NFC polling method, NFC system and related apparatus

Abstract

Provided in the embodiments of the present application are an NFC polling method, an NFC system and a related apparatus. When an NFC card reading device supports a first NFC protocol and a second NFC protocol, the NFC card reading device may be enabled to transmit card search requests of the first NFC protocol and card search requests of the second NFC protocol within each of a plurality of polling duration periods in an order of a card search request of the first NFC protocol, a card search request of the second NFC protocol, a card search request of the first NFC protocol and a card search request of the second NFC protocol. When an NFC apparatus supports the first NFC protocol and the second NFC protocol, after entering a radio frequency field, the NFC apparatus may preferentially choose to reply to the NFC card reading device with a card search response of the first NFC protocol, such that the NFC card reading device and the NFC apparatus preferentially choose the first NFC protocol to perform NFC interaction.

Description

NFC polling method, NFC system and related device

[0001] This application claims priority to Chinese Patent Application No. 202410990197.1, filed on July 23, 2024, entitled “NFC Polling Method, NFC System and Related Device,” and Chinese Patent Application No. 202411489258.2, filed on October 23, 2024, entitled “NFC Polling Method, NFC System and Related Device,” both of which are incorporated by reference in their entirety. TECHNICAL FIELD

[0002] The present application relates to the field of near field communication technology, and in particular to an NFC polling method, an NFC system and related device. BACKGROUND

[0003] With the development of wireless communication technology, near field communication (NFC) technology has been widely applied. NFC technology is evolved from non-contact radio frequency identification (RFID) and interconnection technology. In NFC technology, the working mode of an NFC device with NFC function when communicating through NFC technology can be divided into three types: proximity coupling device (PCD) mode (also known as reader mode), proximity integrated circuit card (PICC) mode (also known as card simulation mode), and point to point (P2P) mode.

[0004] The NFC reading device in the PCD mode can generate a radio frequency field. The NFC device in the PICC mode can enter the radio frequency field generated by the NFC reading device. The NFC reading device can perform polling: the NFC reading device can periodically send a card search request and wait for the NFC device in the PICC mode to reply to a card search response. If the NFC protocol supported by the NFC device in the PICC mode can identify the card search request sent by the NFC reading device, it indicates that the NFC reading device and the NFC device in the PICC mode both support the same NFC protocol. Therefore, the NFC device in the PICC mode replies to the NFC reading device with a card search response corresponding to the card search request. If the NFC reading device supports multiple NFC protocols, because the card search requests corresponding to different NFC protocols are different, how to perform polling of multiple NFC protocols so that the NFC reading device can quickly find a suitable NFC device in the PICC mode becomes a problem to be solved by those skilled in the art. SUMMARY

[0005] The present application provides a NFC polling method, a NFC system and related devices, which realize that the NFC reading device sends a card search request of a first NFC protocol and a card search request of a second NFC protocol in the order of the card search request of the first NFC protocol, the card search request of the second NFC protocol, the card search request of the first NFC protocol and the card search request of the second NFC protocol in each polling duration of multiple polling durations. When the NFC device supports the first NFC protocol and the second NFC protocol, the NFC device can preferentially select to reply to the NFC reading device with a card search response of the first NFC protocol after entering the radio frequency field, so that the NFC reading device and the NFC device preferentially select the first NFC protocol for NFC interaction.

[0006] In a first aspect, the embodiments of the present application provide a NFC polling method applied to a NFC reading device, the method comprising: continuously sending a card search request of a first NFC protocol and a card search request of a second NFC protocol, wherein the first NFC protocol is different from the second NFC protocol, and one or more card search requests of the first NFC protocol are sent between adjacent two card search requests of the second NFC protocol; if a card search response of the first NFC protocol or a card search response of the second NFC protocol sent by a NFC device is received, the sending of the card search request of the first NFC protocol and the card search request of the second NFC protocol is stopped.

[0007] When the NFC reading device supports the first NFC protocol and the second NFC protocol, the NFC reading device can send the card search request of the first NFC protocol and the card search request of the second NFC protocol in the order of the card search request of the first NFC protocol, the card search request of the second NFC protocol, the card search request of the first NFC protocol and the card search request of the second NFC protocol in each polling duration period of the plurality of polling duration periods. When the NFC device supports the first NFC protocol and the second NFC protocol, the NFC device can preferentially select the card search response of the first NFC protocol to the NFC reading device after entering the radio frequency field, so that the NFC reading device and the NFC device preferentially select the first NFC protocol to perform NFC interaction.

[0008] In a possible implementation, the card search request of the first NFC protocol is a probe frame, and the card search response of the first NFC protocol is a probe acknowledgment frame.

[0009] In a possible implementation, the second NFC protocol includes a class-A NFC protocol and / or a class-B NFC protocol and / or a class-F NFC protocol.

[0010] In a possible implementation, when the second NFC protocol includes the class-A NFC protocol but does not include the class-B NFC protocol and the class-F NFC protocol, the card search request of the second NFC protocol includes a class-A request command REQ_A, and the card search response of the second NFC protocol includes a class-A request response ATQ_A; and the continuously sending the card search request of the first NFC protocol and the card search request of the second NFC protocol specifically includes: sending one or more probe frames first and then sending one REQ_A in each polling duration period of one or more polling duration periods.

[0011] In this way, when the NFC reading device supports the first NFC protocol and the class-A NFC protocol, the NFC reading device can alternately send the card search request of the first NFC protocol and the card search request of the class-A NFC protocol, so that the NFC device supporting the first NFC protocol and / or the class-A NFC protocol has an opportunity to perform NFC interaction with the NFC reading device.

[0012] In a possible implementation, in a case where the second NFC protocol includes the B-class NFC protocol but does not include the A-class NFC protocol and the F-class NFC protocol, the card search request of the second NFC protocol includes a B-class request command REQ B, and the card search response of the second NFC protocol includes a B-class request response ATQ B; and the continuously sending the card search request of the first NFC protocol and the card search request of the second NFC protocol specifically includes: in each polling time period in the one or more polling duration periods, first sending one or more Probe frames, and then sending one REQ B.

[0013] In this way, when the NFC card reading device supports the first NFC protocol and the B-class NFC protocol, the NFC card reading device can be caused to alternately send the card search request of the first NFC protocol and the card search request of the B-class NFC protocol, so that the NFC device supporting the first NFC protocol and / or the B-class NFC protocol has an opportunity to interact with the NFC card reading device.

[0014] In a possible implementation, in a case where the second NFC protocol includes the F-class NFC protocol but does not include the A-class NFC protocol and the B-class NFC protocol, the card search request of the second NFC protocol includes a sensing request command SENS REQ, and the card search response of the second NFC protocol includes a sensing response SENS RES; and the continuously sending the card search request of the first NFC protocol and the card search request of the second NFC protocol specifically includes: in each polling time period in the one or more polling duration periods, first sending one or more Probe frames, and then sending one SENS REQ.

[0015] In this way, when the NFC card reading device supports the first NFC protocol and the F-class NFC protocol, the NFC card reading device can be caused to alternately send the card search request of the first NFC protocol and the card search request of the F-class NFC protocol, so that the NFC device supporting the first NFC protocol and / or the F-class NFC protocol has an opportunity to interact with the NFC card reading device.

[0016] In a possible implementation, in a case where the second NFC protocol includes the A-class NFC protocol and the B-class NFC protocol but does not include the F-class NFC protocol, the card search request of the second NFC protocol includes REQ A and REQ B, and the card search response of the second NFC protocol includes ATQ A or ATQ B; and the continuously sending the card search request of the first NFC protocol and the card search request of the second NFC protocol specifically includes: in each polling time period in the one or more polling duration periods, first sending one or more Probe frames, then sending one REQ A, then sending one or more Probe frames, and then sending one REQ B.

[0017] In this way, when the NFC reading device supports the first NFC protocol, the A-class NFC protocol and the B-class NFC protocol, the NFC reading device can be caused to send the multiple NFC protocol probe requests in the order of the first NFC protocol probe request, the A-class NFC protocol probe request, the first NFC protocol probe request and the B-class NFC protocol probe request in each of the one or more polling duration periods, so that the NFC devices supporting the first NFC protocol and / or the A-class NFC protocol and / or the B-class NFC protocol all have the opportunity to communicate with the NFC reading device in NFC, and the NFC devices preferentially select the first NFC protocol for NFC interaction.

[0018] In a possible implementation, in a case where the second NFC protocol includes the A-class NFC protocol and the F-class NFC protocol but does not include the B-class NFC protocol, the probe request of the second NFC protocol includes REQ_A and SENS_REQ, and the probe response of the second NFC protocol includes ATQ_A or SENS_RES; and the continuously sending the first NFC protocol probe request and the second NFC protocol probe request specifically includes: in each of the one or more polling duration periods, first sending one or more Probe frames, then sending one REQ_A, then sending one or more Probe frames, and then sending one SENS_REQ.

[0019] In this way, when the NFC reading device supports the first NFC protocol, the A-class NFC protocol and the F-class NFC protocol, the NFC reading device can be caused to send the multiple NFC protocol probe requests in the order of the first NFC protocol probe request, the A-class NFC protocol probe request, the first NFC protocol probe request and the F-class NFC protocol probe request in each of the one or more polling duration periods, so that the NFC devices supporting the first NFC protocol and / or the A-class NFC protocol and / or the F-class NFC protocol all have the opportunity to communicate with the NFC reading device in NFC, and the NFC devices preferentially select the first NFC protocol for NFC interaction.

[0020] In a possible implementation, in a case where the second NFC protocol includes the B-class NFC protocol and the F-class NFC protocol but does not include the A-class NFC protocol, the probe request of the second NFC protocol includes REQ_B and SENS_REQ, and the probe response of the second NFC protocol includes ATQ_B or SENS_RES; and the continuously sending the first NFC protocol probe request and the second NFC protocol probe request specifically includes: in each of the one or more polling duration periods, first sending one or more Probe frames, then sending one REQ_B, then sending one or more Probe frames, and then sending one SENS_REQ.

[0021] In this way, when the NFC card reading device supports the first NFC protocol, the B-class NFC protocol and the F-class NFC protocol, the NFC card reading device can be caused to send the multiple NFC protocol probe requests in the order of the first NFC protocol probe request, the B-class NFC protocol probe request, the first NFC protocol probe request and the F-class NFC protocol probe request in each of the multiple polling duration periods, so that the NFC devices supporting the first NFC protocol and / or the B-class NFC protocol and / or the F-class NFC protocol all have the opportunity to communicate with the NFC card reading device in NFC, and the NFC devices preferentially select the first NFC protocol for NFC interaction.

[0022] In a possible implementation, when the second NFC protocol includes the A-class NFC protocol, the B-class NFC protocol and the F-class NFC protocol, the probe request of the second NFC protocol includes REQ_B, REQ_B and SENS_REQ, and the probe response of the second NFC protocol includes ATQ_A or ATQ_B or SENS_RES; and the continuously sending the first NFC protocol probe request and the second NFC protocol probe request specifically includes: in each of the one or more polling duration periods, sending one or more Probe frames first, then sending one REQ_A, then sending one or more Probe frames, then sending one REQ_B, then sending one or more Probe frames, and then sending one SENS_REQ.

[0023] In this way, when the NFC card reading device supports the first NFC protocol, the A-class NFC protocol, the B-class NFC protocol and the F-class NFC protocol, the NFC card reading device can be caused to send the multiple NFC protocol probe requests in the order of the first NFC protocol probe request, the A-class NFC protocol probe request, the first NFC protocol probe request, the B-class NFC protocol probe request, the first NFC protocol probe request and the F-class NFC protocol probe request in each of the multiple polling duration periods, so that the NFC devices supporting the first NFC protocol and / or the A-class NFC protocol and / or the B-class NFC protocol and / or the F-class NFC protocol all have the opportunity to communicate with the NFC card reading device in NFC, and the NFC devices preferentially select the first NFC protocol for NFC interaction.

[0024] In a possible implementation, the method further includes: adjusting the number of first NFC protocol probe requests sent between adjacent two sent second NFC protocol probe requests according to the proportion of the first NFC protocol probe responses received in a historical period of time.

[0025] In this way, the number of the card search requests of the first NFC protocol sent between two adjacent card search requests of the second NFC protocol can be adjusted according to the proportion of the card search responses of the first NFC protocol in the historical records, so that the speed of the NFC card reading device discovering the NFC device is adjusted.

[0026] In a possible implementation, the greater the proportion of the card search responses of the first NFC protocol received in the historical period, the more the number of the card search requests of the first NFC protocol sent between two adjacent card search requests of the second NFC protocol.

[0027] In this way, the sending frequency of the card search requests of the first NFC protocol can be adjusted according to the proportion of the card search responses of the first NFC protocol in the historical records, so that the NFC card reading device can quickly discover the NFC device supporting the first NFC protocol.

[0028] In a possible implementation, the method further includes: sending, to a server, first geographic location information of the NFC card reading device; receiving a first instruction sent by the server, the first instruction being used to instruct the NFC card reading device to send a first number of card search requests of the first NFC protocol between two adjacent card search requests of the second NFC protocol; and after receiving the first instruction, sending the first number of card search requests of the first NFC protocol between two adjacent card search requests of the second NFC protocol.

[0029] In this way, the server can adjust the number of the card search requests of the first NFC protocol sent between two adjacent card search requests of the second NFC protocol according to the proportion of the first NFC protocol used by a large number of NFC card reading devices in a certain geographic region in the historical records, so that the NFC card reading device can quickly discover the NFC device.

[0030] In a possible implementation, the method further includes: if the card search response of the first NFC protocol sent by the NFC device is received, interacting with the NFC device based on the first NFC protocol.

[0031] In a possible implementation, the method further includes: if the card search response of the second NFC protocol sent by the NFC device is received, interacting with the NFC device based on the second NFC protocol.

[0032] In a second aspect, the embodiments of the present application provide another NFC polling method, applied to an NFC device, the method comprising: if a first card search request successfully received after entering a radio frequency field generated by an NFC card reading device is a card search request of a first NFC protocol, sending a card search response of the first NFC protocol to the NFC card reading device in response to the first card search request; if the first card search request successfully received after entering the radio frequency field generated by the NFC card reading device is a card search request of a second NFC protocol, continuing to receive a second card search request; if the second card search request successfully received after entering the radio frequency field generated by the NFC card reading device is the card search request of the first NFC protocol, sending the card search response of the first NFC protocol to the NFC card reading device in response to the second card search request.

[0033] By the NFC polling method provided by the embodiments of the present application, when the NFC device supports the first NFC protocol and the second NFC protocol, the NFC device can preferentially reply to the NFC card reading device with a card search response of the first NFC protocol after entering the radio frequency field generated by the NFC card reading device, so that the NFC card reading device and the NFC device preferentially select the first NFC protocol for NFC interaction.

[0034] In a possible implementation, the method further comprises: if the second card search request successfully received after entering the radio frequency field generated by the NFC card reading device is a card search request of the second NFC protocol, sending a card search response of the second NFC protocol to the NFC card reading device in response to the second card search request.

[0035] In a possible implementation, the card search request of the first NFC protocol is a Probe frame, and the card search response of the first NFC protocol is a Probe ACK frame.

[0036] In a possible implementation, the card search request of the second NFC protocol comprises REQ_A or REQ_B or SENS_REQ, and the card search response of the second NFC protocol comprises ATQ_A or ATQ_B or SENS_RES.

[0037] In a third aspect, the embodiments of the present application provide an NFC system, comprising: an NFC card reading device and an NFC device; wherein the NFC card reading device is configured to perform the NFC polling method in the first aspect and any possible implementation of the first aspect; and the NFC device is configured to perform the NFC polling method in the second aspect and any possible implementation of the second aspect.

[0038] In a fourth aspect, an embodiment of the present application provides an NFC card reading device, comprising one or more processors, one or more memories, and a transceiver. The transceiver, the one or more memories, and the one or more processors are coupled, and the one or more memories are configured to store a computer program. When the one or more processors execute the computer program, the NFC card reading device performs the NFC polling method in the first aspect and any possible implementation of the first aspect.

[0039] In a fifth aspect, an embodiment of the present application provides an NFC device, comprising one or more processors, one or more memories, and a transceiver. The transceiver, the one or more memories, and the one or more processors are coupled, and the one or more memories are configured to store a computer program. When the one or more processors execute the computer program, the NFC device performs the NFC polling method in the second aspect and any possible implementation of the second aspect.

[0040] In a sixth aspect, an embodiment of the present application provides a computer storage medium, storing a computer program. When the computer program is executed by a processor, the NFC polling method in the first aspect and any possible implementation of the first aspect is implemented.

[0041] In a seventh aspect, an embodiment of the present application provides a computer storage medium, storing a computer program. When the computer program is executed by a processor, the NFC polling method in the second aspect and any possible implementation of the second aspect is implemented.

[0042] In an eighth aspect, an embodiment of the present application provides a computer program product, comprising a computer program. When the computer program is executed by a processor, the NFC polling method in the first aspect and any possible implementation of the first aspect is implemented.

[0043] In a ninth aspect, an embodiment of the present application provides a computer program product, comprising a computer program. When the computer program is executed by a processor, the NFC polling method in the second aspect and any possible implementation of the second aspect is implemented.

[0044] The beneficial effects of the third aspect to the ninth aspect and any possible implementation of the third aspect to the ninth aspect can refer to the beneficial effects of the first aspect and any possible implementation of the first aspect or the second aspect and any possible implementation of the second aspect, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0045] FIG. 1 is a schematic diagram of an NFC working principle according to an embodiment of the present application;

[0046] Figure 2 is a schematic diagram of an architecture of an NFC system according to an embodiment of the present application;

[0047] Figure 3 is a schematic diagram of an architecture of an electronic device according to an embodiment of the present application;

[0048] Figure 4 is a schematic diagram of an NFC protocol stack according to an embodiment of the present application;

[0049] Figure 5 is a schematic diagram of a polling mechanism of a single NFC protocol according to an embodiment of the present application;

[0050] Figure 6 is a schematic diagram of a multi-NFC protocol polling mechanism of a first NFC protocol and a class A NFC protocol according to an embodiment of the present application;

[0051] Figure 7 is a schematic diagram of a multi-NFC protocol polling mechanism of a first NFC protocol and a class B NFC protocol according to an embodiment of the present application;

[0052] Figure 8 is a schematic diagram of a multi-NFC protocol polling mechanism of a first NFC protocol and a class F NFC protocol according to an embodiment of the present application;

[0053] Figure 9 is a schematic diagram of a multi-NFC protocol polling mechanism of a first NFC protocol, a class A NFC protocol and a class B NFC protocol according to an embodiment of the present application;

[0054] Figure 10 is a schematic diagram of a multi-NFC protocol polling mechanism of a first NFC protocol, a class A NFC protocol and a class F NFC protocol according to an embodiment of the present application;

[0055] Figure 11 is a schematic diagram of a multi-NFC protocol polling mechanism of a first NFC protocol, a class B NFC protocol and a class F NFC protocol according to an embodiment of the present application;

[0056] Figure 12 is a schematic diagram of a multi-NFC protocol polling mechanism of a first NFC protocol, a class A NFC protocol, a class B NFC protocol and a class F NFC protocol according to an embodiment of the present application;

[0057] Figure 13 is a flowchart of a NFC polling method according to an embodiment of the present application;

[0058] Figure 14A is a schematic diagram of a polling of a first NFC protocol and a class A NFC protocol according to an embodiment of the present application;

[0059] Figure 14B is a schematic diagram of a polling of a first NFC protocol and a class B NFC protocol according to an embodiment of the present application;

[0060] Figure 14C is a schematic diagram of a polling of a first NFC protocol and a class F NFC protocol according to an embodiment of the present application;

[0061] FIG. 14D is a schematic diagram of polling of the first NFC protocol, the A-type NFC protocol and the B-type NFC protocol according to an embodiment of the present application;

[0062] FIG. 14E is a schematic diagram of polling of the first NFC protocol, the A-type NFC protocol and the F-type NFC protocol according to an embodiment of the present application;

[0063] FIG. 14F is a schematic diagram of polling of the first NFC protocol, the B-type NFC protocol and the F-type NFC protocol according to an embodiment of the present application;

[0064] FIG. 14G is a schematic diagram of polling of the first NFC protocol, the A-type NFC protocol, the B-type NFC protocol and the F-type NFC protocol according to an embodiment of the present application;

[0065] FIG. 15 is a schematic diagram of a hardware structure of an electronic device according to an embodiment of the present application;

[0066] FIG. 16 is a schematic diagram of a structure of a communication apparatus according to an embodiment of the present application;

[0067] FIG. 17 is a schematic diagram of a structure of another communication apparatus according to an embodiment of the present application;

[0068] FIG. 18 is a schematic diagram of a structure of another communication apparatus according to an embodiment of the present application;

[0069] FIG. 19 is a schematic diagram of a structure of another communication apparatus according to an embodiment of the present application. DETAILED DESCRIPTION

[0070] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in the text only means a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which means that there are three cases of A alone, A and B together, and B alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0071] Hereinafter, the terms "first" and "second" are only for descriptive purposes, and cannot be understood as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first" and "second" can explicitly or implicitly include one or more features, and in the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more than two.

[0072] The working principle of NFC in the embodiments of the present application will be described below.

[0073] FIG. 1 shows a schematic diagram of a working principle of NFC according to an embodiment of the present application.

[0074] As shown in FIG. 1, the two parties communicating using NFC technology can include a proximity coupling device (PCD) (also referred to as an NFC card reader) and a proximity intelligent card (PICC). The PCD can achieve proximity contactless communication with the PICC. The PCD and the PICC can allow near field communication at a specific data rate (for example, 106 kbps, 212 kbps, 424 kbps or 848 kbps) and a specific frequency (for example, 13.56 MHz). The communication between the PCD and the PICC can occur within a close distance, for example, within a range of about 2 to 4 centimeters.

[0075] The PCD can generate high-frequency alternating current to generate a radio frequency field at a specified frequency (for example, 13.56 MHz) and transmit data to the PICC through the radio frequency field. After the PICC approaches the PCD, the PICC can induct the radio frequency field emitted by the PCD. The PICC can obtain energy from the radio frequency field of the PCD through electromagnetic induction after entering the radio frequency field emitted by the PCD, and generate power by means of the obtained energy to drive the circuit inside the PICC, analyze the data transmitted by the PCD through the radio frequency field, and thus realize data transmission from the PCD to the PICC. The PICC can also send data to the PCD by modulating the radio frequency field, thus realizing data transmission from the PICC to the PCD.

[0076] In the embodiments of the present application, the PICC can be a physical NFC tag card, and some electronic devices (for example, mobile phones, tablets, smart watches and other electronic devices) can also simulate themselves into a PICC conforming to NFC related standards by using the data of an NFC simulation card to realize the functions of the PICC and interact with the PCD through NFC.

[0077] The following describes an NFC system provided in the embodiments of the present application.

[0078] FIG. 2 shows a schematic diagram of an architecture of an NFC system 10 according to an embodiment of the present application.

[0079] As shown in FIG. 2, the NFC system 10 can include an electronic device 100 and an NFC card reader 200. The electronic device 100 can simulate itself into a PICC conforming to NFC related standards by using the data information of an NFC simulation card to realize the functions of the PICC. The NFC card reader 200 can interact with the electronic device 100 in the PICC mode through NFC as a PCD.

[0080] In a possible case, the electronic device 100 can support both the PICC mode and the PCD mode. In the PCD mode, the electronic device 100 can communicate with the PICC as a PCD by transmitting a radio frequency field. In the PICC mode, the electronic device 100 can be simulated as a PICC conforming to the NFC related standards by the data information of the NFC analog card, passively receive the radio frequency field transmitted by the PCD, and interact with the PCD by the NFC through the load modulation technology.

[0081] In the embodiments of the present application, the device type of the electronic device 100 can be any one of a mobile phone, a tablet computer, a handheld computer, a desktop computer, a laptop computer, an ultra-mobile personal computer (UMPC), a netbook, a cellular phone, a personal digital assistant (PDA), and a smart large screen, a smart speaker, and the like smart home device, a smart bracelet, a smart watch, smart glasses, and the like wearable device, an augmented reality (AR), a virtual reality (VR), a mixed reality (MR), and the like extended reality (XR) device, a vehicle-mounted device or a smart city device, and the like.

[0082] The device type of the NFC card reading device 200 can be any one of a mobile phone, a tablet computer, a handheld computer, a desktop computer, a laptop computer, an ultra-mobile personal computer, a netbook, a cellular phone, a personal digital assistant, and a smart large screen, a smart speaker, and the like smart home device, a smart bracelet, a smart watch, smart glasses, and the like wearable device, an augmented reality, a virtual reality, a mixed reality, and the like extended reality device, a vehicle, a gate, a smart door lock, a card swiping device, a point of sale (POS) terminal, a ticket buying and / or checking terminal, a bank service terminal, an identification card reading device, and the like.

[0083] The structure of the electronic device 100 provided in the embodiments of the present application is introduced below.

[0084] FIG. 3 shows a structure of an electronic device 100 provided in the embodiments of the present application.

[0085] As shown in FIG. 3, the electronic device 100 can include a processor 101 and an NFC module 102. Among them, one or more applications can be run in the processor 101. Among them, one or more applications can include one or more of a wallet application, one or more host-based card emulation (HCE) applications, and the like. Optionally, the electronic device 100 can also include a secure element (SE) 103 and / or a subscriber identity module (SIM) card. The processor 101 can be connected with the NFC module 102, the SE 103, and the SIM card 104, respectively. The NFC module 102 can also be connected with the SE 103 and the SIM card 104.

[0086] The NFC module 102 can include an NFC controller (not shown in FIG. 3), an NFC transceiver (not shown in FIG. 3), and an NFC memory (not shown in FIG. 3). Among them, the NFC controller can be connected with the processor 101, and the NFC controller can also be connected with the NFC transceiver and the NFC memory, respectively.

[0087] The NFC controller is mainly used for the modulation and demodulation of non-contact communication signals, controls the input and output of data in the NFC memory, and interacts with the processor 101. The NFC transceiver is used to realize the sending and receiving of NFC signals (for example, 13.56 MHz radio frequency signals), which can include an electromagnetic compatibility (EMC) filter circuit, a matching circuit, a receiving circuit, and an NFC antenna, etc., wherein the NFC antenna can be a loop antenna, which is used to realize the proximity-based non-contact communication capability of the NFC module 102. The NFC memory can be used to store data sent by the NFC module 102 to the NFC card reading device 200, and data received from the NFC card reading device 200. In some embodiments, the NFC memory can be one memory, which can be shared by the above components in the NFC module 102, for example, some data in the NFC memory can be called by the NFC controller, and other data can be called by the SE 103.

[0088] In some embodiments, the NFC memory can also store routing information. In some embodiments, the routing information can be controlled or managed by the NFC controller. The routing information can include a routing table, which is composed of a list of routing rules. Each routing rule can include an applet identifier (AID) and a destination. The destination can be where the applet that implements the business logic of the NFC emulation card is running. The destination can include a HCE application running in the processor 101 of the electronic device 100, or the SE 103 or the SIM card 104 connected to the NFC controller.

[0089] In some embodiments, the NFC memory can also store routing information. In some embodiments, the routing information can be controlled or managed by the NFC controller. The routing information can include a routing table, which is composed of a list of routing rules. Each routing rule can include an applet identifier (AID) and a destination. The destination can be where the applet that implements the business logic of the NFC emulation card is running. The destination can include a HCE application running in the processor 101 of the electronic device 100, or the SE 103 or the SIM card 104 connected to the NFC controller.

[0090] The SE 103 and the NFC module 102 can be two independent chips. Alternatively, the SE 103 and the NFC module 102 can be packaged in one chip.

[0091] The electronic device 100 can open one or more NFC emulation cards in an application according to the user's input, so that the electronic device 100 supports one or more NFC services. The service processing logic of the NFC emulation card in the electronic device 100 is implemented by an applet. The applet can be stored and run in the hardware device or software module (e.g., HCE application, SIM card, SE, etc.) corresponding to the NFC emulation card.

[0092] The NFC emulation mode on the electronic device 100 can be divided into a hardware-based virtual card mode and a software-based HCE mode.

[0093] 1. In the hardware-based virtual card mode, the electronic device 100 can provide a running environment of an Applet corresponding to an NFC emulation card and storage and processing of service data of the NFC emulation card through the SE 103 or the SIM card 104. The NFC module 102, as a front end of contactless communication, forwards a command received from an external PCD to the SE 103 or the SIM card 104, and then the command is processed by an Applet in the SE 103 or the SIM card 104 and response data is sent to the external PCD through the NFC module 102. A user can open one or more NFC emulation cards in a wallet application, and the wallet application can write the Applet and card data of the one or more NFC emulation cards into the SE 103. Alternatively, the user can open one or more NFC emulation cards in a SIM card application. The SIM card application can write the Applet and card data of the one or more NFC emulation cards into the SIM card 104 for storage.

[0094] 2. In the software-based HCE mode, an HCE application running in the processor 101 can provide a running environment of an Applet corresponding to an NFC emulation card and storage and processing of service data of the NFC emulation card. After receiving a command sent by an external PCD, the NFC module 102 can send the command to the HCE application. The HCE application can process the command received by the NFC module through an Applet running in the HCE application or a cloud server, and generate response data for the PCD. The HCE application can send the response data to the NFC module 102. The NFC module 102 can send the response data to the external PCD. A user can open one or more NFC emulation cards in the HCE application, and the HCE application can run the Applet of the one or more NFC emulation cards and save the card data of the NFC emulation cards on a local storage of the electronic device 100 or on a cloud server.

[0095] Optionally, the processor 101 can also run an NFC basic service module. The NFC basic service module can be used to provide common management functions for one or more NFC services. The common management functions can include file management, card long activation, security management, service routing management, and the like.

[0096] Exemplarily, in the card emulation scenario described above, a native application related to NFC is installed in the electronic device 100, and in addition, a third-party application can also be downloaded and installed in the electronic device 100 by a user through an application store. Generally, the native application can adopt a hardware-based virtual card scheme, and the third-party application can adopt an HCE scheme. The native application can be a wallet application or the like. The above examples are merely used for explaining the present application, and should not be construed as limiting.

[0097] Next, a NFC protocol stack provided in an embodiment of the present application is introduced.

[0098] FIG. 4 shows a NFC protocol stack provided in an embodiment of the present application.

[0099] As shown in FIG. 4, the NFC protocol stack can include a physical layer, a radio frequency layer, an access layer, a transmission layer and an application layer.

[0100] The physical layer can be used to implement physical characteristics in NFC technology communication.

[0101] The radio frequency layer can be used to implement radio frequency specifications in NFC technology communication, for example, data rate, frequency of radio frequency signals and the like.

[0102] The access layer can be used to implement functions such as polling and device discovery, service result notification, card conflict management, transmission protocol negotiation, timeout and retransmission mechanism, PICC / PCD mode switching, and fusion card selection.

[0103] The transmission layer includes a high-speed data transmission protocol, through which data transmission between PCD and PICC in the application layer can be implemented.

[0104] The application layer can be used to implement one or more NFC services and one or more service management strategies. The one or more NFC services can include codeless payment, electronic ticket, access control, digital ID card, full-scene tap-to-tap, near field data transmission and the like. The one or more service management strategies can include any one or more of file management, card long activation, security management, and service routing management. The processing logic of the NFC service can be executed by an Applet. In a possible implementation manner, the processing logic of the service management strategy can be executed by an NFC base service module.

[0105] Next, a polling mechanism of a single NFC protocol provided in an embodiment of the present application is introduced.

[0106] FIG. 5 shows a polling mechanism of a single NFC protocol provided in an embodiment of the present application.

[0107] As shown in FIG. 5, the NFC reader 200 can support a single NFC protocol, and the NFC reader 200 can periodically send a card search request of the NFC protocol in a polling process until receiving a card search response of the NFC protocol.

[0108] If the NFC protocol is a first NFC protocol, the card search request of the first NFC protocol can be a Probe frame, and the card search response of the first NFC protocol can be a Probe ACK frame.

[0109] If the NFC protocol is a Type A NFC protocol, the card search request of the Type A NFC protocol can be a request command type A (REQ_A), and the card search response of the Type A NFC protocol can be an answer to request type A (ATQ_A).

[0110] If the NFC protocol is a Type B NFC protocol, the card search request of the Type B NFC protocol can be a request command type B (REQ_B), and the card search response of the Type B NFC protocol can be an answer to request type B (ATQ_B).

[0111] If the NFC protocol is a Type F NFC protocol, the card search request of the Type F NFC protocol can be a sense request command (SENS_REQ), and the card search response of the Type F NFC protocol can be a sense response (SENSF_RES).

[0112] The polling mechanism of the single NFC protocol is as follows:

[0113] 5.1. When the NFC reader 200 is in a PCD mode, the NFC reader 200 can generate a radio frequency field and send a card search request according to a polling period. Each polling period includes a polling phase and a listening phase. In a polling period, the listening phase is after the polling phase. The NFC reader 200 can send a card search request in the polling phase and wait for a card search response returned by an NFC device in the listening phase.

[0114] For example, in the polling phase of the i-th polling cycle, the NFC reader 200 can send a card search request 1. In the listening phase of the i-th polling cycle, since the NFC reader 200 does not receive a card search response, the NFC reader 200 continues to send a card search request 2 in the polling phase of the i+1-th polling cycle. In the listening phase of the i+1-th polling cycle, since the NFC reader 200 does not receive a card search response, the NFC reader 200 continues to send a card search request 3 in the polling phase of the i+2-th polling cycle.

[0115] 5.2 When the NFC device is in the PICC mode and enters the radio frequency field generated by the NFC reader 200, the NFC device can receive the card search request sent by the NFC reader 200 and send a card search response to the NFC reader 200 after receiving the card search request.

[0116] In each polling cycle, the duration of the listening phase can be referred to as a frame guard time. Since the end time of sending the card search request by the NFC reader 200 can be different in each polling cycle, the duration of the listening phase in different polling cycles is different. In order to ensure that the card search response sent by the NFC device can be received by the NFC reader 200 within the duration of the listening phase, the time of sending the card search response by the NFC device needs to meet the following requirements: min-fgt > T transfer + T f-req + T f-res + T ack-timeout + ΔT req + ΔT res Formula (1)

[0117] In formula (1), T min-fgt is the minimum value of the frame guard time, that is, the minimum value of the duration of the listening phase. T transfer is the transmission time of the card search request from the NFC reader 200 to the NFC device, which can also be referred to as the transmission time of the card search request. T f-req is the time length of the card search request. T f-res is the time length of the card search response. T ack - timeout is the maximum time interval between the time of receiving the card search request by the NFC device and the time of replying the card search response, which can also be referred to as the confirmation time (ACK_Timeout). ΔT req is the time of analyzing the card search request by the NFC device after receiving the card search request. ΔT res is the time of analyzing the card search response by the NFC reader 200 after receiving the card search response.

[0118] As can be seen from the above formula (1), the NFC device needs to start sending the card search response to the NFC card reading device 200 within the confirmation time length after receiving the card search request, so as to ensure that the NFC card reading device 200 can receive the card search response in the listening stage.

[0119] For example, the NFC device can enter the radio frequency field generated by the NFC card reading device 200 in the listening stage of the i+1th polling cycle. After entering the radio frequency field generated by the NFC card reading device 200, the NFC device successfully receives the card search request 3 sent by the NFC card reading device 200 in the polling stage of the i+2th polling cycle, which indicates that the NFC device supports the NFC protocol supported by the NFC card reading device 200. Therefore, the NFC device can start sending the card search response to the NFC card reading device 200 within the confirmation time length after successfully receiving the card search request 3. After receiving the card search response sent by the NFC device, the NFC card reading device 200 can determine that the NFC device supports the same NFC protocol as the NFC card reading device 200, and therefore the NFC card reading device 200 can stop polling. If the NFC device does not support the NFC protocol supported by the NFC card reading device 200, the NFC device can not send the card search response, and the NFC card reading device 200 does not receive the card search response in the listening stage of the i+2th polling cycle, and therefore continues to poll.

[0120] The polling mechanisms of two NFC protocols provided in the embodiments of the present application are described below.

[0121] FIG. 6 shows the multi-NFC protocol polling mechanism of the first NFC protocol and the A-class NFC protocol provided in the embodiments of the present application.

[0122] As shown in FIG. 6, the NFC card reading device 200 can support the first NFC protocol and the A-class NFC protocol, and the NFC card reading device 200 can periodically and alternately send the card search request of the first NFC protocol and the card search request of the A-class NFC protocol in the polling process. The card search request of the first NFC protocol can be a Probe frame, and the card search response of the first NFC protocol can be a Probe ACK frame. The card search request of the A-class NFC protocol can be a REQ_A command, and the card search response of the A-class NFC protocol can be an ATQ_A response.

[0123] The polling mechanism of the first NFC protocol and the A-class NFC protocol can be as follows:

[0124] 6.1, When the NFC reader 200 is in PCD mode, the NFC reader 200 can generate a radio frequency field and send a card search request of a first NFC protocol and a card search request of a class A NFC protocol according to a polling period. In each polling period, the NFC reader 200 sends a card search request of one NFC protocol, and in adjacent two polling periods, the NFC reader 200 sends a card search request of different NFC protocols. Each polling period includes a polling phase and a listening phase, and the listening phase is after the polling phase in each polling period. The NFC reader 200 can send a card search request in the polling phase in the polling period, and can wait for a card search response returned by the NFC device in the listening phase in the polling period.

[0125] For example, in the polling phase in the ith polling period, the NFC reader 200 can send a Probe frame 1. If the NFC reader 200 does not receive a card search response in the listening phase in the ith polling period, the NFC reader 200 can send a class A request command 1 (REQ_A1) in the polling phase in the (i+1)th polling period. If the NFC reader 200 does not receive a card search response in the listening phase in the (i+1)th polling period, the NFC reader 200 can send a Probe frame 2 in the polling phase in the (i+2)th polling period. If the NFC reader 200 does not receive a card search response in the listening phase in the (i+2)th polling period, the NFC reader 200 can send a class A request command 2 (REQ_A2) in the polling phase in the (i+3)th polling period. If the NFC reader 200 does not receive a card search response in the listening phase in the (i+3)th polling period, the NFC reader 200 can send a Probe frame 3 in the polling phase in the (i+4)th polling period.

[0126] 6.2, When the NFC device is in PICC mode and the NFC device enters the radio frequency field generated by the NFC reader 200, the NFC device can receive the card search request sent by the NFC reader 200.

[0127] Case 6.2.1: If the NFC device supports the first NFC protocol and the class A NFC protocol, and the first card search request successfully received by the NFC device after the NFC device enters the radio frequency field of the NFC reader 200 is a Probe frame, the NFC device sends a Probe ACK frame to the NFC reader 200 within a confirmation time length after the NFC device successfully receives the first card search request.

[0128] For example, the NFC device can enter the radio frequency field generated by the NFC reader 200 in the listening phase of the i+3thpolling period. The first card search request successfully received by the NFC device after entering the radio frequency field generated by the NFC reader 200 is the Probe frame 3 sent by the NFC reader 200 in the polling phase of the i+4thpolling period. Therefore, the NFC device can start sending the Probe ACK frame to the NFC reader 200 within the confirmation duration after successfully receiving the Probe frame 3. After successfully receiving the Probe ACK frame sent by the NFC device, the NFC reader 200 stops polling and performs the NFC interaction process of the first NFC protocol with the NFC device.

[0129] Case 6.2.2: If the NFC device supports the first NFC protocol and the A-type NFC protocol and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC reader 200 is REQ_A, the NFC device continues to receive the second card search request after entering the radio frequency field of the NFC reader 200. If the second card search request is a Probe frame, the NFC device sends the Probe ACK frame to the NFC reader 200 within the confirmation duration after successfully receiving the second card search request. If the second card search request is REQ_A, the NFC device sends the ATQ_A to the NFC reader 200 within the confirmation duration after successfully receiving the second card search request.

[0130] For example, the NFC device can enter the radio frequency field generated by the NFC reader 200 in the listening phase of the i+2thpolling period. The first card search request successfully received by the NFC device after entering the radio frequency field generated by the NFC reader 200 is the REQ_A2 sent by the NFC reader 200 in the polling phase of the i+3thpolling period. Therefore, the NFC device can continue to receive the second card search request after successfully receiving the REQ_A2. The second card search request successfully received by the NFC device after entering the radio frequency field generated by the NFC reader 200 is the Probe frame 3 sent by the NFC reader 200 in the polling phase of the i+3thpolling period. Therefore, the NFC device can start sending the Probe ACK frame to the NFC reader 200 within the confirmation duration after successfully receiving the Probe frame 3.

[0131] Case 6.2.3: If the NFC device supports the first NFC protocol but not the Class A NFC protocol, the NFC device will not be able to successfully receive the card search request of the Class A NFC protocol. Therefore, after entering the radio frequency field of the NFC card reader 200, if the NFC device successfully receives the Probe frame, it will send a Probe ACK frame to the NFC card reader 200 within the confirmation time after successfully receiving the Probe frame.

[0132] Case 6.2.4: If the NFC device supports Class A NFC protocol but not the first NFC protocol, the NFC device will not be able to successfully receive the card search request of the first NFC protocol. Therefore, after entering the radio frequency field of the NFC card reader 200, if the NFC device successfully receives REQ_A, it will send ATQ_A to the NFC card reader 200 within the confirmation time after successfully receiving REQ_A.

[0133] In the embodiments of this application, the relationship between the confirmation duration and the frame protection interval can be referred to the above formula (1), which will not be repeated here.

[0134] According to the NFC polling method provided in this application embodiment, when the NFC card reader 200 supports both the first NFC protocol and the Class A NFC protocol, it can alternately send card search requests using the first NFC protocol and the Class A NFC protocol. When the NFC device supports both the first NFC protocol and the Class A NFC protocol, after entering the radio frequency field, the NFC device can preferentially choose to reply with a card search response using the first NFC protocol to the NFC card reader 200, thereby allowing the NFC card reader 200 and the NFC device to preferentially choose the first NFC protocol for NFC interaction.

[0135] Figure 7 illustrates the multi-NFC protocol polling mechanism of the first NFC protocol and the Class B NFC protocol provided in the embodiments of this application.

[0136] As shown in Figure 7, the NFC card reader 200 can support both the first NFC protocol and the Class B NFC protocol. During the polling process, the NFC card reader 200 can periodically and alternately send card search requests using the first NFC protocol and the Class B NFC protocol. Specifically, the card search request using the first NFC protocol can be a probe frame, and the card search response using the first NFC protocol can be a probe ACK frame. The card search request using the Class B NFC protocol can be a Class B request command (REQ_B), and the card search response using the Class B NFC protocol can be a Class B request response (ATQ_B).

[0137] The polling mechanisms for the first NFC protocol and the Class B NFC protocol are as follows:

[0138] 7.1 When the NFC card reader 200 is in PCD mode, it can generate a radio frequency field and send card search requests for the first NFC protocol and the Class B NFC protocol according to a polling cycle. Specifically, one NFC protocol card search request is sent in each polling cycle, and card search requests for different NFC protocols are sent in adjacent polling cycles. Each polling cycle includes a polling phase and a listening phase, with the listening phase following the polling phase. During the polling phase of the polling cycle, the NFC card reader 200 can send a card search request, and during the listening phase of the polling cycle, it can wait for a card search response from the NFC device.

[0139] For example, during the polling phase of the i-th polling cycle, the NFC card reader 200 can send Probe frame 1. If the NFC card reader 200 does not receive a card search response during the listening phase of the i-th polling cycle, it can send a Type B request command 1 (REQ_B1) during the polling phase of the (i+1)-th polling cycle. If the NFC card reader 200 does not receive a card search response during the listening phase of the (i+1)-th polling cycle, it can send Probe frame 2 during the polling phase of the (i+2)-th polling cycle. If the NFC card reader 200 does not receive a card search response during the listening phase of the (i+2)-th polling cycle, it can send a Type B request command 2 (REQ_B2) during the polling phase of the (i+3)-th polling cycle. If the NFC card reader 200 does not receive a card search response during the listening phase in the (i+3)th polling cycle, the NFC card reader 200 may send Probe frame 3 during the polling phase in the (i+4)th polling cycle.

[0140] 7.2 When the NFC device is in PICC mode and enters the radio frequency field generated by the NFC card reader 200, the NFC device can receive the card search request sent by the NFC card reader 200.

[0141] Case 7.2.1: If the NFC device supports the first NFC protocol and the Class B NFC protocol, and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC card reader 200 is a Probe frame, then the NFC device sends a Probe ACK frame to the NFC card reader 200 within the confirmation time after successfully receiving the first card search request.

[0142] For example, the NFC device can enter the radio frequency field generated by the NFC reader 200 during the listening phase of the (i+3)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is Probe frame 3 sent by the NFC reader 200 during the polling phase of the (i+4)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC reader 200 within the acknowledgment time after successfully receiving Probe frame 3. After successfully receiving the Probe ACK frame sent by the NFC device, the NFC reader 200 stops polling and executes the NFC interaction process of the first NFC protocol with the NFC device.

[0143] Case 7.2.2: If the NFC device supports both the first NFC protocol and the Class B NFC protocol, and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC reader 200 is REQ_B, then the NFC device continues to receive the second card search request after entering the radio frequency field of the NFC reader 200. If the second card search request is a Probe frame, the NFC device sends a Probe ACK frame to the NFC reader 200 within the confirmation time after successfully receiving the second card search request. If the second card search request is REQ_B, the NFC device sends an ATQ_B frame to the NFC reader 200 within the confirmation time after successfully receiving the second card search request.

[0144] For example, the NFC device can enter the radio frequency field generated by the NFC card reader 200 during the listening phase of the (i+2)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is REQ_B2 sent by the NFC card reader 200 during the polling phase of the (i+3)th polling cycle. Therefore, after successfully receiving REQ_B2, the NFC device can continue to receive the second card search request. The second card search request successfully received by the NFC device after entering the radio frequency field is Probe frame 3 sent by the NFC card reader 200 during the polling phase of the (i+3)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC card reader 200 within the acknowledgment time after successfully receiving Probe frame 3.

[0145] Case 7.2.3: If the NFC device supports the first NFC protocol but not the Class B NFC protocol, the NFC device cannot successfully receive the card search request of the Class B NFC protocol. Therefore, after entering the radio frequency field of the NFC card reader 200, if the NFC device successfully receives the Probe frame, it will send a Probe ACK frame to the NFC card reader 200 within the confirmation time after successfully receiving the Probe frame.

[0146] Case 7.2.4: If the NFC device supports the Class B NFC protocol but not the first NFC protocol, the NFC device cannot successfully receive the card search request of the first NFC protocol. Therefore, after entering the radio frequency field of the NFC card reader 200, if the NFC device successfully receives REQ_B, it will send ATQ_B to the NFC card reader 200 within the confirmation time after successfully receiving REQ_B.

[0147] In the embodiments of this application, the relationship between the confirmation duration and the frame protection interval can be referred to the above formula (1), which will not be repeated here.

[0148] Using the NFC polling method shown in Figure 7, when the NFC card reader 200 supports both the first NFC protocol and the Class B NFC protocol, it can alternately send card search requests using both the first NFC protocol and the Class B NFC protocol. When the NFC device supports both the first NFC protocol and the Class B NFC protocol, after entering the radio frequency field, the NFC device can preferentially respond with a card search response using the first NFC protocol to the NFC card reader 200, thus allowing the NFC card reader 200 and the NFC device to preferentially use the first NFC protocol for NFC interaction.

[0149] Figure 8 illustrates the multi-NFC protocol polling mechanism of the first NFC protocol and the F-type NFC protocol provided in the embodiments of this application.

[0150] As shown in Figure 8, the NFC card reader 200 can support both the first NFC protocol and the Class F NFC protocol. During the polling process, the NFC card reader 200 can periodically and alternately send card search requests using the first NFC protocol and the Class F NFC protocol. Specifically, the card search request using the first NFC protocol can be a probe frame, and the card search response using the first NFC protocol can be a probe ACK frame. The card search request using the Class F NFC protocol can be a sensing request command (SENS_REQ), and the card search response using the Class F NFC protocol can be a sensing response (SENSF_RES).

[0151] The polling mechanisms for the first NFC protocol and the F-type NFC protocol are as follows:

[0152] 8.1 When the NFC card reader 200 is in PCD mode, it can generate a radio frequency field and send card search requests for the first NFC protocol and the F-type NFC protocol according to a polling cycle. Specifically, one NFC protocol card search request is sent in each polling cycle, and card search requests for different NFC protocols are sent in adjacent polling cycles. Each polling cycle includes a polling phase and a listening phase, with the listening phase following the polling phase. During the polling phase of a polling cycle, the NFC card reader 200 can send a card search request, and during the listening phase of a polling cycle, it can wait for a card search response from the NFC device.

[0153] For example, during the polling phase of the i-th polling cycle, the NFC card reader 200 can send Probe frame 1. If the NFC card reader 200 does not receive a card search response during the listening phase of the i-th polling cycle, it can send a Sensing Request Command 1 (SENS_REQ1) during the polling phase of the (i+1)-th polling cycle. If the NFC card reader 200 does not receive a card search response during the listening phase of the (i+1)-th polling cycle, it can send Probe frame 2 during the polling phase of the (i+2)-th polling cycle. If the NFC card reader 200 does not receive a card search response during the listening phase of the (i+2)-th polling cycle, it can send a Sensing Request Command 1 (SENS_REQ2) during the polling phase of the (i+3)-th polling cycle. If the NFC card reader 200 does not receive a card search response during the listening phase in the (i+3)th polling cycle, the NFC card reader 200 may send Probe frame 3 during the polling phase in the (i+4)th polling cycle.

[0154] 8.2 When the NFC device is in PICC mode and enters the radio frequency field generated by the NFC card reader 200, the NFC device can receive the card search request sent by the NFC card reader 200.

[0155] Case 8.2.1: If the NFC device supports the first NFC protocol and the F-type NFC protocol, and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC card reader 200 is a Probe frame, then the NFC device sends a Probe ACK frame to the NFC card reader 200 within the confirmation time after successfully receiving the first card search request.

[0156] For example, the NFC device can enter the radio frequency field generated by the NFC reader 200 during the listening phase of the (i+3)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is Probe frame 3 sent by the NFC reader 200 during the polling phase of the (i+4)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC reader 200 within the acknowledgment time after successfully receiving Probe frame 3. After successfully receiving the Probe ACK frame sent by the NFC device, the NFC reader 200 stops polling and executes the NFC interaction process of the first NFC protocol with the NFC device.

[0157] Case 8.2.2: If the NFC device supports the first NFC protocol and the Class F NFC protocol, and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC reader 200 is SENS_REQ, then the NFC device continues to receive the second card search request after entering the radio frequency field of the NFC reader 200. If the second card search request is a Probe frame, the NFC device sends a Probe ACK frame to the NFC reader 200 within the confirmation time after successfully receiving the second card search request. If the second card search request is SENS_REQ, the NFC device sends SENS_RES to the NFC reader 200 within the confirmation time after successfully receiving the second card search request.

[0158] For example, the NFC device can enter the radio frequency field generated by the NFC card reader 200 during the listening phase of the (i+2)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is SENS_REQ2 sent by the NFC card reader 200 during the polling phase of the (i+3)th polling cycle. Therefore, after successfully receiving SENS_REQ2, the NFC device can continue to receive the second card search request. The second card search request successfully received by the NFC device after entering the radio frequency field is Probe frame 3 sent by the NFC card reader 200 during the polling phase of the (i+3)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC card reader 200 within the acknowledgment time after successfully receiving Probe frame 3.

[0159] Case 8.2.3: If the NFC device supports the first NFC protocol but not the Class F NFC protocol, the NFC device will not be able to successfully receive the card search request of the Class F NFC protocol. Therefore, after entering the radio frequency field of the NFC card reader 200, if the NFC device successfully receives the Probe frame, it will send a Probe ACK frame to the NFC card reader 200 within the confirmation time after successfully receiving the Probe frame.

[0160] Case 8.2.4: If the NFC device supports the Class F NFC protocol but not the first NFC protocol, the NFC device will not be able to successfully receive the card search request of the first NFC protocol. Therefore, after entering the radio frequency field of the NFC card reader 200, if the NFC device successfully receives SENS_REQ, it will send SENS_RES to the NFC card reader 200 within the confirmation time after successfully receiving SENS_REQ.

[0161] In the embodiments of this application, the relationship between the confirmation duration and the frame protection interval can be referred to the above formula (1), which will not be repeated here.

[0162] Using the NFC polling method shown in Figure 8, when the NFC card reader 200 supports both the first NFC protocol and the Class F NFC protocol, it can alternately send card search requests using both the first NFC protocol and the Class F NFC protocol. When the NFC device supports both the first NFC protocol and the Class F NFC protocol, after entering the radio frequency field, the NFC device can preferentially respond with a card search response using the first NFC protocol to the NFC card reader 200, thus allowing the NFC card reader 200 and the NFC device to preferentially use the first NFC protocol for NFC interaction.

[0163] The polling mechanisms of the three NFC protocols provided in the embodiments of this application are described below.

[0164] Figure 9 illustrates the multi-NFC protocol polling mechanism provided in this embodiment of the application, which includes the first NFC protocol and Class A and Class B NFC protocols.

[0165] As shown in Figure 9, the NFC card reader 200 can support the first NFC protocol, the Class A NFC protocol, and the Class B NFC protocol. Specifically, the card search request for the first NFC protocol can be a probe frame, and the card search response can be a probe ACK frame. The card search request for the Class A NFC protocol can be a Class A request command (REQ_A), and the card search response can be a Class A request response (ATQ_A). The card search request for the Class B NFC protocol can be a Class B request command (REQ_B), and the card search response can be a Class A request response (ATQ_B).

[0166] The polling mechanisms for the first NFC protocol, the Class A NFC protocol, and the Class B NFC protocol are as follows:

[0167] 9.1 When the NFC card reader 200 is in PCD mode, it can generate a radio frequency field and send card search requests for the first NFC protocol, the Type A NFC protocol, and the Type B NFC protocol according to a polling cycle. Within each polling cycle, one NFC protocol card search request is sent. The NFC card reader 200 can send the card search requests in the order of Probe frame, REQ_A, Probe frame, REQ_B. Each polling cycle includes a polling phase and a listening phase, with the listening phase following the polling phase. During the polling phase of a polling cycle, the NFC card reader 200 can send a card search request, and during the listening phase, it can wait for a card search response from the NFC device.

[0168] For example, during the polling phase of the i-th polling cycle, the NFC card reader 200 can send Probe frame 1. If the NFC card reader 200 does not receive a card search response during the listening phase of the i-th polling cycle, it can send a Type A request command 1 (REQ_A1) during the polling phase of the (i+1)-th polling cycle. If the NFC card reader 200 does not receive a request response during the listening phase of the (i+1)-th polling cycle, it can send Probe frame 2 during the polling phase of the (i+2)-th polling cycle. If the NFC card reader 200 does not receive a card search response during the listening phase of the (i+2)-th polling cycle, it can send a Type B request command 1 (REQ_B1) during the polling phase of the (i+3)-th polling cycle. If the NFC card reader 200 does not receive a card search response during the listening phase of the (i+3)th polling cycle, the NFC card reader 200 may send Probe frame 3 during the polling phase of the (i+4)th polling cycle. If the NFC card reader 200 does not receive a card search response during the listening phase of the (i+4)th polling cycle, the NFC card reader 200 may send a Type A request command 2 (REQ_A2) during the polling phase of the (i+5)th polling cycle. If the NFC card reader 200 does not receive a card search response during the listening phase of the (i+5)th polling cycle, the NFC card reader 200 may send Probe frame 4 during the polling phase of the (i+6)th polling cycle.

[0169] 9.2 When the NFC device is in PICC mode and enters the radio frequency field generated by the NFC card reader 200, the NFC device can receive the card search request sent by the NFC card reader 200.

[0170] Case 9.2.1: If the NFC device supports the first NFC protocol (regardless of whether it supports Class A NFC protocol and / or Class B NFC protocol) and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC card reader 200 is a Probe frame, then the NFC device sends a Probe ACK frame to the NFC card reader 200 within the confirmation time after successfully receiving the first card search request.

[0171] For example, the NFC device can enter the radio frequency field generated by the NFC reader 200 during the listening phase of the (i+5)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is Probe frame 4 sent by the NFC reader 200 during the polling phase of the (i+6)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC reader 200 within the acknowledgment time after successfully receiving Probe frame 4. After successfully receiving the Probe ACK frame sent by the NFC device, the NFC reader 200 stops polling and executes the NFC interaction process of the first NFC protocol with the NFC device.

[0172] Case 9.2.2: If the NFC device supports the first NFC protocol and the Class A NFC protocol (regardless of whether it supports the Class B NFC protocol), and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC reader 200 is REQ_A, then the NFC device continues to receive the second card search request after entering the radio frequency field of the NFC reader 200. If the second card search request is a Probe frame, then the NFC device sends a Probe ACK frame to the NFC reader 200 within the confirmation time after successfully receiving the second card search request. If the second card search request is REQ_A, then the NFC device sends an ATQ_A frame to the NFC reader 200 within the confirmation time after successfully receiving the second card search request.

[0173] For example, the NFC device can enter the radio frequency field generated by the NFC card reader 200 during the listening phase of the (i+4)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is REQ_A2 sent by the NFC card reader 200 during the polling phase of the (i+5)th polling cycle. Therefore, after successfully receiving REQ_A2, the NFC device can continue to receive the second card search request. The second card search request successfully received by the NFC device after entering the radio frequency field is Probe frame 4 sent by the NFC card reader 200 during the polling phase of the (i+6)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC card reader 200 within the acknowledgment time after successfully receiving Probe frame 4.

[0174] Case 9.2.3: If the NFC device supports the first NFC protocol and the Class B NFC protocol (regardless of whether it supports the Class A NFC protocol), and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC reader 200 is REQ_B, then the NFC device continues to receive the second card search request after entering the radio frequency field of the NFC reader 200. If the second card search request is a Probe frame, then the NFC device sends a Probe ACK frame to the NFC reader 200 within the confirmation time after successfully receiving the second card search request. If the second card search request is REQ_B, then the NFC device sends an ATQ_B to the NFC reader 200 within the confirmation time after successfully receiving the second card search request.

[0175] For example, the NFC device can enter the radio frequency field generated by the NFC card reader 200 during the listening phase of the (i+2)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is REQ_B1 sent by the NFC card reader 200 during the polling phase of the (i+3)th polling cycle. Therefore, after successfully receiving REQ_B1, the NFC device can continue to receive the second card search request. The second card search request successfully received by the NFC device after entering the radio frequency field is Probe frame 3 sent by the NFC card reader 200 during the polling phase of the (i+4)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC card reader 200 within the acknowledgment time after successfully receiving Probe frame 3.

[0176] Case 9.2.4: If the NFC device supports Class A NFC protocol but not Class 1 or Class B NFC protocol, the NFC device cannot successfully receive the card search request (Probe frame) of Class 1 NFC protocol and the card search request (REQ_B) of Class B NFC protocol. Therefore, after entering the radio frequency field of NFC card reader 200, if the NFC device successfully receives REQ_A, it will send ATQ_A to NFC card reader 200 within the confirmation time after successfully receiving REQ_A.

[0177] Case 9.2.5: If the NFC device supports the Class B NFC protocol but not the first NFC protocol or the Class A NFC protocol, the NFC device cannot successfully receive the card search request (Probe frame) of the first NFC protocol and the card search request (REQ_A) of the Class A NFC protocol. Therefore, after entering the radio frequency field of the NFC card reader 200, if the NFC device successfully receives REQ_B, it will send ATQ_B to the NFC card reader 200 within the confirmation time after successfully receiving REQ_B.

[0178] Case 9.2.6: If the NFC device supports both Type A and Type B NFC protocols but not the first NFC protocol, the NFC device cannot successfully receive the probe frame of the first NFC protocol. Therefore, after entering the radio frequency field of the NFC reader 200, if the first probe request successfully received is REQ_A, the NFC device will send ATQ_A to the NFC reader 200 within the confirmation period after successfully receiving the first probe request. If the first probe request successfully received is REQ_B, the NFC device will send ATQ_B to the NFC reader 200 within the confirmation period after successfully receiving the first probe request.

[0179] Using the NFC polling method shown in Figure 9, when the NFC reader 200 supports the first NFC protocol, the Class A NFC protocol, and the Class B NFC protocol, the NFC reader 200 can send card search requests for multiple NFC protocols in the following order within each polling duration: card search request for the first NFC protocol, card search request for the Class A NFC protocol, card search request for the first NFC protocol again, and card search request for the Class B NFC protocol. When the NFC device supports the first NFC protocol, the Class A NFC protocol, and the Class B NFC protocol, after entering the radio frequency field, the NFC device can preferentially choose to reply with a card search response using the first NFC protocol to the NFC reader 200, thereby allowing the NFC reader 200 and the NFC device to preferentially choose the first NFC protocol for NFC interaction.

[0180] Figure 10 illustrates the multi-NFC protocol polling mechanism provided in this embodiment of the application, which includes the first NFC protocol and Class A and Class F NFC protocols.

[0181] As shown in Figure 10, the NFC card reader 200 can support the first NFC protocol, the Class A NFC protocol, and the Class F NFC protocol. Specifically, the card search request for the first NFC protocol can be a probe frame, and the card search response can be a probe ACK frame. The card search request for the Class A NFC protocol can be a Class A request command (REQ_A), and the card search response can be a Class A request response (ATQ_A). The card search request for the Class F NFC protocol can be a sensing request (SENS_REQ), and the card search response can be a sensing response (SENS_RES).

[0182] The polling mechanisms for the first NFC protocol, the Class A NFC protocol, and the Class F NFC protocol are as follows:

[0183] 10.1 When the NFC card reader 200 is in PCD mode, it can generate a radio frequency field and send card search requests for the first NFC protocol, the Class A NFC protocol, and the Class F NFC protocol according to a polling cycle. Within each polling cycle, one NFC protocol card search request is sent. The NFC card reader 200 can send the card search requests in the order of Probe frame, REQ_A, Probe frame, and SENS_REQ. Each polling cycle includes a polling phase and a listening phase, with the listening phase following the polling phase. During the polling phase of a polling cycle, the NFC card reader 200 can send a card search request, and during the listening phase, it can wait for a card search response from the NFC device.

[0184] For example, during the polling phase of the i-th polling cycle, the NFC reader 200 can send Probe frame 1. If the NFC reader 200 does not receive a card search response during the listening phase of the i-th polling cycle, it can send a Type A request command 1 (REQ_A1) during the polling phase of the (i+1)-th polling cycle. If the NFC reader 200 does not receive a request response during the listening phase of the (i+1)-th polling cycle, it can send Probe frame 2 during the polling phase of the (i+2)-th polling cycle. If the NFC reader 200 does not receive a card search response during the listening phase of the (i+2)-th polling cycle, it can send a sensing request 1 (SENS_REQ1) during the polling phase of the (i+3)-th polling cycle. If the NFC card reader 200 does not receive a card search response during the listening phase of the (i+3)th polling cycle, the NFC card reader 200 may send Probe frame 3 during the polling phase of the (i+4)th polling cycle. If the NFC card reader 200 does not receive a card search response during the listening phase of the (i+4)th polling cycle, the NFC card reader 200 may send a Type A request command 2 (REQ_A2) during the polling phase of the (i+5)th polling cycle. If the NFC card reader 200 does not receive a card search response during the listening phase of the (i+5)th polling cycle, the NFC card reader 200 may send Probe frame 4 during the polling phase of the (i+6)th polling cycle.

[0185] 10.2 When the NFC device is in PICC mode and enters the radio frequency field generated by the NFC card reader 200, the NFC device can receive the card search request sent by the NFC card reader 200.

[0186] Case 10.2.1: If the NFC device supports the first NFC protocol (regardless of whether it supports Class A NFC protocol and / or Class F NFC protocol) and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC card reader 200 is a Probe frame, then the NFC device sends a Probe ACK frame to the NFC card reader 200 within the confirmation time after successfully receiving the first card search request.

[0187] For example, the NFC device can enter the radio frequency field generated by the NFC reader 200 during the listening phase of the (i+5)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is Probe frame 4 sent by the NFC reader 200 during the polling phase of the (i+6)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC reader 200 within the acknowledgment time after successfully receiving Probe frame 4. After successfully receiving the Probe ACK frame sent by the NFC device, the NFC reader 200 stops polling and executes the NFC interaction process of the first NFC protocol with the NFC device.

[0188] Case 10.2.2: If the NFC device supports the first NFC protocol and the Class A NFC protocol (regardless of whether it supports the Class F NFC protocol), and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC reader 200 is REQ_A, then the NFC device continues to receive the second card search request after entering the radio frequency field of the NFC reader 200. If the second card search request is a Probe frame, then the NFC device sends a Probe ACK frame to the NFC reader 200 within the confirmation time after successfully receiving the second card search request. If the second card search request is REQ_A, then the NFC device sends an ATQ_A frame to the NFC reader 200 within the confirmation time after successfully receiving the second card search request.

[0189] For example, the NFC device can enter the radio frequency field generated by the NFC card reader 200 during the listening phase of the (i+4)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is REQ_A2 sent by the NFC card reader 200 during the polling phase of the (i+5)th polling cycle. Therefore, after successfully receiving REQ_A2, the NFC device can continue to receive the second card search request. The second card search request successfully received by the NFC device after entering the radio frequency field is Probe frame 4 sent by the NFC card reader 200 during the polling phase of the (i+6)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC card reader 200 within the acknowledgment time after successfully receiving Probe frame 4.

[0190] Case 10.2.3: If the NFC device supports the first NFC protocol and the Class F NFC protocol (regardless of whether it supports the Class A NFC protocol), and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC reader 200 is SENS_REQ, then the NFC device continues to receive the second card search request after entering the radio frequency field of the NFC reader 200. If the second card search request is a Probe frame, then the NFC device sends a Probe ACK frame to the NFC reader 200 within the confirmation time after successfully receiving the second card search request. If the second card search request is SENS_REQ, then the NFC device sends SENS_RES to the NFC reader 200 within the confirmation time after successfully receiving the second card search request.

[0191] For example, the NFC device can enter the radio frequency field generated by the NFC card reader 200 during the listening phase of the (i+2)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is SENS_REQ1 sent by the NFC card reader 200 during the polling phase of the (i+3)th polling cycle. Therefore, after successfully receiving SENS_REQ1, the NFC device can continue to receive the second card search request. The second card search request successfully received by the NFC device after entering the radio frequency field is Probe frame 3 sent by the NFC card reader 200 during the polling phase of the (i+4)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC card reader 200 within the acknowledgment time after successfully receiving Probe frame 3.

[0192] Case 10.2.4: If the NFC device supports Class A NFC protocol but not the first NFC protocol or the Class F NFC protocol, the NFC device cannot successfully receive the card search request (Probe frame) of the first NFC protocol and the card search request (SENS_REQ) of the Class F NFC protocol. Therefore, after entering the radio frequency field of the NFC card reader 200, if the NFC device successfully receives REQ_A, it will send ATQ_A to the NFC card reader 200 within the confirmation time after successfully receiving REQ_A.

[0193] Case 10.2.5: If the NFC device supports the Class F NFC protocol but not the first NFC protocol or the Class A NFC protocol, the NFC device cannot successfully receive the card search request (Probe frame) of the first NFC protocol and the card search request (REQ_A) of the Class A NFC protocol. Therefore, after entering the radio frequency field of the NFC card reader 200, if the NFC device successfully receives the SENS_REQ, it will send the SENS_REQ to the NFC card reader 200 within the confirmation time after successfully receiving the SENS_REQ.

[0194] Case 10.2.6: If the NFC device supports both Class A and Class F NFC protocols but not the first NFC protocol, the NFC device cannot successfully receive the probe frame of the first NFC protocol. Therefore, after entering the radio frequency field of the NFC reader 200, if the first probe request successfully received is REQ_A, the NFC device will send ATQ_A to the NFC reader 200 within the confirmation period after successfully receiving the first probe request. If the first probe request successfully received is SENS_REQ, the NFC device will send SENS_RES to the NFC reader 200 within the confirmation period after successfully receiving the first probe request.

[0195] Using the NFC polling method shown in Figure 10, when the NFC reader 200 supports the first NFC protocol, the Class A NFC protocol, and the Class F NFC protocol, the NFC reader 200 can send card search requests for multiple NFC protocols in the following order within each polling duration: card search request for the first NFC protocol, card search request for the Class A NFC protocol, card search request for the first NFC protocol again, and card search request for the Class F NFC protocol. When the NFC device supports the first NFC protocol, the Class A NFC protocol, and the Class F NFC protocol, after entering the radio frequency field, the NFC device can preferentially choose to reply with a card search response using the first NFC protocol to the NFC reader 200, thereby allowing the NFC reader 200 and the NFC device to preferentially choose the first NFC protocol for NFC interaction.

[0196] Figure 11 illustrates the multi-NFC protocol polling mechanism provided in this embodiment of the application, which includes the first NFC protocol and the Class B and Class F NFC protocols.

[0197] As shown in Figure 11, the NFC card reader 200 can support the first NFC protocol, the Class B NFC protocol, and the Class F NFC protocol. Specifically, the card search request for the first NFC protocol can be a probe frame, and the card search response can be a probe ACK frame. The card search request for the Class B NFC protocol can be a Class B request command (REQ_B), and the card search response can be a Class B request response (ATQ_A). The card search request for the Class F NFC protocol can be a sensing request (SENS_REQ), and the card search response can be a sensing response (SENS_RES).

[0198] The polling mechanisms for the first NFC protocol, the Class B NFC protocol, and the Class F NFC protocol are as follows:

[0199] 11.1 When the NFC card reader 200 is in PCD mode, it can generate a radio frequency field and send card search requests for the first NFC protocol, the Class B NFC protocol, and the Class F NFC protocol according to a polling cycle. Within each polling cycle, one NFC protocol card search request is sent. The NFC card reader 200 can send the card search requests in the order of Probe frame, REQ_B, Probe frame, and SENS_REQ. Each polling cycle includes a polling phase and a listening phase, with the listening phase following the polling phase. During the polling phase of a polling cycle, the NFC card reader 200 can send a card search request, and during the listening phase, it can wait for a card search response from the NFC device.

[0200] For example, during the polling phase of the i-th polling cycle, the NFC reader 200 can send Probe frame 1. If the NFC reader 200 does not receive a card search response during the listening phase of the i-th polling cycle, it can send a Type B request command 1 (REQ_B1) during the polling phase of the (i+1)-th polling cycle. If the NFC reader 200 does not receive a request response during the listening phase of the (i+1)-th polling cycle, it can send Probe frame 2 during the polling phase of the (i+2)-th polling cycle. If the NFC reader 200 does not receive a card search response during the listening phase of the (i+2)-th polling cycle, it can send a sensing request 1 (SENS_REQ1) during the polling phase of the (i+3)-th polling cycle. If the NFC reader 200 does not receive a card search response during the listening phase of the (i+3)th polling cycle, the NFC reader 200 may send Probe frame 3 during the polling phase of the (i+4)th polling cycle. If the NFC reader 200 does not receive a card search response during the listening phase of the (i+4)th polling cycle, the NFC reader 200 may send a Type B request command 2 (REQ_B2) during the polling phase of the (i+5)th polling cycle. If the NFC reader 200 does not receive a card search response during the listening phase of the (i+5)th polling cycle, the NFC reader 200 may send Probe frame 4 during the polling phase of the (i+6)th polling cycle.

[0201] 11.2 When the NFC device is in PICC mode and enters the radio frequency field generated by the NFC card reader 200, the NFC device can receive the card search request sent by the NFC card reader 200.

[0202] Case 11.2.1: If the NFC device supports the first NFC protocol (regardless of whether it supports the Class B NFC protocol and / or the Class F NFC protocol) and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC card reader 200 is a Probe frame, then the NFC device sends a Probe ACK frame to the NFC card reader 200 within the confirmation time after successfully receiving the first card search request.

[0203] For example, the NFC device can enter the radio frequency field generated by the NFC reader 200 during the listening phase of the (i+5)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is Probe frame 4 sent by the NFC reader 200 during the polling phase of the (i+6)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC reader 200 within the acknowledgment time after successfully receiving Probe frame 4. After successfully receiving the Probe ACK frame sent by the NFC device, the NFC reader 200 stops polling and executes the NFC interaction process of the first NFC protocol with the NFC device.

[0204] Case 11.2.2: If the NFC device supports the first NFC protocol and the Class B NFC protocol (regardless of whether it supports the Class F NFC protocol) and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC reader 200 is REQ_B, then the NFC device continues to receive the second card search request after entering the radio frequency field of the NFC reader 200. If the second card search request is a Probe frame, then the NFC device sends a Probe ACK frame to the NFC reader 200 within the confirmation time after successfully receiving the second card search request. If the second card search request is REQ_B, then the NFC device sends an ATQ_B to the NFC reader 200 within the confirmation time after successfully receiving the second card search request.

[0205] For example, the NFC device can enter the radio frequency field generated by the NFC card reader 200 during the listening phase of the (i+4)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is REQ_B2 sent by the NFC card reader 200 during the polling phase of the (i+5)th polling cycle. Therefore, after successfully receiving REQ_B2, the NFC device can continue to receive the second card search request. The second card search request successfully received by the NFC device after entering the radio frequency field is Probe frame 4 sent by the NFC card reader 200 during the polling phase of the (i+6)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC card reader 200 within the acknowledgment time after successfully receiving Probe frame 4.

[0206] Case 11.2.3: If the NFC device supports the first NFC protocol and the Class F NFC protocol (regardless of whether it supports the Class B NFC protocol), and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC reader 200 is SENS_REQ, then the NFC device continues to receive the second card search request after entering the radio frequency field of the NFC reader 200. If the second card search request is a Probe frame, then the NFC device sends a Probe ACK frame to the NFC reader 200 within the confirmation time after successfully receiving the second card search request. If the second card search request is SENS_REQ, then the NFC device sends SENS_RES to the NFC reader 200 within the confirmation time after successfully receiving the second card search request.

[0207] For example, the NFC device can enter the radio frequency field generated by the NFC card reader 200 during the listening phase of the (i+2)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is SENS_REQ1 sent by the NFC card reader 200 during the polling phase of the (i+3)th polling cycle. Therefore, after successfully receiving SENS_REQ1, the NFC device can continue to receive the second card search request. The second card search request successfully received by the NFC device after entering the radio frequency field is Probe frame 3 sent by the NFC card reader 200 during the polling phase of the (i+4)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC card reader 200 within the acknowledgment time after successfully receiving Probe frame 3.

[0208] Case 11.2.4: If the NFC device supports the Class B NFC protocol but not the first NFC protocol or the Class F NFC protocol, the NFC device cannot successfully receive the card search request (Probe frame) of the first NFC protocol and the card search request (SENS_REQ) of the Class F NFC protocol. Therefore, after entering the radio frequency field of the NFC card reader 200, if the NFC device successfully receives REQ_B, it will send ATQ_B to the NFC card reader 200 within the confirmation time after successfully receiving REQ_B.

[0209] Case 11.2.5: If the NFC device supports the Class F NFC protocol but not the first NFC protocol or the Class B NFC protocol, the NFC device cannot successfully receive the card search request (Probe frame) of the first NFC protocol and the card search request (REQ_B) of the Class B NFC protocol. Therefore, after entering the radio frequency field of the NFC card reader 200, if the NFC device successfully receives the SENS_REQ, it will send the SENS_REQ to the NFC card reader 200 within the confirmation time after successfully receiving the SENS_REQ.

[0210] Case 11.2.6: If the NFC device supports both Class B and Class F NFC protocols but not the first NFC protocol, the NFC device cannot successfully receive the first NFC protocol's probe request (probe frame). Therefore, after entering the RF field of the NFC reader 200, if the first successfully received probe request is REQ_B, the NFC device will send ATQ_B to the NFC reader 200 within the confirmation period following the successful receipt of the first probe request. If the first successfully received probe request is SENS_REQ, the NFC device will send SENS_RES to the NFC reader 200 within the confirmation period following the successful receipt of the first probe request.

[0211] Using the NFC polling method shown in Figure 11, when the NFC card reader 200 supports the first NFC protocol, the Class B NFC protocol, and the Class F NFC protocol, the NFC card reader 200 can send card search requests for multiple NFC protocols in the following order within each polling duration: card search request for the first NFC protocol, card search request for the Class B NFC protocol, card search request for the first NFC protocol, and card search request for the Class F NFC protocol. When the NFC device supports the first NFC protocol, the Class B NFC protocol, and the Class F NFC protocol, after entering the radio frequency field, the NFC device can preferentially choose to reply with a card search response using the first NFC protocol to the NFC card reader 200, thereby allowing the NFC card reader 200 and the NFC device to preferentially choose the first NFC protocol for NFC interaction.

[0212] The polling mechanisms of the four NFC protocols provided in the embodiments of this application are described below.

[0213] Figure 12 illustrates the multi-NFC protocol polling mechanism provided in the embodiments of this application, which includes the first NFC protocol, the Class A NFC protocol, the Class B NFC protocol, and the Class F NFC protocol.

[0214] As shown in Figure 12, the NFC card reader 200 can support the first NFC protocol, the Class B NFC protocol, and the Class F NFC protocol. Specifically, the card search request for the first NFC protocol can be a probe frame, and the card search response can be a probe ACK frame. The card search request for the Class B NFC protocol can be a Class B request command (REQ_B), and the card search response can be a Class B request response (ATQ_A). The card search request for the Class F NFC protocol can be a sensing request (SENS_REQ), and the card search response can be a sensing response (SENS_RES).

[0215] The polling mechanisms for the first NFC protocol, Class A NFC protocol, Class B NFC protocol, and Class F NFC protocol are as follows:

[0216] 12.1 When the NFC card reader 200 is in PCD mode, it can generate a radio frequency field and send card search requests for the first NFC protocol, the Class A NFC protocol, the Class B NFC protocol, and the Class F NFC protocol according to a polling cycle. Within each polling cycle, one NFC protocol card search request is sent. The NFC card reader 200 can send the card search requests in the order of Probe frame, REQ_A, Probe frame, REQ_B, Probe frame, and SENS_REQ. Each polling cycle includes a polling phase and a listening phase, with the listening phase following the polling phase within the polling cycle. During the polling phase of the polling cycle, the NFC card reader 200 can send a card search request, and during the listening phase of the polling cycle, it can wait for a card search response from the NFC device.

[0217] For example, during the polling phase of the i-th polling cycle, the NFC card reader 200 can send Probe frame 1. If the NFC card reader 200 does not receive a card search response during the listening phase of the i-th polling cycle, it sends a Type A request command 1 (REQ_A1) during the polling phase of the (i+1)-th polling cycle. If the NFC card reader 200 does not receive a request response during the listening phase of the (i+2)-th polling cycle, it can send Probe frame 2 during the polling phase of the (i+3)-th polling cycle. If the NFC card reader 200 does not receive a card search response during the listening phase of the (i+2)-th polling cycle, it can send a Type B request command 1 (REQ_B1) during the polling phase of the (i+3)-th polling cycle. If the NFC reader 200 does not receive a card search response during the listening phase of the (i+3)th polling cycle, the NFC reader 200 may send Probe frame 3 during the polling phase of the (i+4)th polling cycle. If the NFC reader 200 does not receive a card search response during the listening phase of the (i+4)th polling cycle, the NFC reader 200 may send a Class F request command 1 (SENS_REQ1) during the polling phase of the (i+5)th polling cycle. If the NFC reader 200 does not receive a card search response during the listening phase of the (i+5)th polling cycle, the NFC reader 200 may send Probe frame 4 during the polling phase of the (i+6)th polling cycle.

[0218] 12.2 When the NFC device is in PICC mode and enters the radio frequency field generated by the NFC card reader 200, the NFC device can receive the card search request sent by the NFC card reader 200.

[0219] Case 12.2.1: If the NFC device supports the first NFC protocol (regardless of whether it supports Class A NFC protocol and / or Class B NFC protocol and / or Class F NFC protocol) and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC card reader 200 is a Probe frame, then the NFC device sends a Probe ACK frame to the NFC card reader 200 within the confirmation time after successfully receiving the first card search request.

[0220] For example, the NFC device can enter the radio frequency field generated by the NFC reader 200 during the listening phase of the (i+5)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is Probe frame 4 sent by the NFC reader 200 during the polling phase of the (i+6)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC reader 200 within the acknowledgment time after successfully receiving Probe frame 4. After successfully receiving the Probe ACK frame sent by the NFC device, the NFC reader 200 stops polling and executes the NFC interaction process of the first NFC protocol with the NFC device.

[0221] Case 12.2.2: If the NFC device supports the first NFC protocol and the Class A NFC protocol (regardless of whether it supports the Class B NFC protocol and / or / or Class F NFC protocol), and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC reader 200 is REQ_A, then the NFC device continues to receive the second card search request after entering the radio frequency field of the NFC reader 200. If the second card search request is a Probe frame, then the NFC device sends a Probe ACK frame to the NFC reader 200 within the confirmation time after successfully receiving the second card search request. If the second card search request is REQ_A, then the NFC device sends an ATQ_A frame to the NFC reader 200 within the confirmation time after successfully receiving the second card search request.

[0222] For example, the NFC device can enter the radio frequency field generated by the NFC card reader 200 during the listening phase of the i-th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is REQ_A1 sent by the NFC card reader 200 during the polling phase of the (i+1)-th polling cycle. Therefore, after successfully receiving REQ_A1, the NFC device can continue to receive the second card search request. The second card search request successfully received by the NFC device after entering the radio frequency field is Probe frame 2 sent by the NFC card reader 200 during the polling phase of the (i+2)-th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC card reader 200 within the acknowledgment time after successfully receiving Probe frame 2.

[0223] Case 12.2.3: If the NFC device supports the first NFC protocol and the Class B NFC protocol (regardless of whether it supports the Class A NFC protocol and / or / or Class F NFC protocol), and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC reader 200 is REQ_B, then the NFC device continues to receive the second card search request after entering the radio frequency field of the NFC reader 200. If the second card search request is a Probe frame, then the NFC device sends a Probe ACK frame to the NFC reader 200 within the confirmation time after successfully receiving the second card search request. If the second card search request is REQ_B, then the NFC device sends an ATQ_B to the NFC reader 200 within the confirmation time after successfully receiving the second card search request.

[0224] For example, the NFC device can enter the radio frequency field generated by the NFC card reader 200 during the listening phase of the (i+2)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is REQ_B1 sent by the NFC card reader 200 during the polling phase of the (i+3)th polling cycle. Therefore, after successfully receiving REQ_B1, the NFC device can continue to receive the second card search request. The second card search request successfully received by the NFC device after entering the radio frequency field is Probe frame 3 sent by the NFC card reader 200 during the polling phase of the (i+4)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC card reader 200 within the acknowledgment time after successfully receiving Probe frame 3.

[0225] Case 12.2.4: If the NFC device supports the first NFC protocol and the Class F NFC protocol (regardless of whether it supports the Class A NFC protocol and / or / or Class B NFC protocol), and the first card search request successfully received by the NFC device after entering the radio frequency field of the NFC reader 200 is SENS_REQ, then the NFC device continues to receive the second card search request after entering the radio frequency field of the NFC reader 200. If the second card search request is a Probe frame, then the NFC device sends a Probe ACK frame to the NFC reader 200 within the confirmation time after successfully receiving the second card search request. If the second card search request is SENS_REQ, then the NFC device sends SENS_RES to the NFC reader 200 within the confirmation time after successfully receiving the second card search request.

[0226] For example, the NFC device can enter the radio frequency field generated by the NFC card reader 200 during the listening phase of the (i+4)th polling cycle. After entering the radio frequency field, the first card search request successfully received by the NFC device is SENS_REQ1 sent by the NFC card reader 200 during the polling phase of the (i+5)th polling cycle. Therefore, after successfully receiving SENS_REQ1, the NFC device can continue to receive the second card search request. The second card search request successfully received by the NFC device after entering the radio frequency field is Probe frame 4 sent by the NFC card reader 200 during the polling phase of the (i+6)th polling cycle. Therefore, the NFC device can start sending a Probe ACK frame to the NFC card reader 200 within the acknowledgment time after successfully receiving Probe frame 4.

[0227] Case 12.2.5: If the NFC device does not support the first NFC protocol but supports Class A and / or Class B and / or Class F NFC protocols, the NFC device cannot successfully receive the card probe request (Probe frame) of the first NFC protocol. Therefore, after entering the radio frequency field of the NFC reader 200, if the first successfully received card probe request is REQ_A, the NFC device sends ATQ_A to the NFC reader 200 within the confirmation period after successfully receiving the first card probe request. If the first successfully received card probe request is REQ_B, the NFC device sends ATQ_B to the NFC reader 200 within the confirmation period after successfully receiving the first card probe request. If the first successfully received card probe request is SENS_REQ, the NFC device sends SENS_RES to the NFC reader 200 within the confirmation period after successfully receiving the first card probe request.

[0228] Using the NFC polling method shown in Figure 12, when the NFC reader 200 supports the first NFC protocol, Class A NFC protocol, Class B NFC protocol, and Class F NFC protocol, it can send card search requests for these multiple NFC protocols in the following order within each polling duration: card search request for the first NFC protocol, card search request for the Class A NFC protocol, card search request for the first NFC protocol, card search request for the Class B NFC protocol, card search request for the first NFC protocol, and card search request for the Class F NFC protocol. When the NFC device supports the first NFC protocol, Class A NFC protocol, Class B NFC protocol, and Class F NFC protocol, after entering the radio frequency field, the NFC device can preferentially choose to reply with a card search response using the first NFC protocol to the NFC reader 200, thereby allowing the NFC reader 200 and the NFC device to preferentially choose the first NFC protocol for NFC interaction.

[0229] The NFC polling method provided in the embodiments of this application is described below.

[0230] Figure 13 is a flowchart illustrating the NFC polling method provided in an embodiment of this application.

[0231] As shown in Figure 13, this NFC polling method can be applied to the NFC system of NFC card reader 200 and NFC device, wherein NFC card reader 200 can be in PCD mode and NFC device can be in PICC mode.

[0232] The NFC polling method may include the following steps:

[0233] S1301. The NFC card reader 200 continuously sends a card search request using a first NFC protocol and a card search request using a second NFC protocol, wherein the first NFC protocol is different from the second NFC protocol, and one or more card search requests using the first NFC protocol are sent between two adjacent card search requests using the second NFC protocol.

[0234] Among them, the card search request of the first NFC protocol can be a Probe frame, and the card search response of the first NFC protocol can be a Probe ACK frame.

[0235] In one possible implementation, the second NFC protocol may include a Class A NFC protocol and / or a Class B NFC protocol and / or a Class F NFC protocol. The Class A NFC protocol's card search request is REQ_A, and its card search response is ATQ_A. The Class B NFC protocol's card search request is REQ_B, and its card search response is ATQ_B. The Class F NFC protocol's card search request is SENS_REQ, and its card search response is SENS_RES.

[0236] The NFC card reader 200 can send a card search request during the polling phase of each polling cycle and wait to receive a card search response during the listening phase of each polling cycle. The listening phase follows the polling phase within the polling cycle.

[0237] 1. If the NFC reader 200 supports the first NFC protocol and the Class A NFC protocol but not the Class B or Class F NFC protocols, the aforementioned second NFC protocol can be the Class A NFC protocol. The second NFC card search request may include REQ_A, and the second NFC protocol card search response may include ATQ_A. The NFC reader 200 may send one or more Probe frames and then send one REQ_A frame within each of one or more polling duration periods. The number of Probe frames sent within different polling duration periods may be the same or different.

[0238] For example, as shown in Figure 14A, the card search request sent by the NFC card reader 200 during the polling process may include a Probe frame and a REQ_A. The NFC card reader 200 may send X1 Probe frames followed by one REQ_A within polling duration segment 1; send X2 Probe frames followed by one REQ_A within polling duration segment 2; and send Xn Probe frames followed by one REQ_A within polling duration segment n. Here, X1, X2…Xn are all positive integers, and X1, X2…Xn may all be the same or not.

[0239] The polling process when one Probe frame is sent between two adjacent REQ_A transmissions can be referred to the embodiment shown in Figure 6 above, and will not be repeated here.

[0240] 2. If the NFC reader 200 supports the first NFC protocol and the Class B NFC protocol but not the Class A and Class F NFC protocols, the aforementioned second NFC protocol can be the Class B NFC protocol. The card search request of the aforementioned second NFC protocol may include REQ_B, and the card search response of the second NFC protocol may include ATQ_B. The NFC reader 200 may send one or more Probe frames and then send one REQ_B in each of one or more polling duration periods. The number of Probe frames sent in different polling duration periods may be the same or different.

[0241] For example, as shown in Figure 14B, the card search request sent by the NFC card reader 200 during the polling process may include a Probe frame and a REQ_B. The NFC card reader 200 may send X1 Probe frames followed by one REQ_B within polling duration segment 1; send X2 Probe frames followed by one REQ_B within polling duration segment 2; and send Xn Probe frames followed by one REQ_B within polling duration segment n. Here, X1, X2…Xn are all positive integers, and X1, X2…Xn may all be the same or not.

[0242] The polling process when one Probe frame is sent between two adjacent REQ_B transmissions can be referred to the embodiment shown in Figure 7 above, and will not be repeated here.

[0243] 3. If the NFC reader 200 supports the first NFC protocol and the Class F NFC protocol but not the Class A and Class B NFC protocols, the aforementioned second NFC protocol can be the Class F NFC protocol. The card search request of the aforementioned second NFC protocol may include SENS_REQ, and the card search response of the second NFC protocol may include SENS_RES. The NFC reader 200 may send one or more Probe frames and then send one SENS_REQ within each of one or more polling duration periods. The number of Probe frames sent within different polling duration periods can be the same or different.

[0244] For example, as shown in Figure 14C, the card search request sent by the NFC card reader 200 during the polling process may include Probe frames and SENS_REQ. The NFC card reader 200 may send X1 Probe frames followed by one SENS_REQ during polling duration segment 1; send X2 Probe frames followed by one SENS_REQ during polling duration segment 2; and send Xn Probe frames followed by one SENS_REQ during polling duration segment n. Here, X1, X2…Xn are all positive integers, and X1, X2…Xn may all be the same or not.

[0245] The polling process when one Probe frame is sent between two adjacent SENS_REQ transmissions can be referred to the embodiment shown in Figure 8 above, and will not be repeated here.

[0246] 4. If the NFC reader 200 supports the first NFC protocol, the Class A NFC protocol, and the Class B NFC protocol but does not support the Class F NFC protocol, the aforementioned second NFC protocol may include the Class A NFC protocol and the Class B NFC protocol. The card search request of the aforementioned second NFC protocol may include REQ_A and REQ_B, and the card search response of the second NFC protocol may include ATQ_A or ATQ_B. The NFC reader 200 may send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, and then send one REQ_B within each of one or more polling duration periods. The number of Probe frames sent in different polling duration periods may be the same or different. The number of Probe frames before REQ_A in a polling duration period may be the same or different from the number of Probe frames between REQ_A and REQ_B.

[0247] For example, as shown in Figure 14D, the card search request sent by the NFC card reader 200 during the polling process may include Probe frames, REQ_A, and REQ_B. The NFC card reader 200 may send X1 Probe frames, then one REQ_A, then Y1 Probe frames, and then one REQ_B within polling duration segment 1. Similarly, within polling duration segment n, it may send Xn Probe frames, then one REQ_A, then Yn Probe frames, and then one REQ_B. Here, X1, X2…Xn and Y1, Y2…Yn are all positive integers, and X1, X2…Xn and Y1, Y2…Yn may or may not be all the same.

[0248] The polling process when one Probe frame is sent between adjacent REQ_A and REQ_B can be referred to the embodiment shown in Figure 9 above, and will not be repeated here.

[0249] In one possible implementation, there can be multiple REQ_A transmissions within each polling duration, and / or multiple REQ_B transmissions.

[0250] For example, the NFC card reader 200 may first send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, then send one REQ_A again, then send one or more Probe frames, then send one REQ_B, then send one or more Probe frames, then send one REQ_B again.

[0251] For example, the NFC card reader 200 may first send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, then send one REQ_B.

[0252] For example, the NFC card reader 200 may first send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, then send one REQ_B, then send one or more Probe frames, and then send one REQ_B again within each of one or more polling duration periods.

[0253] The above examples are merely for explaining the embodiments of this application and are not intended to be limiting.

[0254] 5. If the NFC reader 200 supports the first NFC protocol, the Class A NFC protocol, and the Class F NFC protocol but does not support the Class B NFC protocol, the aforementioned second NFC protocol may include the Class A NFC protocol and the Class F NFC protocol. The card search request of the aforementioned second NFC protocol may include REQ_A and SENS_REQ, and the card search response of the second NFC protocol may include ATQ_A or SENS_RES. The NFC reader 200 may, within each of one or more polling duration segments, first send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, and then send one SENS_REQ. The number of Probe frames sent in different polling duration segments may be the same or different. The number of Probe frames before REQ_A in a polling duration segment may be the same or different from the number of Probe frames between REQ_A and SENS_REQ.

[0255] For example, as shown in Figure 14E, the card search request sent by the NFC card reader 200 during the polling process may include Probe frames, REQ_A, and SENS_REQ. The NFC card reader 200 may send X1 Probe frames, then one REQ_A, then Y1 Probe frames, and then one SENS_REQ within polling duration segment 1. Alternatively, within polling duration segment n, it may send Xn Probe frames, then one REQ_A, then Yn Probe frames, and then one SENS_REQ. Here, X1, X2…Xn and Y1, Y2…Yn are all positive integers, and X1, X2…Xn and Y1, Y2…Yn may all be the same or not.

[0256] The polling process when one Probe frame is sent between adjacent REQ_A and SENS_REQ frames can be referred to the embodiment shown in Figure 10 above, and will not be repeated here.

[0257] In one possible implementation, there can be multiple REQ_A transmissions within each polling duration, and / or multiple SENS_REQ transmissions.

[0258] For example, the NFC card reader 200 may first send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, then send one SENS_REQ, then send one or more Probe frames, then send one SENS_REQ, then send one or more Probe frames, then send one SENS_REQ.

[0259] For example, the NFC card reader 200 may first send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, and then send one SENS_REQ.

[0260] For example, the NFC card reader 200 may first send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, then send one SENS_REQ, then send one or more Probe frames, and then send one SENS_REQ again within each of one or more polling duration periods.

[0261] The above examples are merely for explaining the embodiments of this application and are not intended to be limiting.

[0262] 6. If the NFC reader 200 supports the first NFC protocol, the Class B NFC protocol, and the Class F NFC protocol but does not support the Class A NFC protocol, the aforementioned second NFC protocol may include the Class B NFC protocol and the Class F NFC protocol. The card search request of the aforementioned second NFC protocol may include REQ_B and SENS_REQ, and the card search response of the second NFC protocol may include ATQ_B or SENS_RES. The NFC reader 200 may, within each of one or more polling duration segments, first send one or more Probe frames, then send one REQ_B, then send one or more Probe frames, and then send one SENS_REQ. The number of Probe frames sent in different polling duration segments may be the same or different. The number of Probe frames before REQ_B in a polling duration segment may be the same or different from the number of Probe frames between REQ_B and SENS_REQ.

[0263] For example, as shown in Figure 14F, the card search request sent by the NFC card reader 200 during the polling process may include a Probe frame, REQ_B, and SENS_REQ. The NFC card reader 200 may send X1 Probe frames, then one REQ_B, then Y1 Probe frames, and then one SENS_REQ within polling duration segment 1. Alternatively, within polling duration segment n, it may send Xn Probe frames, then one REQ_B, then Yn Probe frames, and then one SENS_REQ. Here, X1, X2…Xn and Y1, Y2…Yn are all positive integers, and X1, X2…Xn and Y1, Y2…Yn may all be the same or not.

[0264] The polling process when one Probe frame is sent between adjacent REQ_B and SENS_REQ frames can be referred to the embodiment shown in Figure 11 above, and will not be repeated here.

[0265] In one possible implementation, there can be multiple REQ_B transmissions within each polling duration, and / or multiple SENS_REQ transmissions.

[0266] For example, the NFC card reader 200 may first send one or more Probe frames, then send one REQ_B, then send one or more Probe frames, then send one REQ_B, then send one or more Probe frames, then send one SENS_REQ, then send one or more Probe frames, then send one SENS_REQ, then send one or more Probe frames, then send one SENS_REQ.

[0267] For example, the NFC card reader 200 may first send one or more Probe frames, then send one REQ_B, then send one or more Probe frames, then send one REQ_B, then send one or more Probe frames, and then send one SENS_REQ.

[0268] For example, the NFC card reader 200 may first send one or more Probe frames, then send one REQ_B, then send one or more Probe frames, then send one SENS_REQ, then send one or more Probe frames, and then send one SENS_REQ again within each of one or more polling duration periods.

[0269] The above examples are merely for explaining the embodiments of this application and are not intended to be limiting.

[0270] 7. If the NFC reader 200 supports the first NFC protocol, the Class A NFC protocol, the Class B NFC protocol, and the Class F NFC protocol, the aforementioned second NFC protocol may include the Class A NFC protocol, the Class B NFC protocol, and the Class F NFC protocol. The card search request of the aforementioned second NFC protocol may include REQ_A, REQ_B, and SENS_REQ, and the card search response of the second NFC protocol may include ATQ_A, ATQ_B, or SENS_RES. The NFC reader 200 may, within each of one or more polling duration segments, first send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, then send one REQ_B, then send one or more Probe frames, and then send one SENS_REQ. The number of Probe frames sent in different polling duration segments may be the same or different. The number of Probe frames before REQ_A, the number of Probe frames between REQ_A and REQ_B, and the number of Probe frames between REQ_B and SENS_REQ in the polling duration segment may all be the same or not all be the same.

[0271] For example, as shown in Figure 14G, the card search request sent by the NFC card reader 200 during the polling process may include Probe frames, REQ_A, REQ_B, and SENS_REQ. The NFC card reader 200 may send X1 Probe frames, then one REQ_A, then Y1 Probe frames, then one REQ_B, then Z1 Probe frames, and then one SENS_REQ within polling duration segment 1. Alternatively, within polling duration segment n, it may send Xn Probe frames, then one REQ_B, then Yn Probe frames, then one SENS_REQ, then Zn Probe frames, and then one SENS_REQ. Where X1, X2…Xn, Y1, Y2…Yn and Z1, Z2…Zn are all positive integers. X1, X2…Xn, Y1, Y2…Yn and Z1, Z2…Zn can be all the same or not all the same.

[0272] The polling process in the case where one probe frame is sent between adjacent REQ_A and REQ_B, and one probe frame is sent between adjacent REQ_B and SENS_REQ, can be referred to the embodiment shown in Figure 12 above, and will not be repeated here.

[0273] In this embodiment of the application, the sending positions of REQ_A, REQ_B, and SENS_REQ can be interchanged during the polling duration.

[0274] In one possible implementation, there can be multiple REQ_A transmissions within each polling duration, and / or multiple REQ_B transmissions within each polling duration, and / or multiple SENS_REQ transmissions.

[0275] For example, the NFC card reader 200 may also send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, then send one REQ_B, then send one or more Probe frames, then send one REQ_B, then send one or more Probe frames, then send one SENS_REQ, then send one or more Probe frames, then send one SENS_REQ.

[0276] For example, the NFC card reader 200 may first send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, then send one REQ_A again, then send one or more Probe frames, then send one REQ_B, then send one or more Probe frames, then send one SENS_REQ.

[0277] For example, the NFC card reader 200 may first send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, then send one REQ_B, then send one or more Probe frames, then send one REQ_B, then send one or more Probe frames, then send one SENS_REQ.

[0278] For example, the NFC card reader 200 may first send one or more Probe frames, then send one REQ_A, then send one or more Probe frames, then send one REQ_B, then send one or more Probe frames, then send one SENS_REQ, then send one or more Probe frames, then send one SENS_REQ, then send one or more Probe frames, then send one SENS_REQ.

[0279] The above examples are merely for explaining the embodiments of this application and are not intended to be limiting.

[0280] In one possible implementation, the NFC card reader 200 can adjust the number of first NFC protocol card search requests sent between two adjacent second NFC protocol card search requests based on the proportion of first NFC protocol card search responses received within a historical period. Specifically, the higher the proportion of first NFC protocol card search responses received within a historical period, the more first NFC protocol card search requests will be sent between two adjacent second NFC protocol card search requests. Thus, by adjusting the number of first NFC protocol card search requests sent between two adjacent second NFC protocol card search requests based on the historical proportion of NFC interactions performed by the NFC card reader 200 using the first NFC protocol, the NFC card reader 200 can quickly discover NFC devices.

[0281] In one possible implementation, the server can receive card swipe records sent by one or more NFC card reader devices within each geographical area. These card swipe records include the number and time of when the NFC card reader device received a card search response using a first NFC protocol, and the number and time of when it received a card search response using a second NFC protocol. Based on the card swipe records sent by one or more NFC card reader devices within each geographical area, the server can determine the number of first NFC protocol card search requests sent between two adjacent second NFC protocol card search requests within each geographical area. Therefore, the server can determine a first correspondence between each geographical area and the number of first NFC protocol card search requests sent between two adjacent second NFC protocol card search requests. The NFC card reader device 200 can send first geographical location information of its location to the server. The server can determine a first quantity corresponding to the first geographical location information based on the first geographical location information and the first correspondence. The server can send a first instruction to the NFC card reader device 200. This first instruction can be used to instruct the NFC card reader device 200 to send a first quantity of first NFC protocol card search requests between two adjacent second NFC protocol card search requests, where the first quantity is a positive integer. After receiving the first instruction, the NFC card reader 200 can send a first number of first NFC protocol card search requests between two adjacent second NFC protocol card search requests. In this way, the server can adjust the number of first NFC protocol card search requests sent between two adjacent second NFC protocol card search requests based on the proportion of NFC card readers using the first NFC protocol in a certain geographical area according to historical records, allowing the NFC card reader 200 to quickly discover NFC devices.

[0282] S1302. The NFC device enters the radio frequency field generated by the NFC card reader 200.

[0283] S1303. If the first card search request successfully received after the NFC device enters the radio frequency field generated by the NFC card reader 200 is a card search request of the first NFC protocol, in response to the first card search request, a card search response of the first NFC protocol is sent to the NFC card reader 200.

[0284] In one possible implementation, if the first card search request successfully received by the NFC device after entering the radio frequency field generated by the NFC card reader 200 is a card search request of the first NFC protocol, the NFC device can send a card search response of the first NFC protocol to the NFC card reader 200 within the confirmation time after successfully receiving the first card search request.

[0285] S1304. If the first card search request successfully received after the NFC device enters the radio frequency field generated by the NFC card reader 200 is a card search request of the second NFC protocol, the device continues to receive the second card search request.

[0286] S1305. If the second card search request successfully received after the NFC device enters the radio frequency field generated by the NFC card reader 200 is a card search request of the first NFC protocol, in response to the second card search request, a card search response of the first NFC protocol is sent to the NFC card reader 200.

[0287] In one possible implementation, if the second card search request successfully received by the NFC device after entering the radio frequency field generated by the NFC card reader 200 is a card search request of the first NFC protocol, the NFC device can send a card search response of the first NFC protocol to the NFC card reader 200 within the confirmation time after successfully receiving the second card search request.

[0288] S1306. If the second card search request successfully received after the NFC device enters the radio frequency field generated by the NFC card reader 200 is a card search request of the second NFC protocol, in response to the second card search request, a card search response of the second NFC protocol is sent to the NFC card reader 200.

[0289] In one possible implementation, if the second card search request successfully received by the NFC device after entering the radio frequency field generated by the NFC card reader 200 is a card search request of the second NFC protocol, the NFC device can send a card search response of the second NFC protocol to the NFC card reader 200 within the confirmation time after successfully receiving the second card search request.

[0290] S1307. If the NFC card reader 200 receives a card search response in the first NFC protocol sent by the NFC device, it stops sending the card search request in the first NFC protocol and the card search request in the second NFC protocol, and performs NFC interaction with the NFC device based on the first NFC protocol.

[0291] S1308. If the NFC card reader 200 receives a card search response in the second NFC protocol sent by the NFC device, it stops sending the card search request in the first NFC protocol and the card search request in the second NFC protocol, and performs NFC interaction with the NFC device based on the second NFC protocol.

[0292] For details, please refer to the embodiments shown in Figures 6-12 above, which will not be repeated here.

[0293] In some embodiments, the NFC device may support a first NFC protocol and a second NFC protocol, and the NFC device may have an NFC emulator card enabled with the first NFC protocol and / or an NFC emulator card enabled with the second NFC protocol.

[0294] In scenario A, the NFC device has an NFC simulation card with the second NFC protocol enabled, but not an NFC simulation card with the first NFC protocol enabled.

[0295] In scenario A, if the NFC device successfully receives a first card search request using the second NFC protocol after entering the radio frequency field generated by the NFC card reader 200, in response to the first card search request, the NFC device can send a second NFC protocol card search response to the NFC card reader 200. If the NFC device successfully receives a first card search request using the first NFC protocol after entering the radio frequency field generated by the NFC card reader 200, it can continue to receive a second card search request. If the NFC device successfully receives a second card search request using the second NFC protocol after entering the radio frequency field generated by the NFC card reader 200, in response to the second card search request, the NFC device can send a second NFC protocol card search response to the NFC card reader 200. If the NFC device successfully receives a second card search request after entering the radio frequency field generated by the NFC card reader 200, and the second card search request is a card search request of the first NFC protocol, the NFC device can continue to receive subsequent card search requests until it receives a card search request of the second NFC protocol. In response to the card search request of the second NFC protocol, the NFC device sends a card search response of the second NFC protocol to the NFC card reader 200.

[0296] In this way, when the NFC device supports both the first and second NFC protocols, and an NFC emulator card with the second NFC protocol activated but not the first NFC protocol activated, if the NFC device receives a card search request using the second NFC protocol from the NFC card reader 200, it can immediately send a card search response using the second NFC protocol to the NFC card reader. This eliminates the need to wait for the first NFC protocol card search request before sending a response. This speeds up the card swiping process between the NFC card reader 200 and the NFC device using the second NFC protocol.

[0297] For example, the NFC device supports both the first NFC protocol and the Class A NFC protocol. The NFC device has activated an NFC emulator card using the Class A NFC protocol but has not activated an NFC emulator card using the first NFC protocol.

[0298] If the first card search request successfully received by the NFC device after entering the radio frequency field generated by the NFC card reader 200 is REQ_A, the NFC device can respond to the first card search request by sending ATQ_A to the NFC card reader 200.

[0299] If the first card search request successfully received by the NFC device after entering the radio frequency field generated by the NFC card reader 200 is not REQ_A, the NFC device can continue to receive subsequent card search requests until it receives REQ_A. At that time, the NFC device can send ATQ_A to the NFC card reader 200.

[0300] For example, the NFC device supports both the first NFC protocol and the Class B NFC protocol. The NFC device has activated an NFC emulator card using the Class B NFC protocol but has not activated an NFC emulator card using the first NFC protocol.

[0301] If the first card search request successfully received by the NFC device after entering the radio frequency field generated by the NFC card reader 200 is REQ_B, the NFC device can respond to the first card search request by sending ATQ_B to the NFC card reader 200.

[0302] If the first card search request successfully received by the NFC device after entering the radio frequency field generated by the NFC card reader 200 is not REQ_B, the NFC device can continue to receive subsequent card search requests until it receives REQ_B. At that time, the NFC device can send ATQ_B to the NFC card reader 200.

[0303] For example, the NFC device supports both the first NFC protocol and the F-type NFC protocol. The NFC device has activated an NFC emulator card using the F-type NFC protocol but has not activated an NFC emulator card using the first NFC protocol.

[0304] If the first card search request successfully received by the NFC device after entering the radio frequency field generated by the NFC card reader 200 is SENS_REQ, the NFC device can respond to the first card search request by sending SENS_RES to the NFC card reader 200.

[0305] If the first card search request successfully received by the NFC device after entering the radio frequency field generated by the NFC card reader 200 is not SENS_REQ, the NFC device can continue to receive subsequent card search requests until it receives SENS_REQ. At that time, the NFC device can send SENS_RES to the NFC card reader 200.

[0306] For example, the NFC device supports the first NFC protocol, the Class A NFC protocol, and the Class B NFC protocol.

[0307] If the NFC device has activated an NFC emulator card using the Class A NFC protocol but not the Class B or the first NFC protocol, and the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is REQ_A, the NFC device can respond to this first card search request by sending ATQ_A to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is not REQ_A, the NFC device can continue to receive subsequent card search requests until it receives REQ_A, at which point it can send ATQ_A to the NFC reader 200.

[0308] If an NFC device has activated both a Type A NFC protocol emulator and a Type B NFC protocol emulator but not an NFC protocol emulator, and the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is REQ_A, the NFC device can respond to this first card search request by sending ATQ_A to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is REQ_B, the NFC device can respond to this first card search request by sending ATQ_B to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is not REQ_A or REQ_B, the NFC device can continue to receive subsequent card search requests until it receives REQ_A or REQ_B, at which point it stops receiving card search requests. If the NFC device receives REQ_A, it can send ATQ_A to the NFC reader 200. If the NFC device receives REQ_B, the NFC device can send ATQ_B to the NFC card reader 200.

[0309] For example, the NFC device supports the first NFC protocol, the Class A NFC protocol, and the Class F NFC protocol.

[0310] If the NFC device has activated an NFC emulator for Class A NFC protocol but not for Class F or Class 1 NFC protocol, and the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is REQ_A, the NFC device can respond to this request by sending ATQ_A to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is not REQ_A, the NFC device can continue to receive subsequent card search requests until it receives REQ_A, at which point it can send ATQ_A to the NFC reader 200.

[0311] If the NFC device has activated NFC emulator cards for both Class A and Class F NFC protocols but not for the first NFC protocol, and the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is REQ_A, the NFC device can respond to this request by sending ATQ_A to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is SENS_REQ, the NFC device can respond to this request by sending SENS_RES to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is neither REQ_A nor SENS_REQ, the NFC device can continue to receive subsequent card search requests until it receives REQ_A or SENS_REQ, at which point it stops receiving card search requests. If the NFC device receives REQ_A, it can send ATQ_A to the NFC reader 200. If the NFC device receives SENS_REQ, the NFC device can send SENS_RES to the NFC card reader 200.

[0312] For example, the NFC device supports the first NFC protocol, the Class B NFC protocol, and the Class F NFC protocol.

[0313] If the NFC device has activated a Class B NFC protocol NFC emulator but not a Class F NFC protocol NFC emulator or a Class 1 NFC protocol NFC emulator, and the first card search request successfully received after entering the radio frequency field generated by the NFC card reader 200 is REQ_B, the NFC device can respond to this first card search request by sending ATQ_B to the NFC card reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC card reader 200 is not REQ_B, the NFC device can continue to receive subsequent card search requests until it receives REQ_B, at which point the NFC device can send ATQ_B to the NFC card reader 200.

[0314] If the NFC device has activated NFC emulator cards with both Class B and Class F NFC protocols but not with the first NFC protocol, and the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is REQ_B, the NFC device can respond to this request by sending ATQ_B to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is SENS_REQ, the NFC device can respond to this request by sending SENS_RES to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is neither REQ_B nor SENS_REQ, the NFC device can continue to receive subsequent card search requests. If the NFC device receives REQ_B, it can send ATQ_B to the NFC reader 200. If the NFC device receives SENS_REQ, the NFC device can send SENS_RES to the NFC card reader 200.

[0315] For example, the NFC device supports the first NFC protocol, the Class A NFC protocol, the Class B NFC protocol, and the Class F NFC protocol.

[0316] If an NFC device has activated an NFC emulator for Class A NFC protocol but not for Class B, Class F, or the first NFC protocol, and the first card search request is successfully received by the NFC reader 200 after entering its radio frequency field, the NFC device can respond to this request by sending ATQ_A to the NFC reader 200. If the first card search request successfully received by the NFC device after entering its radio frequency field is not REQ_A, the NFC device can continue to receive subsequent card search requests until it receives REQ_A, at which point it can send ATQ_A to the NFC reader 200.

[0317] If an NFC device has activated a Class B NFC protocol NFC emulator but not a Class A, Class F, or first NFC protocol NFC emulator, and the first NFC protocol NFC emulator is activated, then if the first card search request successfully received after the NFC device enters the radio frequency field generated by the NFC reader 200 is REQ_B, the NFC device can respond to this first card search request by sending ATQ_B to the NFC reader 200. If the first card search request successfully received after the NFC device enters the radio frequency field generated by the NFC reader 200 is not REQ_B, the NFC device can continue to receive subsequent card search requests until it receives REQ_B, at which point the NFC device can send ATQ_B to the NFC reader 200.

[0318] If an NFC device has activated an NFC emulator for the F-class NFC protocol but not for the A-class, B-class, or first-class NFC protocols, and the first card search request is successfully received by the NFC reader 200 after entering its radio frequency field, the NFC device can respond to this request by sending a SENS_RES to the NFC reader 200. If the first card search request successfully received by the NFC device after entering its radio frequency field is not a SENS_REQ, the NFC device can continue to receive subsequent card search requests until it receives a SENS_REQ, at which point it can send a SENS_RES to the NFC reader 200.

[0319] If the NFC device has activated NFC emulator cards with Class A and Class B NFC protocols but not Class F or Class I NFC protocols, and the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is REQ_A, then the NFC device can respond to this first card search request by sending ATQ_A to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is REQ_B, then the NFC device can respond to this first card search request by sending ATQ_B to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is neither REQ_A nor REQ_B, then the NFC device can continue to receive subsequent card search requests until it receives REQ_A or REQ_B, at which point it stops receiving card search requests. If the NFC device receives REQ_A, it can send ATQ_A to the NFC card reader 200. If the NFC device receives REQ_B, it can send ATQ_B to the NFC card reader 200.

[0320] If the NFC device has activated NFC emulator cards with Class A and Class F NFC protocols but not Class B or Class I NFC protocols, and the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is REQ_A, then the NFC device can respond to this first card search request by sending ATQ_A to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is SENS_REQ, then the NFC device can respond to this first card search request by sending SENS_RES to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is not REQ_A or SENS_REQ, then the NFC device can continue to receive subsequent card search requests until it receives REQ_A or SENS_REQ and then stops receiving card search requests. If the NFC device receives REQ_A, it can send ATQ_A to the NFC card reader 200. If the NFC device receives SENS_REQ, it can send SENS_RES to the NFC card reader 200.

[0321] If the NFC device has activated NFC emulator cards with Class B and Class F protocols but not Class A or Class I protocols, and the first NFC protocol is not activated, then if the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is REQ_B, the NFC device can respond to this request by sending ATQ_B to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is SENS_REQ, the NFC device can respond to this request by sending SENS_RES to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is neither REQ_B nor SENS_REQ, the NFC device can continue to receive subsequent card search requests. If the NFC device receives REQ_B, it can send ATQ_B to the NFC reader 200. If the NFC device receives SENS_REQ, the NFC device can send SENS_RES to the NFC card reader 200.

[0322] If an NFC device has activated NFC emulator cards of type A, type B, and type F protocols but not the first NFC protocol, and the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is REQ_A, then the NFC device can respond to this first card search request by sending ATQ_A to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is REQ_B, then the NFC device can respond to this first card search request by sending ATQ_B to the NFC reader 200. If the first card search request successfully received after entering the radio frequency field generated by the NFC reader 200 is SENS_REQ, then the NFC device can respond to this first card search request by sending SENS_RES to the NFC reader 200. If the first card search request successfully received by the NFC device after entering the radio frequency field generated by the NFC card reader 200 is not REQ_A, REQ_B, or SENS_REQ, the NFC device can continue to receive subsequent card search requests until it receives REQ_A, REQ_B, or SENS_REQ, at which point it stops receiving card search requests. If the NFC device receives REQ_A, it can send ATQ_A to the NFC card reader 200. If the NFC device receives REQ_B, it can send ATQ_B to the NFC card reader 200. If the NFC device receives SENS_REQ, it can send SENS_RES to the NFC card reader 200.

[0323] Scenario B: The NFC device has an NFC emulator card with the first NFC protocol enabled, but no NFC emulator card with the second NFC protocol enabled.

[0324] In scenario B, if the NFC device successfully receives a first card search request after entering the radio frequency field generated by the NFC card reader 200, and that request is a card search request using the first NFC protocol, the NFC device can send a card search response using the first NFC protocol to the NFC card reader 200 in response to the first card search request. If the NFC device successfully receives a first card search request after entering the radio frequency field generated by the NFC card reader 200, and that request is a card search request using the second NFC protocol, the NFC device can continue to receive a second card search request. If the NFC device successfully receives a second card search request after entering the radio frequency field generated by the NFC card reader 200, and that request is a card search response using the first NFC protocol, the NFC device can send a card search response using the first NFC protocol to the NFC card reader 200 in response to the second card search request. If the second card search request successfully received by the NFC device after entering the radio frequency field generated by the NFC card reader 200 is the second NFC protocol, the NFC device can continue to receive subsequent card search requests until it receives a card search request of the first NFC protocol. In response to the card search request of the first NFC protocol, the NFC device sends a card search response of the first NFC protocol to the NFC card reader 200.

[0325] In this way, when the NFC device supports both the first and second NFC protocols, and an NFC analog card with the first NFC protocol enabled but not the second NFC protocol enabled, if the NFC device receives a card search request using the first NFC protocol from the NFC card reader 200, it can immediately send a card search response using the first NFC protocol to the NFC card reader. This eliminates the need to wait for a card search request using the second NFC protocol before sending a card search response using the first NFC protocol back to the NFC card reader. This speeds up the card swiping process between the NFC card reader 200 and the NFC device using the first NFC protocol.

[0326] Using the NFC polling method shown in Figure 13, when the NFC reader 200 supports both the first and second NFC protocols, it can send card search requests for the first and second NFC protocols in the following order within each of the multiple polling durations: card search request for the first NFC protocol, card search request for the second NFC protocol, and card search request for the first and second NFC protocols in the same order. When the NFC device supports both the first and second NFC protocols, after entering the radio frequency field, it can preferentially respond to the card search response of the first NFC protocol to the NFC reader 200, thus allowing the NFC reader 200 and the NFC device to preferentially choose the first NFC protocol for NFC interaction.

[0327] The following describes another hardware structure of an electronic device 100 provided in the embodiments of this application.

[0328] Figure 15 shows a schematic diagram of the hardware structure of an electronic device 100 provided in an embodiment of this application.

[0329] The following description uses electronic device 100 as an example to illustrate the embodiment. It should be understood that electronic device 100 shown in FIG. 15 is merely an example, and electronic device 100 may have more or fewer components than shown in FIG. 15, may combine two or more components, or may have different component configurations. The various components shown in FIG. 15 can be implemented in hardware, software, or a combination of hardware and software, including one or more signal processing and / or application-specific integrated circuits.

[0330] Electronic device 100 may include: processor 110, external memory interface 120, internal memory 121, universal serial bus (USB) interface 130, charging management module 140, power management module 141, battery 142, antenna 1, antenna 2, mobile communication module 150, wireless communication module 160, audio module 170, speaker 170A, receiver 170B, microphone 170C, headphone jack 170D, sensor module 180, button 190, motor 191, indicator 192, camera 193, display screen 194, and subscriber identification module (SIM) card interface 195, etc. The sensor module 180 may include one or more of the following: pressure sensor 180A, gyroscope sensor 180B, barometric pressure sensor 180C, magnetic sensor 180D, accelerometer sensor 180E, distance sensor 180F, proximity sensor 180G, fingerprint sensor 180H, temperature sensor 180J, touch sensor 180K, ambient light sensor 180L, bone conduction sensor 180M, etc.

[0331] It is understood that the structures illustrated in the embodiments of this application do not constitute a specific limitation on the electronic device 100. In other embodiments of this application, the electronic device 100 may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0332] Processor 110 may include one or more processing units, such as an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, memory, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural network processing unit (NPU). Different processing units may be independent devices or integrated into one or more processors. The controller can generate operation control signals based on instruction opcodes and timing signals to control instruction fetching and execution. Processor 110 may also include memory for storing instructions and data. In some embodiments, the memory in processor 110 is a cache memory. This memory can store instructions or data that processor 110 has just used or is recurring. If processor 110 needs to reuse the instruction or data, it can directly retrieve it from the memory. This avoids repeated access, reduces the waiting time of processor 110, and thus improves system efficiency.

[0333] In some embodiments, the processor 110 may include one or more interfaces. Interfaces may include an inter-integrated circuit (I2C) interface, an inter-integrated circuit sound (I2S) interface, a pulse code modulation (PCM) interface, a universal asynchronous receiver / transmitter (UART) interface, a mobile industry processor interface (MIPI), a general-purpose input / output (GPIO) interface, a subscriber identity module (SIM) interface, and / or a universal serial bus (USB) interface, etc.

[0334] It is understood that the interface connection relationships between the modules illustrated in the embodiments of this application are merely illustrative and do not constitute a structural limitation on the electronic device 100. In other embodiments of this application, the electronic device 100 may also employ different interface connection methods or combinations of multiple interface connection methods as described in the above embodiments.

[0335] The charging management module 140 receives charging input from the charger. The power management module 141 connects to the battery 142, and the charging management module 140 connects to the processor 110. The power management module 141 receives input from the battery 142 and / or the charging management module 140 to power the processor 110, internal memory 121, external memory, display 194, camera 193, and wireless communication module 160, etc.

[0336] The wireless communication function of electronic device 100 can be implemented through antenna 1, antenna 2, mobile communication module 150, wireless communication module 160, modem processor, and baseband processor. Antenna 1 and antenna 2 are used to transmit and receive electromagnetic wave signals. Each antenna in electronic device 100 can be used to cover one or more communication frequency bands. Different antennas can also be multiplexed to improve antenna utilization. For example, antenna 1 can be multiplexed as a diversity antenna for a wireless local area network. In some other embodiments, the antennas can be used in conjunction with tuning switches.

[0337] The mobile communication module 150 can provide solutions for wireless communication, including 2G / 3G / 4G / 5G, applied to the electronic device 100. The mobile communication module 150 may include at least one filter, switch, power amplifier, low noise amplifier (LNA), etc. The mobile communication module 150 can receive electromagnetic waves via antenna 1, and perform filtering, amplification, and other processing on the received electromagnetic waves before transmitting them to a modem processor for demodulation. The mobile communication module 150 can also amplify the signal modulated by the modem processor and convert it into electromagnetic waves for radiation via antenna 1. In some embodiments, at least some functional modules of the mobile communication module 150 may be housed in the processor 110. In some embodiments, at least some functional modules of the mobile communication module 150 and at least some modules of the processor 110 may be housed in the same device.

[0338] The wireless communication module 160 can provide solutions for wireless communication applications on the electronic device 100, including wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), and infrared (IR) technologies. The wireless communication module 160 can be one or more devices integrating at least one communication processing module. The wireless communication module 160 receives electromagnetic waves via antenna 2, performs frequency modulation and filtering of the electromagnetic wave signals, and sends the processed signal to processor 110. The wireless communication module 160 can also receive signals to be transmitted from processor 110, perform frequency modulation and amplification, and convert them into electromagnetic waves for radiation via antenna 2.

[0339] In some embodiments, antenna 1 of electronic device 100 is coupled to mobile communication module 150, and antenna 2 is coupled to wireless communication module 160, enabling electronic device 100 to communicate with networks and other devices via wireless communication technology. The wireless communication technology may include Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Time-Division Code Division Multiple Access (TD-SCDMA), Long Term Evolution (LTE), BT, GNSS, WLAN, NFC, FM, and / or IR technologies, etc. The GNSS may include the Global Positioning System (GPS), the Global Navigation Satellite System (GLONASS), the BeiDou Navigation Satellite System (BDS), the Quasi-Zenith Satellite System (QZSS), and / or satellite-based augmentation systems (SBAS).

[0340] Electronic device 100 implements display functions through a GPU, a display screen 194, and an application processor. The GPU is a microprocessor for image processing, connected to the display screen 194 and the application processor. The GPU is used to perform mathematical and geometric calculations and for graphics rendering. Processor 110 may include one or more GPUs, which execute program instructions to generate or modify display information.

[0341] Display screen 194 is used to display images, videos, etc. Display screen 194 includes a display panel. The display panel can be a liquid crystal display (LCD). The display panel can also be manufactured using organic light-emitting diodes (OLEDs), active-matrix organic light-emitting diodes (AMOLEDs), flexible light-emitting diodes (FLEDs), miniled, microled, micro-OLEDs, quantum dot light-emitting diodes (QLEDs), etc. In some embodiments, electronic device 100 may include one or N displays 194, where N is a positive integer greater than 1.

[0342] Electronic device 100 can perform shooting functions through ISP, camera 193, video codec, GPU, display 194 and application processor.

[0343] The external memory interface 120 can be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the electronic device 100. The internal memory 121 can be used to store computer-executable program code, which includes instructions. The processor 110 executes various functional applications and data processing of the electronic device 100 by running the instructions stored in the internal memory 121. The internal memory 121 may include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback, image playback, etc.), etc. The data storage area may store data created during the use of the electronic device 100 (such as audio data, phonebook, etc.). Furthermore, the internal memory 121 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, universal flash storage (UFS), etc.

[0344] Electronic device 100 can implement audio functions, such as music playback and recording, through audio module 170, speaker 170A, receiver 170B, microphone 170C, headphone jack 170D, and application processor.

[0345] Pressure sensor 180A is used to sense pressure signals and convert them into electrical signals. Gyroscope sensor 180B can be used to determine the motion posture of electronic device 100. Barometric pressure sensor 180C is used to measure air pressure. Magnetic sensor 180D includes a Hall sensor. Accelerometer sensor 180E can detect the magnitude of acceleration of electronic device 100 in various directions (generally three axes). Distance sensor 180F is used to measure distance. Proximity sensor 180G may include, for example, a light-emitting diode (LED) and a photodetector, such as a photodiode. Ambient light sensor 180L is used to sense ambient light intensity. Fingerprint sensor 180H is used to collect fingerprints. Temperature sensor 180J is used to detect temperature. Touch sensor 180K, also called a "touch panel". Touch sensor 180K can be set on display screen 194, and touch sensor 180K and display screen 194 form a touch screen, also called a "touch screen". Touch sensor 180K is used to detect touch operations applied to or near it. A touch sensor can transmit detected touch operations to an application processor to determine the type of touch event. Visual output related to the touch operation can be provided via display screen 194. In some embodiments, touch sensor 180K may also be located on the surface of electronic device 100, in a different position than display screen 194. Bone conduction sensor 180M can acquire vibration signals. Buttons 190 include a power button, volume buttons, etc. Motor 191 can generate vibration cues. Indicator 192 may be an indicator light, used to indicate charging status, battery level changes, or to indicate messages, missed calls, notifications, etc.

[0346] The SIM card interface 195 is used to connect a SIM card. The SIM card can be inserted into or removed from the SIM card interface 195 to make contact with and separate from the electronic device 100. The electronic device 100 can support one or N SIM card interfaces, where N is a positive integer greater than 1. The SIM card interface 195 can support Nano SIM cards, Micro SIM cards, SIM cards, etc. Multiple cards can be inserted into the same SIM card interface 195 simultaneously. The multiple cards can be of the same or different types. The SIM card interface 195 is also compatible with different types of SIM cards. The SIM card interface 195 is also compatible with external memory cards. The electronic device 100 interacts with the network through the SIM card to realize functions such as calls and data communication. In some embodiments, the electronic device 100 uses an eSIM, i.e., an embedded SIM card. The eSIM card can be embedded in the electronic device 100 and cannot be separated from the electronic device 100.

[0347] In some embodiments, the wireless communication module 160 can specifically be used to establish a short-range wireless communication link with the NFC card reader 200, so that the two can perform short-range wireless data transmission with each other. Exemplarily, the aforementioned short-range wireless communication link can be a Bluetooth link, a Wi-Fi link, an NFC link, a UWB link, etc. Therefore, the wireless communication module 160 can specifically include one or more of a Bluetooth communication module, a Wi-Fi communication module, an NFC module, and a UWB module. The NFC module can include any suitable components for enabling proximity-based contactless communication between the electronic device 100 and the NFC card reader 200, thereby providing NFC functionality to the electronic device 100. A description of the NFC module can be found in the embodiment shown in FIG3 above, and will not be repeated here.

[0348] The foregoing details the method provided in this application. In order to facilitate better implementation of the above-described solutions in the embodiments of this application, the embodiments of this application also provide corresponding devices or equipment.

[0349] This application embodiment can divide the electronic device 100 and NFC card reader 200 into functional modules according to the above method example. For example, each function can be divided into its own functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0350] The communication device of the present application embodiment will now be described in detail with reference to Figures 16 to 19.

[0351] Referring to FIG16, which is a schematic diagram of the structure of a communication device 1600 provided in an embodiment of this application, the communication device 1600 can be the NFC device in the above embodiments. Optionally, the communication device 1600 can be a chip / chip system, such as an NFC chip. As shown in FIG16, the communication device 1600 may include a transceiver unit 1610 and a processing unit 1620.

[0352] The transceiver unit 1610 can also be used to perform NFC sending and NFC receiving functions performed by the NFC device in the above embodiments of this application.

[0353] Optionally, the processing unit 1620 can also be used to perform functional steps related to NFC protocol parsing and encapsulation, NFC service processing flow, and display, which are performed by the NFC device in the above embodiments of this application.

[0354] It should be understood that the communication device 1600 in this design can perform the method steps performed by the NFC device in the aforementioned embodiments, and for the sake of brevity, it will not be described again here.

[0355] Referring to FIG17, which is a schematic diagram of the structure of a communication device 1700 provided in an embodiment of this application, the communication device 1700 can be the NFC card reader 200 in the above embodiments. As shown in FIG17, the communication device 1700 may include a transceiver unit 1710 and a processing unit 1720.

[0356] Optionally, the transceiver unit 1710 can also be used to perform the NFC sending and NFC receiving functions performed by the NFC card reader 200 in the above embodiments of this application.

[0357] Optionally, the processing unit 1720 can also be used to execute the functional steps related to NFC protocol parsing and encapsulation and NFC service processing flow executed by the NFC card reader 200 in the above embodiments of this application.

[0358] It should be understood that the communication device 1700 in this design can perform the method steps executed by the NFC card reader 200 in the aforementioned embodiment, and for the sake of brevity, it will not be described again here.

[0359] The NFC device and NFC card reader 200 of the present application embodiments have been described above. It should be understood that any product with the functions of the NFC device described in FIG16 above, or any product with the functions of the NFC card reader 200 described in FIG17 above, falls within the protection scope of the present application embodiments.

[0360] As a possible product form, the NFC device described in this application embodiment can be implemented using a general bus architecture.

[0361] Referring to Figure 18, which is a schematic diagram of the structure of a communication device 1800 provided in an embodiment of this application, the communication device 1800 can be an NFC device or a device within an NFC device. As shown in Figure 18, the communication device 1800 includes a processor 1801 and a transceiver 1802 internally connected and communicating with the processor 1801. The processor 1801 can be a general-purpose processor or a dedicated processor, for example, a central processing unit and / or an NFC controller. The transceiver 1802 can be referred to as a transceiver unit, transceiver, or transceiver circuit, etc., and is used to implement transceiver functions. The transceiver 1802 can include a receiver and a transmitter. The receiver can be referred to as a receiver or receiving circuit, etc., and is used to implement a receiving function, such as an NFC receiving function; the transmitter can be referred to as a transmitter or transmitting circuit, etc., and is used to implement a transmitting function, such as an NFC transmitting function. Optionally, the communication device 1800 may also include an antenna 1803 and / or a radio frequency unit (not shown in Figure 18), for example, an NFC antenna, wherein the NFC antenna can be a coil-type antenna. The antenna 1803 and / or radio frequency unit may be located inside the communication device 1800 or separate from the communication device 1800, that is, the antenna 1803 and / or radio frequency unit may be deployed remotely or in a distributed manner.

[0362] Optionally, the communication device 1800 may include one or more memories 1804, which may store instructions, which may be computer programs, that can be executed on the communication device 1800 to cause the communication device 1800 to perform the method steps described in the above embodiments of this application. Optionally, the memory 1804 may also store data. The communication device 1800 and the memory 1804 may be provided separately or integrated together.

[0363] The processor 1801, transceiver 1802, and memory 1804 can be connected via a communication bus.

[0364] In one design, the communication device 1800 can be used to perform the functions of the NFC device in the foregoing embodiments: the processor 1801 can be used to perform the functional steps related to NFC protocol parsing and encapsulation, NFC service processing flow and display performed by the NFC device in the above method embodiments of this application and / or other processes used in the technology described herein; the transceiver 1802 can be used to perform the functional steps related to NFC sending and NFC receiving performed by the NFC device in the above method embodiments of this application and / or other processes used in the technology described herein.

[0365] In any of the above designs, the processor 1801 may include a transceiver for implementing receive and transmit functions. For example, the transceiver may be a transceiver circuit, an interface, or an interface circuit. The transceiver circuit, interface, or interface circuit for implementing receive and transmit functions may be separate or integrated. The aforementioned transceiver circuit, interface, or interface circuit may be used for reading and writing code / data, or it may be used for transmitting or relaying signals.

[0366] In any of the above designs, the processor 1801 may store instructions, which may be computer programs. These computer programs, running on the processor 1801, cause the communication device 1800 to execute the method steps performed by the NFC device in the above embodiments of this application. The computer program may be embedded in the processor 1801; in this case, the processor 1801 may be implemented in hardware.

[0367] In one implementation, the communication device 1800 may include circuitry capable of performing the functions of transmitting, receiving, or communicating as described in the foregoing method embodiments. The processor and transceiver described in this application can be implemented on integrated circuits (ICs), analog ICs, radio frequency integrated circuits (RFICs), mixed-signal ICs, application-specific integrated circuits (ASICs), printed circuit boards (PCBs), electronic devices, etc. The processor and transceiver can also be manufactured using various IC process technologies, such as complementary metal oxide semiconductors (CMOS), n-metal-oxide-semiconductor (NMOS), p-type metal oxide semiconductors (PMOS), bipolar junction transistors (BJTs), bipolar CMOS (BiCMOS), silicon germanium (SiGe), gallium arsenide (GaAs), etc.

[0368] The scope of the communication device described in this application is not limited thereto, and the structure of the communication device is not limited to that shown in FIG18. Communication device 1800 may be a standalone device or part of a larger device. For example, the communication device 1800 may be:

[0369] (1) A standalone integrated circuit IC, or chip, or chip system or subsystem; (2) A collection of one or more ICs, optionally including storage components for storing data or computer programs; (3) An ASIC, such as an NFC chip; (4) A module that can be embedded in other devices; (5) A receiver, terminal, smart terminal, cellular phone, wireless device, handheld device, mobile unit, vehicle device, network device, cloud device, artificial intelligence device, etc.; (6) Others, etc.

[0370] As a possible product form, the NFC card reader 200 described in this application embodiment can be implemented using a general bus architecture.

[0371] Referring to Figure 19, which is a schematic diagram of the structure of a communication device 1900 provided in an embodiment of this application, the communication device 1900 may be an NFC card reader device 200, or a device therein. As shown in Figure 19, the communication device 1900 includes a processor 1901 and a transceiver 1902 internally connected and communicating with the processor 1901. The processor 1901 may be a general-purpose processor or a dedicated processor, for example, an NFC controller. The transceiver 1902 may be referred to as a transceiver unit, transceiver, or transceiver circuit, etc., and is used to implement transceiver functions. The transceiver 1902 may include a receiver and a transmitter. The receiver may be referred to as a receiver or receiving circuit, etc., and is used to implement a receiving function; the transmitter may be referred to as a transmitter or transmitting circuit, etc., and is used to implement a transmitting function. Optionally, the communication device 1900 may also include an antenna 1903 and / or a radio frequency unit (not shown in the figure). The antenna 1903 and / or radio frequency unit may be located inside the communication device 1900 or separate from the communication device 1900, that is, the antenna 1903 and / or radio frequency unit may be deployed remotely or in a distributed manner.

[0372] Optionally, the communication device 1900 may include one or more memories 1904, which may store instructions, which may be computer programs, that can be executed on the communication device 1900 to cause the communication device 1900 to perform the method steps described in the above embodiments of this application. Optionally, the memory 1904 may also store data. The communication device 1900 and the memory 1904 may be provided separately or integrated together.

[0373] The processor 1901, transceiver 1902, and memory 1904 can be connected via a communication bus.

[0374] In one design, the communication device 1900 can be used to perform the functions of the NFC card reader 200 in the foregoing embodiments: the processor 1901 can be used to perform the functional steps related to NFC protocol parsing and encapsulation, NFC service processing flow and / or other processes used in the technology described herein, performed by the NFC card reader 200 in the above method embodiments; the transceiver 1902 can be used to perform the functional steps related to NFC sending and NFC receiving performed by the NFC card reader 200 in the above method embodiments and / or other processes used in the technology described herein.

[0375] In any of the above designs, the processor 1901 may include a transceiver for implementing receive and transmit functions. For example, the transceiver may be a transceiver circuit, an interface, or an interface circuit. The transceiver circuit, interface, or interface circuit for implementing receive and transmit functions may be separate or integrated. The aforementioned transceiver circuit, interface, or interface circuit may be used for reading and writing code / data, or it may be used for transmitting or relaying signals.

[0376] In any of the above designs, the processor 1901 may store instructions, which may be computer programs. These computer programs, running on the processor 1901, cause the communication device 1900 to execute the method steps performed by the NFC card reader 200 in the above method embodiments. The computer program may be embedded in the processor 1901; in this case, the processor 1901 may be implemented in hardware.

[0377] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, can implement the steps performed by the NFC device in the above-described method embodiments.

[0378] This application also provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it can implement the steps performed by the NFC card reader 200 in the above-described method embodiments.

[0379] This application also provides a computer program product, including a computing program, which, when run on a computer, enables the computer to perform the steps executed by the NFC device in the above-described method embodiments.

[0380] This application also provides a computer program product, including a computing program, which, when run on a computer, enables the computer to perform the steps executed by the NFC card reader 200 in the above-described method embodiments.

[0381] This application also provides a chip system, which includes a processing circuit interface circuit. The interface circuit receives code instructions and transmits them to the processing circuit. The processing circuit executes the code instructions to enable the chip system to perform the steps executed by the NFC device in any of the method embodiments of this application. The chip system can be a single chip or a chip module composed of multiple chips.

[0382] This application also provides a chip system, which includes a processing circuit interface circuit. The interface circuit receives code instructions and transmits them to the processing circuit. The processing circuit executes the code instructions to enable the chip system to perform the steps executed by the NFC card reader 200 in any method embodiment of this application. The chip system can be a single chip or a chip module composed of multiple chips.

[0383] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A near field communication (NFC) polling method applied to an NFC card reading device, characterized in that, The method comprises: continuously sending a card search request of a first NFC protocol and a card search request of a second NFC protocol, wherein the first NFC protocol is different from the second NFC protocol, one or more card search requests of the first NFC protocol are sent between two adjacent card search requests of the second NFC protocol; if a card search response of the first NFC protocol or a card search response of the second NFC protocol sent by an NFC device is received, stopping sending the card search request of the first NFC protocol and the card search request of the second NFC protocol.

2. The method of claim 1, wherein, The card search request of the first NFC protocol is a Probe frame, and the card search response of the first NFC protocol is a Probe ACK frame.

3. The method of claim 2, wherein, The second NFC protocol comprises an A-type NFC protocol and / or a B-type NFC protocol and / or an F-type NFC protocol.

4. The method of claim 3, wherein, In a case where the second NFC protocol comprises the A-type NFC protocol but does not comprise the B-type NFC protocol and the F-type NFC protocol, the card search request of the second NFC protocol comprises an A-type request command REQ_A, and the card search response of the second NFC protocol comprises an A-type request response ATQ_A. The continuously sending the card search request of the first NFC protocol and the card search request of the second NFC protocol specifically comprises: in each polling time period in one or more polling duration periods, one or more Probe frames are sent first, and then one REQ_A is sent.

5. The method of claim 3, wherein, In a case where the second NFC protocol comprises the B-type NFC protocol but does not comprise the A-type NFC protocol and the F-type NFC protocol, the card search request of the second NFC protocol comprises a B-type request command REQ_B, and the card search response of the second NFC protocol comprises a B-type request response ATQ_B. The continuously sending the card search request of the first NFC protocol and the card search request of the second NFC protocol specifically comprises: in each polling time period in one or more polling duration periods, one or more Probe frames are sent first, and then one REQ_B is sent.

6. The method of claim 3, wherein, In a case where the second NFC protocol comprises the F-type NFC protocol but does not comprise the A-type NFC protocol and the B-type NFC protocol, the card search request of the second NFC protocol comprises a sensing request command SENS_REQ, and the card search response of the second NFC protocol comprises a sensing response SENS_RES. The continuously sending the card search request of the first NFC protocol and the card search request of the second NFC protocol specifically comprises: in each polling time period in one or more polling duration periods, one or more Probe frames are sent first, and then one SENS_REQ is sent.

7. The method of claim 3, wherein, In a case where the second NFC protocol comprises the A-type NFC protocol and the B-type NFC protocol but does not comprise the F-type NFC protocol, the card search request of the second NFC protocol comprises REQ_A and REQ_B, and the card search response of the second NFC protocol comprises ATQ_A or ATQ_B; The continuously sending the card search request of the first NFC protocol and the card search request of the second NFC protocol specifically comprises: In each polling time period in one or more polling duration periods, one or more Probe frames are first sent, then a REQ_A is sent, then one or more Probe frames are sent, and then a SENS_REQ is sent.

8. The method of claim 3, wherein, In a case where the second NFC protocol comprises the A-type NFC protocol and the F-type NFC protocol but does not comprise the B-type NFC protocol, the card search request of the second NFC protocol comprises a REQ_A and a SENS_REQ, and the card search response of the second NFC protocol comprises an ATQ_A or a SENS_RES; The continuously sending the card search request of the first NFC protocol and the card search request of the second NFC protocol specifically comprises: In each polling time period in one or more polling duration periods, one or more Probe frames are first sent, then a REQ_A is sent, then one or more Probe frames are sent, and then a SENS_REQ is sent.

9. The method of claim 3, wherein, In a case where the second NFC protocol comprises the B-type NFC protocol and the F-type NFC protocol but does not comprise the A-type NFC protocol, the card search request of the second NFC protocol comprises a REQ_B and a SENS_REQ, and the card search response of the second NFC protocol comprises an ATQ_B or a SENS_RES; The continuously sending the card search request of the first NFC protocol and the card search request of the second NFC protocol specifically comprises: In each polling time period in one or more polling duration periods, one or more Probe frames are first sent, then a REQ_B is sent, then one or more Probe frames are sent, and then a SENS_REQ is sent.

10. The method of claim 3, wherein, In a case where the second NFC protocol comprises the A-type NFC protocol, the B-type NFC protocol and the F-type NFC protocol, the card search request of the second NFC protocol comprises a REQ_B, a REQ_B and a SENS_REQ, and the card search response of the second NFC protocol comprises an ATQ_A or an ATQ_B or a SENS_RES; The continuously sending the card search request of the first NFC protocol and the card search request of the second NFC protocol specifically comprises: In each polling time period in one or more polling duration periods, one or more Probe frames are first sent, then a REQ_A is sent, then one or more Probe frames are sent, then a REQ_B is sent, then one or more Probe frames are sent, and then a SENS_REQ is sent.

11. The method according to any one of claims 1-10, characterized in that, The method further comprises: According to a proportion of the card search response of the first NFC protocol received in a historical period of time, the number of the card search request of the first NFC protocol sent between adjacent two times of sending the card search request of the second NFC protocol is adjusted.

12. The method of claim 11, wherein, The greater the proportion of the card search response of the first NFC protocol received in the historical period, the more the number of the card search request of the first NFC protocol sent between the adjacent two times of sending the card search request of the second NFC protocol.

13. The method according to any one of claims 1-10, characterized in that, The method further comprises: sending first geographical position information of the NFC card reading device to a server; receiving a first instruction sent by the server, the first instruction being used for instructing the NFC card reading device to send a first number of the card search request of the first NFC protocol between the adjacent two times of sending the card search request of the second NFC protocol; after receiving the first instruction, sending the first number of the card search request of the first NFC protocol between the adjacent two times of sending the card search request of the second NFC protocol.

14. The method of any one of claims 1-13, wherein, The method further comprises: if the card search response of the first NFC protocol sent by the NFC device is received, interacting with the NFC device based on the first NFC protocol.

15. The method of any one of claims 1-14, wherein, The method further comprises: if the card search response of the second NFC protocol sent by the NFC device is received, interacting with the NFC device based on the second NFC protocol.

16. A method of NFC polling, applied to an NFC device, characterized in that, The method comprises: if the first card search request successfully received after entering the radio frequency field generated by the NFC card reading device is the card search request of the first NFC protocol, sending the card search response of the first NFC protocol to the NFC card reading device in response to the first card search request; if the first card search request successfully received after entering the radio frequency field generated by the NFC card reading device is the card search request of the second NFC protocol, continuing to receive the second card search request; if the second card search request successfully received after entering the radio frequency field generated by the NFC card reading device is the card search request of the first NFC protocol, sending the card search response of the first NFC protocol to the NFC card reading device in response to the second card search request.

17. The method of claim 16, wherein, The method further comprises: if the second card search request successfully received after entering the radio frequency field generated by the NFC card reading device is the card search response of the second NFC protocol, sending the card search response of the second NFC protocol to the NFC card reading device in response to the second card search request.

18. The method of claim 16 or 17, wherein, The card search request of the first NFC protocol is a Probe frame, and the card search response of the first NFC protocol is a Probe ACK frame.

19. The method of claim 18, wherein, The card search request of the second NFC protocol comprises REQ_A or REQ_B or SENS_REQ, and the card search response of the second NFC protocol comprises ATQ_A or ATQ_B or SENS_RES.

20. An NFC system, characterized in that comprise an NFC card reading device and an NFC device; wherein the NFC card reading device is used for executing the NFC polling method as claimed in any one of claims 1-15; the NFC device is used for executing the NFC polling method as claimed in any one of claims 16-19.

21. An NFC card reading device, characterized by comprise: One or more processors, one or more memories, and a transceiver, wherein the transceiver, the one or more memories, and the one or more processors are coupled, the one or more memories are configured to store a computer program, and the one or more processors, when executing the computer program, are configured to implement the NFC polling method of any one of claims 1-15.

22. An NFC device, characterized in that, comprising: One or more processors, one or more memories, and a transceiver, wherein the transceiver, the one or more memories, and the one or more processors are coupled, the one or more memories are configured to store a computer program, and the one or more processors, when executing the computer program, are configured to implement the NFC polling method of any one of claims 16-19.

23. A computer-readable storage medium, characterized in that, A computer program is stored, and when the computer program is executed by a processor, the NFC polling method of any one of claims 1-15 is implemented.

24. A computer-readable storage medium, characterized in that, A computer program is stored, and when the computer program is executed by a processor, the NFC polling method of any one of claims 16-19 is implemented.

25. A computer program product, characterised in that, comprising a computer program, which when executed by a processor, implements the NFC polling method of any one of claims 1-15.

26. A computer program product, characterised in that, comprising a computer program, which when executed by a processor, implements the NFC polling method of any one of claims 16-19.

27. A chip system, characterized by comprising processing circuitry and interface circuitry configured to receive code instructions and transmit the code instructions to the processing circuitry, the processing circuitry configured to execute the code instructions to perform the NFC polling method of any one of claims 1-15.

28. A chip system, characterized by comprising processing circuitry and interface circuitry configured to receive code instructions and transmit the code instructions to the processing circuitry, the processing circuitry configured to execute the code instructions to perform the NFC polling method of any one of claims 16-19.

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