Transmitter, wireless communication method, wireless communication system, and receiver

Abstract

A transmitting device (10, 20) includes a control unit (12, 22) that generates packet data convergence protocol (PDCP) data including information indicating at least a portion of the hyper frame number (HFN) values held by the transmitting device, and a transmitting unit (11, 21) that transmits the PDCP data generated by the control unit to a receiving device.

Description

Technical Field

[0001] The present disclosure relates to a transmission device, a wireless communication method, a wireless communication system, a reception device, and a program.

Background Art

[0002] A technique for performing wireless communication using PDCP (Packet Data Convergence Protocol) is known (see, for example, Patent Documents 1 and 2). Note that PDCP provides functions such as transfer of user plane (U-plane) data and control plane (C-plane) data, header compression, and encryption.

[0003] In PDCP, when detecting non-reception of a response signal (Window stall) for transmission data, it is defined in the 3GPP (Third Generation Partnership Project) standard that the transmission device transmits a control signal to the reception device and initializes the Window (see, for example, Non-Patent Document 1). Here, the control signal is an RRC (Radio Resource Control) message including full configuration. When the UE receives the control signal, it initializes the window by reconfiguring PDCP.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Non-Patent Documents

[0005]

Non-Patent Document 1

[0006] However, related technologies have a problem in that if the reception of a response signal to transmitted data fails, the window is reset, resulting in a longer period during which data communication is suspended. In view of the above-mentioned problems, the purpose of this disclosure is to provide a transmitting device, a wireless communication method, a wireless communication system, a receiving device, and a program that can shorten the period during which data communication cannot be properly performed. [Means for solving the problem]

[0007] In a first aspect of the present disclosure, the transmitting device includes a control unit that generates PDCP (Packet Data Convergence Protocol) data including information indicating at least a portion of the HFN (Hyper Frame Number) value held by the transmitting device, and a transmitting unit that transmits the PDCP data generated by the control unit to a receiving device.

[0008] Furthermore, in the second aspect of this disclosure, the transmitting device generates PDCP (Packet Data Convergence Protocol) data that includes information indicating at least a portion of the HFN (Hyper Frame Number) value held by the transmitting device, and transmits the generated PDCP data to the receiving device.

[0009] Furthermore, in a third aspect relating to the present disclosure, there is a wireless communication system having a transmitting device and a receiving device, wherein the transmitting device includes a transmitting device control unit that generates PDCP (Packet Data Convergence Protocol) data including information indicating at least a portion of the HFN (Hyper Frame Number) value held by the transmitting device, and a transmitting unit that transmits the PDCP data generated by the transmitting device control unit to a receiving device, and the receiving device includes a receiving unit that receives the PDCP data transmitted from the transmitting device, and a receiving device control unit that updates the HFN value held by the receiving device based on information indicating at least a portion of the HFN value included in the PDCP data received by the receiving unit.

[0010] Furthermore, in a fourth aspect relating to this disclosure, the receiving device includes a receiving unit that receives PDCP (Packet Data Convergence Protocol) data which includes information indicating at least a portion of the HFN (Hyper Frame Number) value held by the transmitting device, and a control unit that updates the HFN value held by the receiving device based on the information indicating at least a portion of the HFN value contained in the PDCP data received by the receiving unit.

[0011] Furthermore, in the fifth aspect relating to this disclosure, the program is made to perform the following processes: receiving PDCP (Packet Data Convergence Protocol) data which includes information indicating at least a portion of the HFN (Hyper Frame Number) value held by the transmitting device; and updating the HFN value held by the receiving device based on the information indicating at least a portion of the HFN value contained in the received PDCP data. [Effects of the Invention]

[0012] From one perspective, this can shorten the period during which data communication cannot be performed properly. [Brief explanation of the drawing]

[0013] [Figure 1] It is a diagram showing a configuration example of a wireless communication system according to an embodiment. [Figure 2] It is a diagram showing an example of the configuration of a base station according to an embodiment. [Figure 3] It is a diagram showing an example of the configuration of a terminal according to an embodiment. [Figure 4] It is a sequence diagram showing an example of the processing of a wireless communication system according to an embodiment. [Figure 5] It is a diagram showing an example (Part 1) of the data format of PDCP that can include a Window update instruction according to an embodiment. [Figure 6] It is a diagram showing an example (Part 2) of the data format of PDCP that can include a Window update instruction according to an embodiment. [Figure 7] It is a diagram showing an example of the configuration of a base station and a terminal according to an embodiment.

MODE FOR CARRYING OUT THE INVENTION

[0014] The principles of the present disclosure are described with reference to several exemplary embodiments. These embodiments are described for illustrative purposes only and are intended to help those skilled in the art understand and implement the present disclosure without suggesting any limitations on the scope of the present disclosure. The disclosure described herein may be implemented in various ways other than those described below.

[0015] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs.

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. <SYSTEM CONFIGURATION> FIG. 1 is a diagram showing a configuration example of a wireless communication system 1 according to an embodiment. In FIG. 1, the wireless communication system 1 includes a base station 10 and a terminal 20. The range (coverage) within which the terminal 20 can receive radio waves from the base station 10 is also referred to as a cell 30. Note that the numbers of the base station 10 and the terminal 20 are not limited to the example in FIG. 1. One of the base station 10 and the terminal 20 is an example of a "transmission device", and the other is an example of a "reception device".

[0017] The base station 10 and the terminal 20 are connected so as to be able to communicate by wireless communication such as, for example, the fifth-generation mobile communication system (5G), the fourth-generation mobile communication system (4G), or wireless LAN (Local Area Network).

[0018] Note that the term "base station" (BS: Base Station) used in the present disclosure refers to a device that can provide or host a cell or coverage with which the terminal 20 can communicate. Examples of the base station 10 include, for example, gNB (NR Node B), Node B (NodeB or NB), Evolved Node B (eNodeB or eNB), Remote Radio Unit (RRU), and the like. Examples of the base station 10 also include, for example, Radio Head (RH), Remote Radio Head (RRH), and low-power nodes (for example, femto nodes, pico nodes), but are not limited thereto.

[0019] As used in this disclosure, the term “Terminal” refers to any device having wireless or wired communication capabilities. Examples of Terminal 20 include user equipment (UE), personal computers, desktops, mobile phones, cellular phones, smartphones, wearable devices, and personal digital assistants (PDAs). Other examples of Terminal 20 include portable computers, image capture devices such as digital cameras, game devices, music storage and playback devices, or internet devices that enable internet access and browsing.

[0020] The communications (wireless communications) described in this disclosure may conform to standards such as 5G (5th generation mobile communication system, NR: New Radio), 4G (4th generation mobile communication system), and 3G (3rd generation mobile communication system). 4G may include, for example, LTE (Long Term Evolution) Advanced, WiMAX2, and LTE. Furthermore, the wireless communications described in this disclosure may conform to standards such as Wideband Code Division Multiple Access (W-CDMA), Code Division Multiple Access (CDMA), Global System for Mobile (GSM), and Wireless LAN (Local Area Network). The wireless communications described in this disclosure may also be implemented according to any currently known or future-developed generation of wireless communications protocol. In this disclosure, "downlink" refers to the link from base station 10 to terminal 20, and "uplink" refers to the link from terminal 20 to base station 10.

[0021] The following describes an example where a window stall occurs during a downlink transmission from base station 10 to terminal 20, resulting in the failure to receive a response signal for transmitted data. In the case of a downlink, base station 10 is an example of a "transmitting device," and terminal 20 is an example of a "receiving device."

[0022] In the case of an uplink, where data is transmitted from terminal 20 to base station 10, base station 10 is an example of a "receiving device," and terminal 20 is an example of a "transmitting device." In the case of an uplink, the source (transmitter) and destination (receiver) of the data are reversed compared to the downlink case described below. Therefore, in the case of an uplink, in the explanation of the downlink below, for example, base station 10 and terminal 20 should be read as each other, and downlink should be read as uplink, etc.

[0023] <Structure> Next, the configurations of the base station 10 and terminal 20 according to the embodiment will be described with reference to Figures 2 and 3. Figure 2 is a diagram showing an example of the configuration of the base station 10 according to the embodiment. Figure 3 is a diagram showing an example of the configuration of the terminal 20 according to the embodiment. Note that the configurations shown in Figures 2 and 3 are merely examples. Any name may be used for each part as long as it can perform the processing of this disclosure.

[0024] <<Base station 10>> The base station 10 has a transmitting unit 11 and a control unit 12. The transmitting unit 11 converts digital data into radio waves and transmits it from the antenna to the terminal 20, following instructions from the control unit 12. The transmitting unit 11 transmits, for example, PDCP (Packet Data Convergence Protocol) data generated by the control unit 12 to the terminal 20. The control unit 12 performs various controls. For example, the control unit 12 performs various processes for the base station 10 to perform wireless communication with the terminal 20. For example, the control unit 12 generates PDCP data that includes information indicating at least a portion of the HFN (Hyper Frame Number) value held by the base station 10.

[0025] <<Terminal 20>> The terminal 20 has a receiving unit 21 and a control unit 22. The receiving unit 21 receives radio waves transmitted from the base station 10 using an antenna and converts the received radio waves into digital signals. The receiving unit 21 receives PDCP data, for example, which includes information indicating at least a portion of the HFN value held by the base station 10. The control unit 22 performs various controls. For example, the control unit 22 performs various processes for the terminal 20 to communicate wirelessly with the base station 10. For example, the control unit 22 updates the HFN value held by the terminal 20 based on information indicating at least a portion of the HFN value included in the PDCP data received by the receiving unit 21.

[0026] <Processing> Next, with reference to Figure 4, an example of the processing of the wireless communication system 1 according to the embodiment will be described. Figure 4 is a sequence diagram showing an example of the processing of the wireless communication system 1 according to the embodiment. Figure 5 is a diagram showing an example (1) of a PDCP data format that can include a window update instruction according to the embodiment. Figure 6 is a diagram showing an example (2) of a PDCP data format that can include a window update instruction according to the embodiment.

[0027] In step S101, the control unit 12 of the base station 10 (transmitter) detects that it has failed to receive a response signal for the transmitted data (window stall). Here, the base station 10 may execute the process in step S102 if, for example, the window stall is not expected to be resolved because it continues for a certain period of time.

[0028] Next, the transmitter 11 of the base station 10 stops downlink data communication with the terminal 20 (step S102). Then, the transmitter 11 of the base station 10 sends a window update instruction to the terminal 20 (step S103). At this point, the control unit 12 of the base station 10 generates PDCP data that includes information indicating at least a portion of the HFN value held by the base station 10. Then, the transmitter 11 of the base station 10 transmits the PDCP data generated by the control unit 12 to the terminal 20.

[0029] Therefore, the base station 10 according to the embodiment of this disclosure transmits to the terminal 20 a window update instruction in the downlink PDCP data, rather than a control signal in the RRC message containing the full configuration. This allows the module in the terminal 20 that processes PDCP layer communication to be instructed to update the window.

[0030] Furthermore, Non-Patent Document 1, a 3GPP standard concerning PDCP, specifies that a 32-bit format COUNT value is used to generate confidential data bits. It also specifies that the COUNT value includes a 14-bit HFN value and an 18-bit PDCP SN (Sequence Number) value.

[0031] For the confidentiality process to function correctly, both terminal 20 and base station 10 must maintain the same COUNT value. Furthermore, according to Non-Patent Document 1, the PDCP SN value is notified along with the data. On the other hand, the HFN value is not notified from base station 10 to terminal 20 or from terminal 20 to base station 10, but is maintained internally by both terminal 20 and base station 10.

[0032] In PDCP window control, the receiving side notifies the transmitting side of the PDCP SN value that has been confirmed as received, and the PDCP window is advanced starting from that PDCP SN value. The PDCP SN value is incremented with each data transmission. The HFN value is also incremented when the PDCP SN value cycles (for example, changes from 262,143 to 0). Because the PDCP SN value cycles repeatedly, PDCP window control is necessary to ensure that the recognition of the HFN value, which indicates which cycle (how many cycles have passed) the PDCP SN value is, does not become inconsistent between the base station 10 and the terminal 20.

[0033] Figure 5 shows an example of a PDCP data format that can include a window update instruction according to an embodiment of this disclosure. In the example of data format 501 in Figure 5, information for resynchronizing the window is included in the range of 5 reserved (unused) bits (R) 502 as defined in the standard (Non-Patent Literature 1, Section 6.2.2.3, "Data PDU for DRBs with 18 bits PDCP SN"). In the example in Figure 5, in a PDU (Protocol Data Unit) where the PDCP SN value is represented by 18 bits, one bit of the 5 reserved bits 502 is used as bit 503 for the synchronization instruction (Sync. Ind.). The remaining 4 bits 504 (bits 3 to 6 in the PDU) are set to the lower 4 bits of the HFN value held by the transmitting side.

[0034] Figure 6 also shows another example of a PDCP data format that can include a window update instruction according to the embodiment of this disclosure. In the example of data format 601 in Figure 6, the range of 3 reserved bits as defined in the standard (Non-Patent Literature 1, Section 6.2.2.2, "Data PDU for DRBs with 12 bits PDCP SN") includes information for resynchronizing the window. In the example in Figure 6, in a PDU where the PDCP SN value is represented by 12 bits, one of the 3 reserved bits 602 is used as bit 603 for the synchronization instruction (Sync. Ind.). The remaining 2 bits 604 (the 3rd and 4th bits in the PDU) are set to the lower 2 bits of the HFN value held by the transmitting side. Note that in Figures 5 and 6, D / C stands for Data or Control.

[0035] Furthermore, the larger the number of bits that represent at least a portion of the HFN value included in the transmitted data, the larger the PDCP window shift that allows for resynchronization. As shown in Figure 6, if the lower 2 bits of the HFN value are included, resynchronization is possible up to a shift of 3 cycles of the PDCP SN. Also, as shown in Figure 5, if the lower 4 bits of the HFN value are included, resynchronization is possible up to a shift of 15 cycles of the PDCP SN.

[0036] When the base station 10 uses the data format 501 shown in Figure 5, the control unit 12 sets the synchronization instruction bit 503 to "1" and sets the lower 4 bits of the updated HFN value in the remaining 4 bits 504. When the base station 10 uses the data format 601 shown in Figure 6, it sets the synchronization instruction bit 603 to "1" and sets the lower 2 bits of the updated HFN value in the remaining 2 bits 604. This allows the base station 10 to forcibly advance the window.

[0037] Next, the control unit 22 of terminal 20 (receiving side) updates (synchronizes) the window based on the received window update instruction (step S104). Here, the control unit 22 of terminal 20 updates the HFN value held in terminal 20 based on information indicating at least a portion of the HFN value contained in the PDCP data received by the receiving unit 21.

[0038] In this case, terminal 20 updates the HFN value it holds with the HFN value set in the PDCP data, where the synchronization instruction bit is set to "1". In this case, terminal 20 updates (replaces, overwrites) one or more of the lower bits of the HFN value it holds with one or more of the lower bits 504 or 604 of the HFN value set in the received PDCP data. As a result, the receiving Window is synchronized again with the transmitting Window.

[0039] Furthermore, if the base station 10 does not perform the process of forcibly advancing the window, it may set the synchronization instruction bit "0" and leave bits 504 or 604, which are 1 or more from the lower end of the HFN value, unset. If the synchronization instruction bit "0" is set, the terminal 20 may not perform the window resynchronization process in step S104, but instead perform the same processing as known processing for PDCP data.

[0040] <<Regarding the effects of this disclosure>> If the transmitting side advances the PDCP window without synchronizing with the receiving side, the receiving side will determine that newly received data within a predetermined range (for example, SN=131072~26143) has already been received and discard it. The receiving side will then process newly received data from SN=0 onwards, assuming it is within the PDCP window. However, because the receiving side cannot recognize that the received data is SN=0 data at HFN=3, it processes it as SN=0 data at HFN=2. This results in a mismatch in HFN value recognition. When a mismatch in HFN value recognition occurs, the data bits generated for security purposes will be inconsistent between terminal 20 and base station 10, resulting in the security process not working correctly and garbled characters appearing in the decoded data.

[0041] If the sender cannot receive notification of the PDCP SN value from the receiver due to packet loss or other reasons, the PDCP window cannot be advanced, resulting in a PDCP window stall and preventing data transmission.

[0042] In related technologies such as the 3GPP standard, a PDCP window stall is resolved by sending a control signal via an RRC message containing the full configuration from the base station 10 to the terminal 20. Therefore, it is necessary for the base station 10 and the terminal 20 to cooperate (control, inter-process communication, inter-thread communication) between the module that processes the PDCP layer and the module that processes the control signals. Then, the PDCP layer needs to be initialized (reconfigured).

[0043] On the other hand, in the technology disclosed herein, PDCP transmission data with synchronization information attached is transmitted from the base station 10 to the terminal 20. Therefore, coordination between the module that processes the PDCP layer and the module that processes the control signals is not required in the base station 10 and the terminal 20. In addition, since control signals such as RRC messages including full configuration are not used, the terminal 20 and the base station 10 do not need to reconfigure the PDCP layer. As a result, the period during which data communication is stopped when the reception of a response signal to the transmitted data fails can be shortened.

[0044] The following describes modifications of embodiments of the present disclosure. Each of the following modifications may be implemented in appropriate combination with embodiments of the present disclosure. <Example 1> The examples in Figures 5 and 6 above illustrate how to set bits for synchronization instructions. Alternatively, the synchronization instruction bits may be omitted. In this case, the base station 10 may, for example, set the lower 5 bits of the HFN value held by the transmitting side to 5bit 502 (bits 2 to 6 in the PDU) in Figure 5. Alternatively, the base station 10 may, for example, set the lower 3 bits of the HFN value held by the transmitting side to 3bit 602 (bits 2 to 4 in the PDU) in Figure 6.

[0045] Then, if the first HFN value held by terminal 20 does not match the second HFN value set in the received PDCP data, terminal 20 updates the first HFN value to the second HFN value. In this case, terminal 20 updates (replaces, overwrites) one or more bits from the lower end of the HFN value held by terminal 20 with one or more bits 502 or 602 from the lower end of the HFN value set in the received PDCP data. This resynchronizes the receiving side's Window with the transmitting side's Window. Therefore, the period during which data communication cannot be performed properly can be shortened.

[0046] <Modification 2> In the example described above, the base station 10 performs window resynchronization processing when it detects that a window stall has occurred in step S101 of Figure 4. Alternatively, the base station 10 may perform the window resynchronization processing in steps S103 and S104 of Figure 4 at predetermined intervals, such as periodically. Furthermore, the base station 10 may perform the window resynchronization processing in steps S103 and S104 of Figure 4 when it is notified by the terminal 20 that there is a mismatch in the HEN value. This allows the mismatch to be resolved not only when a PDCP window stall occurs, but also when there is a mismatch in the HFN value between the terminal 20 and the base station 10. As a result, the period during which data communication cannot be performed properly can be shortened.

[0047] <Variation 3> The following describes a case where the base station 10 has a CU / DU separation configuration in which a central base station (CU) controls one or more remote stations (DUs). In this case, the control unit 12 of the base station 10 may be located in the CU. The transmission unit 11 of the base station 10 may be located in the DU. The control unit 12 (CU) may generate PDCP data containing window update instructions in the data format shown in Figure 5, etc. The transmission unit 11 (DU) may then transmit the PDCP data containing window update instructions generated by the CU to the terminal 20.

[0048] <Modification 4> Figure 7 shows an example of the configuration of a computer 100 when at least a part of the base station 10 (e.g., the control unit 12) or at least a part of the terminal 20 (e.g., the control unit 22) is implemented by a computer and program. In the example in Figure 7, the computer 100 includes a processor 101, memory 102, and a communication interface 103. These parts may be connected by a bus or the like. The memory 102 stores at least a part of the program 104. The communication interface 103 includes interfaces necessary for communication with other network elements. In the case of the base station 10, the communication interface 103 includes, for example, an interface for communication with the terminal 20 via one or more antennas, an interface for communication between base stations, and an interface for communication with various servers on the core network side.

[0049] When program 104 is executed in cooperation with the processor 101 and memory 102, etc., the computer 100 performs at least some of the processing of embodiments of this disclosure. Memory 102 may be any type suitable for a local technology network. Memory 102 may, in non-limiting examples, be a non-temporary computer-readable storage medium. Memory 102 may also be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. Although only one memory 102 is shown for computer 100, computer 100 may have several physically different memory modules. Processor 101 may be any type. Processor 101 may include one or more general-purpose computers, dedicated computers, microprocessors, digital signal processors (DSPs), and, in non-limiting examples, processors based on multicore processor architectures. Computer 100 may have multiple processors, such as application-specific integrated circuit chips that are time-dependent to a clock that synchronizes the main processor.

[0050] Embodiments of the present disclosure may be implemented in hardware or in dedicated circuitry, software, logic, or any combination thereof. Some embodiments may be implemented in hardware, while others may be implemented in firmware or software that can be executed by a controller, microprocessor, or other computing device.

[0051] This disclosure also provides at least one computer program product tangibly stored on a non-temporary computer-readable storage medium. The computer program product includes computer-executable instructions, such as instructions contained in a program module, and is executed on a device on a target real or virtual processor to perform the processes or methods of this disclosure. The program module includes routines, programs, libraries, objects, classes, components, data structures, etc., that perform a specific task or implement a specific abstract data type. The functionality of the program module may be combined or divided among the program module as desired in various embodiments. The machine-executable instructions of the program module can be executed on a local or distributed device. On a distributed device, the program module can reside on both local and remote storage media.

[0052] Program code for performing the methods of this disclosure may be written in any combination of one or more programming languages. These program codes are provided to a processor or controller of a general-purpose computer, a dedicated computer, or other programmable data processing device. When the program code is executed by the processor or controller, the functions / operations in the flowchart and / or block diagrams it implements are performed. The program code may run entirely on a machine, partially on a machine, partially as a standalone software package, partially on a machine, partially on a remote machine, or entirely on a remote machine or server.

[0053] Programs can be stored and supplied to a computer using various types of non-temporary computer-readable media. Non-temporary computer-readable media include various types of tangible recording media. Examples of non-temporary computer-readable media include magnetic recording media, magneto-optical recording media, optical disc media, and semiconductor memory. Magnetic recording media include, for example, flexible disks, magnetic tapes, and hard disk drives. Magneto-optical recording media include, for example, magneto-optical disks. Optical disc media include, for example, Blu-ray discs, CD (Compact Disc)-ROM (Read Only Memory), CD-R (Recordable), and CD-RW (ReWritable). Semiconductor memory includes, for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, and RAM (random access memory). Programs may also be supplied to a computer using various types of temporary computer-readable media. Examples of temporary computer-readable media include electrical signals, optical signals, and electromagnetic waves. Temporary computer-readable media can supply programs to a computer via wired communication channels such as electric wires and optical fibers, or via wireless communication channels.

[0054] It should be noted that the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention.

[0055] Some or all of the above embodiments may also be described as follows, but are not limited to the following: (Note 1) A transmitting device, A control means for generating PDCP (Packet Data Convergence Protocol) data that includes information indicating at least a portion of the HFN (Hyper Frame Number) value held by the transmitting device, A transmission means for transmitting PDCP data generated by the control means to a receiving device, A transmitting device having (Note 2) The control means, upon detecting a predetermined event, generates PDCP data that includes information indicating at least a portion of the HFN value held by the transmitting device. The transmitting device described in Appendix 1. (Note 3) The aforementioned predetermined event is the failure to receive the response signal to the PDCP transmission data. The transmitting device described in Appendix 2. (Note 4) The control means generates PDCP data that includes one or more bits from the lower end of the HFN value held by the transmitting device. A transmitting device as described in any one of the items 1 to 3 of the appendix. (Note 5) The control means generates PDCP data in a PDU (Protocol Data Unit) where the PDCP SN (Sequence Number) value is represented by 18 bits, and at least the 3rd to 6th bits include the lower four bits of the HFN value held by the transmitting device. The transmitting device described in Appendix 4. (Note 6) The control means generates PDCP data in a PDU (Protocol Data Unit) where the PDCP SN value is represented by 12 bits, including at least two bits from the lower end of the HFN value held by the transmitting device in at least the third and fourth bits. The transmitting device described in Appendix 4 or 5. (Note 7) The transmitting device, The transmitting device generates PDCP (Packet Data Convergence Protocol) data that includes information indicating at least a portion of the HFN (Hyper Frame Number) value held by the transmitting device. A wireless communication method for transmitting generated PDCP data to a receiving device. (Note 8) To the transmitting device, A process for generating PDCP (Packet Data Convergence Protocol) data that includes information indicating at least a portion of the HFN (Hyper Frame Number) value held by the aforementioned transmitting device, A non-temporary computer-readable medium containing a program that executes the process of sending the generated PDCP data to a receiving device. (Note 9) It has a transmitting device and a receiving device, The transmitting device is A transmitting device control means that generates PDCP (Packet Data Convergence Protocol) data including information indicating at least a portion of the HFN (Hyper Frame Number) value held by the transmitting device, A transmission means that transmits the PDCP data generated by the transmission device control means to a receiving device, It has, The receiving device is, A receiving means for receiving PDCP data transmitted from the aforementioned transmitting device, The receiving device control means updates the HFN value held by the receiving device based on information indicating at least a portion of the HFN value contained in the PDCP data received by the receiving means. Wireless communication system. (Note 10) The transmitting device control means, upon detecting a predetermined event, generates PDCP data that includes information indicating at least a portion of the HFN value held by the transmitting device. The wireless communication system described in Appendix 9. (Note 11) A receiving device, A receiving means for receiving PDCP (Packet Data Convergence Protocol) data that includes information indicating at least a portion of the HFN (Hyper Frame Number) value held by the transmitting device, The receiving device has a control means that updates the HFN value held by the receiving device based on information indicating at least a portion of the HFN value contained in the PDCP data received by the receiving means. Receiving device. (Note 12) The receiving means receives PDCP data, which includes information indicating at least a portion of the HFN value held by the transmitting device, when a predetermined event is detected by the transmitting device. The receiving device described in Appendix 11. (Note 13) The receiving device, The transmitting device receives PDCP (Packet Data Convergence Protocol) data that includes information indicating at least a portion of the HFN (Hyper Frame Number) value held by the transmitting device. A wireless communication method for updating the HFN value held by the receiving device based on information indicating at least a portion of the HFN value contained in the received PDCP data. (Note 14) To the receiving device, The process of receiving PDCP (Packet Data Convergence Protocol) data that includes information indicating at least a portion of the HFN (Hyper Frame Number) value held by the transmitting device, A non-temporary computer-readable medium containing a program that causes a receiving device to perform a process of updating the HFN value it holds based on information indicating at least a portion of the HFN value contained in the received PDCP data.

[0056] Although the present invention has been described above with reference to embodiments, the present invention is not limited thereto. Various modifications to the structure and details of the present invention can be made that are understandable to those skilled in the art within the scope of the invention.

[0057] This application claims priority based on Japanese Patent Application No. 2021-044619, filed on 18 March 2021, and incorporates all of its disclosures herein. [Explanation of symbols]

[0058] 1. Wireless communication system 10 base station 11 Transmitter 12 Control Unit 20 devices 21 Receiving unit 22 Control Unit 30 cells

Claims

1. A transmitting device, A control means that, upon detecting a predetermined event, generates PDCP (Packet Data Convergence Protocol) data including information indicating at least a portion of the HFN (Hyper Frame Number) value held by the transmitting device, A transmission means for transmitting the PDCP data generated by the control means to a receiving device, It has, The aforementioned predetermined event is the failure to receive the response signal to the PDCP transmission data. Transmitter.

2. The control means generates PDCP data that includes one or more bits from the lower end of the HFN value held by the transmitting device. The transmitting device according to claim 1.

3. The control means generates PDCP data in a PDU (Protocol Data Unit) where the PDCP SN (Sequence Number) value is represented by 18 bits, and at least the third to sixth bits include four or more bits from the lower end of the HFN value held by the transmitting device. The transmitting device according to claim 2.

4. The control means generates PDCP data in a PDU (Protocol Data Unit) where the PDCP SN value is represented by 12 bits, and at least the third and fourth bits include two or more bits from the lower end of the HFN value held by the transmitting device. The transmitting device according to claim 2 or 3.

5. The transmitting device, When a predetermined event is detected, the transmitting device generates PDCP (Packet Data Convergence Protocol) data that includes information indicating at least a portion of the HFN (Hyper Frame Number) value it holds. The generated PDCP data is sent to the receiving device. The aforementioned predetermined event is the failure to receive the response signal to the PDCP transmission data. Wireless communication method.

6. It has a transmitting device and a receiving device, The transmitting device is A transmitting device control means that, upon detecting a predetermined event, generates PDCP (Packet Data Convergence Protocol) data including information indicating at least a portion of the HFN (Hyper Frame Number) value held by the transmitting device, A transmission means for transmitting PDCP data generated by the transmission device control means to a receiving device, It has, The aforementioned predetermined event is the failure to receive the response signal to the PDCP transmission data. The receiving device is, Receiving means for receiving PDCP data transmitted from the transmitting device, The receiving device control means updates the HFN value held by the receiving device based on information indicating at least a portion of the HFN value included in the PDCP data received by the receiving means. Wireless communication system.

7. A receiving device, A receiving means that, when a transmission device detects a predetermined event, receives PDCP (Packet Data Convergence Protocol) data that includes information indicating at least a portion of the HFN (Hyper Frame Number) value held by the transmission device, The receiving device has a control means that updates the HFN value held by the receiving device based on information indicating at least a portion of the HFN value contained in the PDCP data received by the receiving means, The aforementioned predetermined event is the failure to receive the response signal to the PDCP transmission data. Receiving device.

8. The receiving device, When a predetermined event is detected by the transmitting device, the transmitting device receives PDCP (Packet Data Convergence Protocol) data that includes information indicating at least a portion of the HFN (Hyper Frame Number) value held by the transmitting device. Based on information indicating at least a portion of the HFN value contained in the received PDCP data, the HFN value held in the receiving device is updated. The aforementioned predetermined event is the failure to receive the response signal to the PDCP transmission data. Wireless communication method.

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