the transmission of the authentication request message.

[0453] FIG. 70 is a diagram for explaining an exchange sequence of ADT data packets regarding an authentication request message according to another embodiment. The embodiment of FIG. 70 simplifies synchronization by having a wireless power transmission device divide a total 35-byte authentication request message into 4-byte 0th ADT data packet (ADT_PTx(0)), 4-byte 1st ADT data packet (ADT_PTx(1)),..., 4-byte 7th ADT data packet (ADT_PTx(7)), and 3-byte 8th ADT data packet (ADT_PTx(8)), toggling (header A <-> header B) the header of each ADT data packet according to rule 3, and using the same header as previously used (header B in FIG. 58) when retransmitting an ADT data packet, which is different from the embodiment of FIG. 70 in that it instructs retransmission.

[0454] FIG. 71 is a diagram for explaining an exchange sequence of ADT data packets regarding an authentication request message according to still another embodiment. The embodiment of FIG. 71 is the same as the embodiment of FIG. 70 in that a wireless power transmission device divides a total 35-byte authentication request message into 4-byte 0th ADT data packet (ADT_PTx(0)), 4-byte 1st ADT data packet (ADT_PTx(1)),..., 4-byte 7th ADT data packet (ADT_PTx(7)), and 3-byte 8th ADT data packet (ADT_PTx(8)), and toggles (header A <-> header B) the header of each ADT data packet according to rule 3, but is different from the embodiment of FIG. 70 in that a wireless power receiving device uses GRP to poll the wireless power transmission device, and in response thereto, the wireless power transmission device uses SOD to start transmitting an ADT data packet.

[0455] FIG. 72 is a diagram for explaining an exchange sequence of ADT data packets regarding an authentication request message according to another embodiment. The embodiment of FIG. 72 is different from the embodiment of FIG. 71 in that, when a wireless power transmission device divides a total 35-byte authentication request message into 4-byte 0th ADT data packet (ADT_PTx(0)), 4-byte 1st ADT data packet (ADT_PTx(1)),..., 4-byte 7th ADT data packet (ADT_PTx(7)), and 3-byte 8th ADT data packet (ADT_PTx(8)) and transmits them, the wireless power transmission device transmits an RPP in mode 0 and obtains a transmission opportunity for the ADT data packet by transmitting an RFA bit pattern. Also, when the transmission of the 1st ADT data packet (ADT_PTx(1)) fails, although the header must not be toggled, the 1st ADT data packet (ADT_PTx(1)) is retransmitted with the header toggled, which is also different from the embodiment of FIG. 71.

[0456] FIG. 73 is a diagram for explaining an exchange sequence of ADT data packets regarding an authentication request message according to another embodiment. The embodiment of FIG. 73 explains a scenario where, when a wireless power transmission device divides a total 35-byte authentication request message into 4-byte 0th ADT data packet (ADT_PTx(0)), 4-byte 1st ADT data packet (ADT_PTx(1)),..., 4-byte 7th ADT data packet (ADT_PTx(7)), and 3-byte 8th ADT data packet (ADT_PTx(8)) and transmits them, the transmission of the 0th ADT data packet (ADT_PTx(0)) is successful, but there is no response to the 1st ADT data packet (ADT_PTx(1)) and the transmission fails.

[0457] FIG. 74 is a diagram for explaining an exchange sequence of ADT data packets regarding an authentication response message according to an embodiment.

[0458] As shown in FIG. 74, when a bit stream (e.g., 99 bytes) for an authentication response message is prepared, the wireless power receiving device transmits an ADT data packet composed of a header (e.g., 1 byte) and a payload (e.g., 34 bytes) from the lower level. Here, the authentication response message can be, for example, a CHALLENGE_AUTH_RESPONSE message.

[0459] The wireless power receiving device successfully transmits the 0th ADT data packet (ADT_PRx(0)) and then receives an ACK. However, the wireless power receiving device fails to transmit the 1st ADT data packet (ADT_PRx(1)) and receives a NACK. Thereafter, the wireless power receiving device re-transmits the 1st ADT data packet (ADT_PRx(1)), but fails to receive an ACK for this and receives a NACK. When the wireless power transmitting device responds with an ACK to this, it is confirmed that the re-transmission of the 1st ADT data packet (ADT_PRx(1)) has been successful, so the wireless power receiving device transmits the 2nd ADT data packet (ADT_PRx(2)). After repeating such a transmission sequence of ADT packets, the wireless power transmitting device successfully transmits the last remaining ADT data packet (ADT_PRx) and then receives an ACK. In response to this, the wireless power receiving device successfully transmits an EOD and receives an ACK, thereby ending the transmission of the authentication response message.

[0460] FIG. 75 is a diagram for explaining an exchange sequence of ADT data packets regarding an authentication response message according to another embodiment. In the embodiment of FIG. 75, a wireless power receiving device divides a total 99-byte authentication response message into 16-byte 0th ADT data packet (ADT_PRx(0)), 16-byte 1st ADT data packet (ADT_PRx(1)),..., 16-byte 5th ADT data packet (ADT_PRx(5)), and 3-byte 6th ADT data packet (ADT_PRx(6)) for transmission. When transmitting each ADT data packet, the header is toggled (header A <-> header B) according to Rule 3, and when retransmitting the 1st ADT data packet, the previously used header is used identically (header B in FIG. 75), thereby performing simplified synchronization, which is different from the embodiment of FIG. 75 in that it indicates retransmission.

[0461] FIG. 76 is also a diagram for explaining an exchange sequence of ADT data packets regarding an authentication response message according to another embodiment. In the embodiment of FIG. 76, a wireless power receiving device divides a total 99-byte authentication response message into 16-byte 0th ADT data packet (ADT_PRx(0)), 16-byte 1st ADT data packet (ADT_PRx(1)),..., 16-byte 5th ADT data packet (ADT_PRx(5)), and 3-byte 6th ADT data packet (ADT_PRx(6)) for transmission. When transmitting the 1st ADT data packet (ADT_PRx(1)), although the header should not be toggled when transmission fails, retransmission of the 1st ADT data packet (ADT_PRx(1)) occurs with the header toggled, which is different from the embodiment of FIG. 75.

[0462] FIG. 77 is a diagram for explaining an exchange sequence of ADT data packets regarding an authentication response message according to another embodiment. The embodiment of FIG. 77 describes a scenario in which a wireless power receiving device divides a total 99-byte authentication response message into 16-byte 0th ADT data packet (ADT_PRx(0)), 16-byte 1st ADT data packet (ADT_PRx(1)),..., 16-byte 5th ADT data packet (ADT_PRx(5)), and 3-byte 6th ADT data packet (ADT_PRx(6)) and transmits them. The transmission of the 0th ADT data packet (ADT_PRx(0)) is successful, but there is no response to the 1st ADT data packet (ADT_PRx(1)), and the transmission fails.

[0463] 2-3) Concurrent Authentication between PRx and PTx

[0464] Both the wireless power transmitting device and the wireless power receiving device can simultaneously operate as authentication initiators.

[0465] As an example, the wireless power transmitting device can transmit an ADT including an authentication-related packet instead of an ADT including an ACK for a packet received from the wireless power receiving device. In this case, the wireless power receiving device can implicitly consider that it has received an ACK by receiving the ADT including the authentication-related packet and perform the next operation. That is, when the wireless power transmitting device transmits an ADT including data (authentication-related packet), the wireless power receiving device can determine that the ADT data it transmitted to the wireless power transmitting device was successfully transmitted even if it receives a data ADT instead of an ACK. However, if a communication error occurs in the ADT data received from the wireless power receiving device immediately before, the wireless power transmitting device can transmit a NACK. Of course, the ADT including the authentication-related packet can further include an ACK.

[0466] As another example, the wireless power receiving device can transmit an ADT including an authentication-related packet instead of an ADT including an ACK for a packet received from the wireless power transmitting device. In this case, the wireless power transmitting device can perform the next operation by implicitly receiving an ACK upon receiving the ADT including the authentication-related packet. That is, when the wireless power receiving device transmits an ADT including data (authentication-related packet), the wireless power transmitting device can determine that the ADT data it transmitted to the wireless power receiving device immediately before was successfully transmitted even if it receives a data ADT instead of an ACK. Of course, the ADT including the authentication-related packet can further include an ACK.

[0467] 2-4) Communication Start Protocol by the Wireless Power Transmission Device

[0468] While the wireless power transmitting device is operating as a slave based on Rule 1, the wireless power receiving device can provide an opportunity for communication (PTx initiated communication) started by the wireless power transmitting device by performing regular polling. In this case, the start of communication of the wireless power transmitting device is highly dependent on the wireless power receiving device. The wireless power receiving device can regularly poll the wireless power transmitting device to check whether the wireless power transmitting device has a packet to transmit. In this case, a GRP can be used as shown in FIG. 78. As shown in FIG. 78, for example, the wireless power receiving device can perform polling by setting a general request packet to "0xFF" or "00" or "FF". If the wireless power transmitting device receives a GRP set to "0xFF" or "00" or "FF", the wireless power transmitting device will be in a state where it can transmit any type of packet it intends to transmit.

[0469] As another solution to better guarantee the opportunity of communication initiated by the wireless power transmission device, the wireless power transmission device can transmit a request for communication (RFC) bit pattern for communication as a response to the RPP (excluding mode '100'b) of the wireless power reception device. When the wireless power reception device receives the RFC response, the wireless power reception device polls the wireless power transmission device using the GRP at an appropriate timing for itself. Although the wireless power reception device does not exactly know the time point when the value of the target power managed by the wireless power transmission device changes, the RFC response of the wireless power transmission device can relatively well guarantee the communication start time desired by the wireless power transmission device.

[0470] In particular, the response deadline polling of the RFC can be used for power management (PTx-initiated power management) initiated by the wireless power transmission device. Through the power management initiated by the wireless power transmission device, the wireless power transmission device can change (increase or decrease) the target power in consideration of the current surrounding charging conditions.

[0471] FIG. 79 is a transmission sequence related to power management initiated by a wireless power transmission device according to an embodiment.

[0472] As shown in FIG. 79, the wireless power transmission device transmits an alert including an RFC response (bit pattern) to the wireless power reception device as a response to the RPP (mode 0) of the wireless power reception device. The wireless power reception device transmits a GRP with the request value set to "0xFF" to the wireless power transmission device. Thereafter, the wireless power transmission device transmits a target power packet to the wireless power reception device. The wireless power reception device can adjust the operation mode according to the changed target power.

[0473] 6. Applications Related to the Authentication Procedure

[0474] The authentication function is set to On / Off by the user. For example, a smartphone can display to the user the activation / deactivation of the authentication function by an application, and activate or deactivate the authentication function when selection information regarding activation (ON) or deactivation (OFF) is input from the user.

[0475] The wireless power transmission and reception device can provide a very convenient user experience and interface (UX / UI). That is, a smart wireless charging service can be provided, and the smart wireless charging service can be realized based on the UX / UI of a smartphone including a wireless power transmission device. For such an application, the interface between the processor of the smartphone and the wireless charging reception device allows "drop and play" two-way communication between the wireless power transmission device and the reception device.

[0476] As an example, a user can experience a smart wireless charging service in a hotel. When the user enters the hotel room and places the smartphone on the wireless charger in the room, the wireless charger transmits wireless power to the smartphone, and the smartphone receives the wireless power. During this process, the wireless charger transmits information about the smart wireless charging service to the smartphone. When the smartphone senses that it is located on the wireless charger, senses the reception of wireless power, or receives information about the smart wireless charging service from the wireless charger, the smartphone enters a state of asking the user for consent (opt-in) to additional features. For this purpose, the smartphone can display a message on the screen in a form that includes or does not include an alarm sound. An example of the message can include a statement such as "Welcome to hotel. Select 'Yes' to activate smart charging functions: Yes | No Thanks." When the smartphone receives the selection of Yes or No Thanks entered by the user, the smartphone performs the next procedure selected by the user. If Yes is selected, the smartphone transmits the corresponding information to the wireless charger. Then, the smartphone and the wireless charger perform the smart charging function.

[0477] The smart wireless charging service can also include receiving automatic filling of WiFi credentials. For example, the wireless charger transmits the WiFi credentials to the smartphone, and the smartphone runs an appropriate app to automatically enter the WiFi credentials received from the wireless charger.

[0478] The smart wireless charging service can also include running a hotel application that provides hotel promotions or obtaining remote check-in / check-out and contact information.

[0479] As another example, a user can experience a smart wireless charging service inside a vehicle. When the user gets into the vehicle and places the smartphone on the wireless charger, the wireless charger transmits wireless power to the smartphone, and the smartphone receives the wireless power. In such a process, the wireless charger transmits information regarding the smart wireless charging service to the smartphone. When the smartphone senses that it is positioned on the wireless charger, senses the reception of wireless power, or receives information regarding the smart wireless charging service from the wireless charger, the smartphone enters a state of asking the user to confirm their identity.

[0480] In this state, the smartphone automatically connects to the vehicle via WiFi and / or Bluetooth. The smartphone can display a message on the screen with or without an alarm sound. An example of the message can include a statement such as "Welcome to your car. Select 'Yes' to synch device with in-car controls : Yes | No Thanks." When the user inputs by selecting Yes or No Thanks, the smartphone performs the next procedure selected by the user. If Yes is selected, the smartphone transmits the corresponding information to the wireless charger. Then, the smartphone and the wireless charger can jointly perform the in-vehicle smart control function by driving the in-vehicle application / display software. The user can enjoy the desired music and check the position of the official map. The in-vehicle application / display software can include the performance of providing a synchronization approach for the passengers.

[0481] As another example, a user can experience smart wireless charging at home. When the user enters a room and places the smartphone on a wireless charger inside the room, the wireless charger transmits wireless power to the smartphone, and the smartphone receives the wireless power. In this process, the wireless charger transmits information regarding the smart wireless charging service to the smartphone. When the smartphone senses that it is positioned on the wireless charger, senses the reception of wireless power, or receives information regarding the smart wireless charging service from the wireless charger, the smartphone enters a state of asking the user for opt-in to additional features. For this purpose, the smartphone can display a message on the screen in a form that includes or does not include an alarm sound. An example of the message can include a statement such as "Hi xxx, Would you like to activate night mode and secure the building? : Yes | No Thanks." When the smartphone selects Yes or No Thanks entered by the user, the smartphone performs the next procedure selected by the user. If Yes is selected, the smartphone transmits the corresponding information to the wireless charger. The smartphone and the wireless charger can at least recognize the user's pattern and recommend to the user to close the doors and windows, extinguish the fire, or set an alarm.

[0482] In the wireless power transmission method and apparatus, or the reception apparatus and method according to the embodiments of the present invention described above, since not all components or steps are essential, the wireless power transmission apparatus and method, or the reception apparatus and method can be performed including some or all of the components or steps described above. Also, the embodiments of the wireless power transmission apparatus and method, or the reception apparatus and method described above can be combined with each other. Further, each of the components or steps described above does not necessarily have to be performed in the order described, and it is also possible that the steps described later are performed prior to the steps described earlier.

[0483] The above description merely exemplarily explains the technical idea of the present invention. For those with ordinary knowledge in the technical field to which the present invention pertains, various modifications and variations are possible without departing from the essential characteristics of the present invention. Therefore, the embodiments of the present invention described above can also be realized separately or in combination with each other.

[0484] Therefore, the embodiments disclosed in the present invention are not for limiting the technical idea of the present invention, but for the purpose of explanation, and the scope of the technical idea of the present invention is not limited by such embodiments. The protection scope of the present invention should be interpreted by the scope of the claims, and all technical ideas within the equivalent scope should be construed as being included in the scope of the rights of the present invention.

Claims

1. A wireless power transmission device, comprising: a power conversion unit configured to transmit wireless power to the wireless power receiving device by forming a magnetic coupling with the wireless power receiving device; a communication / control unit configured to communicate with the wireless power receiving device and control the wireless power; wherein the wireless power transmission device , when having data to be sent by the wireless power transmission device to the wireless power receiving device, transmits a bit pattern requesting communication started by the wireless power transmission device to the wireless power receiving device; receives, in response to the bit pattern, a packet for polling the data to be transmitted from the wireless power receiving device; is configured to transmit a data stream to the wireless power receiving device based on receiving the packet for polling; the data stream includes a sequence of ADT (auxiliary data transports) packets; the sequence of the ADT packets is located after the start of an SOD (a start of data transport) packet; the SOD packet defines the start of the data stream, the wireless power transmission device.

2. The wireless power transmission device according to claim 1, wherein the bit pattern and the packet for polling are each 8 bits.

3. A method for a wireless power transmission device to transmit wireless power to a wireless power receiving device, the method comprising: when having data to be transmitted by the wireless power transmission device to the wireless power receiving device, transmitting, to the wireless power receiving device, a data packet requesting communication started by the wireless power transmission device in a bit pattern; receiving, in response to the bit pattern, a packet for polling the data transmitted from the wireless power receiving device; transmitting, based on receiving the packet for polling, a data stream to the wireless power receiving device, the data stream includes a sequence of ADT (auxiliary data transports) packets; the sequence of the ADT packets is located after the start of an SOD (a start of data transport) packet; the SOD packet defines the start of the data stream, the communication method.

4. The communication method according to claim 3, wherein the bit pattern and the packet for polling are each 8 bits.

5. A wireless power receiving device, a power pickup unit that forms a magnetic coupling with a wireless power transmitting device and receives wireless power from the wireless power transmitting device, and a communication / control unit that communicates with the wireless power transmitting device and controls the wireless power, wherein the wireless power receiving device receives a digital ping from the wireless power transmitting device, when the wireless power transmitting device has data to transmit to the wireless power receiving device, receives a bit pattern that requests communication started by the wireless power transmitting device, transmits a packet for polling the data to be transmitted to the wireless power transmitting device in response to the bit pattern, is configured to receive a data stream based on the wireless power transmitting device transmitting the packet for polling, the data stream includes a sequence of ADT (auxiliary data transports) packets, the sequence of ADT packets is located after the start of a SOD (a start of data transport) packet, the SOD packet defines the start of the data stream, a wireless power receiving device.

6. The wireless power receiving device according to claim 5, wherein the bit pattern and the packet are each 8 bits.

7. A method of receiving wireless power from a wireless power transmitting device executed by a wireless power receiving device, comprising: receiving, from the wireless power transmitting device, a bit pattern for requesting communication started by the wireless power transmitting device when the wireless power transmitting device has data to transmit to the wireless power receiving device; transmitting, in response to the bit pattern, a packet for polling the data to be transmitted to the wireless power transmitting device; and receiving a data stream based on the wireless power transmitting device transmitting the packet for polling, wherein the data stream includes a sequence of ADT (auxiliary data transports) packets. The sequence of the ADT packets is located after the start of an SOD (a start of data transport) packet, The SOD packet is a communication method that defines the start of the data stream. **Claim 8** The communication method according to claim 7, wherein the bit pattern and the packet are each 8 bits.

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