Apparatus and method for performing authentication in a wireless power transfer system

Abstract

The present invention relates to an apparatus and method of performing authentication in a wireless power transfer system. Disclosed in the present specification is an authentication method in a wireless power transfer system, including the steps of: receiving a first packet including indication information about whether a target device supports an authentication function from the target device; and if the target device supports the authentication function, transmitting an authentication request message to the target device; receiving an authentication response message including a certificate for wireless charging from the target device in response to the authentication request message; and confirming authentication of the target device based on the authentication response message.

Description

[0001] This application is a divisional application of patent application No. 201880026272.5 (PCT / KR2018 / 005071), filed on October 21, 2019, with a filing date of May 2, 2018, entitled "Apparatus and Method for Performing Authentication in a Wireless Power Transmission System". Technical Field

[0002] This invention relates to wireless power transmission, and more particularly, to apparatus and methods for performing authentication in a wireless power transmission system. Background Technology

[0003] Wireless power transfer (or transmission) technology corresponds to technologies that can wirelessly transfer (or transmit) power between a power source and an electronic device. For example, by allowing the batteries of wireless devices such as smartphones or tablet PCs to be recharged simply by mounting the wireless device on a wireless charging pad, wireless power transfer technology offers significantly greater mobility, convenience, and security than traditional wired charging environments using wired charging connectors. Beyond wireless charging for wireless devices, wireless power transfer technology is gaining attention as an alternative to traditional wired power transfer environments in various fields such as electric vehicles, Bluetooth headsets, 3D glasses, various wearable devices, home appliances, furniture, underground facilities, buildings, medical devices, robotics, and entertainment.

[0004] Wireless power transfer (or transmission) methods are also known as contactless power transfer methods, contactless power transfer methods, or wireless charging methods. A wireless power transmission system can be configured with a wireless power transmitter and a wireless power receiver. The wireless power transmitter supplies electrical energy using the wireless power transfer method, and the wireless power receiver receives the electrical energy supplied by the wireless power transmitter and supplies received electrical energy to a receiver such as a battery cell.

[0005] Wireless power transfer technologies encompass various methods, such as those using magnetic coupling, radio frequency (RF) transmission, microwave transmission, and ultrasound (or ultrasonic waves). Magnetic coupling-based methods are categorized into magnetic induction and magnetic resonance methods. Magnetic induction transmits power based on the electromagnetic coupling between the transmitting and receiving coils, using a magnetic field generated by the transmitter's coil battery cell to induce a current in the receiver's coil. Magnetic resonance is similar to magnetic induction in its use of a magnetic field. However, the difference lies in the fact that energy is transmitted due to the concentration of the magnetic field (caused by the generated resonance) at both the transmitting and receiving ends.

[0006] Wireless power systems implemented according to specific standard technologies can address safety issues caused by overheating due to foreign objects. However, uncertified products lacking certification for relevant technical standards or specifications are already circulating in the market, potentially exposing users to hazards. Therefore, stability and reliability must be ensured through mutual authentication between the wireless power transmitting and receiving devices before and after wireless charging. Summary of the Invention

[0007] Technical issues

[0008] This invention provides an apparatus and method for performing authentication in a wireless power transmission system.

[0009] The present invention also provides a wireless power transmitting device and method for performing authentication of a wireless power receiving device.

[0010] The present invention also provides a wireless power receiving device and method for performing authentication of a wireless power transmitting device.

[0011] Technical solution

[0012] In one aspect, a method for authenticating a target device in a wireless power transmission system is provided. The method includes: receiving from the target device a first packet including indication information regarding whether the target device supports authentication functionality; and when the target device supports authentication functionality, sending an authentication request message to the target device; in response to the authentication request message, receiving from the target device an authentication response message including a certificate related to wireless charging; and confirming the authentication of the target device based on the authentication response message. Here, the certificate format may include a certificate type indicating whether the certificate is a root certificate, intermediate certificate, or leaf certificate, and an indication of whether the certificate is a certificate and leaf certificate related to the wireless power transmission device PTx.

[0013] In another scenario, the target device may be a wireless power transmitting device, the first packet may be a capability packet of the wireless power transmitting device, and the indication information may be configured with 1 bit and may indicate whether the authentication function of the wireless power transmitting device is supported or not.

[0014] In another scenario, the target device may be a wireless power receiving device, the first packet may be a configuration packet of the wireless power receiving device, and the indication information may be configured with 1 bit and may indicate whether the authentication function of the wireless power receiving device is supported or not.

[0015] In another aspect, the first group may include at least one of first information regarding whether the target device can operate as an authentication initiator (AI) and second information regarding whether the target device can operate as an authentication responder (AR).

[0016] On the other hand, authentication request messages and authentication response messages can be sent based on the low-level Auxiliary Data Transmission (ADT) data transaction protocol.

[0017] In another approach, authentication request messages or authentication response messages can be sequentially divided into multiple ADT data packets and sent, and the header value can be switched each time a new ADT data packet is sent.

[0018] On the other hand, when the transmission of ADT data packets fails, the header value does not need to be switched when retransmitting ADT data packets.

[0019] In another aspect, in at least one of receiving the first packet, sending the authentication request message, and receiving the authentication response message, wireless charging can be performed using power based on the baseline power profile.

[0020] In another aspect, multiple ADT data packets may include a first ADT data packet indicating the start of the data stream (SOD) and a second ADT data packet indicating the end of the data stream (EOD) at their beginning and end, respectively, and the first and second ADT data packets may have an ADT control packet structure and may be configured to have 1 byte.

[0021] In another aspect, the method may further include: polling for the existence of a message that the wireless power transmitting device wants to send, and polling may include: the wireless power receiving device setting a specific value for the request field of a 1-byte General Packet Request (GRP) and sending it to the wireless power transmitting device.

[0022] In another aspect, the method may further include: in response to a receive power packet (RPP) from the wireless power receiving device, the wireless power transmitting device sending a communication request (RFC) bit pattern; and the wireless power receiving device sending a general request packet (GRP) in response to the RFC bit pattern to obtain the target power of the wireless power transmitting device.

[0023] In another scenario, another ADT data packet can be used in place of an ACK in response to the successful reception of an ADT data packet.

[0024] In another aspect, an apparatus is provided for authenticating a target device in a wireless power transmission system. The apparatus includes: a communication unit that receives from a target device a first packet including indication information regarding whether the target device supports authentication functionality, and sends an authentication request message to the target device when the target device supports authentication functionality; and in response to the authentication request message, receives from the target device an authentication response message including a certificate regarding wireless charging, and confirms the authentication of the target device based on the authentication response message; and a coil that performs wireless charging based on magnetic coupling to the target device. Here, the certificate format may include a certificate type indicating whether the certificate is a root certificate, intermediate certificate, or leaf certificate, and an indication of whether the certificate is a certificate and leaf certificate for a wireless power transmission device PTx.

[0025] In another scenario, the target device may be a wireless power transmitting device, the first packet may be a capability packet of the wireless power transmitting device, and the indication information may be configured with 1 bit and may indicate whether the authentication function of the wireless power transmitting device is supported or not.

[0026] In another scenario, the target device may be a wireless power receiving device, the first packet may be a configuration packet of the wireless power receiving device, and the indication information may be configured with 1 bit and may indicate whether the authentication function of the wireless power receiving device is supported or not.

[0027] In another aspect, the first group may include at least one of first information regarding whether the target device can operate as an authentication initiator (AI) and second information regarding whether the target device can operate as an authentication responder (AR).

[0028] On the other hand, authentication request messages and authentication response messages can be sent based on the low-level Auxiliary Data Transmission (ADT) data transaction protocol.

[0029] In another aspect, the communication unit can sequentially divide the authentication request message or authentication response message into multiple ADT data packets and send them, and can switch the header value each time a new ADT data packet is sent.

[0030] On the other hand, when the transmission of ADT data packets fails, the header value does not need to be switched when retransmitting ADT data packets.

[0031] In another aspect, in at least one of receiving the first packet, sending the authentication request message, and receiving the authentication response message, the coil can perform wireless charging using power according to the baseline power profile.

[0032] Technical effect

[0033] This invention clearly provides the essential elements for mutual authentication between wireless power transmitting and receiving devices, such as the format of wireless charging certificates, indication information regarding authentication function support, timing between authentication-related processes and wireless charging phases, authentication processes and authentication messages, and lower-level protocols supporting the authentication process, ensuring stability and reliability even during high-power wireless charging. Attached Figure Description

[0034] Figure 1 This is a block diagram of a wireless power system (10) according to an exemplary embodiment of the present invention.

[0035] Figure 2 This is a block diagram of a wireless power system (10) according to another exemplary embodiment of the present invention.

[0036] Figure 3 Exemplary implementations of various electronic devices employing wireless power systems are shown.

[0037] Figure 4 This is a block diagram of a wireless power system according to another exemplary embodiment of the present invention.

[0038] Figure 5 It is a state transition diagram used to describe the wireless power transmission process.

[0039] Figure 6 A power control method according to an exemplary embodiment of the present invention is shown.

[0040] Figure 7 This is a block diagram of a wireless power transmitter according to another exemplary embodiment of the present invention.

[0041] Figure 8 A wireless power receiver according to another exemplary embodiment of the present invention is shown.

[0042] Figure 9 A communication frame structure according to an exemplary embodiment of the present invention is shown.

[0043] Figure 10 This is the structure of a synchronization mode according to an exemplary embodiment of the present invention.

[0044] Figure 11 The operation of a wireless power transmitter and a wireless power receiver in a shared mode according to an exemplary embodiment of the present invention is shown.

[0045] Figure 12 This is a block diagram illustrating a wireless charging certificate format according to an embodiment.

[0046] Figure 13aThis is a block diagram illustrating a wireless charging certificate format according to another embodiment.

[0047] Figure 13b This is a block diagram illustrating a wireless charging certificate format according to another embodiment.

[0048] Figure 14 A capability grouping structure for a wireless power transmitting device according to an embodiment is shown.

[0049] Figure 15 A capability grouping structure for a wireless power transmission device according to another embodiment is shown.

[0050] Figure 16 The configuration grouping structure of a wireless power receiving device according to an embodiment is shown.

[0051] Figure 17 A configuration grouping structure for a wireless power receiving device according to another embodiment is shown.

[0052] Figure 18 This is a flowchart illustrating the sequence of transmitted and received packets when the wireless power receiving device performs authentication of the wireless power transmitting device (PRx authentication of PTx) according to an embodiment.

[0053] Figure 19 An example of the GET_DIGESTS message structure is shown.

[0054] Figure 20 Another example of the GET_DIGESTS message structure is shown.

[0055] Figure 21 The physical packet structure for sending DIGESTS and the method for sending the physical packet structure are shown.

[0056] Figure 22 An example of the GET_CERTIFICATE message structure is shown.

[0057] Figure 23 An example is shown of the physical packet structure for sending a certificate and the method for sending that physical packet structure.

[0058] Figure 24 An example of a physical packet structure for sending an authentication response message from a wireless power transmitting device and a method for sending that physical packet structure is shown.

[0059] Figure 25 An example of the CHALLENGE message structure is shown.

[0060] Figure 26An example is shown of the physical packet structure for sending CHALLENGE_AUTH and the method for sending that physical packet structure.

[0061] Figure 27 This is a flowchart illustrating the sequence of transmitted and received packets when the wireless power transmitting device performs authentication of the wireless power receiving device (PTx authentication of PRx) according to an embodiment.

[0062] Figure 28 An example of the message structure for GET_DIGESTS sent by a wireless power transmitting device is shown.

[0063] Figure 29 An example of the GET_CERTIFICATE message structure sent by a wireless power transmitting device is shown.

[0064] Figure 30 An example is shown of the physical packet structure for sending a certificate of a wireless power receiving device and a method for sending that physical packet structure.

[0065] Figure 31 An example of the CHALLENGE message structure sent by a wireless power transmitting device is shown.

[0066] Figure 32 An example is shown of the physical packet structure for transmitting CHALLENGE_AUTH from a wireless power receiving device and a method for transmitting that physical packet structure.

[0067] Figure 33 An example of a physical packet structure for sending an authentication response message from a wireless power receiving device and a method for sending such a physical packet structure are shown.

[0068] Figure 34 Another example is shown of the physical packet structure for sending an authentication response message from a wireless power receiving device and a method for sending that physical packet structure.

[0069] Figure 35 This is a flowchart illustrating the sequence of transmitted and received packets when the wireless power transmitting device performs authentication of the wireless power receiving device (PTx authentication of PRx) according to another embodiment.

[0070] Figure 36 The diagram illustrates the structure of a wireless power receiving device sending packets for in-band communication to a wireless power transmitting device.

[0071] Figure 37 The diagram illustrates the structure of a wireless power transmitting device sending packets for in-band communication to a wireless power receiving device.

[0072] Figure 38The diagram illustrates the packet transmission and reception sequence between a wireless power receiving device and a transmitting device, viewed from a lower-level perspective according to an embodiment.

[0073] Figure 39 The diagram illustrates a sequence of packet transmission and reception between a wireless power receiving device and a transmitting device, viewed from a lower-level perspective according to another embodiment.

[0074] Figure 40 The structure of extended control error grouping according to an implementation method is shown.

[0075] Figure 41 The structure of an End Power Transfer (EPT) packet according to an embodiment is shown.

[0076] Figure 42 The structure of an extended receive power packet according to an embodiment is shown.

[0077] Figure 43 The diagram illustrates the packet transmission and reception sequence between a wireless power receiving device and a transmitting device, viewed from a lower-level perspective according to an embodiment.

[0078] Figure 44 Data transmission according to an embodiment is shown.

[0079] Figure 45 Data transmission according to another embodiment is shown.

[0080] Figure 46 The structure of an ADT data packet (ADT_PRx data packet) on a wireless power receiving device according to an embodiment is shown.

[0081] Figure 47 The structure of the ADT response packet (ADT_PRx response packet) of the wireless power receiving device according to an embodiment is shown.

[0082] Figure 48 The structure of the ADT control packet (ADT_PRx control packet) of a wireless power receiving device according to an embodiment is shown.

[0083] Figure 49 The structure of an ADT data packet (ADT_PTx data packet) of a wireless power transmitting device according to an embodiment is shown.

[0084] Figure 50 The structure of the ADT response packet (ADT_PTx response packet) of the wireless power transmitting device according to an embodiment is shown.

[0085] Figure 51The structure of the ADT response / control packet (ADT_PTx response / control packet) of a wireless power transmitting device according to an embodiment is shown.

[0086] Figure 52 The structure of the ADT control packet (ADT_PTx control packet) of a wireless power transmitting device according to an embodiment is shown.

[0087] Figure 53 This is a schematic diagram illustrating the state machine for writing ADT data packets according to an embodiment.

[0088] Figure 54 The high-level and low-level transmission sequences of the wireless power transmitting device and the wireless power receiving device when exchanging ADT data packets are illustrated according to an embodiment.

[0089] Figure 55 The high-level and low-level transmission sequences of the wireless power transmitting device and the wireless power receiving device when exchanging ADT data packets are shown according to another embodiment.

[0090] Figure 56 The high-level and low-level transmission sequences of the wireless power transmitting device and the wireless power receiving device when exchanging ADT data packets are shown according to another embodiment.

[0091] Figure 57 The diagram illustrates the exchange sequence of ADT data packets for an authentication request message according to an implementation.

[0092] Figure 58 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment.

[0093] Figure 59 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment.

[0094] Figure 60 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment.

[0095] Figure 61 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment.

[0096] Figure 62 The exchange sequence of ADT data packets for the authentication response message according to an embodiment is shown.

[0097] Figure 63 An exchange sequence of ADT data packets for an authentication response message according to another embodiment is shown.

[0098] Figure 64 An exchange sequence of ADT data packets for an authentication response message according to another embodiment is shown.

[0099] Figure 65 An exchange sequence of ADT data packets for an authentication response message according to another embodiment is shown.

[0100] Figure 66 An exchange sequence of ADT data packets for an authentication response message according to another embodiment is shown.

[0101] Figure 67 The high-level and low-level transmission sequences of the wireless power transmitting device and the wireless power receiving device when exchanging ADT data packets are illustrated according to an embodiment.

[0102] Figure 68 The high-level and low-level transmission sequences of the wireless power transmitting device and the wireless power receiving device when exchanging ADT data packets are shown according to another embodiment.

[0103] Figure 69 The diagram illustrates the exchange sequence of ADT data packets for an authentication request message according to an implementation.

[0104] Figure 70 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment.

[0105] Figure 71 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment.

[0106] Figure 72 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment.

[0107] Figure 73 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment.

[0108] Figure 74 The exchange sequence of ADT data packets for the authentication response message according to an embodiment is shown.

[0109] Figure 75 An exchange sequence of ADT data packets for an authentication response message according to another embodiment is shown.

[0110] Figure 76 An exchange sequence of ADT data packets for an authentication response message according to another embodiment is shown.

[0111] Figure 77An exchange sequence of ADT data packets for an authentication response message according to another embodiment is shown.

[0112] Figure 78 The structure of GRP according to an embodiment is shown.

[0113] Figure 79 A power management transmission sequence initiated by a wireless power transmitting device according to an embodiment is shown. Detailed Implementation

[0114] The term "wireless power," as used in this specification, will refer to any form of energy relating to electric, magnetic, and electromagnetic fields, in which energy is transferred (or transmitted) from a wireless power transmitter to a wireless power receiver without the use of any physical electromagnetic conductor. Wireless power can also be referred to as a wireless power signal, and it can refer to the oscillating magnetic flux enclosed by primary and secondary coils. For example, the specification will describe power conversion for wirelessly charging devices in the system, including mobile phones, cordless phones, iPods, MP3 players, headphones, etc. Generally, the basic principles of wireless power transmission technology include, for example, all of the following: methods of transmitting power using magnetic coupling, methods of transmitting power using radio frequency (RF), methods of transmitting power using microwaves, and methods of transmitting power using ultrasound (or ultrasonic waves).

[0115] Figure 1 This is a block diagram of a wireless power system (10) according to an exemplary embodiment of the present invention.

[0116] refer to Figure 1 The wireless power system (10) includes a wireless power transmitter (100) and a wireless power receiver (200).

[0117] The wireless power transmitter (100) is supplied with power from an external power source (S) and generates a magnetic field. The wireless power receiver (200) uses the generated magnetic field to generate current, thereby enabling it to wirelessly receive power.

[0118] Furthermore, in the wireless power system (10), the wireless power transmitter (100) and the wireless power receiver (200) can transmit and / or receive various information required for wireless power transmission. Here, communication between the wireless power transmitter (100) and the wireless power receiver (200) can be performed (or established) according to either in-band communication or out-of-band communication, wherein in-band communication uses a magnetic field for wireless power transmission (or transmission), and out-of-band communication uses a separate communication carrier.

[0119] Here, the wireless power transmitter (100) can be configured as either fixed or mobile (or portable). Examples of fixed transmitter types can include embedded and in-wall types, wherein an embedded transmitter is embedded in an indoor ceiling or wall or in furniture such as a table, and an in-wall transmitter is installed in an outdoor parking lot, bus stop, subway station, etc., or in a vehicle such as a car or train. A mobile (or portable) wireless power transmitter (100) can be implemented as part of another device, such as a cover for a mobile device or laptop computer of portable size or weight.

[0120] Furthermore, the wireless power receiver (200) should be understood as a comprehensive concept encompassing various household appliances and devices that operate by being wirelessly supplied with power, rather than various electronic devices equipped with batteries and power cables. Typical examples of a wireless power receiver (200) may include portable terminals, cellular phones, smartphones, personal digital assistants (PDAs), portable media players (PDPs), Wibro terminals, tablet PCs, tablet phones, laptops, digital cameras, navigation terminals, televisions, electric vehicles (DVs), etc.

[0121] In the wireless power system (10), one or more wireless power receivers (200) may be present. Although in Figure 1 The diagram shows a wireless power transmitter (100) and a wireless power receiver (200) transmitting data to or receiving data from each other in a one-to-one correspondence (or relationship), but as... Figure 2 As shown, a wireless power transmitter (100) may also transmit power to multiple wireless power receivers (200-1, 200-2, ..., 200-M) simultaneously. More specifically, when performing wireless power transmission (or transmission) using magnetic resonance, a wireless power transmitter (100) can transmit power to multiple wireless power receivers (200-1, 200-2, ..., 200-M) by using synchronous transmission (or transmission) or time-division transmission (or transmission) methods.

[0122] In addition, although in Figure 1 The diagram shows a wireless power transmitter (100) directly transmitting (or sending) power to a wireless power receiver (200). However, the wireless power system (10) can also be equipped with a separate wireless power transceiver, such as a repeater or relay, to increase the wireless power transmission distance between the wireless power transmitter (100) and the wireless power receiver (200). In this case, power is delivered from the wireless power transmitter (100) to the wireless power transceiver, which can then transmit the received power to the wireless power receiver (200).

[0123] Hereinafter, the terms "wireless power receiver," "power receiver," and "receiver" as used in this specification will refer to the wireless power receiver (200). Additionally, the terms "wireless power transmitter," "power transmitter," and "transmitter" as used in this specification will refer to the wireless power transmitter (100).

[0124] Figure 3 Exemplary implementations of various electronic devices employing wireless power systems are shown.

[0125] like Figure 3 As shown, electronic devices included in a wireless power system are classified according to the amount of transmitted power and received power. (Reference) Figure 3 Wearable devices such as smartwatches, smart glasses, head-mounted displays (HMDs), and smart rings, as well as mobile electronic devices (or portable electronic devices) such as headphones, remote controllers, smartphones, PDAs, and tablet PCs, can use low-power (approximately 5W or less or approximately 20W or less) wireless charging methods.

[0126] Small / medium-sized electronic devices such as laptops, robotic vacuum cleaners, TV receivers, audio equipment, and monitors can use medium-power (approximately 50W or less, or approximately 200W or less) wireless charging methods. Kitchen appliances such as blenders, microwave ovens, and rice cookers, and personal transportation devices (or other electric devices or vehicles) such as electric wheelchairs, electric bicycles, electric bikes, and electric vehicles can use high-power (approximately 2kW or less, or approximately 22kW or less) wireless charging methods.

[0127] The above description (or Figure 1 The electric equipment or vehicle shown may include a wireless power receiver, which will be described in detail below. The aforementioned electric equipment or vehicle can then be charged (or recharged) by wirelessly receiving power from the wireless power transmitter.

[0128] The present invention has been described below based on a mobile device employing a wireless power charging method, but this is merely exemplary. Therefore, it should be understood that the wireless charging method according to the present invention can be applied to various electronic devices.

[0129] Standards used for wireless power transfer (or transmission) include the Wireless Power Consortium (WPC), the Air Fuel Consortium (AFA), and the Power Utility Consortium (PMA).

[0130] The WPC standard defines the Baseline Power Profile (BPP) and the Extended Power Profile (EPP). The BPP is associated with wireless power transmitters and receivers that support 5W power transmission, while the EPP is associated with wireless power transmitters and receivers that support power transmissions in the range of greater than 5W and less than 30W.

[0131] Various wireless power transmitters and receivers using different power levels can be covered by each standard and can be classified by different power levels or categories.

[0132] For example, the WPC can classify (or categorize) wireless power transmitters and receivers into PC-1, PC0, PC1, and PC2, and the WPC can provide standard documentation (or specifications) for each power level (PC). The PC-1 standard pertains to wireless power transmitters and receivers that provide guaranteed power of less than 5W. Applications of PC-1 include wearable devices such as smartwatches.

[0133] The PC0 standard relates to wireless power transmitters and receivers providing a guaranteed power of 5W. The PC0 standard includes an EPP with a guaranteed power range extended to 30W. Although in-band (IB) communication corresponds to the mandatory communication protocol of PC0, out-of-band (OOB) communication, used as an optional backup channel, can also be used with PC0. A wireless power receiver can be identified by setting an OOB flag in a configuration packet, indicating whether OOB is supported. Wireless power transmitters supporting OOB can enter the OOB switching phase by sending a bit pattern for OOB switching in response to a configuration packet. The response to the configuration packet can correspond to NAK, ND, or a newly defined 8-bit pattern. Applications of PC0 include smartphones.

[0134] The PC1 standard relates to wireless power transmitters and receivers that provide guaranteed power ranging from 30W to 150W. OOB corresponds to the mandatory communication protocol used for PC1, and IB is used for link establishment and initialization to OOB. A wireless power transmitter can enter the OOB handover phase by sending a bit pattern for OOB handover in response to a configuration packet. Applications of PC1 include laptops and power tools.

[0135] The PC2 standard involves wireless power transmitters and receivers that provide guaranteed power ranging from 200W to 2kW, and its applications include kitchen appliances.

[0136] As mentioned above, PCs can be differentiated based on their respective power levels. Furthermore, information regarding whether compatibility between the same PCs is supported can be optional or mandatory. Here, compatibility between the same PCs indicates that power transmission / reception between the same PCs is possible. For example, if a wireless power transmitter corresponding to PC x can perform charging with a wireless power receiver having the same PC x, it is understood that compatibility between the same PCs is maintained. Similarly, compatibility between different PCs can also be supported. Here, compatibility between different PCs indicates that power transmission / reception between different PCs is also possible. For example, if a wireless power transmitter corresponding to PC x can perform charging with a wireless power receiver having PC y, it is understood that compatibility between different PCs is maintained.

[0137] Supporting compatibility between PCs addresses extremely important issues in terms of infrastructure setup and user experience. However, there are various problems regarding maintaining compatibility between PCs, which will be described below.

[0138] In cases of compatibility between identical PCs, such as when using a wireless power receiver employing a laptop charging method (where stable charging is only possible when power is continuously transmitted), even if the corresponding wireless power transmitter has the same PC, the corresponding wireless power receiver may struggle to reliably receive power from a wireless power transmitter using a power tool method that transmits power intermittently. Furthermore, in cases of compatibility between different PCs, such as when a wireless power transmitter with a minimum guaranteed power of 200W transmits power to a wireless power receiver with a maximum guaranteed power of 5W, the corresponding wireless power receiver may be damaged due to overvoltage. Therefore, it may be unsuitable (or difficult) to use PS as an index / reference standard for indicating / indicating compatibility.

[0139] Then, a new "profile" will be defined based on an index / reference standard indicating compatibility. More specifically, it can be understood that stable power transmission / reception can be performed by maintaining compatibility between wireless power transmitters and receivers with the same "profile," and power transmission / reception between wireless power transmitters and receivers with different "profiles" cannot be performed. The "profile" can be defined based on compatibility and / or application, regardless of (or independent of) power level.

[0140] For example, profiles can be categorized into four different categories, such as i) mobile, ii) power tools, iii) kitchen, and iv) wearables.

[0141] In the case of the "Mobile" profile, the PC can be defined as PC0 and / or PC1, the communication protocol / method can be defined as IB and OOB communication, the operating frequency can be defined as 87 to 205 kHz, and smartphones, laptops, etc. can be used as exemplary applications.

[0142] In the case of the "Power Tools" profile, the PC can be defined as PC1, the communication protocol / method can be defined as IB communication, the operating frequency can be defined as 87 to 145 kHz, and power tools, etc., can exist as exemplary applications.

[0143] In the case of the "Kitchen" profile, the PC can be defined as PC2, the communication protocol / method can be defined as NFC-based communication, the operating frequency can be defined as less than 100kHz, and kitchen / home appliances, etc., can exist as exemplary applications.

[0144] In the case of a “wearable” profile, the PC can be defined as PC-1, the communication protocol / method can be defined as IB communication, the operating frequency can be defined as 87 to 205 kHz, and wearable devices worn by the user can exist as exemplary applications.

[0145] Maintaining compatibility between the same configuration files can be mandatory, while maintaining compatibility between different configuration files can be optional.

[0146] The aforementioned profiles (mobile profiles, power tool profiles, kitchen profiles, and wearable profiles) can be summarized and represented as first to nth profiles, and new profiles can be added / replaced according to WPC standards and exemplary implementations.

[0147] When the configuration file is defined as described above, the wireless power transmitter can optionally only perform power transmission to wireless power receivers that correspond to the same configuration file as the wireless power transmitter, thereby enabling more stable power transmission. Furthermore, since the load (or burden) on the wireless power transmitter can be reduced and power transmission to incompatible wireless power receivers is not attempted, the risk of damage to the wireless power receiver can be decreased.

[0148] PC1, representing a "mobile" profile, can be defined by derivation from optional extensions such as OOB based on PC0. Furthermore, a "power tool" profile can be defined as a simple modified version of the PC1 "mobile" profile. Additionally, while profiles have been defined so far for the purpose of maintaining compatibility between the same profiles, in the future, technology may evolve to a level that maintains compatibility between different profiles. Wireless power transmitters or receivers can use various methods to notify (or announce) their profiles to their peers.

[0149] In the AFA standard, wireless power transmitters are called Power Transmitting Units (PTUs), and wireless power receivers are called Power Receiver Units (PRUs). Furthermore, PTUs are categorized into several classes as shown in Table 1, and PRUs are categorized into several classes as shown in Table 2.

[0150] [Table 1]

[0151]

[0152]

[0153] [Table 2]

[0154] PRU <![CDATA[P RX_OUT_MAX' ]]> Exemplary Applications Category 1 TBD Bluetooth headsets Category 2 3.5W Feature Phone Category 3 6.5W Smartphone Category 4 13W Tablet PC, Tablet Phone Category 5 25W small laptops Category 6 37.5W ordinary laptops Category 7 50W Home appliances

[0155] As shown in Table 1, the maximum output power capability of a class n PTU can be equal to or greater than the corresponding class's PTX_IN_MAX. A PTU cannot draw power higher than the power level specified in the corresponding category.

[0156] Figure 4 This is a block diagram of a wireless power system according to another exemplary embodiment of the present invention.

[0157] refer to Figure 4 The wireless power system (10) includes a mobile device (450) that wirelessly receives power and a base station (400) that wirelessly transmits power.

[0158] As a device for providing induced or resonant power, the base station (400) may include at least one of a wireless power transmitter (100) and a system unit (405). The wireless power transmitter (100) may transmit induced or resonant power and may control the transmission. The wireless power transmitter (100) may include a power conversion unit (110) that converts electrical energy into a power signal by generating a magnetic field via one or more primary coils and a communication and control unit (120) that controls communication and power transmission between the wireless power receiver (200) to transmit an appropriate (or suitable) level of power. The system unit (405) may perform input power supply, control of multiple wireless power transmitters, and other operational controls of the base station (400) (e.g., user interface control).

[0159] The primary coil can generate an electromagnetic field by using alternating current (AC power, voltage, or current). The primary coil is supplied with AC power (or voltage, current) of a specific frequency, which is output from the power conversion unit (110). Therefore, the primary coil can generate a magnetic field of a specific frequency. A non-radial or radial magnetic field can be generated. Furthermore, a wireless power receiver (200) receives the generated magnetic field and then generates a current. In other words, the primary coil wirelessly transmits power.

[0160] In magnetic induction, the primary and secondary coils can have random, suitable shapes. For example, the primary and secondary coils can correspond to copper wire wound around a highly permeable magnetic material (e.g., ferrite or amorphous metal). The primary coil can also be referred to as a primary magnetic core, primary winding, primary loop antenna, etc. Similarly, the secondary coil can be referred to as a secondary magnetic core, secondary winding, secondary loop antenna, pickup antenna, etc.

[0161] In the case of using the magnetic resonance method, the primary coil and secondary coil can be provided separately as a primary resonant antenna and a secondary resonant antenna. The resonant antenna can have a resonant structure including the coil and a capacitor. In this case, the resonant frequency of the resonant antenna can be determined by the inductance of the coil and the capacitance of the capacitor. Here, the coil can be formed into a loop shape. In addition, a magnetic core can be placed inside the loop. The magnetic core can include a physical magnetic core such as a ferrite core or an air core.

[0162] Energy transfer (or transmission) between a primary and secondary resonant antenna can be performed through resonance in a magnetic field. Resonance refers to efficient energy transfer between two coupled resonant antennas when a near-field corresponding to the resonant frequency is present in the resonant antenna and another resonant antenna is present in the vicinity of the corresponding resonant antenna. When a magnetic field corresponding to the resonant frequency is generated between the primary and secondary resonant antennas, the primary and secondary resonant antennas resonate with each other. Therefore, in general, the magnetic field is more efficiently concentrated towards the second resonant antenna than when the magnetic field generated from the primary antenna is radiated into free space. Thus, energy can be efficiently transferred from the first resonant antenna to the second resonant antenna. Magnetic induction can be implemented similarly to magnetic resonance. However, in this case, the frequency of the magnetic field is not required to be the resonant frequency. However, in magnetic induction, it is required that the loops of the primary and secondary coils be matched to each other, and the distance between the loops should be very close.

[0163] Although not shown in the accompanying drawings, the wireless power transmitter (100) may further include a communication antenna. In addition to magnetic field communication, the communication antenna can transmit and / or receive communication signals using a communication carrier. For example, the communication antenna can transmit and / or receive communication signals corresponding to WiFi, Bluetooth, Bluetooth LE, ZigBee, NFC, etc.

[0164] The communication and control unit (120) can send and / or receive information to and from the wireless power receiver (200). The communication and control unit (120) may include at least one of an IB communication module and an OOB communication module.

[0165] The IB communication module can transmit and / or receive information using magnetic waves (which use a specific frequency as their center frequency). For example, the communication and control unit (120) can perform in-band (IB) communication by loading information into the magnetic waves and transmitting the information via a primary coil or by receiving the information-carrying magnetic waves via a primary coil. In this case, the communication and control unit (120) can load information into the magnetic waves or can interpret the information carried by the magnetic waves by using a modulation scheme (e.g., binary phase shift keying (BPSK) or amplitude shift keying (ASK, etc.)) or encoding scheme (e.g., Manchester encoding or non-return-to-zero level (NZR-L) encoding, etc.). By using the above-described IB communication, the communication and control unit (120) can transmit and / or receive information at a data transmission rate of several kbps over a distance of up to several meters.

[0166] The OOB communication module can also perform out-of-band communication via a communication antenna. For example, a communication and control unit (120) can be provided to the near-field communication module. Examples of near-field communication modules may include communication modules such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, etc.

[0167] The communication and control unit (120) can control the overall operation of the wireless power transmitter (100). The communication and control unit (120) can perform various information calculations and processing, and can also control each configuration element of the wireless power transmitter (100).

[0168] The communication and control unit (120) can be implemented in a computer or a similar device such as hardware, software, or a combination thereof. When implemented in hardware form, the communication and control unit (120) can be provided as an electronic circuit that performs control functions by processing electrical signals. And, when implemented in software form, the communication and control unit (120) can be provided as a program that operates the communication and control unit (120).

[0169] The communication and control unit (120) can control the transmission power by controlling the operating point. The controlled operating point can correspond to a combination of frequency (or phase), duty cycle, and voltage amplitude. The communication and control unit (120) can control the transmission power by adjusting any one of the frequency (or phase), duty cycle, and voltage amplitude. In addition, the wireless power transmitter (100) can provide a constant level of power, and the wireless power receiver (200) can control the level of received power by controlling the resonant frequency.

[0170] The mobile device (450) includes a wireless power receiver (200) that receives wireless power through a secondary coil and a load (455) that receives and stores the power received by the wireless power receiver (200) and supplies the received power to the device.

[0171] The wireless power receiver (200) may include a power pickup unit (210) and a communication and control unit (220). The power pickup unit (210) can receive wireless power through a secondary coil and convert the received wireless power into electrical energy. The power pickup unit (210) can correct the alternating current (AC) signal received through the secondary coil and convert the corrected signal into a direct current (DC) signal. The communication and control unit (220) can control the transmission and reception of wireless power (power transmission and reception).

[0172] The secondary coil can receive wireless power transmitted from the wireless power transmitter (100). The secondary coil can receive power by using the magnetic field generated in the primary coil. Here, magnetic resonance can occur between the primary and secondary coils at a specific frequency corresponding to the resonant frequency, thus allowing power to be transmitted more efficiently.

[0173] although Figure 4 Not shown, but the communication and control unit (220) may further include a communication antenna. In addition to magnetic field communication, the communication antenna can transmit and / or receive communication signals using a communication carrier. For example, the communication antenna can transmit and / or receive communication signals corresponding to Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, NFC, etc.

[0174] The communication and control unit (220) can send and / or receive information to and from the wireless power transmitter (100). The communication and control unit (220) may include at least one of an IB communication module and an OOB communication module.

[0175] The IB communication module can transmit and / or receive information using magnetic waves (which use a specific frequency as their center frequency). For example, the communication and control unit (220) can perform IB communication by loading information into the magnetic waves and transmitting the information via a secondary coil or by receiving the information-carrying magnetic waves via a secondary coil. In this case, the communication and control unit (120) can load information into the magnetic waves or can interpret the information carried by the magnetic waves by using a modulation scheme (e.g., binary phase shift keying (BPSK) or amplitude shift keying (ASK)) or encoding scheme (e.g., Manchester encoding or non-return-to-zero level (NZR-L) encoding). By using the above-described IB communication, the communication and control unit (220) can transmit and / or receive information over distances of up to several meters at a data transmission rate of several kbps.

[0176] The OOB communication module can also perform out-of-band communication via a communication antenna. For example, a communication and control unit (220) can be provided to the near-field communication module.

[0177] Examples of near-field communication modules can include communication modules such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, NFC, etc.

[0178] The communication and control unit (220) can control the overall operation of the wireless power receiver (200). The communication and control unit (220) can perform various information calculations and processing, and can also control each configuration element of the wireless power receiver (200).

[0179] The communication and control unit (220) can be implemented in a computer or a similar device such as hardware, software, or a combination thereof. When implemented in hardware form, the communication and control unit (220) can be provided as an electronic circuit that performs control functions by processing electrical signals. And, when implemented in software form, the communication and control unit (220) can be provided as a program that operates the communication and control unit (220).

[0180] The load (455) may correspond to a battery. The battery can store energy by using the power output from the power pickup unit (210). Furthermore, it is not mandatory for the battery to be included in the mobile device (450). For example, the battery may be provided as a removable external feature. As another example, the wireless power receiver may include operating means that can perform various functions of the electronic device in place of the battery.

[0181] As shown in the figure, although the mobile device (450) is shown as being included in the wireless power receiver (200) and the base station (400) is shown as being included in the wireless power transmitter (100), in a broader sense, the wireless power receiver (200) can be identified (or regarded as) the mobile device (450) and the wireless power transmitter (100) can be identified (or regarded as) the base station (400).

[0182] In the following text, a coil or coil unit includes a coil and at least one device that is close to the coil, and the coil or coil unit may also be referred to as a coil assembly, coil unit, or unit.

[0183] Figure 5 It is a state transition diagram used to describe the wireless power transmission process.

[0184] refer to Figure 5 According to an exemplary embodiment of the present invention, the power transmission (or transmission) from a wireless power transmitter to a wireless power receiver can be broadly divided 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 transmission phase (560), and a renegotiation phase (570).

[0185] If a specific error or event is detected when power transmission is initiated or while power transmission is maintained, the selection phase (510) may include transition phases (or steps) S502, S504, S508, S510, and S512. The specific error or event will be specified in detail in the description below. Additionally, during the selection phase (510), the wireless power transmitter may monitor the interface surface for the presence of an object. If the wireless power transmitter detects that an object is placed on the interface surface, the processing steps may transition to the ping phase (520). During the selection phase (510), the wireless power transmitter may transmit an analog ping with a very short pulse and may detect the presence of an object in the effective area of ​​the interface surface based on current changes in the transmitting coil or primary coil.

[0186] In the case where an object is sensed (or detected) during the selection phase (510), the wireless power transmitter can measure the quality factor of the wireless power resonant circuit (e.g., the power transmitting coil and / or resonant capacitor). According to an exemplary embodiment of the invention, during the selection phase (510), the wireless power transmitter can measure the quality factor to determine whether a foreign object is present in the charging area along with the wireless power receiver. In the coil provided in the wireless power transmitter, the inductance and / or component of the series resistance decreases due to environmental changes, and due to this decrease, the quality factor value also decreases. To determine the presence or absence of a foreign object using the measured quality factor value, the wireless power transmitter can receive a reference quality factor value from the wireless power receiver, which is measured in advance in a state where the foreign object is not placed in the charging area. The wireless power transmitter can determine the presence or absence of a foreign object by comparing the measured quality factor value with the reference quality factor value received during the negotiation phase (540). However, the wireless power receiver may have a low reference quality factor value, for example, depending on its type, purpose, characteristics, etc. In the presence of foreign matter, the difference between the reference quality factor and the measured quality factor is small (or insignificant), making it difficult to easily determine the presence of foreign matter. Therefore, in such cases, other decision factors should be considered, or alternative methods should be used to determine the presence or absence of foreign matter.

[0187] According to another exemplary embodiment of the invention, when an object is sensed (or detected) during the selection phase (510), in order to determine whether a foreign object is present in the charging area along with the wireless power receiver, the wireless power transmitter can measure the quality factor value in a specific frequency region (e.g., the operating frequency region). In the coil provided in the wireless power transmitter, the inductance and / or component of the series resistance decreases due to environmental changes, and due to this decrease, the resonant frequency of the wireless power transmitter's coil changes (or shifts). More specifically, the peak quality factor frequency corresponding to the frequency at which the maximum quality factor value is measured in the operating frequency band can be shifted (or shifted).

[0188] During the ping phase (520), if the wireless power transmitter detects the presence of an object, the transmitter activates (or wakes up) the receiver and sends a digital ping to identify whether the detected object corresponds to the wireless power receiver. During the ping phase (520), if the wireless power transmitter fails to receive a response signal (e.g., a signal strength packet) to the digital ping from the receiver, the process may return to the selection phase (510). Alternatively, during the ping phase (520), if the wireless power transmitter receives a signal from the receiver indicating that power transmission is complete (e.g., a charging complete packet), the process may return to the selection phase (510).

[0189] If the ping phase (520) is completed, the wireless power transmitter can move to the identification and configuration phase (530) for identifying the receiver and collecting configuration and status information.

[0190] During the identification and configuration phase (530), if the wireless power transmitter receives an unwanted packet (i.e., an unexpected packet), or if the wireless power transmitter fails to receive a packet within a predetermined time period (i.e., a timeout), or if a packet transmission error occurs (i.e., a transmission error), or if the transmission does not have a configured power contract (i.e., no power transmission contract), the wireless power transmitter may proceed to the selection phase (510).

[0191] The wireless power transmitter can determine (or verify) whether it needs to enter the negotiation phase (540) based on the negotiation field value of the configuration packet received during the identification and configuration phase (530). Based on the verification result, if negotiation is required, the wireless power transmitter enters the negotiation phase (540) and can subsequently perform a predetermined FOD detection procedure. Conversely, if negotiation is not required, the wireless power transmitter can immediately enter the power transmission phase (560).

[0192] During the negotiation phase (540), the wireless power transmitter may receive a Foreign Object Detection (FOD) status packet that includes a reference quality factor value. Alternatively, the wireless power transmitter may receive a FOD status packet that includes a reference peak frequency value. Or, the wireless power transmitter may receive a status packet that includes both a reference quality factor value and a reference peak frequency value. In this case, the wireless power transmitter may determine a quality factor threshold for FO detection based on the reference quality factor value. The wireless power transmitter may determine a peak frequency threshold for FO detection based on the reference peak frequency value.

[0193] A wireless power transmitter can detect the presence or absence of an out-of-charge (FO) in the charging area using a determined quality factor threshold for FO detection and a currently measured quality factor value (i.e., the quality factor value measured before the ping phase). The wireless power transmitter can then control the transmission power based on the FO detection result. For example, power transmission can be stopped upon detecting an FO. However, the invention is not limited to this.

[0194] A wireless power transmitter can detect the presence or absence of an FO (Focus Occurrence) in the charging area by using a determined peak frequency threshold for FO detection and the currently measured peak frequency value (i.e., the peak frequency value measured before the ping phase). The wireless power transmitter can then control the transmission power based on the FO detection result. For example, power transmission can be stopped upon detecting an FO. However, the invention is not limited to this.

[0195] If an FO is detected, the wireless power transmitter can return to the selection phase (510). Conversely, if no FO is detected, the wireless power transmitter can proceed to the calibration phase (550) and then enter the power transmission phase (560). More specifically, if no FO is detected, the wireless power transmitter can determine the strength of the received power received by the receiver during the calibration phase (550) and can measure the power loss in both the receiver and transmitter to determine the strength of the power transmitted from the transmitter. In other words, during the calibration phase (550), the wireless power transmitter can estimate the power loss based on the difference between the transmitted power at the transmitter and the received power at the receiver. The wireless power transmitter according to an exemplary embodiment of the present invention can calibrate a threshold for FOD detection by applying the estimated power loss.

[0196] During the power transmission phase (560), the wireless power transmitter may transition to the selection phase (510) if the wireless power transmitter receives an unwanted packet (i.e., an undesirable packet), or fails to receive a packet during a predetermined time period (i.e., timeout), or violates the predetermined power transmission contract (i.e., breach of the power transmission contract), or if charging is completed.

[0197] Additionally, during the power transmission phase (560), if the wireless power transmitter needs to reconfigure the power transmission contract based on changes in its state, the wireless power transmitter can transition to the renegotiation phase (570). If the renegotiation is successful, the wireless power transmitter can then return to the power transmission phase (560).

[0198] The aforementioned power transmission contract can be configured based on the status and characteristic information of the wireless power transmitter and receiver. For example, the wireless power transmitter status information may include information about the maximum amount of power that can be transmitted, information about the maximum number of receivers that can be accommodated, etc. Additionally, the receiver status information may include information about the required power, etc.

[0199] Figure 6 A power control method according to an exemplary embodiment of the present invention is shown.

[0200] like Figure 6 As shown, during the power transmission phase (560), the wireless power transmitter (100) and the wireless power receiver (200) can control the amount (or magnitude) of the transmitted power by alternating between power transmission and / or reception and communication. The wireless power transmitter and the wireless power receiver operate at a specific control point. This control point indicates the combination of voltage and current supplied from the output of the wireless power receiver during power transmission.

[0201] More specifically, the wireless power receiver selects the desired control point, the desired output current / voltage, the temperature at a specific location of the mobile device, and additionally determines the actual control point at which the receiver is currently operating. The wireless power receiver calculates control error values ​​using the desired and actual control points, and then sends the calculated control error values ​​as control error packets to the wireless power transmitter.

[0202] Additionally, the wireless power transmitter can use received control error packets to configure / control new operating points—amplitude, frequency, and duty cycle—to control power transmission. These control error packets can then be sent / received at constant time intervals during the power transmission phase. According to an exemplary embodiment, when the wireless power receiver attempts to reduce the current of the wireless power transmitter, it can send control error packets by setting the control error value to a negative number. Conversely, when the wireless power receiver wants to increase the current of the wireless power transmitter, it sends control error packets by setting the control error value to a positive number. During induction mode, the wireless power receiver can control power transmission by sending control error packets to the wireless power transmitter as described above.

[0203] In the resonant mode, which will be described in detail below, the device can be operated using a method different from that in the inductive mode. In the resonant mode, a wireless power transmitter should be able to serve multiple wireless power receivers simultaneously. However, if power transmission is controlled only as in the inductive mode, it may be difficult to control the power transmission of other wireless power receivers since the transmitted power is controlled through communication established with one wireless power receiver. Therefore, in the resonant mode according to the invention, the amount of received power is controlled by having the wireless power transmitter normally transmit (or send) the basic power and having the wireless power receiver control its own resonant frequency. However, even during operation in the resonant mode, the above-mentioned limitations are not completely excluded. Figure 6 The method described in [the document]. Furthermore, additional control of the transmit power can be achieved by using [the method described in the document]. Figure 6 The method is used to execute.

[0204] Figure 7 This is a block diagram of a wireless power transmitter according to another exemplary embodiment of the present invention. This can belong to a wireless power transmission system operating in magnetic resonance mode or shared mode. Shared mode can refer to a mode in which many-to-one (or one-to-many) communication and charging are performed between the wireless power transmitter and the wireless power receiver. Shared mode can be implemented using magnetic induction or resonance methods.

[0205] refer to Figure 7 The wireless power transmitter (700) may include at least one of the following: a cover (720) covering the coil assembly, a power adapter (730) supplying power to the power transmitter (740), the power transmitter (740) transmitting wireless power, and a user interface (750) providing information related to power transmission processing and other relevant information. More specifically, the user interface (750) may optionally be included or may be included as another user interface (750) of the wireless power transmitter (700).

[0206] The power transmitter (740) may include at least one of a coil assembly (760), an impedance matching circuit (770), an inverter (780), a communication unit (790), and a control unit (710).

[0207] The coil assembly (760) includes at least one primary coil that generates a magnetic field. Furthermore, the coil assembly (760) may also be referred to as a coil unit.

[0208] Impedance matching circuit (770) provides impedance matching between the inverter and one or more primary coils. Impedance matching circuit (770) can generate resonance from an appropriate frequency that increases the current in one or more primary coils. In a multi-coil power transmitter (740), impedance matching circuit may additionally include a multiplexer that routes signals from the inverter to a subset of the primary coils. Impedance matching circuit may also be referred to as an oscillation circuit.

[0209] Impedance matching circuit (770) may include a capacitor, an inductor, and a switching device that switches the connection between the capacitor and the inductor. Impedance matching can be performed by detecting a reflected wave of wireless power transmitted (or sent) through the coil assembly (760) and switching the switching device based on the detected reflected wave, thereby adjusting the connection state of the capacitor or inductor, or adjusting the capacitance of the capacitor or the inductance of the inductor. In some cases, impedance matching can be achieved even without the impedance matching circuit (770). This specification also includes exemplary embodiments of a wireless power transmitter (700) in which the impedance matching circuit (770) is omitted.

[0210] The inverter (780) converts a DC input to an AC signal. The inverter (780) can operate as a half-bridge inverter or a full-bridge inverter to generate adjustable frequency duty cycles and pulse waves. Additionally, the inverter can include multiple stages to regulate the input voltage level.

[0211] The communication unit (790) can perform communication with the power receiver. The power receiver performs load modulation to transmit information and requests corresponding to the power transmitter. Therefore, the power transmitter (740) can use the communication unit (790) to monitor the amplitude and / or phase of the current and / or voltage of the primary coil, thereby demodulating the data transmitted from the power receiver.

[0212] In addition, the power transmitter (740) can control the output power by using a frequency shift keying (FSK) method, so that data can be transmitted through the communication unit (790).

[0213] The control unit (710) can control the communication and power transmission (or delivery) of the power transmitter (740). The control unit (710) can control the power transmission by adjusting the aforementioned operating point. The operating point can be determined by, for example, at least one of the following: operating frequency, duty cycle, and input voltage.

[0214] The communication unit (790) and the control unit (710) may be provided as separate units / devices / chipsets, or they may be provided as a single unit / device / chipset.

[0215] Figure 8 A wireless power receiver according to another exemplary embodiment of the present invention is shown. This may belong to a wireless power transmission system operating in magnetic resonance mode or shared mode.

[0216] refer to Figure 8 The wireless power receiver (800) may include at least one of a user interface (820) that provides information related to power transmission processing and other relevant information, a power receiver (830) that receives wireless power, a load circuit (840), and a base (850) that supports and covers the coil assembly. More specifically, the user interface (820) may be optionally included, or may be included as another user interface (820) of the wireless power receiver (800).

[0217] The power receiver (830) may include at least one of a power converter (860), an impedance matching circuit (870), a coil assembly (880), a communication unit (890), and a control unit (810).

[0218] The power converter (860) can convert AC power received from the secondary coil into voltage and current suitable for the load circuit. According to an exemplary embodiment, the power converter (860) may include a rectifier. The rectifier can rectify the received wireless power and convert the power from alternating current (AC) to direct current (DC). The rectifier can convert AC to DC using diodes or transistors, and then the rectifier can smooth the converted current using capacitors and resistors. Here, a full-wave rectifier, a half-wave rectifier, a voltage doubler, etc., implemented as a bridge circuit can be used as the rectifier. Additionally, the power converter can be adapted to the reflective impedance of the power receiver.

[0219] Impedance matching circuit (870) can provide impedance matching between the secondary coil and the combination of power converter (860) and load circuit (840). According to an exemplary embodiment, the impedance matching circuit can generate a resonance of approximately 100 kHz, which can enhance power transmission. Impedance matching circuit (870) can include capacitors, inductors, and switching devices that switch combinations of capacitors and inductors. Impedance matching can be performed by controlling the switching devices constituting the circuit of impedance matching circuit (870) based on voltage, current, power, frequency, etc., values ​​of the received wireless power. In some cases, impedance matching can be achieved even without impedance matching circuit (870). This specification also includes an exemplary embodiment of a wireless power receiver (200) in which impedance matching circuit (870) is omitted.

[0220] The coil assembly (880) includes at least one secondary coil, and optionally, the coil assembly (880) may also include elements that shield the metal parts of the receiver from the influence of the magnetic field.

[0221] The communication unit (890) can perform load modulation to transmit requests and other information to the power transmitter.

[0222] For this purpose, the power receiver (830) can perform switching of resistors or capacitors to change the reflected impedance.

[0223] The control unit (810) can control the received power. To this end, 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, by executing a request to adjust the reflection impedance of the power transmitter and / or adjust the operating point of the power transmitter, the difference between the actual operating point and the desired operating point can be adjusted / reduced. Optimal power reception can be achieved by minimizing this difference.

[0224] The communication unit (890) and the control unit (810) can be provided as different devices / chip sets, or as a unified device / chip set.

[0225] Figure 9 A communication frame structure according to an exemplary embodiment of the present invention is shown. This may correspond to the communication frame structure in a shared mode.

[0226] refer to Figure 9In shared mode, different frame formats can be used together. For example, in shared mode, a slotted frame with multiple time slots as shown in (A) and a free-format frame without a specified format as shown in (B) can be used. More specifically, the slotted frame corresponds to a frame used to transmit short data packets from the wireless power receiver (200) to the wireless power transmitter (100). And, since the free-format frame does not consist of multiple time slots, it can correspond to a frame capable of transmitting long data packets.

[0227] Furthermore, those skilled in the art may use various other terms to refer to time-slot frames and free-format frames. For example, a time-slot frame may be alternatively referred to as a channel frame, and a free-format frame may be alternatively referred to as a message frame.

[0228] More specifically, a time-slotted frame may include a synchronization mode indicating the start point (or beginning) of a time slot, a measurement time slot, nine time slots, and an additional synchronization mode having the same time interval before each of the nine time slots.

[0229] Here, the additional synchronization mode corresponds to a synchronization mode different from the synchronization mode that indicates the start point of the frame. More specifically, the additional synchronization mode does not indicate the start point of the frame, but can indicate information about adjacent (or nearby) time slots (i.e., two consecutive time slots located on either side of the synchronization mode).

[0230] In the nine time slots, each synchronization mode can be located between two consecutive time slots. In this case, the synchronization mode can provide information about the two consecutive time slots.

[0231] Furthermore, the nine time slots and the synchronization patterns set before each of these nine time slots can have the same time interval. For example, the nine time slots can have a time interval of 50ms. And the nine synchronization patterns can have a duration of 50ms.

[0232] Furthermore, apart from the synchronization mode indicating the start point of the frame and the measurement time slot, the free-format frame shown in (B) may not have a specific format. More specifically, the free-format frame is configured to perform functions different from those of a time-slotted frame. For example, a free-format frame can be used to perform communication of long data packets (e.g., packets with attached owner information) between a wireless power transmitter and a wireless power receiver, or, in the case of a wireless power transmitter configured with multiple coils, to perform the function of selecting any one of the coils.

[0233] The synchronization modes included in each frame will now be described in more detail with reference to the accompanying drawings.

[0234] Figure 10 This is the structure of a synchronization mode according to an exemplary embodiment of the present invention.

[0235] refer to Figure 10 The synchronization mode can be configured with a preamble, start bit, response field, type field, information field, and parity bit. Figure 10 In this context, the start bit is shown as ZERO (zero).

[0236] More specifically, the preamble consists of consecutive bits, all of which can be set to 0. In other words, the preamble can correspond to bits used to match the duration of the synchronization pattern.

[0237] The number of bits constituting the preamble can depend on the operating frequency, allowing the synchronization mode length to be as close to 50 ms as possible but not exceeding 50 ms. For example, in the case of an operating frequency of 100 kHz, the synchronization mode can be configured with two preamble bits, and in the case of an operating frequency of 105 kHz, the synchronization mode can be configured with three preamble bits.

[0238] The start bit can correspond to the bits following the preamble, and the start bit can indicate ZERO. ZERO can correspond to a bit indicating the type of synchronization mode. Here, the type of synchronization mode can include frame synchronization and slot synchronization, where frame synchronization includes frame-related information, and slot synchronization includes slot information. More specifically, the synchronization mode can be located between consecutive frames and can correspond to frame synchronization indicating the start of a frame, or the synchronization mode can be located between consecutive slots among the multiple slots constituting the frame and can correspond to a synchronization slot including information related to the consecutive slots.

[0239] For example, when ZERO equals 0, this indicates that the corresponding time slot is time slot synchronization between time slots. And when ZERO equals 1, this indicates that the corresponding synchronization mode is frame synchronization between frames.

[0240] The parity bit corresponds to the last bit of the synchronization pattern, and it can indicate information related to the number of bits in the data fields (i.e., response field, type field, and information field) included in the synchronization pattern. For example, if the number of bits in the data fields constituting the synchronization pattern is even, the parity bit can be set to 1; otherwise (i.e., if the number of bits is odd), the parity bit can be set to 0.

[0241] The response field can include information from the wireless power transmitter regarding its communication with the wireless power receiver in a time slot prior to synchronization mode. For example, if no communication is detected between the wireless power transmitter and the wireless power receiver, the response field can have a value of '00'. Alternatively, if a communication error is detected in the communication between the wireless power transmitter and the wireless power receiver, the response field can have a value of '01'. A communication error corresponds to a situation where two or more wireless power receivers attempt to access a time slot, resulting in a collision between the two or more wireless power receivers.

[0242] Additionally, the response field may include information indicating whether the data packet has been accurately received from the wireless power receiver. More specifically, if the wireless power transmitter rejects the data packet, the response field may have a value of '10' (10 - NACK). And if the wireless power transmitter acknowledges the data packet, the response field may have a value of '11' (11 - ACK).

[0243] The type field can indicate the type of synchronization mode. More specifically, when the synchronization mode corresponds to the first synchronization mode of the frame (i.e., as the first synchronization mode, in the case where the synchronization mode is located before the measurement time slot), the type field can have a value '1' indicating frame synchronization.

[0244] Additionally, in time-slotted frames, if the synchronization mode does not correspond to the first synchronization mode of the frame, the type field may have a value '0' indicating time-slot synchronization.

[0245] Additionally, the meaning of the information field's value can be determined based on the synchronization mode type indicated in the type field. For example, when the type field is equal to 1 (i.e., the synchronization mode type indicates frame synchronization), the information field's meaning can indicate the frame type. More specifically, the information field can indicate whether the current frame corresponds to a time-slotted frame or a free-form frame. For example, if the information field is assigned the value '00', this indicates that the current frame corresponds to a time-slotted frame. Conversely, if the information field is assigned the value '01', this indicates that the current frame corresponds to a free-form frame.

[0246] Conversely, when the type field is equal to 0 (i.e., the synchronization mode type indicates time slot synchronization), the information field can indicate the state of the next time slot following the synchronization mode. More specifically, if the next time slot corresponds to a time slot allocated (or assigned) to a specific wireless power receiver, the information field is assigned the value '00'. If the next time slot corresponds to a locked time slot that will be temporarily used by a specific wireless power receiver, the information field is assigned the value '01'. Alternatively, if the next time slot corresponds to a time slot that can be freely used by a random wireless power receiver, the information field is assigned the value '10'.

[0247] Figure 11 The operation of a wireless power transmitter and a wireless power receiver in shared mode according to an exemplary embodiment of the present invention is shown.

[0248] refer to Figure 11 The wireless power receiver operating in shared mode can operate in any of the following phases: selection phase (1100), introduction phase (1110), configuration phase (1120), negotiation phase (1130), and power transfer phase (1140).

[0249] First, a wireless power transmitter according to an exemplary embodiment of the present invention can transmit a wireless power signal to detect a wireless power receiver. More specifically, the process of detecting a wireless power receiver using a wireless power signal can be referred to as simulating a ping.

[0250] Furthermore, the wireless power receiver that receives the wireless power signal can enter the selection phase (1100). As described above, the wireless power receiver that enters the selection phase (1100) can detect whether the FSK signal is present in the wireless power signal.

[0251] In other words, a wireless power receiver can perform communication by using either exclusive mode or shared mode, depending on the presence or absence of an FSK signal.

[0252] More specifically, when the FSK signal is included in the wireless power signal, the wireless power receiver can operate in shared mode; otherwise, the wireless power receiver can operate in exclusive mode.

[0253] When the wireless power receiver operates in shared mode, it can enter the introduction phase (1110). During the introduction phase (1110), the wireless power receiver can send control information (CI) packets to the wireless power transmitter, as is done during the configuration phase, negotiation phase, and power transmission phase. The control information packets may have a header and information about control. For example, the header in the control information packet may correspond to 0x53.

[0254] In the introduction phase (1110), the wireless power receiver performs an attempt to request a free slot for transmitting control information (CI) packets during the subsequent configuration, negotiation, and power transmission phases. At this point, the wireless power receiver selects a free slot and transmits an initial CI packet. If the wireless power transmitter sends an ACK in response to the corresponding CI packet, the wireless power transmitter enters the configuration phase. If the wireless power transmitter sends a NACK in response to the corresponding CI packet, this indicates that another wireless power receiver is performing communication through the configuration and negotiation phases. In this case, the wireless power receiver re-attempts to perform the request for a free slot.

[0255] If the wireless power receiver receives an ACK as a response to a CI packet, it can determine the position of the dedicated time slot within the frame by counting the remaining synchronization time slots until synchronization with the initial frame. In all subsequent time-slot-based frames, the wireless power receiver transmits CI packets through the corresponding time slot.

[0256] If the wireless power transmitter authorizes the wireless power receiver to enter the configuration phase, the wireless power transmitter provides a series of locked time slots specifically for the wireless power receiver. This ensures that the wireless power receiver can proceed to the configuration phase without any conflicts.

[0257] The wireless power receiver transmits a sequence of data packets, such as two identification data packets (IDHI and IDLO), using locked time slots. When this phase is complete, the wireless power receiver enters the negotiation phase. During the negotiation state, the wireless power transmitter continues to provide locked time slots dedicated to the wireless power receiver. This ensures that the wireless power receiver can proceed to the negotiation phase without any collisions.

[0258] The wireless power receiver transmits one or more negotiated data packets using appropriate locking time slots, and these negotiated data packets(s) may be mixed with dedicated data packets. Finally, the response sequence ends (or completes) along with a Specific Request (SRQ) packet. When the response sequence is complete, the wireless power receiver enters the power transmission phase, and the wireless power transmitter ceases providing locking time slots.

[0259] During the power transmission phase, the wireless power receiver performs CI packet transmission using allocated time slots and then receives power. The wireless power receiver may include regulator circuitry. This regulator circuitry can be included in the communication / control unit. The wireless power receiver can adjust its reflected impedance via the regulator circuitry. In other words, the wireless power receiver can adjust the reflected impedance according to the amount of power requested by the external load. This prevents over-reception and overheating.

[0260] In shared mode, (depending on the operating mode) since the wireless power transmitter may not perform power regulation in response to received CI packets, control may be required to prevent overvoltage conditions.

[0261] The following describes the certification between wireless power transmitters and receivers. Wireless power transmitters and receivers are compatible and power transmission can function normally when implemented using the same predefined power transmission and communication interfaces. Even if the wireless power transmitters and receivers are not manufactured by the same company, they can still be compatible if they are produced according to the same technical standards or specifications. However, even when wireless power transmitters and receivers follow the same technical standards, each manufacturer has different implementation quality, and wireless charging may not function smoothly when manufacturers do not faithfully and accurately adhere to the standards. Specifically, products with problems in foreign object detection (FOD) and overheat protection functions pose a risk of safety incidents such as explosions. Therefore, standardization organizations operating technical standards provide services through authorized certification bodies to test whether each manufacturer's wireless power transmitters or receivers accurately comply with standard technologies and whether device interoperability is maintained, as well as genuine product certification services.

[0262] However, since it is practically difficult to fundamentally prevent unauthorized products from circulating in the market, it is necessary to ensure stability and reliability in the pre- and post-wireless charging process by performing mutual certification related to whether the wireless power transmitting and receiving devices already circulating in the market are genuine products. That is, when an authorized certification organization grants genuine product certification before product release—a pre-certification process—the certification process between products performed during wireless charging operations after product release can be called a post-certification process. For example, mutual certification between products can be performed via in-band communication channels and can be compatible with USB-C certification. When certification fails, the wireless power receiving device can warn the user to perform charging in low-power mode or cancel the power signal.

[0263] This specification illustrates the Qi standard of WPC as a standard technology, but the scope of the invention includes implementations of certification based on other standards and the Qi standard.

[0264] When USB-C certification is introduced into wireless power transfer systems using in-band communication, the following table provides a capability index. That is, USB-C can be a model for wireless charging certification.

[0265] [Table 3]

[0266] Authentication type PRx certification for PTx PTx Certification for PRx Fully Authenticated 176,607.5 milliseconds (~2.9 minutes) 26,922.5 milliseconds (~27 seconds) Fast Authentication 18,564.5 milliseconds (~18 seconds) 5,842.5 milliseconds (~6 seconds)

[0267] In Table 3, PRx represents a wireless power receiving device, and PTx represents a wireless power transmitting device. Certification includes authentication of the wireless power receiving device by the wireless power transmitting device, and authentication of the wireless power transmitting device by the wireless power receiving device.

[0268] Authenticating a wireless power transmitter using full authentication can take up to approximately 3 minutes due to the low bit-rate communication protocol used in wireless power transmission systems and the large size of USB-C certificates. This is particularly inconvenient for users in public places where they frequently change wireless charging points, requiring full authentication each time. Therefore, it is necessary to define the size of the packets or chains associated with authentication in a compact or simplified manner. Preferably, a 128-bit security level (ECDSA with SHA256) is maintained in USB-C authentication while keeping the full authentication time within a reasonable period (under 60 seconds). The authentication time can be increased by duplicate data transmissions due to traffic errors.

[0269] The following describes specific implementations of certificates, authentication processes, authentication messages, and lower-level communication protocols for performing authentication processes using standard technologies. All communications, protocols, messages, and packets related to all authentication described below can be generated, manipulated, stored, transmitted, and processed by the communication and control units 220 and 120 and the communication units 790 and 890 described in this specification.

[0270] 1. Wireless charging certificate

[0271] In terms of certificate chain levels, the number of certificate chains can be limited. For example, a certificate chain can have up to three levels. Even with the minimum chain level, manufacturers can issue certificates for their products and reduce the burden on Certificate Authorities (CAs) and manufacturers. A certificate chain is a series of two or more certificates signed by previous certificates in the chain.

[0272] Regarding certificate types, two types of certificates can be defined for transmission between the wireless power transmitting and receiving devices. These two types of certificates can include intermediate certificates and leaf certificates. The root certificate is identical for both certificates supporting mutual authentication. The root certificate is the first certificate in the certificate chain and is self-signed. The leaf certificate is the last certificate in the certificate chain; intermediate certificates are neither root certificates nor leaf certificates in the certificate chain.

[0273] Regarding certificate format, the certificate format can be defined as a reduced or simplified format. Here, "reduced" or "simplified" format can refer to a format for wireless charging that is scaled down or simplified compared to the USB-C certificate format (X.509v3 format). For example, a simplified certificate format for intermediate and leaf certificates can be less than 100 bytes (e.g., 80 bytes). In this case, the root certificate can still follow the USB-C certificate format. Below, the simplified certificate format can be referred to as the wireless charging certificate format or the Qi certificate format. Since wireless power transfer systems that support out-of-band (OOB) communication (such as in PC1) can use a wider bandwidth, wireless charging certificates based on the USB-C format can be provided.

[0274] Figure 12 This is a block diagram illustrating a wireless charging certificate format according to an embodiment.

[0275] refer to Figure 12 The wireless charging certificate format includes certificate type, certificate length, identification information (ID), reserved bits, public key, and signature.

[0276] The certificate type is configured using, for example, a 1-byte parameter, which can indicate that the corresponding certificate is any one of a root certificate, intermediate certificate, or leaf certificate, and that the certificate is for either a wireless power transmitting device or a wireless power receiving device, representing both types of information. For example, when the certificate type bit string b0 to b3 is '0000', it indicates that the certificate is an intermediate certificate; when the bit string b0 to b3 is '0001', it indicates that the certificate is a leaf certificate. When the certificate type bit string b7 to b4 is '0001', it indicates that the certificate is for a wireless power transmitting device; when the bit string b7 to b4 is '0000', it indicates that the certificate is for a wireless power receiving device. Therefore, when the certificate type bit string changes to a specific value, the corresponding certificate is for a wireless power transmitting device and can be a leaf certificate.

[0277] The certificate length is configured using, for example, 2 bytes, and can be indicated in bytes.

[0278] The ID is configured using, for example, 6 bytes and can indicate the manufacturer code of the wireless power transmitting device or the manufacturer code of the wireless power receiving device, or it can represent the wireless power ID (WPID).

[0279] Reserved bits can be configured using, for example, 7 bytes. The public key can be configured using, for example, 32 bytes. The signature can be configured using, for example, 32 bytes or 64 bytes.

[0280] When based on Figure 12When the wireless charging certificate format uses in-band communication to perform authentication, mutual full authentication can be completed within one minute, as shown in Table 4.

[0281] [Table 4]

[0282] Authentication type PRx certification for PTx PTx for PRx certification Fully Authenticated 34,830 milliseconds (~35 seconds) 8,002.5 milliseconds (~8 seconds) Fast Authentication 18,564.5 milliseconds (~18 seconds) 5,842.5 milliseconds (~6 seconds)

[0283] Figure 12 An exemplary case is shown where the certificate format is 80 bytes in size, but this is merely an example, and the implementation of different bit sizes for each field will be obvious to those skilled in the art and corresponds to the technical scope of the present invention.

[0284] Figure 13a This is a block diagram illustrating a wireless charging certificate format according to another embodiment.

[0285] refer to Figure 13a The wireless charging certificate format includes certificate type, PTx and leaf indicator (PTx and leaf), certificate length, identification information (ID), reserved bits, public key and signature.

[0286] exist Figure 13a In the wireless charging certificate format, PTx and leaf are separated from the certificate type so that they can be allocated to bits different from the certificate type within the same byte B0.

[0287] The certificate type is configured using, for example, 6 bits, which can indicate that the corresponding certificate is any of the root certificate / intermediate certificate / leaf certificate, the certificate of the wireless power transmitting device or the certificate of the wireless power receiving device, and all two types of information.

[0288] PTx and leaf indicate whether the corresponding certificate is a certificate of the wireless power transmitting device and is a leaf certificate. That is, PTx and leaf can indicate whether the corresponding certificate is a leaf certificate of the wireless power transmitting device.

[0289] PTx and leaf can be configured, for example, using 2 bits, and can be configured to include a 1-bit PTx indicator and a 1-bit leaf indicator. In this case, the PTx indicator indicates 1 when the corresponding certificate is a certificate for a wireless power transmitting device, and indicates 0 when the corresponding certificate is a certificate for a wireless power receiving device. Additionally, the leaf indicator is configured using 1 bit, and its value can be set to 1 when the corresponding certificate is a leaf certificate, and its value can be set to 0 when the corresponding certificate is not a leaf certificate. Figure 13a This indicates that the corresponding certificate is a PTx leaf certificate, because each bit is set to 1.

[0290] PTx and leaf are included in the same byte B0 as the certificate type, configured in the next bit string to the right of the certificate type, and assigned to bits different from the certificate type.

[0291] The certificate length is configured using, for example, 1 byte, and can indicate the length of the corresponding certificate in bytes.

[0292] The identification information is configured using, for example, 6 bytes and can indicate the manufacturer code of the wireless power transmitting device or the PRx manufacturer code (PRMC) of the wireless power receiving device, or it can represent the wireless power ID (WPID). Alternatively, when the certificate type is an intermediate certificate, the identification information can represent the manufacturer code of the wireless power transmitting device or the manufacturer code of the wireless power receiving device, and when the certificate type is a leaf certificate, the identification information can represent the WPID.

[0293] Reserved bits can be configured using, for example, 4 bytes. Public keys can be configured using, for example, 32 bytes. Signatures can be configured using, for example, 64 bytes.

[0294] When based on Figure 13a When the wireless charging certificate format uses in-band communication to perform authentication, mutual full authentication can be completed within 60 seconds, as shown in Table 5.

[0295] [Table 5]

[0296] Authentication type PRx certification for PTx PTx Certification for PRx Fully Authenticated 39,782.5 milliseconds (~40 seconds) 8,761.5 milliseconds (~9 seconds) Fast Authentication 18,564.5 milliseconds (~18 seconds) 5,842.5 milliseconds (~6 seconds)

[0297] Figure 13a An illustrative example is shown where the certificate format is 108 bytes in size, but this is merely an example. Each field is defined with a different number of bits. Such implementations will be obvious to those skilled in the art and fall within the technical scope of this invention.

[0298] As a business capability requirement, it is preferable that, during the authentication process, the initiator's authentication of the responder is completed within 60 seconds in an environment using in-band communication. Additionally, it is preferable that, during the authentication process, a mechanism be provided to securely identify previously authenticated responders within 20 seconds in an environment using in-band communication.

[0299] Figure 13b This is a block diagram illustrating a wireless charging certificate format according to another embodiment.

[0300] refer to Figure 13b The wireless charging certificate format includes the wireless charging standard certificate structure version (Qi certification certificate structure version), reserved bits (reserved), PTx and leaf indicator (PTx leaf), certificate type, signature offset, serial number, publisher ID, subject ID, public key and signature.

[0301] In the wireless charging certificate format, the PTx and leaf indicator are separated from the certificate type so that they are assigned to bits different from the certificate type in the same byte B0.

[0302] The PTx leaf indicates whether the corresponding certificate is a certificate of the wireless power transmitting device and is a leaf certificate. That is, the PTx leaf can indicate whether the corresponding certificate is a leaf certificate of the wireless power transmitting device.

[0303] Unlike Figure 13a The PTx leaf can be configured using 1 bit. If the PTx leaf is 0, it indicates that the corresponding certificate is not a leaf certificate or is a leaf certificate of a wireless power receiving device. If the PTx leaf is 1, it indicates that the corresponding certificate is a leaf certificate of a wireless power transmitting device.

[0304] Certificate types can be configured using, for example, 2 bits, which can indicate that the corresponding certificate is any one of the root certificate, intermediate certificate, or leaf certificate, or all of the root certificate, intermediate certificate, or leaf certificate.

[0305] 2. Instructions regarding authentication function support

[0306] If either the wireless power transmitter or the wireless power receiver does not support authentication (e.g., a legacy product may not support the new authentication feature), the authentication process between them may not be performed. That is, both the wireless power transmitter and the wireless power receiver need to support authentication to perform the authentication process. However, because authentication may or may not be supported by the product version and the manufacturer, the process for supporting authentication and the messages used in that process need to be determined. Additionally, when only one of the wireless power transmitter and receiver supports authentication and the other is a legacy product, backward compatibility for minimum charging capabilities should be satisfied. Devices that do not support authentication according to system policy should support 5W (or a minimum power of 3W).

[0307] A wireless power transmitting device can use capability packets to notify a wireless power receiving device whether it supports authentication functionality (authentication between the wireless power receiving device and the wireless power transmitting device (PRx to PTx authentication)). A wireless power receiving device can use configuration packets to notify a wireless power transmitting device whether it supports authentication functionality (authentication between the wireless power transmitting device and the wireless power receiving device (PTx to PRx authentication)). The structure of the indication information (capability packets and configuration packets) regarding whether authentication functionality is supported will be described in detail below.

[0308] Figure 14 A capability grouping structure for a wireless power transmitting device according to an embodiment is shown.

[0309] refer to Figure 14The capability packet with a header value of 0x31 is configured using 3 bytes. The first byte (B0) includes the power level and guaranteed power value, the second byte (B1) includes a reserved bit and a potential power value, and the third byte (B2) includes the reserved bit, Auth, NFCPP, NFCD, WPID, and Not Res Sens. Specifically, Auth is configured using 1 bit, and for example, a value of 0 indicates that the wireless power transmitter does not support authentication, while a value of 1 indicates that the wireless power transmitter supports authentication.

[0310] Figure 15 A capability grouping structure for a wireless power transmission device according to another embodiment is shown.

[0311] refer to Figure 15 The capability packet with a header value of 0x31 is configured using 3 bytes. Its first byte B0 includes the power level and guaranteed power value, the second byte B1 includes a reserved bit and a potential power value, and the third byte B2 includes the Authentication Indicator (AI), Authentication Responder (AR), reserved bit, WPID, and Not Res Sens. Specifically, the AI ​​is configured using 1 bit, and for example, when its value is '1b', it instructs the corresponding wireless power transmitter to operate as an authentication initiator. Similarly, the AR is configured using 1 bit, and for example, when its value is '1b', it instructs the corresponding wireless power transmitter to operate as an AR.

[0312] Figure 16 The configuration grouping structure of a wireless power receiving device according to an embodiment is shown.

[0313] refer to Figure 16 The configuration group with a header value of 0x51 is configured using 5 bytes. Its first byte B0 includes the power level and maximum power value; the second byte B1 indicates a reserved bit; the third byte B2 includes Prop, reserved bit, ZERO, and a count; the fourth byte B3 includes the window size and window offset; and the fifth byte B4 includes Neg, polarity, depth, Auth, and a reserved bit. Specifically, Auth is configured using 1 bit, and for example, when its value is 0, it indicates that the corresponding power receiving device does not support authentication, and when its value is 1, it indicates that the wireless power receiving device supports authentication.

[0314] Figure 17 A configuration grouping structure for a wireless power receiving device according to another embodiment is shown.

[0315] refer to Figure 17The configuration packet with a header value of 0x51 is configured using 5 bytes. Its first byte B0 includes the power level and maximum power value; the second byte B1 includes AI, AR, and a reserved bit; the third byte B2 includes Prop, a reserved bit, ZERO, and a count; the fourth byte B3 includes the window size and window offset; and the fifth byte B4 includes Neg, polarity, depth, Auth, and a reserved bit. Specifically, AI is configured using 1 bit, and for example, when its value is '1b', it instructs the corresponding power receiving device to operate as AI. Similarly, AR is configured using 1 bit, and for example, when its value is '1b', it instructs the wireless power receiving device to operate as AR.

[0316] 3. Timing between the wireless charging phase and the certification-related processes

[0317] The process of determining whether to support authentication functionality and the authentication process can be performed through at least one of the following stages: identification and configuration stage, negotiation stage, calibration stage, power transfer stage, renegotiation stage, and introduction stage.

[0318] For example, the authentication process can be performed during the negotiation phase. However, when performing fast authentication during the negotiation phase, the process of reading and determining the DIGEST (summary) using in-band communication takes approximately 4 seconds. Therefore, for user convenience, it is preferable to provide wireless charging at basic power before authentication, even regardless of the authentication process, rather than starting charging after authentication is complete. This is preferable in terms of backward compatibility with devices that do not have authentication capabilities.

[0319] As another example, the authentication process can be performed during the negotiation and power transfer phases. During the identification and configuration phase, packet sequences are strictly controlled, and only unidirectional communication from the wireless power receiving device to the wireless power transmitting device is allowed. However, bidirectional communication is permitted during the negotiation and power transfer phases. Therefore, the authentication process can be performed during the negotiation and power transfer phases, where bidirectional communication is allowed. During the negotiation phase, rapid authentication is performed by the wireless power transmitting or receiving device exchanging {GET_DIGESTS,CHALLENGE} messages. The power contract can be signed based on established trust. When the wireless power transmitting and receiving devices first meet by checking DIGESTS, in order to establish an initial power contract based on system policy and provide the wireless power receiving device with default low power as soon as possible, the wireless power transmitting and receiving devices enter the power transfer phase. During the power transfer phase, full authentication is performed by the wireless power transmitting or receiving device exchanging {GET_CERTIFICATE,CHALLENGE} messages. When full authentication is successfully completed, the wireless power transmitting and / or receiving device updates the power contract.

[0320] As another example, wireless power transmitting and receiving devices can enter the power transfer phase without authentication, and then perform the authentication process during the power transfer phase. If authentication is successful during the power transfer phase, the power contract can be updated through a renegotiation phase, or the wireless power transmitting device can support the target or full power level desired by the wireless power transmitting / receiving device. This increases user convenience.

[0321] As another example, in the case of a wireless power receiving device authenticating a wireless power transmitting device (PRx to PTx authentication), a process to determine whether the wireless power receiving device supports the authentication function of the wireless power transmitting device can be performed during the negotiation phase. In this case, power transmission may have already been performed based on an initial power contract before the negotiation phase. During the negotiation phase, by sending a query packet and determining the response to the query packet, the wireless power receiving device can determine whether it supports the authentication function of the wireless power transmitting device according to this process. On one hand, the query packet can be a general request packet (0x07), and in this case, when the wireless power receiving device sends a general request packet to the wireless power transmitting device, the wireless power transmitting device sends a packet including... Figure 14 or Figure 15 The auth capability packet serves as a response to the wireless power receiving device. On the other hand, the query packet can be a specific request packet (0x20), and in this case, when the wireless power receiving device sends a specific request packet to the wireless power transmitting device, the wireless power transmitting device responds with ACK (when authentication is supported) or NACK (when authentication is not supported). During the negotiation phase, when it is determined that the wireless power transmitting device supports authentication, the wireless power receiving device can establish a power contract (PC0) of 5W or more with the wireless power transmitting device.

[0322] When the wireless power receiving device determines that the wireless power transmitting device supports authentication, it can finally initiate the authentication process. More specifically, the wireless power receiving device can perform authentication with the wireless power transmitting device when it reaches a normal or stable operating point where it sends Control Error Packets (CEPs) at a period of approximately 250 ms. During the power transfer phase, the authentication process can be used to update the existing power contract. That is, to increase the power level according to the existing power contract based on the result of the authentication process, the wireless power receiving device can renegotiate the power contract. In this case, by sending a renegotiation packet (0x09), the wireless power receiving device can update the contract power according to the power management policy. For example, if the authentication process (using DIGEST) is successful, the wireless power receiving device can update the contract power with the increased power or can maintain the current power contract. If the authentication process fails, the wireless power receiving device can update the power contract with the reduced power or can eliminate the power signal.

[0323] As another example, in the case of a wireless power transmitter authenticating a wireless power receiver (PTx to PRx authentication), the process of determining whether the wireless power transmitter supports the authentication function of the wireless power receiver can be performed during the initialization phase. Here, the initialization phase can be a phase preceding the negotiation phase, such as any of the selection phase, ping phase, and identification and setup phase. During the initialization phase, in order to determine whether the wireless power receiver supports the authentication function, the wireless power transmitter receives data from the wireless power receiver including... Figure 16 or Figure 17 The auth configuration group.

[0324] When the wireless power transmitting device determines that the wireless power receiving device supports authentication, the authentication process can be initiated during the negotiation phase. In this case, an initial power contract is signed. More specifically, the wireless power transmitting device waits to receive a DIGESTS from the wireless power receiving device. The authentication process succeeds when the wireless power transmitting device confirms that the wireless power receiving device has been authenticated. If the wireless power transmitting device fails to confirm the DIGESTS, it continues the authentication process during the power transfer phase. Based on the power management policy, the wireless power transmitting device establishes a power contract with the wireless power receiving device. In this case, the wireless power transmitting device can establish a power contract of 5W or higher (PC0) with the wireless power receiving device that has been authenticated as a DIGESTS. During the power transfer phase, when the authentication process is complete, the wireless power transmitting device can renegotiate the power contract to increase the power level.

[0325] During the power transfer phase, after the wireless power receiving device reaches a normal or stable operating point where it transmits CEP (0x03) at a period of approximately 250ms, the wireless power transmitting device can perform an authentication process with the wireless power receiving device. During the power transfer phase, the authentication process can be used to update the existing power contract. That is, to increase the power level according to the existing power contract based on the result of the authentication process, the wireless power receiving device can renegotiate the power contract. In this case, by sending a negotiation packet (0x09), the wireless power receiving device can update the contract power according to the power management policy. For example, if the authentication process (using DIGEST) is successful, the wireless power receiving device can update the contract power with the increased power, or it can maintain the current power contract. However, if the authentication process fails, the wireless power receiving device can update the power contract with the decreased power, or it can eliminate the power signal.

[0326] 4. Authentication process and authentication messages

[0327] The following section describes the authentication process and the various messages used in the authentication process.

[0328] Messages used in the authentication process are called authentication messages. Authentication messages carry information related to authentication. There are two types of authentication messages: authentication requests and authentication responses. Authentication requests are sent by the authentication initiator, and authentication responses are sent by the authentication responder. Both the wireless power transmitting device and the receiving device can be the authentication initiator and the authentication responder, respectively. For example, when the wireless power transmitting device is the authentication initiator, the wireless power receiving device becomes the authentication responder, and vice versa.

[0329] The authentication request message includes GET_DIGESTS (i.e., 4 bytes), GET_CERTIFICATE (i.e., 8 bytes), and CHALLENGE (i.e., 36 bytes).

[0330] The authentication response message includes DIGEST (i.e., 4 + 32 bytes), CERTIFICATE (i.e., 4 + certificate chain (3 x 512 bytes) = 1540 bytes), CHALLENGE_AUTH (i.e., 168 bytes), and ERROR (i.e., 4 bytes).

[0331] Authentication messages can be referred to as authentication packets, and can also be called authentication data and authentication control information. Additionally, messages such as GET_DIGEST and DIGESTS can be referred to as GET_DIGEST packets and DIGEST packets, respectively.

[0332] The following describes the process by which the wireless power receiving device performs authentication of the wireless power transmitting device based on these authentication messages.

[0333] (1) Authentication of wireless power receiving device to wireless power transmitting device (PRx to PTx authentication)

[0334] When the authentication of the wireless power receiving device to the wireless power transmitting device (PRx to PTx authentication) is performed based on in-band communication, the time required for each step can be shown in Tables 6 and 7.

[0335] [Table 6]

[0336]

[0337] Table 6 shows an example of the time required for each authentication message when a power contract is made based on the result of GET_DIGESTS during the negotiation phase. When the wireless power receiving device already knows the DIGEST of the wireless power transmitting device, the send / receive steps of GET_CERTIFICATE and CERTIFICATE can be omitted. Additionally, the power contract can be updated based on the authentication result during the renegotiation phase.

[0338] [Table 7]

[0339]

[0340] 7 represents another example of the time required for each authentication message when a power contract is made based on the result of GET_DIGESTS during the negotiation phase. When the wireless power receiving device already knows the DIGEST of the wireless power transmitting device, the send / receive steps of GET_CERTIFICATE and CERTIFICATE can be omitted. Additionally, the power contract can be updated during the renegotiation phase based on the authentication result. The authentication process that meets the required time will be described below.

[0341] Figure 18 This is a flowchart illustrating the sequence of transmitted and received packets when the wireless power receiving device performs authentication of the wireless power transmitting device (PRx authentication of PTx) according to an embodiment.

[0342] refer to Figure 18To obtain or extract the certificate chain DIGESTS of the wireless power transmitting device, the wireless power receiving device sends GET_DIGESTS to the wireless power transmitting device (S1800). Here, it can be set to REQUEST = PTx'sDIGEST. The predetermined operation of step S1800 may include determining the operation supported by the authentication function in the capability packet received by the wireless power receiving device from the wireless power transmitting device. The wireless power receiving device may send GET_DIGESTS to the wireless power transmitting device using a general request packet during the negotiation phase or renegotiation phase. That is, GET_DIGESTS can be loaded and sent in a general request message.

[0343] Figure 19 An example of the GET_DIGESTS message structure is shown. (Reference) Figure 19 GET_DIGESTS is configured using, for example, a 1-byte parameter and includes a request field. The request field may include, for example, a header for DIGESTS from a wireless power transmitter.

[0344] Figure 20 Another example of the GET_DIGESTS message structure is shown. (Reference) Figure 20 GET_DIGESTS is configured using, for example, 1 byte and includes a reserved bit and a timeslot number. The timeslot number identifies the timeslot where the requested certificate chain is stored and can be configured using, for example, 3 bits.

[0345] Refer again Figure 18 The wireless power transmitting device sends a DIGESTS (S1805) response to the wireless power receiving device in response to GET_DIGESTS. DIGESTS is used when the authentication responder sends a report about the certificate chain digest and a time slot including the valid certificate chain digest. The parameter of DIGESTS can be a 32-byte hash value of the certificate chain.

[0346] Figure 21 The physical packet structure for sending DIGESTS and the method for sending this physical packet structure are shown. (Reference) Figure 21 A DIGESTS packet consists of a 32-byte DIGESTS payload, a 1-byte header indicating that the packet is a DIGESTS packet, and a 2-byte header indicating the length of the packet. The wireless power transmitting device divides this DIGESTS packet into multiple smaller packets of a specific length (e.g., 3 bytes) and adds a checksum to the end of each smaller packet to send the smaller packets in a sequence of 4-byte DIGESTS smaller packets. The last smaller packet in this sequence can be less than 4 bytes in size. These smaller packets can be referred to as segments. Figure 21The diagram limits the size of the packets transmitted by the wireless power transmitter, ensuring that a single authentication response is configured using a maximum of 4 bytes. This division of a single response message into a series of small packets allows (extended) Control Error Packets (CEPs) and (extended) Receive Power Packets (RPPs) to be periodically (approximately 250 ms) sent by the wireless power receiver to the wireless power transmitter, thereby enabling efficient management of the operating point and foreign object detection for power transmission by the wireless power transmitter.

[0347] Refer again Figure 18 Authentication is successful when it is confirmed that the wireless power transmitting device has been previously authenticated. If the wireless power receiving device does not acknowledge DIGESTS, the wireless power receiving device continues to perform authentication during the power transmission phase. Steps S1800 and S1805 can be performed during the negotiation or renegotiation phase. Alternatively, steps S1800 and S1805 can be performed during the power transmission phase.

[0348] Then, in order to obtain the certificate chain of the wireless power transmitting device, the wireless power receiving device sends GET_CERTIFICATE (S1810) to the wireless power transmitting device. Here, GET_CERTIFICATE can be set by offset and length. GET_CERTIFICATE is used to read segments of the target certificate chain.

[0349] Figure 22 An example of the GET_CERTIFICATE message structure is shown. (Reference) Figure 22 GET_CERTIFICATE is configured using, for example, 2 bytes and may include offset and length fields. Here, the offset is the offset from the start of the certificate chain to the start of the read request, and its unit is bytes. The length is the length of the read request, and its unit is bytes. For example, to read 4 bytes from the start of the certificate chain, the offset [11...0] of GET_CERTIFICATE could have a value of 00b, and its length could have a value of 11b.

[0350] Refer again Figure 18 In response to GET_CERTIFICATE, the wireless power transmitting device sends at least a portion of the certificate chain to the wireless power receiving device (S1815). In this case, a portion of the certificate chain may begin after an offset from the start time point, with a length in bytes.

[0351] Figure 23 An example is shown of the physical packet structure for sending a certificate and a method for sending that physical packet structure. (Reference) Figure 23When sending a 1536-byte certificate packet, the wireless power transmitting device extracts a 4-byte certificate from the offset point of the certificate packet, adds a header indicating the certificate to the front of the certificate, and adds a checksum to the back of the certificate to generate and send a certificate segment with a total length of 6 bytes.

[0352] Figure 24 An example is shown of the physical packet structure for sending an authentication response message from a wireless power transmitting device and a method for sending that physical packet structure. (Reference) Figure 24 A certificate packet (i.e., 1543 bytes) may include a certificate chain (i.e., 1540 bytes), a header indicating the certificate (i.e., 1 byte), and a header indicating the length of the certificate packet (i.e., 2 bytes). The wireless power transmitting device divides this certificate packet into multiple smaller packets of a specific length (e.g., 3 bytes) and adds a checksum to the end of each smaller packet to send the smaller packets in a sequence of 4-byte certificate packets. In this case, each of the total 515 data blocks is sent. The size of the last packet in the sequence can be less than 4 bytes. These smaller packets can be referred to as segments. Figure 24 The diagram limits the size of the transmission packets from the wireless power transmitter, ensuring that a single authentication response is configured using a maximum of 4 bytes. This division of a single response message into a series of small packets allows the (extended) Control Error Packet (CEP) and (extended) Receive Power Packet (RPP) to be periodically (approximately 250ms) sent by the wireless power receiver to the wireless power transmitter, thereby enabling efficient management of the operating point and foreign object detection for power transmission from the wireless power transmitter.

[0353] Refer again Figure 18 If necessary, the wireless power receiving device may send a control error (CE) packet and / or a receive power packet (RPP) to the wireless power transmitting device (S1820). Steps S1810 and S1820 may be performed, for example, during the power transmission phase.

[0354] Then, the wireless power receiving device can repeat steps S1810 to S1820 until all certificate chains are read.

[0355] The wireless power receiving device sends a CHALLENGE (S1825) to the wireless power transmitting device. The CHALLENGE is used to initiate product authentication.

[0356] Figure 25 An example of a CHALLENGE message structure is shown. (Reference) Figure 25 CHALLENGE is configured using, for example, 32-bit (4-byte) and can include four Nonce fields. The Nonce is a binary random number chosen by the authentication initiator.

[0357] Refer again Figure 18 To obtain CHALLENGE_AUTH, the wireless power receiving device sends GET_CHALLENGE_AUTH (S1830) to the wireless power transmitting device. Here, GET_CHALLENGE_AUTH can be set to an offset and a length.

[0358] The wireless power transmitting device sends a portion of CHALLENG_AUTH to the wireless power receiving device in response to GET_CHALLENGE_AUTH (S1835). In this case, the portion of CHALLENG_AUTH can begin after the offset from the start time point with a length in bytes.

[0359] Figure 26 An example is shown of the physical packet structure for sending CHALLENGE_AUTH and the method for sending that physical packet structure. References Figure 26 The CHALLENGE_AUTH packet (i.e., 160 bytes) may include a certificate chain hash (i.e., 32 bytes), a salt (i.e., 32 bytes), a context hash (i.e., 32 bytes), and a signature (i.e., 64 bytes). The wireless power transmitting device extracts a specific length (e.g., 4 bytes) from the offset indicated in the CHALLENGE_AUTH packet, adds a header indicating the CHALLENGE_AUTH packet to its front, and adds a checksum to its back to generate and send a certificate segment with a total length of 6 bytes.

[0360] Refer again Figure 18 If necessary, the wireless power receiving device may send control error (CE) packets and / or receive power packets (RPP) to the wireless power transmitting device (S1840).

[0361] Then, the wireless power receiving device can repeat steps S1830 to S1840 until all CHALLENGE_AUTH values ​​are read.

[0362] The following describes the process by which the wireless power transmitting device performs authentication of the wireless power receiving device based on authentication messages.

[0363] (2) Authentication of wireless power transmitting device to wireless power receiving device (authentication of PTx to PRx)

[0364] When the authentication of the wireless power transmitting device to the wireless power receiving device (PTx to PTy authentication) is performed based on in-band communication, the time required for each step is shown in Table 8 or Table 9.

[0365] [Table 8]

[0366]

[0367] Table 8 shows an example of the time required for each authentication message when a power contract is made based on the result of GET_DIGESTS during the negotiation phase. When the wireless power transmitting device already knows the DIGEST of the wireless power receiving device, the send / receive steps of GET_CERTIFICATE and CERTIFICATE can be omitted. Furthermore, the power contract can be updated during the renegotiation phase based on the authentication result.

[0368] [Table 9]

[0369]

[0370] Table 9 shows an example of the time required for each authentication message when a power contract is made based on the result of GET_DIGESTS during the negotiation phase. When the wireless power transmitting device already knows the DIGEST of the wireless power receiving device, the send / receive steps of GET_CERTIFICATE and CERTIFICATE, the communication request step, and the control error packet transmission step can be omitted. Furthermore, the power contract can be updated during the renegotiation phase based on the authentication result. The authentication process that meets the required time is described below.

[0371] Figure 27 This is a flowchart illustrating the sequence of transmitted and received packets when the wireless power transmitting device performs authentication of the wireless power receiving device (PTx authentication of PRx) according to an embodiment.

[0372] refer to Figure 27 The wireless power transmitting device receives DIGESTS from the wireless power receiving device (S2700). DIGESTS is used when the authentication responder sends a report about the certificate chain digest and a time slot including the valid certificate chain digest. The parameter of DIGESTS can be a 32-byte hash value of the certificate chain. The predetermined operations of step S2700 may include determining the authentication function supported by the wireless power receiving device from the capability packet received from the wireless power transmitting device, and the wireless power transmitting device sending GET_DIGESTS to the wireless power receiving device. Step S2700 can be performed during the negotiation or renegotiation phase or the power transfer phase.

[0373] Figure 28 An example of the message structure for GET_DIGESTS sent by a wireless power transmitting device is shown. (Reference) Figure 28GET_DIGESTS is configured using, for example, a 1-byte parameter and includes a request field. GET_DIGESTS includes a reserved bit and a timeslot number. The timeslot number identifies the timeslot where the requested certificate chain is stored and can be configured using, for example, 3 bits.

[0374] Refer again Figure 27 During the power transmission phase, the wireless power receiving device sends a control error packet and a receive power packet to the wireless power transmitting device (S2705).

[0375] The wireless power transmitting device sends a communication request (S2710) in response to a control error packet or a received power packet. The communication request may be, for example, a bit mode request.

[0376] When the wireless power receiving device responds to the communication request with an ACK (S2715), in order to obtain the CHALLENGE_AUTH response or certificate chain from the wireless power receiving device, the wireless power transmitting device sends a GET_CERTIFICATE to the wireless power receiving device (S2720). Here, GET_CERTIFICATE can be set by offset and length. GET_CERTIFICATE is used to read segments of the target certificate chain.

[0377] Figure 29 An example of the structure of a GET_CERTIFICATE message sent by a wireless power transmitting device is shown. (Reference) Figure 29 GET_CERTIFICATE is configured using, for example, 2 bytes and may include offset and length fields. Here, the offset is the offset from the start of the certificate chain to the start of the read request, and its unit is bytes. The length is the length of the read request, and its unit is bytes. For example, to read 40 bytes from the start of the certificate chain, the offset [7...0] of GET_CERTIFICATE could have a value of 00b, and its length could have a value of 110000b.

[0378] Refer again Figure 27 The wireless power receiving device responds to GET_CERTIFICATE by sending at least a portion of the certificate chain to the wireless power transmitting device (S2725). In this case, a portion of the certificate chain may begin after an offset from the start time point, with a length in bytes.

[0379] Figure 30 An example is shown of the physical packet structure for transmitting a certificate for a wireless power receiving device and a method for transmitting that physical packet structure. (Reference) Figure 30When sending a 1536-byte certificate packet, the wireless power receiving device extracts a 40-byte certificate from the offset point of the certificate packet, adds a header indicating the certificate (i.e., 1 byte) to its front end, and adds a checksum (i.e., 1 byte) to its back end to generate and send a certificate segment with a total length of 42 bytes.

[0380] Refer again Figure 27 The wireless power transmitting device can repeat steps S2710 to S2725 until all certificate chains are read.

[0381] If necessary, the wireless power receiving device may send control error (CE) packets and / or receive power packets (RPP) to the wireless power transmitting device (S2730).

[0382] The wireless power transmitting device sends a communication request in response to the CE packet and RPP (S2735). The communication request may be, for example, a bit-mode response.

[0383] When the wireless power receiving device responds to the communication request with an ACK (S2740), the wireless power transmitting device sends a CHALLENGE[n] to the wireless power receiving device (S2745). The CHALLENGE is used to initiate product authentication.

[0384] Figure 31 An example of the structure of a CHALLENGE message sent by a wireless power transmitting device is shown. (Reference) Figure 31 The CHALLENGE is configured using, for example, 32 bits (4 bytes) and can include four Nonce fields. The Nonce is a binary random number chosen by the authentication initiator. By sending 8 CHALLENGE packets, the wireless power transmitting device can provide a total of 32 bytes of Nonce to the wireless power receiving device.

[0385] Refer again Figure 27 After receiving an ACK from the wireless power receiving device, the wireless power transmitting device can repeat steps S2735 to S2750 until all CHALLENGEs are sent.

[0386] The wireless power receiving device may send control error packets and / or receive power packets to the wireless power transmitting device (S2755). In response to the control error packets and receive power packets, the wireless power transmitting device sends a communication request (S2760). The communication request may, for example, be a bit-mode response.

[0387] When the wireless power receiving device responds to the communication request with an ACK (S2765), in order to obtain CHALLENGE_AUTH, the wireless power transmitting device sends GET_CHALLENGE_AUTH to the wireless power receiving device (S2770). Here, GET_CHALLENGE_AUTH can be set to an offset and a length.

[0388] The wireless power receiving device sends at least a portion of CHALLENGE_AUTH to the wireless power transmitting device in response to GET_CHALLENGE_AUTH (S2775). In this case, at least a portion of CHALLENGE_AUTH may begin after an offset from the start time point with a length in bytes.

[0389] Figure 32 An example is shown of the physical packet structure for transmitting the CHALLENGE_AUTH message from a wireless power receiving device and a method for transmitting this physical packet structure. (Reference) Figure 32 The CHALLENGE_AUTH packet (i.e., 160 bytes) may include a certificate chain hash (i.e., 32 bytes), a salt (i.e., 32 bytes), a context hash (i.e., 32 bytes), and a signature (i.e., 64 bytes). The wireless power transmitting device extracts a specific length (i.e., 40 bytes) from the offset of the CHALLENGE_AUTH packet based on the offset and length indicated in the GET_CHALLENGE_AUTH packet, adds a header indicating the CHALLENGE_AUTH packet (i.e., 1 byte) to its front end, and adds a checksum (i.e., 1 byte) to its back end to generate and send a certificate segment with a total length of 42 bytes.

[0390] Then, the wireless power transmitting device can repeat steps S2760 to S2775 until all CHALLENGE_AUTH values ​​are read.

[0391] Figure 33 An example of the physical packet structure for sending an authentication response message from a wireless power receiving device and a method for sending that physical packet structure is shown. (Reference) Figure 33 For example, a certificate packet (i.e., N bytes) may include a certificate chain, a header indicating the certificate (i.e., 1 byte), and a header indicating the length of the certificate packet (i.e., 2 bytes). The wireless power receiving device divides this certificate packet into multiple smaller packets of a specific length (e.g., M-1 bytes) and adds a 1-byte checksum to the end of each smaller packet to send the packet as a sequence of M-byte certificate smaller packets. The last smaller packet in this sequence may be smaller than M bytes. These smaller packets may be referred to as segments. Figure 33The diagram limits the size of the packets transmitted by the wireless power receiving device, making a single authentication response configured using M bytes. Dividing a single response message into a series of small packets allows the wireless power receiving device to send periodically (approximately 250ms) (extended) Control Error Packets (CEP) and (extended) Receive Power Packets (RPP) to the wireless power transmitting device, thereby enabling efficient management of the operating point and foreign object detection for power transmission from the wireless power transmitting device.

[0392] Figure 34 Another example is shown of the physical packet structure for sending an authentication response message from a wireless power receiving device and a method for sending that physical packet structure. (Reference) Figure 34 For example, a certificate packet (i.e., 1543 bytes) may include a certificate chain (i.e., 1540 bytes), a header indicating the certificate (i.e., 1 byte), and a header indicating the length of the certificate packet (i.e., 2 bytes). The wireless power receiving device divides this certificate packet into multiple smaller packets of a specific length (e.g., 38 bytes), adds a preamble (i.e., 1 byte) to the front of each smaller packet, and adds a checksum (i.e., 1 byte) to the back of each smaller packet, to send the packet in a sequence of 40-byte certificate smaller packets. In this case, each of the total 41 data blocks is sent. The size of the last smaller packet in this sequence may be less than 40 bytes. These smaller packets may be referred to as segments. Figure 34 The diagram limits the size of the packets sent by the wireless power receiving device, ensuring that a single authentication response is configured using 40 bytes. Dividing a single response message into a series of small packets allows the wireless power receiving device to send (extended) Control Error Packets (CEP) and (extended) Receive Power Packets (RPP) periodically (approximately 250 ms) to the wireless power transmitting device, thereby enabling efficient management of the operating point and foreign object detection for power transmission from the wireless power transmitting device.

[0393] Figure 35 This is a flowchart illustrating the sequence of transmitted and received packets when the wireless power transmitting device performs authentication of the wireless power receiving device (PTx authentication of PRx) according to another embodiment.

[0394] refer to Figure 35 The wireless power transmitting device receives DIGESTS from the wireless power receiving device (S3500). The predetermined operations of step S3500 may include the wireless power receiving device determining authentication function support from the capability packet received from the wireless power transmitting device, and the wireless power transmitting device sending GET_DIGESTS to the wireless power receiving device. Step S3500 can be performed during the negotiation phase or the power transfer phase.

[0395] During the power transmission phase, the wireless power receiving device sends CEP and RPP (S3505) to the wireless power transmitting device.

[0396] The wireless power transmitting device sends a request for multiple communications in response to CEP and RPP (S3510). The request for multiple communications may be a bit-mode response, for example.

[0397] When the wireless power receiving device responds to a request for multiple communications with an ACK (S3515), the wireless power transmitting device sends a GET_CERTIFICATE to the wireless power receiving device (S3520) in order to obtain the CHALLENGE_AUTH response or certificate chain from the wireless power receiving device. Here, GET_CERTIFICATE can be set by offset and length. GET_CERTIFICATE is used to read segments of the target certificate chain.

[0398] The wireless power receiving device sends at least a portion of a certificate chain to the wireless power transmitting device in response to GET_CERTIFICATE (S3525). In this case, a portion of the certificate chain may begin after an offset from the start time point, with a length in bytes.

[0399] The wireless power transmitting device can repeat steps S3520 to S3525 until all certificate chains are read.

[0400] If necessary, the wireless power receiving device may send control error (CE) packets and / or receive power packets (RPP) to the wireless power transmitting device.

[0401] The wireless power transmitting device sends a request for multiple communications in response to the CE packet and RPP (S3535). The request for multiple communications may be a bit-mode response, for example.

[0402] When the wireless power receiving device responds to a request for multiple communications with an ACK (S3540), the wireless power transmitting device sends a CHALLENGE[n] to the wireless power receiving device (S3545). The CHALLENGE is used to initiate product authentication.

[0403] The wireless power transmitting device receives an ACK (S3550) from the wireless power receiving device, and can repeat steps S3545 to S3550 until all CHALLENGEs are sent.

[0404] The wireless power receiving device can send CE packets and / or RPPs to the power transmitting device (S3555). In response to the CE packets and RPPs, the wireless power transmitting device sends a request for multiple communications (S3560). The request for multiple communications may, for example, be a bit-mode response.

[0405] When the wireless power receiving device responds to a request for multiple communications with an ACK (S3565), in order to obtain CHALLENGE_AUTH, the wireless power transmitting device sends GET_CHALLENGE_AUTH to the wireless power receiving device (S3570). Here, GET_CHALLENGE_AUTH can be set to an offset and a length.

[0406] The wireless power receiving device sends at least a portion of CHALLENGE_AUTH to the wireless power transmitting device in response to GET_CHALLENGE_AUTH (S3575). In this case, at least a portion of CHALLENGE_AUTH may begin after an offset from the start time point with a length in bytes.

[0407] Then, the wireless power transmitting device can repeat steps S3570 to S3575 until all CHALLENGE_AUTH values ​​are read.

[0408] 5. Supports low-level protocols in the authentication process.

[0409] Since the low-level packet sending protocol that supports the authentication process can be configured based on in-band communication, it is necessary to configure the packet structure used for in-band communication to be suitable for the authentication process and authentication messages.

[0410] Figure 36 The diagram illustrates the structure of a wireless power receiving device sending in-band communication packets to a wireless power transmitting device. According to... Figure 36 The groups can be modulated using the ASK scheme.

[0411] refer to Figure 36 The bit rate is 2Kbps, and the packet includes a preamble, header, message, and checksum. For example, the preamble can be set to 11 bits, the header can be set to 1B, and the checksum can be set to 1B (1B->11 bits).

[0412] Figure 37 The structure of a wireless power transmitting device sending in-band communication packets to a wireless power receiving device is shown. According to... Figure 37 The groups can be modulated using the FSK scheme.

[0413] refer to Figure 37The bit rate at a 100kHz operating frequency is 200bps, and the packets include a header, message, and checksum. For example, the header can be set to 1B, and the checksum can be set to 1B (1B->11 bits).

[0414] (1) Low-level authentication sequence

[0415] 1) Authentication of wireless power receiving devices to wireless power transmitting devices (PRx to PTx authentication)

[0416] When the wireless power receiving device is the authentication initiator, the wireless power transmitting device becomes the authentication responder. Alternatively, the wireless power transmitting device can represent the (authentication) target device. As the authentication initiator, the wireless power receiving device sends the messages (or packets) necessary for the authentication of the wireless power transmitting device to the wireless power transmitting device as a request message (or packet). As the authentication responder, the wireless power transmitting device sends an authentication response message configured with a sequence of several packets to the wireless power receiving device. The sending and receiving of this series of messages can be defined by a lower-level packet transmission protocol.

[0417] Figure 38 The diagram illustrates the packet transmission and reception sequence between a wireless power receiving device and a transmitting device, viewed from a lower-level perspective according to an embodiment. Figure 38 This illustrates the process of the wireless power transmitter sending an authentication response packet (DIGESTS) to the wireless power receiver when the wireless power receiver sends a GET_DIGESTS to the wireless power transmitter.

[0418] refer to Figure 38 After each packet in the transmission sequence, the wireless power transmitting device waits for a continue / stop or ACK / NACK signal from the wireless power receiving device. ACK / NACK or continue / stop is included in... Figure 39 The (extended) CEP is then transmitted. The wireless power transmitting device and / or wireless power receiving device repeat the following process until all packets in the sequence have been transmitted.

[0419] If the wireless power transmitter receives "ACK and continue", the wireless power transmitter sends the next packet.

[0420] If the wireless power transmitter receives "ACK and Stop", the wireless power transmitter waits until it receives the next extended CEP, which includes "ACK and Continue".

[0421] If the wireless power transmitter receives "NACK and continue", the wireless power transmitter will retransmit the previous packet.

[0422] If the wireless power transmitter receives "NACK and Stop", the wireless power transmitter waits until it receives the next extended CEP, which includes "ACK and Continue".

[0423] Figure 39 The diagram illustrates a sequence of packet transmission and reception between a wireless power receiving device and a transmitting device, viewed from a lower-level perspective according to another embodiment. Figure 39 This illustrates the process of a wireless power transmitter sending an authentication response packet (CERTIFICATE) to a wireless power receiver when the wireless power receiver sends a GET_CERTIFICATE to the wireless power transmitter.

[0424] refer to Figure 39 After each packet in the transmission sequence, the wireless power transmitting device waits for an ACK / NACK or continuous / stop transmission from the wireless power receiving device. ACK / NACK or continuous / stop is included in... Figure 39 The extended CEP is then transmitted. The wireless power transmitting and / or receiving devices repeat the following process until all packets in the transmission sequence are transmitted.

[0425] If the wireless power transmitting device receives "ACK and continue", it then transmits the next packet. For example, for packet 1, the wireless power transmitting device can receive "ACK and continue" via extended CEP, and for packet m, the wireless power transmitting device can... Figure 42 The extended RPP receives "ACK and continue".

[0426] If the wireless power transmitter receives "ACK and Stop", it waits until it receives the next extended CEP, which includes "ACK and Continue". For example, for packet n, the wireless power transmitter receives "ACK and Stop" via an extended CEP.

[0427] If the wireless power transmitter receives "NACK and continue", the wireless power transmitter will retransmit the previous packet.

[0428] If the wireless power transmitter receives "NACK and Stop", the wireless power transmitter waits until it receives the next extended CEP, which includes "ACK and Continue".

[0429] Figure 40 The structure of the extended CEP according to the implementation method is shown.

[0430] refer to Figure 40The wireless power receiving device transmits an extended CEP in response to a packet from the wireless power transmitting device. In this case, the extended CEP includes a control error value that adjusts the operating point of the wireless power transmitting device and at least one of ACK / NACK or continuous / stop.

[0431] For example, the stop is configured using a 1-bit value, and when its value is '1'b, it instructs the wireless power transmitter to stop transmitting packets, while when its value is '0'b, it instructs the wireless power transmitter to continue transmitting the next packet in the sequence (i.e., continue transmitting). Here, to allow the wireless power receiver to quickly adjust the operating point of the wireless power transmitter, the wireless power receiver can set the stop to 1 to force the wireless power transmitter to pause packet transmission in the next sequence when it is necessary to transmit CEP over a short period of time or when all response packets have been received.

[0432] ACK / NACK is configured using, for example, 4 bits, and when its value is '0000'b, it indicates ACK, while when its value is '1111'b, it indicates NACK. ACK indicates that the wireless power receiving device has successfully received the packet without error, while NACK indicates that the wireless power receiving device has requested a retransmission of the packet from the wireless power transmitting device due to a packet reception error.

[0433] Figure 41 The structure of an End Power Transfer (EPT) packet according to an embodiment is shown.

[0434] refer to Figure 41 The EPT packet corresponding to header value 0x02 can indicate the code value required for the authentication process. For example, when authentication of a wireless power transmitting device fails, a wireless power receiving device can set an EPT code value to indicate a code value different from the existing code value in 0x0E. By sending the new EPT code value, the wireless power receiving device can eliminate power transmission.

[0435] Figure 42 The structure of an extended receive power packet according to an embodiment is shown.

[0436] refer to Figure 42 The extended receive power packet is configured using 24 bits and may include a first reserved bit, a mode, a receive power value, a second reserved bit, a stop, and ACK / NACK. That is, the extended receive power packet includes a receive power value related to the FOD of the wireless power transmitting device and includes at least one of ACK / NACK or continue / stop.

[0437] For example, the stop is configured using a 1-bit flag, and when its value is '1'b, the wireless power transmitter stops transmitting packets, while when its value is '0'b, the wireless power transmitter transmits the next packet in the sequence (i.e., continues transmitting). Here, to allow the wireless power receiver to quickly adjust the operating point of the wireless power transmitter, when it is necessary to transmit a CEP over a short period of time or when all response packets have been received, the wireless power receiver can set the stop flag to 1 to force the wireless power transmitter to pause packet transmission in the next sequence.

[0438] ACK / NACK is configured using, for example, 4 bits. A value of '0000' indicates ACK, while a value of '1111' indicates NACK. ACK indicates that the receiving device has successfully received the packet without error, while NACK indicates that the receiving device has requested a retransmission of the packet from the transmitting device due to a packet reception error.

[0439] 2) Authentication of wireless power transmitting devices to wireless power receiving devices (PTx authentication to PRx)

[0440] When the wireless power transmitting device is the authentication initiator, the wireless power receiving device becomes the authentication responder. Alternatively, the wireless power receiving device can utilize the (authentication) target device representation. As the authentication initiator, the wireless power transmitting device sends the message (or packet) required for authentication to the wireless power receiving device, as a request message (or packet). As the authentication responder, the wireless power receiving device sends an authentication response message configured with a sequence of several packets to the wireless power transmitting device. The sending and receiving of this series of messages can be defined by a lower-level packet transmission protocol.

[0441] Figure 43 The diagram illustrates the packet transmission and reception sequence between a wireless power receiving device and a transmitting device, viewed from a lower-level perspective according to an embodiment. Figure 43 This illustrates the process of a wireless power receiving device sending an authentication response packet (CERTIFICATE) to a wireless power transmitting device when the wireless power transmitting device sends a GET_CERTIFICATE to the wireless power receiving device.

[0442] refer to Figure 43 After each packet in the transmission sequence, the wireless power receiving device waits for an ACK / NACK (bit pattern response) from the wireless power transmitting device. The bit response time can be, for example, 40 ms. The wireless power transmitting and / or receiving device can repeat the following process until all packets in the transmission sequence are transmitted. Between authentication response packets, the wireless power receiving device can send CEP and / or RPP.

[0443] If the wireless power receiving device receives an ACK, it then sends the next packet. For example, for packet 1, when the wireless power receiving device receives the ACK, it sends packet 2 in the next transmission timing.

[0444] If the wireless power receiving device receives 'NACK', the wireless power receiving device will retransmit the previous packet.

[0445] (2) Protocols for lower-level data transactions

[0446] The data transaction protocol will now be described. For lower-level data transactions, this implementation may consider four rules.

[0447] Rule 1 stipulates that the wireless power receiving device operates as the master device. When the wireless power receiving device operates as the master device and the wireless power transmitting device operates as the slave device, the wireless power receiving device determines when to allow communication from the wireless power transmitting device.

[0448] A wireless power receiving device can send a Start of Stream (SOD) ADT_CTRL packet to query whether a data stream is about to be sent by the wireless power transmitting device. Alternatively, to poll the wireless power transmitting device for a packet that it will send, the wireless power receiving device can send a General Request (GPR) packet in which the request is set to '0xFF'.

[0449] Rule 2 is for communication error control. The wireless power receiving or transmitting device can rewrite the ADT packet until an ACK is received. Additionally, an "ACK" ADT_CTRL packet is sent when no communication error has occurred, and a "NACK" ADT_CTRL packet is sent when a communication error is detected.

[0450] Rule 3 is about data stream synchronization. To achieve synchronization, the header of the ADT data packet can be switched whenever a new data packet is sent.

[0451] Rule 4 marks the end of a data stream or marks both the beginning and end of a data stream. Specifically, a Start of Stream (SOD) ADT_CTRL packet can be added to the beginning of the data stream. Alternatively, an End of Stream (EOD) ADT_CTRL packet can be added to the end of the data stream. Here, both SOD and EOD can be added when the length of the data stream is greater than one packet.

[0452] The data transmission and packet structure based on the above rules can be defined as follows.

[0453] 1) Lower-level data transmission and packet structure used for authentication

[0454] The low-level data transmission and packet structure used for authentication will be described in detail below. Two design approaches for low-level data transmission are the dedicated mapping method and the universal bit-control method. The advantage of the universal bit-control method is that it provides application-agnostic data transmission and can be used for other applications in the future besides authentication.

[0455] The design requirements for low-level data transmission based on universal bit tubes are i) minimizing interaction between high-level and low-level systems, and iii) ensuring error recovery and synchronization of low-level data transmission. For i), higher levels encode the data stream to push it to lower levels (write) and decode the data stream provided from lower levels (read). Additionally, lower levels use multiple Auxiliary Data Transmission (ADT) data packets to write or read the data stream (write / read). For ii), a simple and robust communication error recovery mechanism includes rewriting ADT packets until the wireless power transmitter or receiver receives an ACK and rereading ADT packets until no communication error exists. Furthermore, simple synchronization of the data stream between the wireless power transmitter and receiver involves switching the header of data packets when transmitting new ADT data packets.

[0456] Figure 44 Data transmission according to an embodiment is shown. Figure 44 The Update Transfer Data (UDT) is shown.

[0457] refer to Figure 44 UDT is used to carry update data. Update data includes several data packets. For example, update data may include Control Error Packets (CEP), Receive Power Packets (RPP) optionally including ACK or NACK, Auxiliary Data Transmission (ADT), Charge Status Packets (CSP), dedicated packets, Renegotiation Packets (RNG) optionally including ACK or NACK, and reserved packets (the wireless power transmitting device should be flexible with reserved bits).

[0458] ADT is a low-level data packet or transmission used for higher-level applications and includes the same logical layer packets as the capability packets of wireless power transmitting devices.

[0459] Figure 45 Data transmission according to another embodiment is shown. Figure 45 Auxiliary data transmission (ADT) is shown.

[0460] refer to Figure 45 ADT includes the ADT (ADT_PRx) of the wireless power receiving device and the ADT (ADT_PTx) of the wireless power transmitting device.

[0461] The ADT of the wireless power receiving device carries data, response (e.g., ACK, NACK, RFA) packets or control packets from the wireless power receiving device.

[0462] The ADT of the wireless power transmitter carries data, response (e.g., ACK, NACK, RFA) packets, control packets, or ACK / NACK / RFA bit mode responses from the wireless power transmitter.

[0463] As an example, the header of an ADT packet can indicate lower-level data packets used for higher-level applications (e.g., lower-level data packets from a wireless power receiving device and lower-level data packets from a wireless power transmitting device). Higher-level applications may include, for example, authentication processes, dedicated information exchange, firmware updates, and power capability control of wireless power transmitting devices.

[0464] As another example, the header of an ADT packet may indicate a logical layer data packet (e.g., a packet from a wireless power receiving device or a packet from a wireless power transmitting device). As yet another example, the header of an ADT packet may include a control packet.

[0465] As another example, the header of an ADT packet can indicate an ADT data packet, and in this case, the header of the ADT data packet can include multiple types of headers (e.g., two types of headers such as header A and header B). Whenever a new ADT data packet is sent, the header of the ADT data packet is switched to A->B or B->A, thus enabling synchronization of the data stream.

[0466] As another example, the header of an ADT packet can indicate an ADT control packet, and in this case, the header of the ADT packet can include a header of a single type.

[0467] The ADT packet structure for low-level data transmission will now be described. As mentioned above, an ADT consists of a pair of ADTs (ADT_PRx) from a wireless power receiving device and ADTs (ADT_PTx) from a wireless power transmitting device, and the ADT (ADT_PRx) from the wireless power receiving device will be described first.

[0468] Figure 46 The structure of an ADT data packet (ADT_PRx data packet) of a wireless power receiving device according to an embodiment is shown.

[0469] refer to Figure 46ADT data packets, for example, include a payload of (n+1) bytes, and each payload can correspond to any of a number of header types. Table 10 shows the correspondence between the header and payload size of ADT data packets (when n=15, up to 16 bytes).

[0470] [Table 10]

[0471]

[0472] Referring to Table 10, when a specific byte of payload is included in and transmitted within an ADT data packet, either header A or header B can be used. The payload size can range from 1 byte to 16 bytes. When transmitting a new data packet and retransmitting the immediately preceding ADT data packet, the wireless power receiving device and the wireless power transmitting device specifically commit to a pattern of header values ​​to achieve synchronization between them. For example, when the wireless power receiving device transmits a 1-byte payload to an ADT data packet, when transmitting a new ADT data packet, the wireless power receiving device switches the header value from header A (=0x1C) to header B (=0x1D) or from header B (=0x1D) to header A (=0x1C), and when retransmitting the immediately preceding ADT data packet, the wireless power receiving device can retain the immediately preceding header value. Retransmitting the immediately preceding ADT data packet can occur when the wireless power receiving device receives a NACK response from the wireless power transmitting device or when the wireless power receiving device detects a decoding error by the wireless power transmitting device.

[0473] Figure 47 The structure of the ADT response packet (ADT_PRx response packet) of the wireless power receiving device according to an embodiment is shown.

[0474] refer to Figure 47 The ADT response packet of the wireless power receiving device is configured using, for example, 1 byte, and its value can indicate ACK, NACK, and RFA. Table 11 shows the correspondence between the payload values ​​of the ADT response packet and their indicated contents.

[0475] [Table 11]

[0476] Payload Instructions ‘11111111'b ACK ‘00000000'b NACK ‘00110011'b RFA

[0477] In Table 11, when the payload value is '11111111'b, the payload value indicates that the wireless power receiving device successfully received and decoded the ADT data packet (ACK) sent by the wireless power transmitting device in the immediately preceding ADT. When the payload value is '00000000'b, the payload value indicates that the wireless power receiving device failed to receive and decode the ADT data packet sent by the wireless power transmitting device in the immediately preceding ADT (NACK). In this case, the wireless power transmitting device retransmits the immediately preceding ADT data packet in the current ADT, and in this case, the header of the ADT data packet has a value corresponding to the retransmission of the immediately preceding data packet (e.g., 0x1C). When the payload value is '00110011'b, the payload value indicates that the wireless power receiving device requests the wireless power transmitting device to send response data (RFA). In Table 11, the payload values ​​and their indications are examples, and different values ​​can be used as the payload values ​​corresponding to each indication, which are within the scope of the present invention.

[0478] The ADT control packet structure of the wireless power receiving device can be combined with... Figure 47 The same.

[0479] Figure 48 The structure of the ADT control packet (ADT_PRx control packet) of a wireless power receiving device according to an embodiment is shown.

[0480] refer to Figure 48 The ADT control packets of the wireless power receiving device are configured using, for example, 1 byte, and their values ​​can indicate ACK, NACK, SOD, and EOD. Table 12 shows the correspondence between the payload values ​​of the ADT control packets and their indicated contents.

[0481] [Table 12]

[0482] Payload value Instructions ‘11111111'b ACK ‘00000000'b NACK ‘00110011'b SOD ‘11001100'b EOD

[0483] In Table 12, when the payload value is '11111111'b, the payload value indicates that the wireless power receiving device successfully received and decoded the ADT data packet (ACK) sent by the wireless power transmitting device in the immediately preceding ADT. When the payload value is '00000000'b, the payload value indicates that the wireless power receiving device failed to receive and decode the ADT data packet sent by the wireless power transmitting device in the immediately preceding ADT (NACK). In this case, the wireless power transmitting device retransmits the immediately preceding ADT data packet in the current ADT, and in this case, the header of the ADT data packet has a value corresponding to the retransmission of the immediately preceding data packet (e.g., 0x1C). When the payload value is '00110011'b, the payload value indicates the start of a requested ADT data stream (SOD). When the payload value is '11001100'b, the payload value indicates the end of an ADT data stream (EOD).

[0484] In Table 12, the payload values ​​and their indications are examples, and different values ​​can be used as the payload values ​​corresponding to each indication, which correspond to the technical scope of the present invention.

[0485] The following describes the ADT (ADT_PTx) of the wireless power transmitting device.

[0486] Figure 49 The structure of an ADT data packet (ADT_PTx data packet) of a wireless power transmitting device according to an embodiment is shown.

[0487] refer to Figure 49 ADT data packets, for example, include a payload of (n+1) bytes, and each payload can correspond to any of a plurality of header types. Table 13 shows the correspondence between the header and payload sizes of ADT data packets (up to 4 bytes when n=3).

[0488] [Table 13]

[0489] Payload size (bytes) Header A Header B 1 0x1C 0x1D 2 0x2C 0x2D 3 0x3C 0x3D 4 0x4C 0x4D

[0490] Referring to Table 13, when a specific byte of payload is included in and transmitted within an ADT data packet, either header A or header B can be used. The payload size can be 1 to 4 bytes. The wireless power transmitter and receiver can synchronize themselves by specifying header value patterns when transmitting a new ADT data packet and when retransmitting the immediately preceding ADT data packet. For example, when the wireless power transmitter transmits a 1-byte payload to an ADT data packet, it can switch the header value from header A (=0x1C) to header B (=0x1D) or from header B (=0x1D) to header A (=0x1C) when transmitting a new ADT data packet, while maintaining the immediately preceding header value when retransmitting the immediately preceding ADT data packet. Retransmission of the immediately preceding ADT data packet can occur when the wireless power transmitter receives a NACK response from the wireless power receiver or when the wireless power transmitter detects a decoding error at the wireless power receiver.

[0491] Figure 50 The structure of the ADT response packet (ADT_PTx response packet) of the wireless power transmitting device according to an embodiment is shown.

[0492] refer to Figure 50 The ADT response packet from the wireless power transmitting device is configured using, for example, a 1-byte value, 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 content.

[0493] [Table 14]

[0494] Payload value Instructions ‘11111111'b ACK ‘00000000'b NACK ‘00110011'b RFA

[0495] In Table 14, when the payload value is '11111111'b, the payload value indicates that the wireless power transmitting device successfully received and decoded the ADT data packet (ACK) sent by the wireless power receiving device in the immediately preceding ADT. When the payload value is '00000000'b, the payload value indicates that the wireless power transmitting device failed to receive and decode the ADT data packet sent by the wireless power receiving device in the immediately preceding ADT (NACK). In this case, the wireless power receiving device retransmits the immediately preceding ADT data packet in the current ADT, and in this case, the header of the ADT data packet has a value corresponding to the retransmission of the immediately preceding data packet (e.g., 0x1C). When the payload value is '00110011'b, the payload value indicates that the wireless power transmitting device requests the wireless power receiving device to provide an ADT transaction (RFA). In Table 14, the payload values ​​and their indications are examples, and different values ​​can be used as the payload values ​​corresponding to each indication, which correspond to the technical scope of the present invention.

[0496] Figure 51 The structure of the ADT response / control packet (ADT_PTx response / control packet) of a wireless power transmitting device according to an embodiment is shown.

[0497] refer to Figure 51 The ADT response packet from the wireless power transmitting device is configured using, for example, a 1-byte parameter, and its value can indicate ACK and RFA. Table 15 shows the correspondence between the payload values ​​of the ADT response packet and their indicated content.

[0498] [Table 15]

[0499] Payload value Instructions ‘11111111'b ACK ‘00110011'b RFA

[0500] In Table 15, when the payload value is '11111111'b, the payload value indicates that the wireless power transmitting device successfully received and decoded the ADT data packet (ACK) sent by the wireless power receiving device in the immediately preceding ADT. When the payload value is '00110011'b, the payload value indicates that the wireless power transmitting device requests to send response data (RFA) to the wireless power receiving device. According to the present invention, when the wireless power transmitting device fails to receive and decode the ADT data packet sent by the wireless power receiving device in the immediately preceding ADT, the wireless power transmitting device does not send a separate communication error signal (NACK). In Table 15, the payload values ​​and their indications are examples, and different values ​​can be used as the payload values ​​corresponding to each indication, which correspond to the technical scope of the present invention.

[0501] Figure 52 The structure of the ADT control packet (ADT_PTx control packet) of a wireless power transmitting device according to an embodiment is shown.

[0502] refer to Figure 52 The ADT control packets of the wireless power transmitting device are configured using, for example, 1 byte, and their values ​​can indicate ACK, NACK, SOD, and EOD. Table 16 shows the correspondence between the payload values ​​of the ADT control packets and their indicated contents.

[0503] [Table 16]

[0504] Payload value Instructions ‘11111111'b ACK ‘00000000'b NACK ‘00110011'b SOD ‘11001100'b EOD

[0505] In Table 16, when the payload value is '11111111'b, the payload value indicates that the wireless power transmitting device successfully received and decoded the ADT data packet (ACK) sent by the wireless power receiving device in the immediately preceding ADT. When the payload value is '00000000'b, the payload value indicates that the wireless power transmitting device failed to receive and decode the ADT data packet sent by the wireless power receiving device in the immediately preceding ADT (NACK). In this case, the wireless power receiving device retransmits the immediately preceding ADT data packet in the current ADT, and in this case, the header of the ADT data packet has a value corresponding to the retransmission of the immediately preceding data packet (e.g., 0x1C). When the payload value is '00110011'b, the payload value indicates the start of a requested ADT data stream (SOD). When the payload value is '11001100'b, the payload value indicates the end of an ADT data stream (EOD). In Table 16, the payload values ​​and indications are examples, and different values ​​can be used as the payload values ​​corresponding to each indication, which correspond to the technical scope of the present invention.

[0506] The following description discloses an implementation of an authentication sequence based on the same low-level packet structure and data transmission as the ADT described above.

[0507] 2) Lower-level data transaction sequences used for authentication (based on ADT)

[0508] Figure 53 This is a diagram illustrating the state machine for writing ADT data packets according to an embodiment.

[0509] refer to Figure 53 The sending and / or receiving sides perform data stream synchronization according to rule 3, such as... Figure 53As shown. That is, whenever a new ADT data packet [n] is sent for synchronization, the header of the ADT data packet [n] can be switched. The header of the ADT data packet [n] can indicate the ADT data packet, and in this case, the header of the ADT data packet can include multiple types of headers (e.g., header A and header B). Whenever a new ADT data packet is successfully sent (ACK), the header of the ADT data packet is switched to A->B or B->A, thus enabling data stream synchronization. When the wireless power receiving device receives a NACK response from the wireless power transmitting device or when the wireless power receiving device detects a decoding error in the wireless power transmitting device, the wireless power receiving device retransmits the immediately preceding ADT data packet, and in this case, the immediately preceding header value can be retained.

[0510] 2-1) Authentication of wireless power receiving devices to wireless power transmitting devices (PRx authentication of PTx)

[0511] As a low-level authentication sequence based on ADT, the authentication of the wireless power receiving device to the wireless power transmitting device will be described first (PRx = initiator / PTx = responder).

[0512] Figure 54 The high-level and low-level transmission sequences of the wireless power transmitting device and the wireless power receiving device when exchanging ADT data packets are illustrated according to an embodiment.

[0513] refer to Figure 54 H_A represents an A-type header, and H_B represents a B-type header. In the wireless power receiving device (sender), when data 1 from a higher level is sent to a lower level along with header A to the wireless power transmitting device, the lower level of the wireless power transmitting device sends data 1 back to the higher level. When data 1 is successfully received, the wireless power transmitting device sends an ACK for data 1 to the wireless power receiving device. The wireless power receiving device transmits new data 2 from the higher level to the lower level and sends the new data 2 along with header B to the wireless power transmitting device. In this case, if the wireless power transmitting device fails to receive data 2, it sends a NACK to the wireless power receiving device. Since the wireless power receiving device receives the NACK, it retransmits data 2 along with the immediately preceding header B. In this way, the wireless power receiving device and the wireless power transmitting device can achieve synchronization and implement a simple and robust error recovery and synchronization mechanism.

[0514] Figure 55The diagram illustrates the high-level and low-level transmission sequences of a wireless power transmitting device and a wireless power receiving 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 exchange of ADT data packets between the wireless power receiving device and the transmitting device is performed according to the above-described (1) low-level authentication sequence and (2) lower-level data transaction protocol.

[0515] refer to Figure 55 The wireless power receiving device generates an M-byte CHALLENGE message at a higher level to transmit the CHALLENGE message to a lower level, and the lower level loads the CHALLENGE message into an ADT data packet (or transmission) and sends the ADT data packet (or transmission) to the wireless power transmitting device.

[0516] According to the lower-level authentication sequence, the ADT data packets of the CHALLENGE message can be sent multiple times. When the ADT data packets are sent multiple times according to Rule 2, the wireless power transmitting device sends an ACK / NACK for each round of ADT data packets to the wireless power receiving device at the lower level and transmits the ADT data packets to the higher level. When the transmission of the CHALLENGE message (higher-level perspective) or the ADT data packets of the CHALLENGE message (lower-level perspective) is completed through this series of processes, the wireless power receiving device appends an EOD to the end of the ADT data packets of the CHALLENGE message according to Rule 4 to notify of the completion of transmission.

[0517] The wireless power receiving device queries whether there is a data stream to be transmitted by the wireless power transmitting device, which is a slave device according to Rule 1. For this purpose, the wireless power receiving device may send a Single Omission (SOD). In this case, the wireless power receiving device may repeatedly send the SOD until the wireless power transmitting device responds with a data packet or a timeout occurs. When the wireless power transmitting device receives the SOD, it generates an N-byte CHALLENGE_AUTH_RESPONSE at a higher level and sends the CHALLENGE_AUTH_RESPONSE to a lower level. The lower level then loads the CHALLENGE_AUTH_RESPONSE into an ADT data packet (or transmission) and sends the ADT data packet (or transmission) to the wireless power receiving device.

[0518] The ADT data packets of the CHALLENGE_AUTH_RESPONSE message can be sent several times according to the low-level authentication sequence. When the ADT data packets are sent several times according to Rule 2, the wireless power receiving device sends an ACK / NACK for each round of ADT data packets to the wireless power transmitting device at the lower level and transmits the ADT data packets to the higher level. When the transmission of the CHALLENGE_AUTH_RESPONSE message (high-level angle) or the ADT data packets of the CHALLENGE_AUTH_RESPONSE message (lower-level angle) is completed through this series of processes, the wireless power transmitting device appends an EOD to the end of the ADT data packets of the CHALLENGE_AUTH_RESPONSE message according to Rule 4 to notify of the completion of transmission.

[0519] Figure 56 The high-level and low-level transmission sequences of the wireless power transmitting device and the wireless power receiving device when exchanging ADT data packets are shown according to another embodiment.

[0520] Figure 56 Implementation methods and Figure 55 The implementation differs in that SOD and EOD are added strictly according to rule 4, and a general request packet is used instead of SOD for querying (or polling) when sending each ADT data packet according to rule 1.

[0521] Figure 57 The diagram illustrates the exchange sequence of ADT data packets for an authentication request message according to an implementation.

[0522] refer to Figure 57 When the bitstream (i.e., 35 bytes) for the authentication message is ready, the wireless power receiving device transmits an ADT data packet at a low level, including a header (i.e., 1 byte) and a payload (i.e., 34 bytes). Here, the authentication message may be, for example, a CHALLENGE message sent from the wireless power receiving device to the wireless power transmitting device.

[0523] Since a maximum of 16 bytes of ADT data packets can be sent, the 35-byte authentication message is divided into a 16-byte zero ADT data packet (ADT_PRx(0)), a 16-byte first ADT data packet (ADT_PRx(1)), and a 3-byte second ADT data packet (ADT_PRx(2)) and sent.

[0524] First, in the first line, after successfully sending the zeroth ADT data packet (ADT_PRx(0)), the wireless power receiving device receives an ACK, but fails to send the first ADT data packet (ADT_PRx(1)) and receives a NACK. Then, in the second line, the wireless power receiving device retransmits the first ADT data packet (ADT_PRx(1)), but fails to receive its response (ACK or NACK) and sends a NACK. Therefore, when the wireless power transmitting device responds with an ACK, it is determined that the retransmission of the first ADT data packet (ADT_PRx(1)) was successful, and thus the wireless power receiving device successfully sends the remaining 3 bytes of the second ADT data packet (ADT_PRx(2)) and receives an ACK. Therefore, the wireless power receiving device successfully sends an EOD and receives an ACK, thus ending the transmission of the authentication message.

[0525] Figure 58 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment. Figure 58 Implementation methods and Figure 57 The difference in the implementation is that when the wireless power receiving device divides the total 35-byte authentication message into a 16-byte zeroth ADT data packet (ADT_PRx(0)), a 16-byte first ADT data packet (ADT_PRx(1)), and a 3-byte second ADT data packet (ADT_PRx(2)) and transmits them, the wireless power receiving device switches the header of each ADT data packet according to rule 3 (header A <-> header B). However, when the wireless power receiving device retransmits the ADT data packets, it performs simplified synchronization and uses the previously used headers equally. Figure 58 The header B in the message indicates that it should be resent.

[0526] Figure 59 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment. Figure 59 Implementation methods and Figure 58 The commonality in the implementation methods is that when the wireless power receiving device divides the total 35-byte authentication message into a 16-byte zeroth ADT data packet (ADT_PRx(0)), a 16-byte first ADT data packet (ADT_PRx(1)), and a 3-byte second ADT data packet (ADT_PRx(2)) and transmits them, the wireless power receiving device switches the header of each ADT data packet (header A <-> header B) according to rule 3, but Figure 59 Implementation methods and Figure 58 The difference in the implementation method is that the wireless power receiving device adds SOD when initiating the transmission of ADT data packets.

[0527] Figure 60 The exchange order of ADT data packets for an authentication request message according to another embodiment is shown. Figure 60 Implementation methods and Figure 58 The difference in implementation is that when the wireless power receiving device divides the total 35-byte authentication message into a 16-byte zeroth ADT data packet (ADT_PRx(0)), a 16-byte first ADT data packet (ADT_PRx(1)), and a 3-byte second ADT data packet (ADT_PRx(2)) and transmits them, if the transmission of the second ADT data packet (ADT_PRx(2)) fails, the header should not be switched. However, in the state of header switching, the second ADT data packet (ADT_PRx(2)) is retransmitted. Here, a bit-mode response can be used instead of the ADT response packet of the wireless power transmitting device, thereby reducing the ADT switching time.

[0528] Figure 61 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment. Figure 61 The implementation describes the following scenario: when the wireless power receiving device divides a total of 35 bytes of authentication message into a 16-byte zero ADT data packet (ADT_PRx(0)), a 16-byte first ADT data packet (ADT_PRx(1)), and a 3-byte second ADT data packet (ADT_PRx(2)) and sends them, the zero ADT data packet (ADT_PRx(0)) and the 16-byte first ADT data packet (ADT_PRx(1)) are successfully sent, but there is no response to the transmission of the second ADT data packet (ADT_PRx(2)), so the transmission fails.

[0529] Figure 62 The diagram illustrates the exchange sequence of ADT data packets for an authentication request message according to an implementation.

[0530] return Figure 62 Prepare a bitstream (i.e., 99 bytes) for the authentication response message. The authentication response message could be, for example, a CHALLENGE_AUTH_RESPONSE message sent from a wireless power transmitter to a wireless power receiver.

[0531] When using the PTx->PRx direction communication protocol (i.e., FSK), up to 4 bytes of ADT data packets can be sent. Therefore, the 99-byte authentication response message is divided into a 4-byte zeroth ADT data packet (ADT_PTx(0)), a 4-byte first ADT data packet (ADT_PTx(1)), ..., a 4-byte twenty-third ADT data packet (ADT_PTx(23)) and a 3-byte twenty-fourth ADT data packet (ADT_PTx(24)) and sent.

[0532] First, when the wireless power receiving device sends a SOD to the wireless power transmitting device for polling, the wireless power transmitting device receives an ACK after successfully sending the zeroth ADT data packet (ADT_PTx(0)). However, the wireless power transmitting device fails to send the first ADT data packet (ADT_PTx(1)) and receives a NACK. Then, the wireless power transmitting device retransmits the first data packet ADT (ADT_PTx(1)), but fails to receive its ACK and sends a NACK. Then, when the wireless power receiving device responds with an ACK, it determines that the retransmission of the first ADT data packet (ADT_PTx(1)) was successful, so the wireless power transmitting device sends the second ADT data packet (ADT_PTx(2)). After repeating the ADT packet transmission sequence, the wireless power transmitting device successfully sends the last remaining 3 bytes of the twenty-fourth ADT data packet (ADT_PTx(24)) and receives an ACK. Therefore, the wireless power transmitting device successfully sends an EOD and receives an ACK, thus ending the transmission of the authentication response message.

[0533] Figure 63 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment. Figure 63 Implementation methods and Figure 62 The difference in implementation is that when the wireless power transmitting device divides the total 99 bytes of authentication message into a 4-byte zeroth ADT data packet (ADT_PRx(0)), a 4-byte first ADT data packet (ADT_PRx(1)), ..., a 4-byte twenty-third ADT data packet (ADT_PTx(23)), and a 3-byte twenty-fourth ADT data packet (ADT_PTx(24)) and transmits them, the wireless power transmitting device switches the header of each ADT data packet according to rule 3 (header A <-> header B). However, when the wireless power transmitting device retransmits the first ADT data packet, the wireless power transmitting device uses the previously used header equally. Figure 62 The header B in the message performs a simplified synchronization and instructs retransmission.

[0534] Figure 64The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment. Figure 64 Implementation methods and Figure 63 The similarity in the implementation method is that when the wireless power transmitting device divides the total 99 bytes of authentication message into a 4-byte zeroth ADT data packet (ADT_PRx(0)), a 4-byte first ADT data packet (ADT_PRx(1)), ..., a 4-byte twenty-third ADT data packet (ADT_PTx(23)), and a 3-byte twenty-fourth ADT data packet (ADT_PTx(24)) and transmits them, the wireless power receiving device switches the header of each ADT data packet (header A <-> header B) according to rule 3, but Figure 64 Implementation methods and Figure 63 The difference in implementation is that the wireless power receiving device uses GRP when polling the wireless power transmitting device, and the wireless power transmitting device responds with SOD and begins transmitting ADT data packets.

[0535] Figure 65 An exchange sequence of ADT data packets for an authentication response message according to another embodiment is shown. Figure 65 Implementation methods and Figure 64 The difference in implementation is that when the wireless power transmitting device divides the total 99 bytes of authentication message into a 4-byte zero ADT data packet (ADT_PRx(0)), a 4-byte first ADT data packet (ADT_PRx(1)), ..., a 4-byte twenty-third ADT data packet (ADT_PTx(23)) and a 3-byte twenty-fourth ADT data packet (ADT_PTx(24)) and transmits it, if the wireless power receiving device fails to transmit the first ADT data packet (ADT_PRx(1)), the header should not be switched. However, in the state of switching the header, the first data packet ADT (ADT_PTx(1)) is retransmitted.

[0536] Figure 66 An exchange sequence of ADT data packets for an authentication response message according to another embodiment is shown. Figure 66The implementation describes the following scenario: when the wireless power transmitting device divides a total of 99 bytes of authentication message into a 4-byte zero ADT data packet (ADT_PRx(0)), a 4-byte first ADT data packet (ADT_PRx(1)), ..., a 4-byte twenty-third ADT data packet (ADT_PTx(23)) and a 3-byte twenty-fourth ADT data packet (ADT_PTx(24)) and transmits them, the zero ADT data packet (ADT_PRx(0)) is successfully transmitted, but there is no response to the first ADT data packet (ADT_PRx(1)), so the transmission fails.

[0537] 2-2) Authentication of wireless power transmitting devices to wireless power receiving devices (PTx authentication of PRx)

[0538] As a low-level authentication sequence based on ADT, the authentication of the wireless power transmitting device to the wireless power receiving device will be described (PTx = initiator / PRx = responder). When Rule 1 is followed, the wireless power transmitting device is the slave device, therefore, when the wireless power transmitting device is determined to act as the authentication initiator based on the AI ​​bit in the capability packet of the wireless power transmitting device, the wireless power receiving device should provide the ADT to the wireless power transmitting device.

[0539] Figure 67 The high-level and low-level transmission sequences of the wireless power transmitting device and the wireless power receiving device during the exchange of ADT data packets, according to an embodiment, are shown. Here, the wireless power transmitting device is the authentication initiator, and the wireless power receiving device is the authentication responder. The exchange of ADT data packets between the wireless power receiving device and the transmitting device is performed according to the above-described (1) low-level authentication sequence and (2) lower-level data transaction protocol.

[0540] refer to Figure 67 The wireless power transmitting device is polled by a Single Distributed Oscillator (SOD) provided by the wireless power receiving device. At a higher level, an M-byte Challenge message is generated and transmitted to a lower level. The lower level then loads the Challenge message into an ADT data packet (or transmission) and sends the ADT data packet (or transmission) to the wireless power receiving device. In this scenario, the wireless power receiving device can repeatedly send the SOD until the wireless power transmitting device responds with an ADT data packet or a timeout occurs.

[0541] According to the lower-level authentication sequence, the ADT data packets of the CHALLENGE message can be sent multiple times. While the ADT data packets are being sent multiple times according to Rule 2, the wireless power receiving device sends an ACK / NACK for each round of ADT data packets to the wireless power transmitting device at the lower level and transmits the ADT data packets to the higher level. When the transmission of the CHALLENGE message (at the higher level) or the ADT data packets of the CHALLENGE message (at the lower level) is completed through this series of processes, the wireless power transmitting device appends an EOD to the end of the ADT data packets on the CHALLENGE message according to Rule 4 to notify of the completion of transmission.

[0542] Since the wireless power receiving device operates as the master device according to rule 1, the wireless power receiving device generates an N-byte CHALLENGE message at a higher level and transmits the CHALLENGE message to a lower level without polling the CHALLENGE_AUTH_RESPONSE message to be sent separately. The lower level then loads the CHALLENGE message into an ADT data packet (or transmission) and sends the ADT data packet (or transmission) to the wireless power transmitting device.

[0543] According to the low-level authentication sequence, the ADT data packets of the CHALLENGE_AUTH_RESPONSE message can be sent multiple times. When the ADT data packets are sent multiple times according to rule 2, the wireless power transmitting device sends an ACK / NACK for each round of ADT data packets to the wireless power receiving device at the lower level and transmits the ADT data packets to the higher level. When the transmission of the CHALLENGE_AUTH_RESPONSE message (high-level angle) or the ADT data packets of the CHALLENGE_AUTH_RESPONSE message (lower-level angle) is completed through this series of processes, the wireless power receiving device appends an EOD to the end of the ADT data packets of the CHALLENGE_AUTH_RESPONSE message according to rule 4 to notify of the completion of transmission.

[0544] Figure 68 The high-level and low-level transmission sequences of the wireless power transmitting device and the wireless power receiving device during the exchange of ADT data packets, according to another embodiment, are shown.

[0545] Figure 68 The implementation method strictly adds SOD and EOD according to rule 4 when sending each ADT data packet, but with... Figure 67 The difference in implementation is that the wireless power receiving device uses General Request Packets (GRPs) instead of SODs to query (or poll) according to Rule 1.

[0546] Figure 69 The diagram illustrates the exchange sequence of ADT data packets for an authentication request message according to an implementation.

[0547] refer to Figure 69 When the bitstream (i.e., 35 bytes) for the authentication request message is ready, the wireless power transmitting device waits to transmit an ADT data packet, including a header (i.e., 1 byte) and a payload (i.e., 34 bytes), at a lower level. Here, the authentication request message could be, for example, a CHALLENGE message.

[0548] In this scenario, the wireless power receiving device performs a polling operation to determine if there is data to be transmitted from the wireless power transmitting device, and for this purpose, the wireless power receiving device repeatedly sends a SOD until the wireless power transmitting device responds or a timeout occurs.

[0549] When the wireless power transmitting device receives the opportunity to send an authentication request message via SOD, it initiates the transmission of ADT data packets. When using the PTx->PRx direction communication protocol (FSK), up to 4 bytes of ADT data packets can be sent. Therefore, the 35-byte authentication message is divided into a 4-byte zeroth ADT data packet (ADT_PRx(0)), a 4-byte first ADT data packet (ADT_PTx(1)), ..., a 4-byte seventh ADT data packet (ADT_PTx(7)) and a 3-byte eighth ADT data packet (ADT_PTx(8)) and transmitted.

[0550] First, after successfully sending the zeroth ADT data packet (ADT_PTx(0)), the wireless power transmitting device receives an ACK, but fails to send the first ADT data packet (ADT_PTx(1)) and receives a NACK. Then, the wireless power transmitting device retransmits the first ADT data packet (ADT_PTx(1)), but fails to receive its ACK response and sends a NACK. When the wireless power receiving device responds with an ACK, it determines that the retransmission of the first ADT data packet (ADT_PTx(1)) was successful, and therefore the wireless power transmitting device sends the next second ADT data packet (ADT_PTx(2)). When the transmission of all ADT data packets up to the last ADT data packet is completed, the wireless power transmitting device successfully sends an EOD and receives an ACK, thus ending the transmission of the authentication request message.

[0551] Figure 70 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment. Figure 70 Implementation methods and Figure 69The difference in implementation is that when the wireless power transmitting device divides the total 35-byte authentication request message into a 4-byte zeroth ADT data packet (ADT_PTx(0)), a 4-byte first ADT data packet (ADT_PTx(1)), ..., a 4-byte seventh ADT data packet (ADT_PTx(7)) and a 3-byte eighth ADT data packet (ADT_PTx(8)) and transmits them, the wireless power transmitting device switches the header of each ADT data packet according to rule 3 (header A<->B). However, when the wireless power transmitting device retransmits the ADT data packets, the wireless power transmitting device uses the previously used header equally. Figure 58 The header B in the message performs a simplified synchronization and instructs retransmission.

[0552] Figure 71 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment. Figure 71 Implementation methods and Figure 70 The similarity in the implementation method is that when the wireless power transmitting device divides the total 35-byte authentication request message into a 4-byte zeroth ADT data packet (ADT_PTx(0)), a 4-byte first ADT data packet (ADT_PTx(1)), ..., a 4-byte seventh ADT data packet (ADT_PTx(7)), and a 3-byte eighth ADT data packet (ADT_PTx(8)) and transmits them, the wireless power transmitting device switches the header of each ADT data packet according to rule 3 (header A<->B), but... Figure 71 Implementation methods and Figure 70 The difference in implementation is that the wireless power receiving device uses GRP when polling the wireless power transmitting device, and the wireless power transmitting device responds using SOD, thus initiating the transmission of ADT packet data.

[0553] Figure 72 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment. Figure 72 Implementation methods and Figure 71 The difference in implementation is that when the wireless power transmitting device divides the total 35-byte authentication request message into a 4-byte zeroth ADT data packet (ADT_PTx(0)), a 4-byte first ADT data packet (ADT_PTx(1)), ..., a 4-byte seventh ADT data packet (ADT_PTx(7)), and a 3-byte eighth ADT data packet (ADT_PTx(8)) and transmits it, the wireless power transmitting device receives the RPP and transmits the RFA bit mode in mode 0 to obtain the opportunity to transmit the ADT data packet. In addition, Figure 72 Implementation methods and Figure 71 The difference in implementation is that when the transmission of the first ADT data packet (ADT_PTx(1)) fails, the header should not be switched, but the first ADT data packet (ADT_Px(1)) is retransmitted in the state of switching the header.

[0554] Figure 73 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment. Figure 73 The implementation describes the following scenario: when a wireless power transmitting device divides a total of 35 bytes of authentication request message into a 4-byte zero ADT data packet (ADT_PTx(0)), a 4-byte first ADT data packet (ADT_PTx(1)), ..., a 4-byte seventh ADT data packet (ADT_PTx(7)) and a 3-byte eighth ADT data packet (ADT_PTx(8)) and transmits them, the zero ADT data packet (ADT_PTx(0)) is successfully transmitted, but there is no response to the first ADT data packet (ADT_PTx(1)), so the transmission fails.

[0555] Figure 74 The diagram illustrates the exchange sequence of ADT data packets for an authentication request message according to an implementation.

[0556] refer to Figure 74 When the bitstream of the authentication response message (i.e., 99 bytes) is ready, the wireless power receiving device transmits an ADT data packet at a low level, including a header (i.e., 1 byte) and a payload (i.e., 34 bytes). Here, the authentication response message can be, for example, a CHALLENGE_AUTH_RESPONSE message.

[0557] After successfully sending the zeroth ADT data packet (ADT_PRx(0)), the wireless power receiving device receives an ACK. However, the wireless power receiving device fails to send the first ADT data packet (ADT_PRx(1)) and receives a NACK. Then, the wireless power receiving device retransmits the first ADT data packet (ADT_PRx(1)), but fails to receive its ACK and sends a NACK. When the wireless power transmitting device responds with an ACK, it determines that the retransmission of the first ADT data packet (ADT_PRx(1)) was successful, so the wireless power receiving device sends the second ADT data packet (ADT_PRx(2)). After repeating this sequence of ADT packet transmissions, the wireless power transmitting device successfully sends the last remaining ADT data packet (ADT_PRx) and receives an ACK. Then, the wireless power receiving device successfully sends an EOD and receives an ACK, thus ending the transmission of the authentication response message.

[0558] Figure 75 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment. Figure 75 Implementation methods and Figure 74 The difference in implementation is that when the wireless power receiving device divides the total 99-byte authentication response message into a 16-byte zeroth ADT data packet (ADT_PRx(0)), a 16-byte first ADT data packet (ADT_PRx(1)), ..., a 16-byte fifth ADT data packet (ADT_PRx(5)), and a 3-byte sixth ADT data packet (ADT_PRx(6)) and transmits them, the wireless power receiving device switches the header of each ADT data packet according to rule 3 (header A<->B), and when retransmitting the first ADT data packet, the wireless power receiving device uses the previously used header equally ( Figure 75 The header B in the message performs a simplified synchronization and instructs retransmission.

[0559] Figure 76 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment. Figure 76 Implementation methods and Figure 75 The difference in the implementation is that when the wireless power receiving device divides the total 99-byte authentication response message into a 16-byte zero ADT data packet (ADT_PRx(0)), a 16-byte first ADT data packet (ADT_PRx(1)), ..., a 16-byte fifth ADT data packet (ADT_PRx(5)) and a 3-byte sixth ADT data packet (ADT_PRx(6)) and sends it, if the transmission of the first ADT data packet (ADT_PRx(1)) fails, the header should not be switched. However, in the state of switching the header, the first data packet ADT (ADT_PRx(1)) is retransmitted.

[0560] Figure 77 The diagram illustrates an exchange sequence of ADT data packets for an authentication request message according to another embodiment. Figure 77The implementation describes the following scenario: when the wireless power receiving device divides a total of 99 bytes of authentication response message into a 16-byte zero ADT data packet (ADT_PRx(0)), a 16-byte first ADT data packet (ADT_PRx(1)), ... a 16-byte fifth ADT data packet (ADT_PRx(5)) and a 3-byte sixth ADT data packet (ADT_PRx(6)) and sends them, the zero ADT data packet (ADT_PRx(0)) is successfully sent, but there is no response to the sending of the first ADT data packet (ADT_PRx(1)), so the sending fails.

[0561] 2-3) Simultaneous authentication between wireless power transmitting and receiving devices (simultaneous authentication between PTx and PRx) (Time verification)

[0562] Both the wireless power transmitting device and the wireless power receiving device can operate as authentication initiators simultaneously.

[0563] As an example, the wireless power transmitting device may send an ADT that includes an authentication-related packet, instead of an ADT that includes an ACK for a packet received from the wireless power receiving device. In this case, by receiving an ADT that includes an authentication-related packet, it can be assumed that the wireless power receiving device has implicitly received an ACK and can perform the following operation: when the wireless power transmitting device sends an ADT that includes data (the authentication-related packet), even if the wireless power receiving device receives a data ADT instead of an ACK, the wireless power receiving device can determine that the ADT data immediately preceding it was successfully transmitted. However, if a communication error occurs in the ADT data immediately preceding it received from the wireless power receiving device, the wireless power transmitting device may send a NACK. An ADT that includes an authentication-related packet may also include an ACK.

[0564] As another example, the wireless power receiving device may send an ADT that includes an authentication-related packet, instead of an ADT that includes an ACK for a packet received from the wireless power transmitting device. In this case, by receiving an ADT that includes an authentication-related packet, it can be assumed that the wireless power transmitting device has implicitly received an ACK and can perform the following actions. That is, when the wireless power receiving device sends an ADT that includes data (the authentication-related packet), even if the wireless power transmitting device receives a data ADT instead of an ACK, the wireless power receiving device can determine that the ADT data immediately preceding it was successfully transmitted. An ADT that includes an authentication-related packet may also include an ACK.

[0565] 2-4) Communication Start Protocol for Wireless Power Transmitting Devices

[0566] When the wireless power transmitting device operates as a slave device based on Rule 1, the wireless power receiving device can provide opportunities for communication initiated by the wireless power transmitting device (PTx-initiated communication) by performing periodic polling. In this case, the communication of the wireless power transmitting device becomes highly dependent on the wireless power receiving device. By periodically polling the wireless power transmitting device, the wireless power receiving device can determine whether the wireless power transmitting device has packets to transmit. In this case, it can use... Figure 78 GRP. Reference Figure 78 For example, by setting a General Request Packet (GRP) to "0xFF", "00", or "FF", the wireless power receiving device can perform polling. When the wireless power transmitting device receives a GRP set to "0xFF", "00", or "FF", the wireless power transmitting device is in a state where it can transmit any type of packet it wants to send.

[0567] As another method to further ensure communication opportunities initiated by the wireless power transmitting device, the wireless power transmitting device can send a communication request (RFC) bit mode in response to the wireless power receiving device's RPP (except for mode '100'b). When the wireless power receiving device receives the RFC response, it polls the wireless power transmitting device using GPR at a time appropriate to its own. The wireless power receiving device does not know precisely when the target power value managed by the wireless power transmitting device will change, and the desired communication start time of the wireless power transmitting device can be relatively well guaranteed by the RFC response of the wireless power transmitting device.

[0568] Specifically, polling via RFC responses can be used for power management initiated by the wireless power transmitter (PTx-initiated power management). Through power management initiated by the wireless power transmitter, the wireless power transmitter can change (increase or decrease) the target power by taking into account the current peripheral charging conditions.

[0569] Figure 79 A power management transmission sequence initiated by a wireless power transmitting device according to an embodiment is shown.

[0570] refer to Figure 79 The wireless power transmitting device responds to the wireless power receiving device's RPP (Mode 0) by sending an alarm to the wireless power receiving device, including an RFC response (bit mode). The wireless power receiving device sends a GRP to the wireless power transmitting device, where the request value is set to "0xFF". Then, the wireless power transmitting device sends a target power packet to the wireless power receiving device. The wireless power receiving device can control its operating mode based on the changed target power.

[0571] 6. Applications related to the certification process

[0572] The authentication function can be turned on / off by the user. For example, a smartphone can display the activation / deactivation of the authentication function to the user through an application, and receive input from the user regarding the selection information for activation (on) or deactivation (off) to activate or deactivate the authentication function.

[0573] Wireless power transmitting and receiving devices can provide a very convenient user experience and interface (UX / UI). Specifically, they can provide smart wireless charging services. These services can be implemented based on the UX / UI of a smartphone that includes the wireless power transmitting device. For this application, the interface between the smartphone's processor and the wireless charging receiver allows for "drop-and-play" bidirectional communication between the wireless power transmitting and receiving devices.

[0574] As an example, a user can experience a smart wireless charging service in a hotel. When a user enters a hotel room and places their smartphone on the wireless charger in the room, the wireless charger sends wireless power to the smartphone, which receives the power. During this process, the wireless charger sends information about the smart wireless charging service to the smartphone. When the smartphone detects that it has been placed on the wireless charger, when it detects the reception of wireless power, or when it receives information about the smart wireless charging service from the wireless charger, the smartphone enters a state where it asks the user to optionally add additional features. For this purpose, the smartphone can display a message on the screen, with or without a warning sound. Examples of such messages could include phrases like "Welcome to ### Hotel. Select 'Yes' to activate the smart charging function: Yes / No, thank you." The smartphone receives the user's input of "Yes or No, thank you" and proceeds to the next step of the process. When "Yes" is selected, the smartphone sends a message to the wireless charger. The smartphone and the wireless charger then work together to perform the smart charging function.

[0575] Smart wireless charging services can also include the receipt of automatically filled WiFi credentials. For example, the wireless charger sends WiFi credentials to a smartphone, and the smartphone executes an appropriate application to automatically enter the WiFi credentials received from the wireless charger.

[0576] Smart wireless charging services can also include the operation of a hotel app that provides remote check-in / check-out and access to contact information or hotel promotions.

[0577] As another example, users can experience smart wireless charging services in their vehicles. When a user gets into the car and places their smartphone on the wireless charger, the charger sends wireless power to the smartphone, which then receives it. In this process, the wireless charger sends information about the smart wireless charging service to the smartphone. When the smartphone detects that it has been placed on the wireless charger, detects the reception of wireless power, or receives information about the smart wireless charging service from the charger, it enters a state where it asks for the user's identity.

[0578] In this state, the smartphone automatically connects to the vehicle via WiFi and / or Bluetooth. The smartphone may display a message on the screen, with or without a warning sound. Examples of such messages may include phrases like "Welcome to the vehicle. Select 'Yes' to sync your device with in-vehicle controls: Yes / No, thank you." The smartphone receives the user's "Yes or No, thank you" input and executes the next step selected by the user. When 'Yes' is selected, the smartphone sends a message to the wireless charger. The smartphone and wireless charger can power in-vehicle applications / display software to perform intelligent control functions and software within the vehicle. The user can enjoy popular music and determine a regular map location. The in-vehicle applications / display software may include the ability to provide sync access for passersby.

[0579] As another example, users can experience smart wireless charging at home. When a user enters a room and places their smartphone on a wireless charger in the room, the wireless charger sends wireless power to the smartphone, and the smartphone receives the wireless power. In this process, the wireless charger sends information about the smart wireless charging service to the smartphone. When the smartphone detects that it has been placed on the wireless charger, detects the reception of wireless power, or receives information about the smart wireless charging service from the wireless charger, the smartphone enters a state asking the user whether to selectively add additional features. For this purpose, the smartphone can display a message on the screen, with or without a warning sound. Examples of messages may include phrases such as "Hello, xxx, would you like to activate night mode and protect the building?: Yes / No, thank you." The smartphone receives the user's input of "Yes or No, thank you" and executes the next step of the process selected by the user. When "Yes" is selected, the smartphone sends a message to the wireless charger. The smartphone and the wireless charger can at least recognize the user's pattern and may suggest locking doors and windows, turning off lights, or setting warnings for the user.

[0580] In the wireless power transmission method and apparatus or receiving device and method according to embodiments of the present invention, since not all components or steps are necessary, the wireless power transmission device and method or receiving device and method can be performed by including some or all of the aforementioned components or steps. Furthermore, embodiments of the wireless power transmission device and method or receiving device and method can be combined. Additionally, the aforementioned components or steps do not necessarily need to be performed in the above order, and the steps described later may be performed before the steps described earlier.

[0581] The foregoing description merely illustrates the technical concept of the present invention. Those skilled in the art can make various changes and modifications without departing from the essential characteristics of the present invention. Therefore, the foregoing embodiments of the present invention can be implemented individually or in combination.

[0582] Therefore, the embodiments disclosed in this invention are for illustrative purposes only and not for limiting the scope of the invention, and the concepts of the invention are not limited to these embodiments. The scope of protection of this invention should be understood in accordance with the following claims, and all technical ideas within the equivalent scope of the claims should be understood to fall within the scope of this invention.

Claims

1. A method for authenticating a wireless power transmitter by a wireless power receiver in a wireless power transmission system, comprising: During the configuration phase, a configuration packet is sent to the wireless power transmitter, including an AI flag related to whether the wireless power receiver supports the authentication function of the wireless power transmitter, wherein the configuration packet further includes a negotiation Neg field related to entering the negotiation phase or entering the power transmission phase from the configuration phase; Based on entering the negotiation phase, during the negotiation phase, a capability packet including an AR flag related to whether the wireless power transmitter supports the authentication function is received from the wireless power transmitter; Following the negotiation phase, an authentication request message is sent to the wireless power transmitter based on the value of the AR flag; and Receive an authentication response message from the wireless power transmitter.

2. The method according to claim 1, wherein, The AI ​​flag is said to have 1 bit. Wherein, based on the value of the AI ​​flag being '0', the wireless power receiver does not support the authentication function, and Specifically, the wireless power receiver supports the authentication function based on the value of the AI ​​flag being '1'.

3. The method according to claim 2, wherein, Based on the value of the AI ​​flag being '1', the wireless power receiver operates as the authentication initiator.

4. The method according to claim 1, wherein, The AR flag is assigned 1 bit. Wherein, based on the AR flag value of '0', the wireless power transmitter does not support the authentication function, and Specifically, the wireless power transmitter supports the authentication function based on the value of the AR flag being '1'.

5. The method according to claim 4, wherein, The wireless power transmitter operates as an authentication responder based on the value of the AR flag being '1'.

6. A method for authenticating a wireless power transmitter by a wireless power receiver in a wireless power transmission system, comprising: During the configuration phase, a configuration packet is received from the wireless power receiver including an AI flag related to whether the wireless power receiver supports the authentication function of authenticating the wireless power transmitter, wherein the configuration packet further includes a negotiation Neg field related to entering the negotiation phase or entering the power transmission phase from the configuration phase; Based on entering the negotiation phase, during the negotiation phase, a capability packet including an AR flag related to whether the wireless power transmitter supports the authentication function is sent to the wireless power receiver; Following the negotiation phase, an authentication request message is received from the wireless power receiver based on the value of the AR flag; and Send an authentication response message to the wireless power receiver.

7. The method according to claim 6, wherein, The AI ​​flag is said to have 1 bit. Wherein, based on the value of the AI ​​flag being '0', the wireless power receiver does not support the authentication function, and Specifically, the wireless power receiver supports the authentication function based on the value of the AI ​​flag being '1'.

8. The method according to claim 7, wherein, Based on the value of the AI ​​flag being '1', the wireless power receiver operates as the authentication initiator.

9. The method according to claim 6, wherein, The AR flag is assigned 1 bit. Wherein, based on the AR flag value of '0', the wireless power transmitter does not support the authentication function, and Specifically, the wireless power transmitter supports the authentication function based on the value of the AR flag being '1'.

10. The method according to claim 9, wherein, The wireless power transmitter operates as an authentication responder based on the value of the AR flag being '1'.

11. A wireless power receiver for performing authentication of a wireless power transmitter in a wireless power transmission system, wherein the wireless power receiver is configured to: During the configuration phase, a configuration packet is sent to the wireless power transmitter including an AI flag related to whether the wireless power receiver supports the authentication function of the wireless power transmitter. The configuration group further includes a negotiation Neg field related to entering the negotiation phase from the configuration phase or entering the power transmission phase from the configuration phase; Based on entering the negotiation phase, during the negotiation phase, a capability packet including an AR flag related to whether the wireless power transmitter supports the authentication function is received from the wireless power transmitter; Following the negotiation phase, an authentication request message is sent to the wireless power transmitter based on the value of the AR flag; as well as Receive an authentication response message from the wireless power transmitter.

12. The wireless power receiver according to claim 11, wherein, The AI ​​flag is said to have 1 bit. Wherein, based on the value of the AI ​​flag being '0', the wireless power receiver does not support the authentication function, and Specifically, the wireless power receiver supports the authentication function based on the value of the AI ​​flag being '1'.

13. The wireless power receiver according to claim 12, wherein, Based on the value of the AI ​​flag being '1', the wireless power receiver operates as the authentication initiator.

14. The wireless power receiver according to claim 11, wherein, The AR flag is assigned 1 bit. Wherein, based on the AR flag value of '0', the wireless power transmitter does not support the authentication function, and Specifically, the wireless power transmitter supports the authentication function based on the value of the AR flag being '1'.

15. The wireless power receiver according to claim 14, wherein, The wireless power transmitter operates as an authentication responder based on the value of the AR flag being '1'.

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