Security handling for subsequent mobility

Abstract

Methods and apparatus are provided for secure handling for subsequent mobility procedures. The wireless device receives a security mode command including a security configuration from a network, receives information from the network that notifies whether a target cell belongs to a security group, and continues using the security configuration based on the information that the target cell belongs to the security group.

Description

Technical Field

[0001] The present disclosure relates to security handling for subsequent mobility procedures. Background Art

[0002] The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is a technology for implementing high-speed packet communications. Many solutions have been proposed for the LTE goal, including those aimed at reducing user and provider costs, improving service quality, and expanding and improving coverage and system capacity. 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of frequency bands, simple structure, open interfaces, and appropriate power consumption of terminals as higher-level requirements.

[0003] The International Telecommunication Union (ITU) and 3GPP have begun work to develop requirements and specifications for New Radio (NR) systems. 3GPP must identify and develop the technical components needed to successfully standardize a new RAT that meets both urgent market needs in a timely manner and longer-term requirements set forth by the ITU Radiocommunication Sector (ITU-R) International Mobile Telecommunications (IMT)-2020 process. In addition, even in the more distant future, NR should be able to use any spectrum band available for wireless communications up to at least 100 GHz.

[0004] NR aims at a single technology framework that addresses all use cases, requirements and deployment scenarios, including enhanced mobile broadband (eMBB), massive machine type communications (mMTC), ultra-reliable low latency communications (URLLC), etc. NR should be inherently forward compatible.

[0005] In Rel-17 Conditional Secondary Cell (PSCell) Change (CPC) / Conditional PSCell Addition (CPA), a CPC / CPA configured user equipment (UE) must release the CPC / CPA configuration upon completion of random access towards the target PSCell. Therefore, the UE has no chance to perform subsequent CPC / CPA without previous CPC / CPA reconfiguration and reinitialization from the network. This will increase the latency of cell changes and increase signaling overhead, especially in the case of frequent secondary cell group (SCG) changes when operating in frequency range-2 (FR2).

[0006] In Rel-18, 3GPP aims to support optimized mobility procedures for UEs without receiving additional reconfiguration and performing reinitialization using a given conditional mobility command. This means that the UE can maintain a given conditional mobility command regardless of the change of the serving cell and use the conditional mobility command whenever the condition is met. That is, multiple subsequent mobilities can be allowed based on a given conditional mobility command. Summary of the invention

[0007] Technical Solution

[0008] The present disclosure will provide methods and apparatus for handling security updates for subsequent mobility.

[0009] In one aspect, a method performed by a wireless device adapted to operate in a wireless communication system is provided. The method includes the steps of receiving a security mode command including a security configuration from a network, receiving information from the network notifying whether a target cell belongs to a security group, and notifying the target cell that it belongs to the security group based on the information, continuing to use the security configuration.

[0010] In another aspect, a device for implementing the above method is provided.

[0011] Beneficial Effects

[0012] The present disclosure may have various beneficial effects.

[0013] For example, when performing subsequent mobility, the security reuse problem can be solved by cell group-based security information handling.

[0014] The beneficial effects that can be obtained by the specific embodiments of the present disclosure are not limited to the beneficial effects listed above. For example, there are various technical effects that a person of ordinary skill in the relevant field can understand and / or derive from the present disclosure. Therefore, the specific effects of the present disclosure are not limited to those effects explicitly described herein, but can include various effects that can be understood or derived from the technical features of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 An example of a communication system to which implementations of the present disclosure are applied is shown.

[0016] Figure 2 An example of a wireless device to which implementations of the present disclosure are applied is shown.

[0017] Figure 3 An example of a UE to which implementations of the present disclosure are applied is shown.

[0018] Figure 4 and Figure 5 An example of a protocol stack in a 3GPP-based wireless communication system to which implementations of the present disclosure are applied is shown.

[0019] Figure 6 A frame structure in a 3GPP-based wireless communication system to which the present disclosure is applied is shown.

[0020] Figure 7 An example of data flow in a 3GPP NR system to which implementations of the present disclosure are applied is shown.

[0021] Figure 8 An example of MR-DC utilizing selective activation of cell groups to which implementations of the present disclosure are applied is shown.

[0022] Fig. 9 An example of a method performed by a wireless device to which an implementation of the present disclosure is applied is shown.

[0023] Fig.10 An example of a method performed by a base station to which an implementation of the present disclosure is applied is shown. DETAILED DESCRIPTION

[0024] The following techniques, devices and systems can be applied to various wireless multiple access systems. Examples of these multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and multi-carrier frequency division multiple access (MC-FDMA) systems. CDMA can be implemented by radio technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented by radio technologies such as Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), or Enhanced Data Rate for GSM Evolution (EDGE). OFDMA can be implemented by radio technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, or Evolved UTRA (E-UTRA). UTRA is part of Universal Mobile Telecommunications System (UMTS). 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is a part of Evolved UMTS (E-UMTS) using E-UTRA. 3GPP LTE adopts OFDMA in the downlink (DL) and SC-FDMA in the uplink (UL). The evolutions of 3GPP LTE include LTE Advanced (LTE-A), LTE-A Pro and / or 5G New Radio (NR).

[0025] For ease of description, the embodiments of the present disclosure are mainly described with respect to a 3GPP-based wireless communication system. However, the technical features of the present disclosure are not limited thereto. For example, although the following detailed description is given based on a mobile communication system corresponding to a 3GPP-based wireless communication system, aspects of the present disclosure that are not limited to a 3GPP-based wireless communication system are applicable to other mobile communication systems.

[0026] For terms and techniques not specifically described in the terms and techniques adopted in the present disclosure, reference may be made to wireless communication standard documents issued prior to the present disclosure.

[0027] In the present disclosure, "A or B" may mean "only A", "only B", or "both A and B". In other words, in the present disclosure, "A or B" may be interpreted as "A and / or B". For example, in the present disclosure, "A, B or C" may mean "only A", "only B", "only C", or "any combination of A, B, and C".

[0028] In the present disclosure, a slash ( / ) or a comma (,) may mean "and / or". For example, "A / B" may mean "A and / or B". Thus, "A / B" may mean "only A", "only B", or "both A and B". For example, "A, B, C" may mean "A, B, or C".

[0029] In the present disclosure, "at least one of A and B" may mean "only A", "only B", or "both A and B". In addition, the expression "at least one of A or B" or "at least one of A and / or B" in the present disclosure may be interpreted as being the same as "at least one of A and B".

[0030] In addition, in the present disclosure, "at least one of A, B, and C" may mean "only A", "only B", "only C", or "any combination of A, B, and C". In addition, "at least one of A, B, or C" or "at least one of A, B and / or C" may mean "at least one of A, B, and C".

[0031] In addition, the brackets used in the present disclosure may mean "for example". In detail, when it is shown as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information". In other words, in the present disclosure, "control information" is not limited to "PDCCH", and "PDDCH" may be proposed as an example of "control information". In addition, even when it is shown as "control information (ie, PDCCH)", "PDCCH" may be proposed as an example of "control information".

[0032] The technical features described separately in one figure in the present disclosure can be implemented separately or simultaneously.

[0033] Although not limited to this, the various descriptions, functions, processes, suggestions, methods and / or operational flowcharts of the present disclosure disclosed herein may be applied to various fields requiring wireless communication and / or connection between devices (e.g., 5G).

[0034] Hereinafter, the present disclosure will be described in more detail with reference to the accompanying drawings. Unless otherwise specified, the same reference numerals in the following drawings and / or descriptions may refer to the same and / or corresponding hardware blocks, software blocks and / or functional blocks.

[0035] Figure 1An example of a communication system to which an embodiment of the present disclosure is applied is shown.

[0036] exist Figure 1 The 5G usage scenarios shown in the present disclosure are only exemplary, and the technical features of the present disclosure may be applied to Figure 1 Other 5G usage scenarios shown in .

[0037] The three main demand categories for 5G include: (1) enhanced mobile broadband (eMBB) category, (2) massive machine type communication (mMTC) category, and (3) ultra-reliable and low-latency communication (URLLC) category.

[0038] Reference Figure 1 , the communication system 1 includes wireless devices 100a to 100f, a base station (BS) 200, and a network 300. Figure 1 A 5G network is illustrated as an example of a network of the communication system 1 , but embodiments of the present disclosure are not limited to the 5G system and may be applied to future communication systems other than the 5G system.

[0039] BS 200 and network 300 may be implemented as wireless devices, and a specific wireless device may operate as a BS / network node relative to other wireless devices.

[0040] The wireless devices 100a to 100f represent devices that perform communication using a radio access technology (RAT) (e.g., 5G NR or LTE) and may be referred to as communication / wireless / 5G devices. The wireless devices 100a to 100f may include, but are not limited to, a robot 100a, vehicles 100b-1 and 100b-2, an extended reality (XR) device 100c, a handheld device 100d, a home appliance 100e, an Internet of Things (IoT) device 100f, and an artificial intelligence (AI) device / server 400. For example, a vehicle may include a vehicle with a wireless communication function, an autonomous vehicle, and a vehicle capable of performing communication between vehicles. A vehicle may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device may include an augmented reality (AR) / virtual reality (VR) / mixed reality (MR) device and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) installed in a vehicle, a television, a smart phone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, and the like. Handheld devices may include smart phones, smart tablets, wearable devices (e.g., smart watches or smart glasses), and computers (e.g., notebooks). Home appliances may include TVs, refrigerators, and washing machines. IoT devices may include sensors and smart meters.

[0041] In the present disclosure, the wireless devices 100a to 100f may be referred to as user equipment (UE). For example, the UE may include a cellular phone, a smart phone, a laptop computer, a digital broadcast terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, a plate-shaped personal computer (PC), a tablet PC, an ultrabook, a vehicle, a vehicle with an autonomous driving function, a connected car, a UAV, an AI module, a robot, an AR device, a VR device, an MR device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a Fintech device (or a financial device), a security device, a weather / environmental device, a device related to 5G services, or a device related to the field of the fourth industrial revolution.

[0042] The wireless devices 100a to 100f may be connected to the network 300 via the BS 200. AI technology may be applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f may be connected to the AI ​​server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, and a super 5G network. Although the wireless devices 100a to 100f may communicate with each other via the BS 200 / network 300, the wireless devices 100a to 100f may perform direct communication (e.g., sidelink communication) with each other without passing through the BS 200 / network 300. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). An IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0043] Wireless communication / connection 150a, 150b, and 150c may be established between wireless devices 100a to 100f and / or between wireless devices 100a to 100f and BS 200 and / or between BS 200. In this document, wireless communication / connection may be established through various RATs (e.g., 5G NR) such as uplink / downlink communication 150a, sidelink communication (or device-to-device (D2D) communication) 150b, inter-base station communication 150c (e.g., relay, integrated access and backhaul (IAB)), etc. Wireless devices 100a to 100f and BS 200 / wireless devices 100a to 100f may send / receive radio signals to each other through wireless communication / connection 150a, 150b, and 150c. For example, wireless communication / connection 150a, 150b, and 150c may send / receive signals through various physical channels. To this end, various configuration information configuration processes for sending / receiving radio signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, and resource mapping / demapping), and at least a portion of the resource allocation process may be performed based on various proposals of the present disclosure.

[0044] NR supports multiple parameter sets (and / or multiple subcarrier spacing (SCS)) to support various 5G services. For example, if the SCS is 15kHz, wide areas can be supported in traditional cellular bands, and if the SCS is 30kHz / 60kHz, dense cities, lower latency, and wider carrier bandwidths can be supported. If the SCS is 60kHz or higher, bandwidths greater than 24.25GHz can be supported to overcome phase noise.

[0045] The NR frequency band may be defined as two types of frequency ranges, namely, frequency range 1 (FR1) and frequency range 2 (FR2). The numerical values ​​of the frequency ranges may be changed. For example, the two types of frequency ranges (FR1 and FR2) may be as shown in Table 1 below. For ease of explanation, in the frequency range used in the NR system, FR1 may mean "a range below 6 GHz", FR2 may mean "a range above 6 GHz", and may be referred to as millimeter wave (mmW).

[0046] [Table 1]

[0047] Frequency range specification Corresponding frequency range Subcarrier spacing FR1 450MHz–6000MHz 15, 30, 60kHz FR2 24250MHz–52600MHz 60, 120, 240kHz

[0048] As mentioned above, the value of the frequency range of the NR system can be changed. For example, FR1 may include 410 MHz to 7125 MHz as shown in Table 2 below. That is, FR1 may include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or above. For example, the frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or above included in FR1 may include an unlicensed frequency band. The unlicensed frequency band can be used for various purposes, for example, communication of vehicles (e.g., autonomous driving).

[0049] [Table 2]

[0050] Frequency range specification Corresponding frequency range Subcarrier spacing FR1 410MHz–7125MHz 15, 30, 60kHz FR2 24250MHz–52600MHz 60, 120, 240kHz

[0051] Here, the radio communication technology implemented in the wireless device in the present disclosure may include narrowband IoT (NB-IoT) technology for low-power communication as well as LTE, NR and 6G. For example, NB-IoT technology may be an example of a low-power wide area network (LPWAN) technology, which may be implemented in specifications such as LTE Cat NB1 and / or LTE Cat NB2, and may not be limited to the names mentioned above. Additionally and / or alternatively, the radio communication technology implemented in the wireless device in the present disclosure may be based on LTE-M technology for communication. For example, LTE-M technology may be an example of LPWAN technology and is referred to as various names such as enhanced MTC (eMTC). For example, LTE-M technology may be implemented in at least one of various specifications such as 1) LTE CaT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-bandwidth limited (non-BL), 5) LTE-MTC, 6) LTE machine type communication and / or 7) LTE M, and may not be limited to the above names. Additionally and / or alternatively, the radio communication technology implemented in the wireless device in the present disclosure may include at least one of ZigBee, Bluetooth, and / or LPWAN considering low-power communication, and may not be limited to the names mentioned above. For example, ZigBee technology may generate a personal area network (PAN) associated with small / low-power digital communication based on various specifications such as IEEE 802.15.4, and may be referred to as various names.

[0052] Figure 2 An example of a wireless device to which an embodiment of the present disclosure is applied is shown.

[0053] exist Figure 2 In the embodiment, the first wireless device 100 and / or the second wireless device 200 may be implemented in various forms according to the usage / service. For example, {the first wireless device 100 and the second wireless device 200} may correspond to Figure 1At least one of {wireless devices 100a to 100f and BS200}, {wireless devices 100a to 100f and wireless devices 100a to 100f} and / or {BS200 and BS200}. The first wireless device 100 and / or the second wireless device 200 may be configured by various elements, devices / components and / or modules.

[0054] The first wireless device 100 may include at least one transceiver, such as the transceiver 106 ; at least one processing chip, such as the processing chip 101 ; and / or one or more antennas 108 .

[0055] The processing chip 101 may include at least one processor, such as the processor 102, and at least one memory, such as the memory 104. Additionally and / or alternatively, the memory 104 may be placed outside the processing chip 101.

[0056] The processor 102 may control the memory 104 and / or the transceiver 106 and may be adapted to implement the descriptions, functions, processes, suggestions, methods and / or operational flow charts described in the present disclosure. For example, the processor 102 may process the information in the memory 104 to generate a first information / signal, and then transmit a radio signal including the first information / signal through the transceiver 106. The processor 102 may receive a radio signal including a second information / signal through the transceiver 106 and then store information obtained by processing the second information / signal in the memory 104.

[0057] The memory 104 may be operably connected to the processor 102. The memory 104 may store various types of information and / or instructions. The memory 104 may store firmware and / or software code 105 that implements codes, commands, and / or sets of commands that, when executed by the processor 102, perform the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure. For example, the firmware and / or software code 105 may implement instructions that, when executed by the processor 102, perform the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure. For example, the firmware and / or software code 105 may control the processor 102 to execute one or more protocols. For example, the firmware and / or software code 105 may control the processor 102 to execute one or more layers of a radio interface protocol.

[0058] In this document, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 106 may be connected to the processor 102 and transmit and / or receive radio signals through one or more antennas 108. Each of the transceivers 106 may include a transmitter and / or a receiver. The transceiver 106 may be used interchangeably with a radio frequency (RF) unit. In the present disclosure, the first wireless device 100 may represent a communication modem / circuit / chip.

[0059] The second wireless device 200 may include at least one transceiver, such as the transceiver 206 ; at least one processing chip, such as the processing chip 201 ; and / or one or more antennas 208 .

[0060] The processing chip 201 may include at least one processor, such as the processor 202, and at least one memory, such as the memory 204. Additionally and / or alternatively, the memory 204 may be placed outside the processing chip 201.

[0061] The processor 202 may control the memory 204 and / or the transceiver 206 and may be adapted to implement the descriptions, functions, processes, suggestions, methods and / or operational flow charts described in the present disclosure. For example, the processor 202 may process the information in the memory 204 to generate third information / signals, and then transmit a radio signal including the third information / signals through the transceiver 206. The processor 202 may receive a radio signal including fourth information / signals through the transceiver 106, and then store information obtained by processing the fourth information / signals in the memory 204.

[0062] The memory 204 may be operably connected to the processor 202. The memory 204 may store various types of information and / or instructions. The memory 204 may store firmware and / or software code 205 that implements codes, commands, and / or sets of commands that, when executed by the processor 202, perform the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure. For example, the firmware and / or software code 205 may implement instructions that, when executed by the processor 202, perform the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure. For example, the firmware and / or software code 205 may control the processor 202 to execute one or more protocols. For example, the firmware and / or software code 205 may control the processor 202 to execute one or more layers of a radio interface protocol.

[0063] In this document, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 206 may be connected to the processor 202 and transmit and / or receive radio signals through one or more antennas 208. Each of the transceivers 206 may include a transmitter and / or a receiver. The transceiver 206 may be used interchangeably with an RF unit. In the present disclosure, the second wireless device 200 may represent a communication modem / circuit / chip.

[0064] In the following, the hardware elements of the wireless devices 100 and 200 will be described in more detail. One or more protocol layers may be implemented by, but not limited to, one or more processors 102 and 202. For example, one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as physical (PHY), layer, medium access control (MAC) layer, radio link control (RLC) layer, packet data convergence protocol (PDCP) layer, radio resource control (RRC) layer, and service data adaptation protocol (SDAP) layer). One or more processors 102 and 202 may generate one or more protocol data units (PDUs), one or more service data units (SDUs), messages, control information, data, or information according to the descriptions, functions, processes, suggestions, methods, and / or operation flow charts disclosed in the present disclosure. The one or more processors 102 and 202 may generate a signal (e.g., a baseband signal) including a PDU, SDU, message, control information, data, or information according to the description, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure and provide the generated signal to the one or more transceivers 106 and 206. The one or more processors 102 and 202 may receive a signal (e.g., a baseband signal) from the one or more transceivers 106 and 206 and obtain the PDU, SDU, message, control information, data, or information according to the description, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure.

[0065] One or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. As an example, one or more application specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs), or one or more field programmable gate arrays (FPGAs) may be included in one or more processors 102 and 202. For example, one or more processors 102 and 202 may be configured by a collection of a communication control processor, an application processor (AP), an electronic control unit (ECU), a central processing unit (CPU), a graphics processing unit (GPU), and a memory control processor. One or more memories 104 and 204 may be connected to one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, codes, instructions, and / or commands.

[0066] The one or more memories 104 and 204 may be configured by random access memory (RAM), dynamic RAM (DRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EPROM), flash memory, volatile memory and non-volatile memory, hard disk drive, register, cache memory, computer-readable storage medium and / or a combination thereof. The one or more memories 104 and 204 may be located inside and / or outside the one or more processors 102 and 202. The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 through various technologies such as wired or wireless connections.

[0067] One or more transceivers 106 and 206 may send user data, control information, and / or radio signals / channels mentioned in the description, function, process, suggestion, method, and / or operation flow chart disclosed in the present disclosure to one or more other devices. One or more transceivers 106 and 206 may receive user data, control information, and / or radio signals / channels mentioned in the description, function, process, suggestion, method, and / or operation flow chart disclosed in the present disclosure from one or more other devices. For example, one or more transceivers 106 and 206 may be connected to one or more processors 102 and 202 and send and receive radio signals. For example, one or more processors 102 and 202 may perform control so that one or more transceivers 106 and 206 may send user data, control information, or radio signals to one or more other devices. One or more processors 102 and 202 may perform control so that one or more transceivers 106 and 206 may receive user data, control information, or radio signals from one or more other devices.

[0068] One or more transceivers 106 and 206 may be connected to one or more antennas 108 and 208. Additionally and / or alternatively, one or more transceivers 106 and 206 may include one or more antennas 108 and 208. One or more transceivers 106 and 206 may be adapted to transmit and receive user data, control information, and / or radio signals / channels mentioned in the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure. In the present disclosure, one or more antennas 108 and 208 may be multiple physical antennas or multiple logical antennas (e.g., antenna ports).

[0069] The one or more transceivers 106 and 206 may convert the received user data, control information, radio signals / channels, etc. from RF band signals to baseband signals so as to process the received user data, control information, radio signals / channels, etc. using the one or more processors 102 and 202. The one or more transceivers 106 and 206 may convert the user data, control information, radio signals / channels, etc. processed using the one or more processors 102 and 202 from baseband signals to RF band signals. To this end, the one or more transceivers 106 and 206 may include (analog) oscillators and / or filters. For example, the one or more transceivers 106 and 206 may up-convert OFDM baseband signals to OFDM signals through their (analog) oscillators and / or filters under the control of the one or more processors 102 and 202 and transmit the up-converted OFDM signals at the carrier frequency. The one or more transceivers 106 and 206 may receive an OFDM signal at a carrier frequency and down-convert the OFDM signal to an OFDM baseband signal through their (analog) oscillators and / or filters under the control of the one or more processors 102 and 202 .

[0070] Although in Figure 2 140, but the wireless devices 100 and 200 may further include additional components. The additional components 140 may be configured differently depending on the type of the wireless devices 100 and 200. For example, the additional components 140 may include at least one of a power unit / battery, an input / output (I / O) device (e.g., an audio I / O port, a video I / O port), a drive device, and a computing device. The additional components 140 may be coupled to the one or more processors 102 and 202 via various technologies such as wired or wireless connections.

[0071] In an embodiment of the present disclosure, a UE may operate as a transmitting device in UL and as a receiving device in DL. In an embodiment of the present disclosure, a BS may operate as a receiving device in UL and as a transmitting device in DL. In the following, for the convenience of description, it is mainly assumed that the first wireless device 100 is a UE and the second wireless device 200 is a BS. For example, a processor 102 connected to, installed on, or started in the first wireless device 100 may be suitable for executing a UE behavior according to an embodiment of the present disclosure or controlling a transceiver 106 to execute a UE behavior according to an embodiment of the present disclosure. A processor 202 connected to, installed on, or started in the second wireless device 200 may be suitable for executing a BS behavior according to an embodiment of the present disclosure or controlling a transceiver 206 to execute a BS behavior according to an embodiment of the present disclosure.

[0072] In this disclosure, a BS is also referred to as a Node B (NB), an eNode B (eNB), or a gNB.

[0073] Figure 3 An example of a UE to which an embodiment of the present disclosure is applied is shown.

[0074] refer to Figure 3 , UE 100 may correspond to Figure 2 A first wireless device 100 is provided.

[0075] UE 100 includes a processor 102 , a memory 104 , a transceiver 106 , one or more antennas 108 , a power management module 141 , a battery 142 , a display 143 , a keypad 144 , a subscriber identity module (SIM) card 145 , a speaker 146 , and a microphone 147 .

[0076] The processor 102 may be configured to implement the descriptions, functions, processes, suggestions, methods and / or operational flow charts disclosed in the present disclosure. The processor 102 may be configured to control one or more other components of the UE 100 to implement the descriptions, functions, processes, suggestions, methods and / or operational flow charts disclosed in the present disclosure. The layers of the radio interface protocol may be implemented in the processor 102. The processor 102 may include an ASIC, other chipsets, logic circuits and / or data processing devices. The processor 102 may be an application processor. The processor 102 may include at least one of a DSP, a CPU, a GPU, a modem (modulator and demodulator). Examples of the processor 102 may be found in MANUFACTURED BY SNAPDRAGON TM Series processors, Manufactured by EXYNOS TM Series processors, A series processors manufactured by Made by HELIO TM Series processors, ATOM manufactured TM series processors or corresponding next-generation processors.

[0077] The memory 104 is operably connected to the processor 102 and stores various information to operate the processor 102. The memory 104 may include ROM, RAM, flash memory, memory card, storage medium and / or other storage devices. When the embodiment is implemented in software, the technology described herein can be implemented with modules (e.g., processes, functions, etc.) that execute the descriptions, functions, processes, suggestions, methods and / or operational flow charts disclosed in this disclosure. The modules can be stored in the memory 104 and executed by the processor 102. The memory 104 can be implemented within the processor 102 or outside the processor 102, in which case the memory 104 can be communicatively connected to the processor 102 via various means known in the art.

[0078] The transceiver 106 is operably connected to the processor 102 and transmits and / or receives radio signals. The transceiver 106 includes a transmitter and a receiver. The transceiver 106 may include a baseband circuit for processing radio frequency signals. The transceiver 106 controls one or more antennas 108 to transmit and / or receive radio signals.

[0079] The power management module 141 manages the power of the processor 102 and / or the transceiver 106. The battery 142 supplies power to the power management module 141.

[0080] The display 143 outputs the result processed by the processor 102. The keyboard 144 receives input to be used by the processor 102. The keyboard 144 may be shown on the display 143.

[0081] The SIM card 145 is an integrated circuit designed to securely store an International Mobile Subscriber Identity (IMSI) number and its associated keys, which are used to identify and authenticate subscribers on mobile telephony devices such as mobile phones and computers. Contact information can also be stored on many SIM cards.

[0082] The speaker 146 outputs sound related results processed by the processor 102. The microphone 147 receives sound related input to be used by the processor 102.

[0083] Figure 4 and Figure 5 An example of a protocol stack in a 3GPP-based wireless communication system to which implementations of the present disclosure are applied is shown.

[0084] Specifically, Figure 4An example of a radio interface user plane protocol stack between a UE and a BS is illustrated, and Figure 5 An example of a radio interface control plane protocol stack between a UE and a BS is illustrated. The control plane refers to a path through which control messages for managing calls made between a UE and a network are transmitted. The user plane refers to a path through which data generated in an application layer (e.g., voice data or Internet packet data) is transmitted. Figure 4 , the user plane protocol stack can be divided into layer 1 (ie, PHY layer) and layer 2. Figure 5 , the control plane protocol stack can be divided into layer 1 (ie, PHY layer), layer 2, layer 3 (eg, RRC layer), and non-access stratum (NAS) layer. Layer 1, layer 2, and layer 3 are called access stratum (AS).

[0085] In the 3GPP LTE system, Layer 2 is separated into the following sublayers: MAC, RLC, and PDCP. In the 3GPP NR system, Layer 2 is separated into the following sublayers: MAC, RLC, PDCP, and SDAP. The PHY layer provides transport channels to the MAC sublayer, the MAC sublayer provides logical channels to the RLC sublayer, the RLC sublayer provides RLC channels to the PDCP sublayer, and the PDCP sublayer provides radio bearers to the SDAP sublayer. The SDAP sublayer provides Quality of Service (QoS) flows to the 5G core network.

[0086] In the 3GPP NR system, the main services and functions of the MAC sublayer include: mapping between logical channels and transport channels; multiplexing / demultiplexing MAC SDUs belonging to one or different logical channels to / from transport blocks (TBs) on transport channels for delivery to / from the physical layer; scheduling information reporting; error correction through hybrid automatic repeat request (HARQ) (one HARQ entity per cell in the case of carrier aggregation (CA); priority handling between UEs through dynamic scheduling; priority handling between logical channels of one UE through logical channel prioritization; padding. A single MAC entity can support multiple parameter sets, transmission timings, and cells. The mapping restrictions in the logical channel prioritization control which parameter set(s), cell, and transmission timing can be used by the logical channel.

[0087] MAC provides different kinds of data transmission services. In order to accommodate different kinds of data transmission services, multiple types of logical channels are defined, that is, each logical channel supports the transmission of a specific type of information. Each logical channel type is defined by what type of information is transmitted. Logical channels are divided into two groups: control channels and traffic channels. Control channels are used only for the transmission of control plane information, and traffic channels are used only for the transmission of user plane information. The broadcast control channel (BCCH) is a downlink logical channel for broadcasting system control information, the paging control channel (PCCH) is a downlink logical channel for transmitting paging information, system information change notifications, and indications of ongoing public warning services (PWS) broadcasts, the common control channel (CCCH) is a logical channel used to send control information between the UE and the network and is used by UEs that do not have an RRC connection with the network, and the dedicated control channel (DCCH) is a point-to-point bidirectional logical channel used by UEs with RRC connections to send dedicated control information between the UE and the network. The dedicated traffic channel (DTCH) is a point-to-point logical channel dedicated to one UE for transmitting user information. DTCH can exist in both the uplink and downlink. In the downlink, there are the following connections between logical channels and transport channels: BCCH can be mapped to the broadcast channel (BCH); BCCH can be mapped to the downlink shared channel (DL-SCH); PCCH can be mapped to the paging channel (PCH); CCCH can be mapped to DL-SCH; DCCH can be mapped to DL-SCH; and DTCH can be mapped to DL-SCH. In the uplink, there are the following connections between logical channels and transport channels: CCCH can be mapped to the uplink shared channel (UL-SCH); DCCH can be mapped to UL-SCH; and DTCH can be mapped to UL-SCH.

[0088] The RLC sublayer supports three transmission modes: transparent mode (TM), unacknowledged mode (UM) and acknowledged mode (AM). The RLC configuration is per logical channel without dependency on parameter sets and / or transmission duration. In 3GPP NR systems, the main services and functions of the RLC sublayer depend on the transmission mode and include: delivery of upper layer PDUs; sequence numbering independent of sequence numbering in PDCP (UM and AM); error correction through ARQ (AM only); segmentation (AM and UM) and re-segmentation (AM only) of RLC SDUs; reassembly of SDUs (AM and UM); duplicate detection (AM only); RLC SDU discard (AM and UM); RLC reconstruction; protocol error detection (AM).

[0089] In the 3GPP NR system, the main services and functions of the PDCP sublayer for the user plane include: sequence numbering; header compression and decompression using robust header compression (RoHC); transmission of user data; reordering and duplicate detection; in-sequence delivery; PDCP PDU routing (in the case of split bearers); retransmission of PDCP SDU; ciphering, deciphering and integrity protection; PDCP SDU discard; PDCP reestablishment and data recovery for RLC AM; PDCP status reporting for RLC AM; duplication of PDCP PDU and duplicate discard indication to lower layers. The main services and functions of the PDCP sublayer for the control plane include: sequence numbering; ciphering, deciphering and integrity protection; transmission of control plane data; reordering and duplicate detection; in-sequence delivery; duplication of PDCP PDU and duplicate discard indication to lower layers.

[0090] In 3GPP NR system, the main services and functions of SDAP include: mapping between QoS flows and data radio bearers; marking QoS flow ID (QFI) in both DL and UL packets. A single protocol entity of SDAP is configured for each individual PDU session.

[0091] In the 3GPP NR system, the main services and functions of the RRC sublayer include: broadcast of system information related to AS and NAS; paging initiated by the 5G core network (5GC) or the next generation radio access network (NG-RAN); establishment, maintenance and release of the RRC connection between the UE and the NG-RAN; security functions including key management; establishment, configuration, maintenance and release of signaling radio bearers (SRBs) and data radio bearers (DRBs); mobility functions (including: handover and context transfer, UE cell selection and reselection and control of cell selection and reselection, inter-RAT mobility); QoS management functions; UE measurement reporting and control of reporting; detection and recovery of radio link failure; NAS message transmission from UE to NAS / from NAS to UE.

[0092] Figure 6 A frame structure in a 3GPP-based wireless communication system to which the present disclosure is applied is shown.

[0093] Figure 6The frame structure shown in is merely exemplary, and the number of subframes, the number of time slots, and / or the number of symbols in a frame may vary. In a 3GPP-based wireless communication system, OFDM parameter sets (e.g., SCS, transmission time interval (TTI) duration) may be configured differently between multiple cells aggregated for one UE. For example, if the UE is configured with different SCSs for cells aggregated for the cell, the (absolute time) duration of time resources (e.g., subframes, time slots, or TTIs) including the same number of symbols may be different among the aggregated cells. In this article, the symbol may include an OFDM symbol (or a cyclic prefix (CP)-OFDM symbol), an SC-FDMA symbol (or a discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbol).

[0094] Reference Figure 6 , downlink and uplink transmissions are organized into frames. Each frame has T f = 10ms duration. Each frame is divided into two half-frames, where each half-frame has a duration of 5ms. Each half-frame includes 5 sub-frames, where the duration of each sub-frame is T sf is 1ms. Each subframe is divided into slots, and the number of slots in a subframe depends on the subcarrier spacing. Each slot includes 14 or 12 OFDM symbols based on the CP. In a normal CP, each slot includes 14 OFDM symbols, and in an extended CP, each slot includes 12 OFDM symbols. The parameter set is based on an exponentially scalable subcarrier spacing Δf=2 u *15kHz.

[0095] Table 3 shows the subcarrier spacing Δf=2 u *N is the number of OFDM symbols per time slot of 15kHz slot symb , the number of time slots per frame N frame,u slot , and the number of time slots N per subframe for normal CP subframe,u slot .

[0096] [Table 3]

[0097] 4 <![CDATA[N slot symb ]]> <![CDATA[N frame,n slot ]]> <![CDATA[N subframe,u slot ]]> 0 |14 |10 |1 |1 |14 20 2 2 |14 40 4 3 |14 80 8 4 |14 |160 |16

[0098] Table 4 shows the subcarrier spacing Δf=2 u *N is the number of OFDM symbols per time slot of 15kHz slot symb , the number of time slots per frame N frame,u slot and the number of slots N per subframe for the extended CPsubframe,u slot .

[0099] [Table 4]

[0100] u <![CDATA[N slot symb ]]> <![CDATA[N frame,u slot ]]> <![CDATA[N subframe,u slot ]]> 2 |12 40 4

[0101] A slot includes a plurality of symbols (e.g., 14 or 12 symbols) in the time domain. For each parameter set (e.g., subcarrier spacing) and carrier, a common resource block (CRB) N indicated by higher layer signaling (e.g., RRC signaling) is allocated. start,u grid To begin, we define N size,u grid,x *N RB sc subcarriers and N subframe,u symb OFDM symbol resource grid, where N size,u grid,x is the number of resource blocks (RBs) in the resource grid, and the subscript x is DL for the downlink and UL for the uplink. N RB sc is the number of subcarriers per RB. In 3GPP-based wireless communication systems, N RB sc Typically 12. For a given antenna port p, subcarrier spacing configuration u, and transmission direction (DL or UL), there is one resource grid. The carrier bandwidth N for subcarrier spacing configuration u size,u grid Given by high-level parameters (e.g., RRC parameters). Each element in the resource grid for antenna port p and subcarrier spacing configuration u is called a resource element (RE), and one complex symbol can be mapped to each RE. Each RE in the resource grid is uniquely identified by an index k in the frequency domain and an index l representing the symbol position relative to a reference point in the time domain.

[0102] In 3GPP-based wireless communication systems, an RB is defined by 12 consecutive subcarriers in the frequency domain. In 3GPP NR systems, RBs are classified into CRBs and physical resource blocks (PRBs). CRBs are numbered upwards from 0 in the frequency domain for subcarrier spacing configuration u. The center of subcarrier 0 of CRB 0 for subcarrier spacing configuration u coincides with "point A" used as a common reference point for the resource block grid. In 3GPP NR systems, PRBs are defined within bandwidth parts (BWPs) and are numbered from 0 to N. size BWP,i -1 numbering, where i is the number of the bandwidth part. Physical resource block n in bandwidth part i PRB With common resource block n CRB The relationship between them is as follows:PRB =n CRB +N size BWP,i , where N size BWP,i It is a common resource block where the bandwidth part starts relative to CRB 0. A BWP includes multiple consecutive RBs. A carrier can include up to N (e.g., 5) BWPs. A UE can be configured with one or more BWPs on a given component carrier. Only one BWP can be activated at a time among the BWPs configured for a UE. The active BWP defines the operating bandwidth of the UE within the operating bandwidth of the cell.

[0103] In the present disclosure, the term "cell" may refer to a geographical area where one or more nodes provide a communication system or to a radio resource. "Cell" as a geographical area can be understood as a coverage range in which a node can provide services using a carrier, and "cell" as a radio resource (e.g., time-frequency resource) is associated with a bandwidth, which is a frequency range configured by a carrier. A "cell" associated with a radio resource is defined by a combination of downlink resources and uplink resources (e.g., a combination of DL component carriers (CCs) and UL CCs). A cell may be configured only by downlink resources, or may be configured by downlink resources and uplink resources. Since the DL coverage (which is the range in which a node can send a valid signal) and the UL coverage (which is the range in which a node can receive a valid signal from a UE) depend on the carrier carrying the signal, the coverage of a node may be associated with the coverage of a "cell" of a radio resource used by the node. Therefore, the term "cell" may be used to sometimes represent the service coverage of a node, to represent a radio resource at other times, or to represent a range in which a signal using a radio resource can reach with effective strength at other times.

[0104] In CA, two or more CCs are aggregated. The UE can receive or transmit on one or more CCs simultaneously according to its capabilities. CA is supported for both continuous CCs and non-contiguous CCs. When CA is configured, the UE has only one RRC connection with the network. During RRC connection establishment / reconstruction / switching, one serving cell provides NAS mobility information, and during RRC connection reconstruction / switching, one serving cell provides security input. This cell is called the primary cell (PCell). PCell is a cell operating on the primary frequency, where the UE performs an initial connection establishment process or initiates a connection reconstruction process. Depending on the UE capabilities, a secondary cell (SCell) can be configured to form a set of serving cells together with the PCell. SCell is a cell that provides additional radio resources on top of a special cell (PCell). Therefore, the set of configured serving cells for the UE always consists of one PCell and one or more SCells. For dual connection (DC) operation, the term "PCell" refers to the PCell of the primary cell group (MCG) or the primary SCell (PSCell) of the secondary cell group (SCG). SpCell supports physical uplink control channel (PUCCH) transmission and contention-based random access, and is always activated. MCG is a set of serving cells associated with the master node, which includes SpCell (PCell) and optionally one or more SCells. For UEs configured with DC, SCG is a subset of serving cells associated with the secondary node, which includes PSCell and zero or more SCells. For UEs in RRC_CONNECTED that are not configured with CA / DC, there is only one serving cell consisting of PCell. For UEs in RRC_CONNECTED that are configured with CA / DC, the term "serving cell" is used to refer to the set of cells consisting of SpCell and all SCells. In DC, two MAC entities are configured in the UE: one for MCG and one for SCG.

[0105] Figure 7 An example of data flow in a 3GPP NR system to which implementations of the present disclosure are applied is shown.

[0106] Reference Figure 7 , "RB" means radio bearer, and "H" means header. Radio bearers are classified into two groups: DRB for user plane data and SRB for control plane data. MAC PDU is transmitted / received to / from an external device through the PHY layer using radio resources. MAC PDU arrives at the PHY layer in the form of a transport block.

[0107] In the PHY layer, the uplink transport channel UL-SCH and the random access channel (RACH) are mapped to their physical channels, the physical uplink shared channel (PUSCH) and the physical random access channel (PRACH), respectively, and the downlink transport channels DL-SCH, BCH and PCH are mapped to the physical downlink shared channel (PDSCH), the physical broadcast channel (PBCH) and the PDSCH, respectively. In the PHY layer, the uplink control information (UCI) is mapped to the physical PUCCH, and the downlink control information (DCI) is mapped to the physical downlink control channel (PDCCH). The MAC PDU related to the UL-SCH is sent by the UE via the PUSCH based on the UL grant, and the MAC PDU related to the DL-SCH is sent by the BS via the PDSCH based on the DL assignment.

[0108] Network-controlled mobility is applicable to UEs under RRC_CONNECTED and is classified into two types of mobility: cell-level mobility and beam-level mobility. Beam-level mobility includes intra-cell beam-level mobility and inter-cell beam-level mobility.

[0109] Cell-level mobility requires triggering explicit RRC signaling, i.e. handover. For inter-gNB handover, the signaling process consists of at least the following operations.

[0110] 1. The source gNB initiates a handover and sends a HANDOVER REQUEST message through the Xn interface.

[0111] 2. The target gNB performs admission control and provides the new RRC configuration as part of the HANDOVER REQUESTACKNOWLEDGE message.

[0112] 3. The source gNB provides the RRC configuration to the UE by forwarding the RRCReconfiguration message received in the HANDOVER REQUEST ACKNOWLEDGE message. The RRCReconfiguration message includes at least the cell identity (ID) and all information required to access the target cell so that the UE can access the target cell without reading system information. For some cases, the information required for contention-based and contention-free random access may be included in the RRCReconfiguration message. The access information for the target cell may include beam-specific information (if any).

[0113] 4. The UE moves the RRC connection to the target gNB and replies with an RRCReconfigurationComplete message.

[0114] In case of Dual Active Protocol Stack (DAPS) handover, the UE continues DL user data reception from the source gNB until the source cell is released and continues UL user data transmission to the source gNB until the random access procedure to the target gNB is successful.

[0115] During DAPS handover, only the source PCell and the target PCell are used. CA, DC, Supplementary UL (SUL), Multiple Transmit / Receive Points (TRP), Ethernet Header Compression (EHC), Conditional Handover (CHO), User Data Convergence (UDC), NR side link configuration and V2X side link configuration are released by the source gNB before the Handover Command is sent to the UE and are not configured by the target gNB until the DAPS handover is completed (i.e., at the earliest in the same message that releases the source PCell).

[0116] The handover mechanisms triggered by RRC require the UE to at least reset the MAC entity and re-establish the RLC, except for DAPS handover, where upon receiving the handover command, the UE:

[0117] -Create a MAC entity for the target;

[0118] - For each DRB configured with DAPS, establish a targeted RLC entity and associated DTCH logical channel;

[0119] - For each DRB configured with DAPS, reconfigure the PDCP entities with separate security and ROHC functions for the source and target, and associate these PDCP entities with the RLC entities configured by the source and target respectively;

[0120] - Keep the rest of the source configuration until the source is released.

[0121] RRC managed handover with and without PDCP entity re-establishment is supported. For DRBs using RLC AM mode, PDCP can re-establish with a security key change or initiate a data recovery procedure without a key change. For DRBs using RLC UM mode, PDCP can re-establish with a security key change or remain intact without a key change. For SRBs, PDCP can remain intact, discard its stored PDCP PDU / SDU without a key change, or re-establish with a security key change.

[0122] When the target gNB uses the same DRB configuration as the source gNB, data forwarding, in-sequence delivery, and duplication avoidance at handover can be guaranteed.

[0123] A timer-based handover failure procedure is supported in NR. The RRC connection reestablishment procedure is used to recover from a handover failure, except in certain CHO or DAPS handover scenarios:

[0124] - When DAPS handover fails, the UE falls back to the source cell configuration, resumes the connection with the source cell, and if the source link has not been released, reports the DAPS handover failure via the source without triggering RRC connection re-establishment.

[0125] - When the initial CHO execution attempt fails or HO fails, the UE performs cell selection, and if the selected cell is a CHO candidate and if the network configures the UE to attempt CHO after handover / CHO failure, the UE attempts CHO execution once, otherwise performs re-establishment.

[0126] Beam level mobility does not require triggering explicit RRC signaling. Beam level mobility can be intra-cell or inter-cell, the latter being referred to as inter-cell beam management (ICBM). For ICBM, the UE can receive or send UE-specific channels / signals via a TRP associated with a physical cell ID (PCI) different from the serving cell's PCI, while non-UE-specific channels / signals can only be received via a TRP associated with the serving cell's PCI. The gNB provides the UE with a measurement configuration via RRC signaling, which contains synchronization signal block (SSB) / channel state information (CSI) resources and resource sets, reports, and configuration of trigger states for triggering channel and interference measurements and reports. In the case of ICBM, the measurement configuration includes SSB resources associated with a PCI different from the serving cell's PCI. Beam level mobility is then handled at a low level with the help of physical layer and MAC layer control signaling, and RRC is not required to know which beam is being used at a given point in time.

[0127] SSB-based beam-level mobility is based on the SSB associated with the initial DL BWP and can only be configured for the initial DL BWP and the DL BWP containing the SSB associated with the initial DL BWP. For other DL BWPs, beam-level mobility can only be performed based on CSI-RS.

[0128] CHO is defined as a handover performed by the UE when one or more handover execution conditions are met. The UE starts evaluating the execution conditions when receiving the CHO configuration and stops evaluating the execution conditions once the handover is performed.

[0129] The following principles apply to CHO:

[0130] -CHO configuration contains the configuration of CHO candidate cells generated by the candidate gNB and the execution conditions generated by the source gNB.

[0131] - The execution condition can consist of one or two trigger conditions (CHO events A3 / A5). Only a single reference signal (RS) type is supported, and up to two different trigger quantities (e.g., reference signal received power (RSRP) and reference signal received quality (RSRQ), RSRP to noise plus interference ratio (SINR), etc.) can be configured simultaneously for the evaluation of the CHO execution condition of a single candidate cell.

[0132] - Before any CHO execution conditions are met, upon receiving a HO command (without CHO configuration), the UE performs the HO procedure regardless of any previously received CHO configuration.

[0133] - While performing CHO, ie from the time the UE starts synchronizing with the target cell, the UE does not monitor the source cell.

[0134] AS security includes integrity protection and encryption of SRBs and DRBs.

[0135] RRC handles the configuration of AS security parameters as part of AS configuration: integrity protection algorithm, encryption algorithm (if integrity protection and / or encryption are enabled for DRB), and two parameters (i.e., keySetChangeIndicator and nextHopChainingCount) which are used by the UE to determine the AS security keys upon synchronization reconfiguration (with key change), connection reestablishment and / or connection resumption.

[0136] The integrity protection algorithm is common to SRB1, SRB2, SRB3 (if configured), SRB4 (if configured), and DRBs configured with integrity protection and with the same keyToUse value. The encryption algorithm is common to SRB1, SRB2, SRB3 (if configured), SRB4 (if configured), and DRBs configured with the same keyToUse value. Neither integrity protection nor encryption is applicable to SRB0.

[0137] All DRBs associated with the same PDU Session have the same enable / disable setting for ciphering and the same enable / disable setting for integrity protection.

[0138] RRC integrity protection and ciphering are always activated together, i.e. in one message / procedure. RRC integrity protection and ciphering for SRBs are never deactivated. However, it is possible to switch to the "NULL" ciphering algorithm (nea0).

[0139] The "NULL" integrity protection algorithm (nia0) is only used for UEs in SRB and limited service mode, and when used for SRB, integrity protection is disabled for DRB. In the case of using the "NULL" integrity protection algorithm, the "NULL" encryption algorithm is also used.

[0140] The lower layer discards the RRC message that fails the integrity protection check and indicates the integrity protection verification failure to the RRC.

[0141] The AS applies four different security keys: one for integrity protection of RRC signaling (K RRCint ), a cipher for RRC signaling (K RRCenc ), one for integrity protection of user data (K UPint ), and one for encryption of user data (K UPenc All four AS keys are derived from K gNB Key derivation. K gNB The key is based on K handled by the upper layer AMF Key.

[0142] The integrity protection and encryption algorithms only change with synchronization reconfiguration. The AS key (K gNB , K RRCint , K RRCenc , K UPin and K UPenc ) is changed during synchronization reconfiguration (if masterKeyUpdate is included) and during connection reestablishment and connection recovery.

[0143] For each radio bearer, a separate counter (COUNT) is maintained for each direction. For each radio bearer, the COUNT is used as input for ciphering and integrity protection.

[0144] For a given security key, it is not allowed to use the same COUNT value more than once. The network is responsible for avoiding reuse of COUNT with the same RB identity and the same key, e.g. due to transfer of large amounts of data, release and establishment of new RBs and multiple termination point changes for RLC-AM bearers and multiple termination point changes for RLC-UM bearers due to PDCP re-establishment with SN termination (COUNT reset) while the key stream input (i.e., bearer ID, security keys) at the MN has not been updated yet, in addition to multiple termination point changes for RLC-AM bearers due to SN-only full configuration. To avoid such reuse, the network may, for example, use different RB identities for RB establishment, change AS security keys or transitions of RRC_CONNECTED to RRC_IDLE / RRC_INACTIVE and then to RRC_CONNECTED.

[0145] To limit the signaling overhead, each message / packet includes a short sequence number (PDCP SN). In addition, an overflow counter mechanism is used: the Hyper Frame Number (HFN). The HFN needs to be synchronized between the UE and the network.

[0146] For each SRB, the value of the 5-bit BEARER parameter provided by the RRC to lower layers to derive the input for ciphering and integrity protection is the value of the corresponding srb-Identity with the MSB padded with zeros.

[0147] For UEs with sk-Counter set, keyToUse indicates whether the UE should use the master key (K gNB ) or the secondary key (SK eNB or SK gNB ) for a specific DRB. The secondary key is derived from the primary key and sk-Counter. Whenever the secondary key needs to be refreshed, for example, when the MN gNB When the UE is in NR-DC, even when the secondary key (SK gNB )When establishing a DRB, the network may also provide the sk-Counter to a UE configured with an SCG to allow configuration of SRB3. When using an SN terminated MCG bearer, the network may provide the sk-Counter to the UE even if an SCG is not configured.

[0148] For AS security key update, the UE can:

[0149] 1> If the UE is connected to E-UTRA / EPC or E-UTRA / 5GC:

[0150] 2>When receiving sk-Counter:

[0151] 3> Based on K eNB key and updates SK with the received sk-Counter value gNB Key;

[0152] 3>Derivation of K RRCenc and K UPenc Key;

[0153] 3>Derivation of K RRCint and K UPint Key.

[0154] 1> Otherwise, if the process was initiated due to receiving a masterKeyUpdate:

[0155] 2> If nas-Container is included in the received masterKeyUpdate:

[0156] 3> Forward nas-Container to the upper layer;

[0157] 2>If keySetChangeIndicator is set to true:

[0158] 3> Based on K AMF Key derivation or update K gNB Key;

[0159] 2> Otherwise:

[0160] 3> Use the nextHopChainingCount value indicated in the received masterKeyUpdate to gNB Key or NH derivation or update K gNB Key;

[0161] 2>Store nextHopChainingCount value;

[0162] 2> The following derivation and K gNB Key associated with the key:

[0163] 3>If securityAlgorithmConfig is included in SecurityConfig:

[0164] 4>Derivation of K associated with the cipheringAlgorithm indicated in securityAlgorithmConfig RRCenc and K UPenc Key;

[0165] 4>Derivation of K associated with the integrityProtAlgorithm indicated in securityAlgorithmConfig RRCint and K UPint Key;

[0166] 3> Otherwise:

[0167] 4>Derive the K associated with the current cipheringAlgorithm RRCenc and K UPenc Key;

[0168] 4>Derive the K associated with the current integrityProtAlgorithm RRCint and K UPint Key.

[0169] 1> Otherwise, if the procedure is initiated due to the reception of sk-Counter (UE is in NE-DC or NR-DC, or is configured with SN terminated bearers):

[0170] 2> Based on the KgNB key and using the received sk-Counter value, derive or update the secondary key (SK gNB or S-KeNB);

[0171] 2> Use the secondary key (SK gNB or S-KeNB) associated with the RadioBearerConfig to derive K RRCenc Key and K UPenc Key;

[0172] 2> Use the secondary key (SK gNB or S-KeNB) associated with the RadioBearerConfig to derive K RRCenc Key and K UPenc Key;

[0173] The introduction of subsequent mobility in Rel-18 has been discussed. In subsequent mobility, the UE can maintain a given conditional mobility command regardless of the change of the serving cell, and use the conditional mobility command whenever a condition is met. Therefore, without receiving additional reconfiguration and without performing reinitialization using the given conditional mobility command, the UE can perform one or more subsequent mobilities based on the given conditional mobility command.

[0174] Multi-Radio (MR)-DC with selective activation of cell groups aims to enable subsequent conditional PSCell change (CPC) / conditional PSCell addition (CPA) after SCG change without reconfiguration and reinitialization of CPC / CPA preparation from the network. This results in reduction of signaling overhead and interruption time for SCG change.

[0175] Figure 8 An example of MR-DC utilizing selective activation of cell groups to which implementations of the present disclosure are applied is shown.

[0176] about Figure 8A typical scenario of an example may be that the UE moves around in the coverage of multiple micro gNBs and one macro gNB. To reduce the interruption time and signaling overhead for SCG / PSCell change, the UE may continue to evaluate conditional reconfiguration for SCG, and therefore, subsequent CPC may be performed based on the previous CPC / CPA configuration that was not released after the previous PSCell change / addition procedure.

[0177] Reference Figure 8 , the UE can move back and forth within the coverage of multiple micro gNBs, and the UE may change to the same PSCell more than once. This implies that conditional reconfiguration for the same candidate PSCell may be applied more than once. In this case, there may be security key reuse issues.

[0178] For example, to update the security key for the SN, the MN may generate a K for the SN. SN And send it to SN via Xn-C. In order to generate K SN , MN associated counter sk-Counter. And, based on sk-Counter and MN's security key, K SN MN sends the value of sk-Counter to UE through RRCR configuration. That is, the security of SN depends only on sk-Counter and MN's security key.

[0179] For subsequent CPCs, the stored secondary key configuration (e.g., sk-Counter) in the conditional reconfiguration for CPC is used. Therefore, for multiple subsequent CPCs on the same candidate PSCell, if the same sk-Counter stored in the conditional reconfiguration for CPC is used, the same security key may be generated. Different packets may be encrypted with the same security key and PDCP COUNT value, which is not allowed and will lead to security key reuse issues.

[0180] In addition, sk-Counter can be calculated by MN for each additional K SN However, for the subsequent CPC, since the UE's moving trajectory is random, the network may not be able to configure an appropriate sk-Counter for each candidate PSCell to meet the monotonically increasing principle.

[0181] In other words, whenever mobility is performed, information for subsequent mobility (e.g., conditional mobility commands and / or UE variables VarConditionalReconfig) may be maintained. Therefore, when the UE keeps changing the serving cell in subsequent mobility, the UE may not update the security configuration that has been used in the previous serving cell, and therefore, the same security key value and sk-Counter may be reused. For example, when another packet is sent based on the same security configuration, the reused security key may cause security problems. This is because, if there is no security update for the next mobility from the network, the cell configuration including the security information initially provided may be used as is. Such security problems may occur in particular when the previous serving cell becomes a target cell again while continuously performing subsequent mobility.

[0182] Therefore, there is a need for a way to address the situation of preventing the reuse of security keys.

[0183] According to an implementation of the present disclosure, the UE may check whether the target cell is in the list of cells that allow group security information when performing mobility. The list of cells that allow group security information may be referred to as a security group. If the target cell is in the cell list and the UE is using group security information in the current cell (ie, the source cell), the UE may maintain the current security information without a security update. Otherwise, if the target cell is not in the cell list, but the UE is using group security key information in the current cell (ie, the source cell), the UE may update the security information according to the security configuration in the mobility command (ie, RRC reconfiguration with reconfigurationWithSyncc) for the target cell. After updating the security information, the UE may notify the target cell that the UE has used the group security information in the source cell. The UE may indicate to the network that the UE maintains the group security information for the next mobility.

[0184] According to an implementation of the present disclosure, for group security information, the network may provide at least one of the following items:

[0185] - Encryption Algorithm: You can indicate the encryption algorithm to be used for SRB and DRB

[0186] -Integrity Algorithm: can indicate the integrity protection algorithm to be used for SRB and DRB

[0187] -Key to use: This may indicate that the radio bearer associated with this security information is using a master key (e.g., K gNB or K eNB ) or a secondary key (e.g., SK gNB or SK eNB) to derive encryption and / or integrity protection keys.

[0188] -sk-Counter: can indicate the initial configuration SK gNB or SK eNB When refreshing SK gNB or SK eNB The counter used when

[0189] -Key set change indicator: can indicate whether the UE should derive a new K gNB If reconfigurationWithSync is included, a value of true can indicate that K gNB The key is obtained from the most recent successful NAS Security Mode Command (SMC) process or using the gNB K for re-keying AMF K used in the changed N2 switching process AMF Key derivation. A value of false can indicate that a new K gNB The key is from the current K gNB The key may be obtained from the next hop (NH).

[0190] -Next hop chain count: can be used to update K gNB Key.

[0191] - Cell List: May indicate a list of cells to which this group security information may be applied. For all cells in the cell list, all mobility commands for cells may include the same group security information (since the network cannot decide which cell will be selected for subsequent mobility).

[0192] The network may provide the same cell list in the group security information as the cell list for subsequent mobility. If the cell list for the group security information is the same as the cell list for subsequent mobility, the network may provide a single cell list for both the group security information and subsequent mobility, rather than providing two identical cell lists.

[0193] According to an implementation of the present disclosure, when the UE performs mobility using a target cell included in a cell list, the current security key may continue to be used without a security key change. If group security has been activated and the security configuration in the mobility command for subsequent mobility is the same information of the group security, the UE may use the current security key without changing the security key. In addition, the UE may not reset the PDCP count value. In addition, because the UE maintains the current security key, even if there is any security information to be updated in the mobility command for the target cell, the UE may discard the security information to be updated in the mobility command for the target cell.

[0194] According to an implementation of the present disclosure, when the UE performs mobility using another target cell that is not included in the cell list, the UE may check whether the network explicitly commands the UE to perform mobility without security key update (i.e., without security key refresh). If there is no explicit indication of performing mobility without security key change in the mobility command for the other target cell, the UE may update the security key. That is, the UE may update K gNB or SK gNB , and use the new sk-Counter (if received), the newly derived K RRCenc and K Upenc Key, K RRCint and K UPint After the security update, the UE may send dedicated RRC signaling (eg, RRCReconfigurationComplete message) to indicate that the UE still maintains the group security information for the next subsequent mobility.

[0195] The following figures are created to explain specific embodiments of the present disclosure. The names of specific devices or names of specific signals / messages / fields shown in the figures are provided by way of example, so the technical features of the present disclosure are not limited to the specific names used in the following figures.

[0196] Fig. 9 An example of a method performed by a wireless device to which an implementation of the present disclosure is applied is shown.

[0197] At step S900 , the method includes: receiving a security mode command including a security configuration from a network.

[0198] At step S910 , the method includes: considering the security of the AS to be activated based on the security configuration.

[0199] At step S920 , the method includes: receiving a mobility command for a target cell from a network.

[0200] At step S930 , the method includes: receiving information from the network informing whether the target cell belongs to a security group.

[0201] At step S940 , the method includes performing mobility to a target cell based on the mobility command.

[0202] At step S950 , the method includes: continuing to use the security configuration based on the information notifying that the target cell belongs to the security group.

[0203] In some implementations, the information may be received by being included in group security information. The group security information may include at least one of an encryption algorithm, an integrity algorithm, a key to use, a Sk counter, a key set change indicator, or an NCC.

[0204] In some implementations, the information may correspond to a list of cells to which the group security information can be applied. All mobility commands for all target cells included in the cell list may include the same group security information. The list of cells to which the group security information can be applied may be the same as the list of cells for subsequent mobility.

[0205] In some implementations, the method may further include checking whether the target cell is in the security group and whether the wireless device is using group security information in the source cell.

[0206] In some implementations, continuing to use the security configuration can include maintaining current security information without requiring an AS security update.

[0207] In some implementations, the method may further include: updating AS security according to a second security configuration based on the information notifying the target cell that the target cell does not belong to the security group. The second security configuration may be received via a mobility command for the target cell. The method may further include: notifying the target cell that the wireless device has used the group security information in the source cell. The method may further include: notifying the target cell that the wireless device maintains the group security information for the next mobility.

[0208] In some implementations, a wireless device may communicate with at least one of a mobile device other than the wireless device, a network, and / or an autonomous vehicle.

[0209] In addition, the above Fig. 9 The method described in the wireless device perspective can be implemented by Figure 2 The first wireless device 100 and / or Figure 3 The UE 100 shown in FIG.

[0210] The wireless device includes at least one transceiver, at least one processor, and at least one memory capable of being operatively connected to the at least one processor and storing instructions, the instructions being executed based on being executed by the at least one processor Fig. 9 The method described in .

[0211] More specifically, the wireless device receives a security mode command including a security configuration from a network.

[0212] The wireless device considers the AS security to be activated based on the security configuration.

[0213] The wireless device receives a mobility command from the network for a target cell.

[0214] The wireless device receives information from the network informing whether the target cell belongs to the security group.

[0215] The wireless device performs mobility to the target cell based on the mobility command.

[0216] Based on the information notifying that the target cell belongs to the security group, the wireless device continues to use the security configuration.

[0217] In some implementations, the information may be received by being included in group security information. The group security information may include at least one of an encryption algorithm, an integrity algorithm, a key to use, a Sk counter, a key set change indicator, or an NCC.

[0218] In some implementations, the information may correspond to a list of cells to which the group security information can be applied. All mobility commands for all target cells included in the cell list may include the same group security information. The list of cells to which the group security information can be applied may be the same as the list of cells for subsequent mobility.

[0219] In some implementations, the wireless device may also check whether the target cell is in the security group and whether the wireless device is using group security information in the source cell.

[0220] In some implementations, continuing to use the security configuration can include maintaining current security information without requiring an AS security update.

[0221] In some implementations, based on the information notifying that the target cell does not belong to the security group, the wireless device may also update the AS security according to the second security configuration. The second security configuration may be received via a mobility command for the target cell. The wireless device may also notify the target cell that the wireless device has used the group security information in the source cell. The wireless device may also notify the target cell that the wireless device maintains the group security information for the next mobility.

[0222] In addition, the above Fig. 9 The method described in the wireless device perspective can be controlled by Figure 2 The processor 102 in the first wireless device 100 shown in FIG. 1 and / or by controlling the Figure 3 The process is executed by the processor 102 in the UE 100 shown in FIG.

[0223] A processing device adapted to control a wireless device comprises at least one processor and at least one memory operatively connected to the at least one processor. The at least one processor is adapted to execute Fig. 9The method described in .

[0224] In addition, the above Fig. 9 The method described in the wireless device perspective may be performed by storing in a Figure 2 The software code 105 in the memory 104 in the first wireless device 100 shown in FIG. 1 is executed.

[0225] The technical features of the present disclosure may be implemented directly in hardware, in software executed by a processor, or in a combination of the two. For example, the method performed by a wireless device in wireless communication may be implemented in hardware, software, firmware, or any combination thereof. For example, the software may reside in RAM, flash memory, ROM, EPROM, EEPROM, registers, hard disk, removable disk, CD-ROM, or any other storage medium.

[0226] Some examples of storage media may be coupled to a processor so that the processor can read information from the storage media. In an alternative, the storage media may be integrated into the processor. The processor and the storage media may reside in an ASIC. For other examples, the processor and the storage media may reside as discrete components.

[0227] The computer-readable medium may include tangible and non-transitory computer-readable storage media.

[0228] For example, non-transitory computer-readable media may include RAM, such as synchronous DRAM (SDRAM), ROM, non-volatile RAM (NVRAM), EEPROM, flash memory, magnetic or optical data storage media, or any other media that can be used to store instructions or data structures. Non-transitory computer-readable media may also include combinations of the foregoing.

[0229] Furthermore, the methods described herein may be implemented at least in part by a computer-readable communication medium that carries or communicates code in the form of instructions or data structures and can be accessed, read, and / or executed by a computer.

[0230] According to some implementations of the present disclosure, a non-transitory computer readable medium (CRM) stores instructions that are executed based on at least one processor. Fig. 9 The method described in .

[0231] Fig.10 An example of a method performed by a base station to which an implementation of the present disclosure is applied is shown.

[0232] At step S1000, the method includes: sending a security mode command including a security configuration to a wireless device. Considering the AS security to be activated based on the security configuration.

[0233] At step S1010 , the method includes: sending a mobility command for a target cell to a wireless device.

[0234] In step S1020, the method includes: sending information from the network notifying whether the target cell belongs to a security group.

[0235] In step S1030, mobility to the target cell is performed based on the mobility command, and based on the information notifying that the target cell belongs to the security group, the security configuration continues to be used.

[0236] In addition, the above Fig.10 The method described in the perspective of the base station serving the second serving cell may be performed by Figure 2 The second wireless device 200 shown in FIG.

[0237] The base station includes at least one transceiver, at least one processor, and at least one memory capable of being operatively connected to the at least one processor and storing instructions that are executed based on being executed by the at least one processor. Fig.10 The method described in .

[0238] More specifically, the base station sends a security mode command including a security configuration to the wireless device. The AS security to be activated is considered based on the security configuration.

[0239] The base station sends a mobility command to the wireless device for the target cell.

[0240] The base station sends information from the network notifying whether the target cell belongs to a security group.

[0241] Mobility to the target cell is performed based on the mobility command, and based on the information notifying that the target cell belongs to the security group, the security configuration continues to be used.

[0242] An example of UE operation according to an implementation of the present disclosure may be as follows.

[0243] When the UE receives RRCReconfiguration, the UE may:

[0244] 1> If RRCReconfiguration includes masterCellGroup:

[0245] 2>Execute cell group configuration for the received masterCellGroup;

[0246] 1> If RRCReconfiguration includes masterKeyUpdate:

[0247] 2>Execute the AS security key update process;

[0248] 1> If RRCReconfiguration includes sk-Counter:

[0249] 2>Execute the security key update process;

[0250] 1> If RRCReconfiguration includes group security information:

[0251] 2>Execute the AS security key update process;

[0252] 1> If RRCReconfiguration includes secondaryCellGroup:

[0253] 2>Perform cell group configuration for SCG;

[0254] For AS security key update, the UE can:

[0255] 1> If group security for subsequent mobility has been activated and the procedure is initiated due to receiving a group security configuration:

[0256] 2> Continue to use without updating K gNB or SK gNB Or a new derivation of K RRCenc and K UPenc Key and K RRCint and K UPint The security configuration used in case of keys;

[0257] 1> Otherwise, if the UE is connected to E-UTRA / EPC or E-UTRA / 5GC:

[0258] 2> Upon receiving the sk-Counter or group security sk-Counter:

[0259] 3> Based on K eNB key and updates SK with the received sk-Counter value gNB Key;

[0260] 3>Derivation of K RRCenc and K UPenc Key;

[0261] 3>Derivation of K RRCint and K UPint Key.

[0262] 1> Otherwise, if the process was initiated due to receiving a masterKeyUpdate or a group security's masterKeyUpdate:

[0263] 2> If nas-Container is included in the received masterKeyUpdate:

[0264] 3> Forward nas-Container to the upper layer;

[0265] 2>If keySetChangeIndicator is set to true:

[0266] 3> Based on K AMF Key derivation or update K gNB Key;

[0267] 2> Otherwise:

[0268] 3> Use the nextHopChainingCount value indicated in the received masterKeyUpdate to gNB Key or NH derivation or update K gNB Key;

[0269] 2>Store nextHopChainingCount value;

[0270] 2> The following derivation and K gNB Key associated with the key:

[0271] 3>If securityAlgorithmConfig is included in SecurityConfig:

[0272] 4>Derivation of K associated with the cipheringAlgorithm indicated in securityAlgorithmConfig RRCenc and K UPenc Key;

[0273] 4>Derivation of K associated with the integrityProtAlgorithm indicated in securityAlgorithmConfig RRCint and K UPint Key;

[0274] 3> Otherwise:

[0275] 4>Derive the K associated with the current cipheringAlgorithm RRCenc and K UPenc Key;

[0276] 4>Derive the K associated with the current integrityProtAlgorithm RRCint and K UPint Key.

[0277] 1> Otherwise, if the procedure is initiated due to the reception of sk-Counter or sk-Counter for group security (UE is in NE-DC or NR-DC, or is configured with SN terminated bearers):

[0278] 2> Based on the KgNB key and using the received sk-Counter value, derive or update the secondary key (SK gNB or S-KeNB);

[0279] 2> Use the secondary key (SK gNB or S-KeNB) associated with the RadioBearerConfig to derive K RRCenc Key and K UPenc Key;

[0280] 2> Use the secondary key (SK gNB or S-KeNB) associated with the RadioBearerConfig to derive K RRCenc Key and K UPenc Key;

[0281] For SRB addition / modification, the UE can:

[0282] 1> If any DAPS bearer is configured, for each SRB:

[0283] 2> Establish a PDCP entity for the target cell group, which has the same configuration as the PDCP entity for the source cell group;

[0284] 2> If masterKeyUpdate is received and group security has not been activated for subsequent mobility:

[0285] 3>Configure the PDCP entity using the security algorithm according to securityConfig and apply the master key (K gNB ) is associated with the key (K RRCenc and K RRCint );

[0286] 2> Otherwise:

[0287] 3> The PDCP entity for the target cell group is configured with state variable continuity, and it has the same security configuration as the PDCP entity for the source cell group;

[0288] 1> For each srb-Identity value included in the srb-ToAddModList that is not part of the current UE configuration (reconfiguration or SRB establishment from E-UTRA PDCP to NR PDCP):

[0289] 2> Establish PDCP entity;

[0290] 2> If AS security has been activated:

[0291] 3> If the target RAT of the handover is E-UTRA / 5GC; or

[0292] 3> If the UE is connected to E-UTRA / 5GC:

[0293] 4> If the UE is capable of E-UTRA / 5GC but not NGEN-DC:

[0294] 5> Using the configured / derived security algorithm and key (K RRCenc and K RRCint ) configure the PDCP entity;

[0295] 4> Otherwise (i.e., the UE is capable of NGEN-DC):

[0296] 5> Configure the PDCP entity with the security algorithm according to securityConfig and, if applicable, apply the master key (K eNB ) or secondary key (SK gNB ) is associated with the key (K RRCenc and K RRCint );

[0297] 3> Otherwise (i.e., UE is connected to NR or UE is connected to E-UTRA / EPC):

[0298] 4> Configure the PDCP entity with the security algorithm according to securityConfig and, if applicable, apply the master key (K eNB / K gNB ) or secondary key (SK gNB ) is associated with the key (K RRCenc and K RRCint );

[0299] 2> If the current UE configuration configured by E-UTRA includes an SRB identified with the same srb-Identity value:

[0300] 3> Associate the DCCH and E-UTRA RLC entity of the SRB with the NR PDCP entity;

[0301] 3> Release the E-UTRA PDCP entity of the SRB;

[0302] 2> If pdcp-Config is included:

[0303] 3>Configure the PDCP entity according to the received pdcp-Config;

[0304] 2> Otherwise:

[0305] 3>Configure the PDCP entity according to the default configuration for the corresponding SRB;

[0306] 1> If any DAPS bearer is configured, then for each srb-Identity value included in the srb-ToAddModList that is part of the current UE configuration:

[0307] 2> If pdcp-Config is included:

[0308] 3> Reconfigure the PDCP entity for the target cell group according to the received pdcp-Config;

[0309] 1> Otherwise, for each srb-Identity value included in the srb-ToAddModList that is part of the current UE configuration:

[0310] 2> If reestablishPDCP is set:

[0311] 3> If the target RAT of the handover is E-UTRA / 5GC; or

[0312] 3> If the UE is connected to E-UTRA / 5GC:

[0313] 4> If the UE is capable of E-UTRA / 5GC but not NGEN-DC:

[0314] 5> Configure the PDCP entity to apply the integrity protection algorithm and the configured / derived K RRCint The key, i.e. the integrity protection configuration shall be applied to all subsequent messages received and sent by the UE (including messages indicating successful completion of the procedure);

[0315] 5> Configure the PDCP entity to apply the encryption algorithm and the configured / derived K RRCenc The key, i.e. the cipher configuration, shall be applied to all subsequent messages received and sent by the UE (including messages indicating successful completion of the procedure);

[0316] 4> Otherwise (i.e., the UE is capable of NGEN-DC):

[0317] 5> Configure the PDCP entity to apply the integrity protection algorithm and the master key (K eNB ) or secondary key (SK gNB ) associated with K RRCint The key, i.e. the integrity protection configuration shall be applied to all subsequent messages received and sent by the UE (including messages indicating successful completion of the procedure);

[0318] 5> Configure the PDCP entity to apply the encryption algorithm and the master key (K eNB ) or secondary key (SK gNB ) associated with K RRCenc The key, i.e. the cipher configuration, shall be applied to all subsequent messages received and sent by the UE (including messages indicating successful completion of the procedure);

[0319] 3> Otherwise (i.e., the UE is connected to a UE in NR or EN-DC):

[0320] 4> Configure the PDCP entity to apply the integrity protection algorithm and the master key (K eNB / K gNB ) or secondary key (SK gNB ) associated with K RRCint The key, i.e. the integrity protection configuration shall be applied to all subsequent messages received and sent by the UE (including messages indicating successful completion of the procedure);

[0321] 4> Configure the PDCP entity to apply the encryption algorithm and the master key (K eNB / K gNB ) or secondary key (SK gNB ) associated with K RRCenc The key, i.e. the cipher configuration, shall be applied to all subsequent messages received and sent by the UE (including messages indicating successful completion of the procedure);

[0322] 3> Reestablish the PDCP entity of the SRB;

[0323] 2> Otherwise, if discardOnPDCP is set:

[0324] 3> Trigger the PDCP entity to discard SDU;

[0325] 2> If pdcp-Config is included:

[0326] 3> Reconfigure the PDCP entity according to the received pdcp-Config.

[0327] For DRB addition / modification, the UE can:

[0328] 1> For each drb-Identity value included in the drb-ToAddModList that is not part of the current UE configuration (DRB establishment includes the case where the full configuration option is used):

[0329] 2> Establish a PDCP entity and configure it according to the received pdcp-Config;

[0330] 2> If the PDCP entity of the DRB is not configured with cipheringDisabled:

[0331] 3> If the target RAT of the handover is E-UTRA / 5GC; or

[0332] 3> If the UE is connected to E-UTRA / 5GC:

[0333] 4> If the UE is capable of E-UTRA / 5GC but not NGEN-DC:

[0334] 5> Using encryption algorithm and configuration / derived K UPenc Key configuration PDCP entity;

[0335] 4> Otherwise (i.e., the UE is capable of NGEN-DC):

[0336] 5> Configure the PDCP entity with the encryption algorithm according to securityConfig and, if applicable, apply the master key (K eNB ) or secondary key (SK gNB ) is associated with the key (K UPenc );

[0337] 3> Otherwise (i.e., UE is connected to NR or UE is connected to E-UTRA / EPC):

[0338] 4> Configure the PDCP entity using the encryption algorithm according to securityConfig and apply the master key (K eNB / K gNB ) or secondary key (SK gNB / SK eNB ) associated with K UPenc Key;

[0339] 2> If the PDCP entity of the DRB is configured with integrityProtection:

[0340] 3> Configure the PDCP entity using the integrity protection algorithm according to securityConfig and apply the master key (K eNB / K gNB ) or secondary key (SK gNB ) associated with K UPint Key;

[0341] 2> If sdap-Config is included:

[0342] 3> If there is no SDAP entity with the received pdu-Session:

[0343] 4>Establish SDAP entity;

[0344] 4> If there was no SDAP entity with the received pdu-Session before receiving this reconfiguration:

[0345] 5> Instruct the upper layer to establish user plane resources for pdu-Session;

[0346] 3>Configure the SDAP entity according to the received sdap-Config and associate the DRB with the SDAP entity;

[0347] 3> For each QFI value added to mappedQoS-FlowsToAdd, if the QFI value was previously configured, release the QFI value from the old DRB;

[0348] 2> If the DRB is associated with eps-BearerIdentity:

[0349] 3> If the DRB was configured with the same eps-BearerIdentity by NR or E-UTRA before receiving this reconfiguration:

[0350] 4> Associate the created DRB with the corresponding eps-BearerIdentity;

[0351] 3> Otherwise:

[0352] 4> Indicate to the upper layer the establishment of the DRB and the eps-BearerIdentity of the established DRB;

[0353] 1> For each drb-Identity value included in the drb-ToAddModList as part of the current UE configuration and configured as a DAPS bearer:

[0354] 2> Reconfigure the PDCP entity to configure DAPS with the encryption function, integrity protection function and ROHC function of the target cell group, and configure it according to the received pdcp-Config;

[0355] 2> If masterKeyUpdate is received and group security has not been activated for subsequent mobility:

[0356] 3> If the encryption function of the target cell group PDCP entity is not configured with cipheringDisabled:

[0357] 4> Configure the encryption function of the target cell group PDCP entity using the encryption algorithm according to securityConfig, and apply the master key (K gNB ) associated with K UPenc The key, i.e. the ciphering configuration shall be applied to all subsequent PDCP PDUs received from and sent by the UE to the target cell group;

[0358] 3> If the integrity protection function of the target cell group PDCP entity is configured with integrityProtection:

[0359] 4> Configure the integrity protection function of the target cell group PDCP entity using the integrity protection algorithm according to securityConfig, and apply the master key (K gNB ) associated with K UPint Key;

[0360] 2> Otherwise:

[0361] 3> Configure the encryption function and integrity protection function of the target cell group PDCP entity with the same security configuration as the PDCP entity for the source cell group;

[0362] 2> If sdap-Config is included, and when an indication of successful completion of random access towards the target cell is received from lower layers:

[0363] 3>Reconfigure the SDAP entity according to the received sdap-Config;

[0364] 3> For each QFI value added to mappedQoS-FlowsToAdd, if the QFI value was previously configured, release the QFI value from the old DRB;

[0365] 1> For each drb-Identity value included in the drb-ToAddModList as part of the current UE configuration and not configured as a DAPS bearer:

[0366] 2> If reestablishPDCP is set:

[0367] 3> If the target RAT of the handover is E-UTRA / 5GC; or

[0368] 3> If the UE is connected to E-UTRA / 5GC:

[0369] 4> If the UE is capable of E-UTRA / 5GC but not NGEN-DC:

[0370] 5> If the PDCP entity of the DRB is not configured with cipheringDisabled:

[0371] 6> Using encryption algorithm and configuration / derived K UPenc Key configuration PDCP entity, i.e., the ciphering configuration shall be applied to all subsequent PDCP PDUs received and transmitted by the UE;

[0372] 4> Otherwise (i.e., the UE is capable of NGEN-DC):

[0373] 5> If the PDCP entity of the DRB is not configured with cipheringDisabled:

[0374] 6>Use the encryption algorithm and the master key (K eNB ) or secondary key (SK gNB ) associated with K UPenc Key configuration PDCP entity, i.e., the ciphering configuration shall be applied to all subsequent PDCP PDUs received and transmitted by the UE;

[0375] 3> Otherwise (i.e., UE connected to NR or UE connected to E-UTRA / EPC (in EN-DC or capable of EN-DC)):

[0376] 4> If the PDCP entity of the DRB is not configured with cipheringDisabled:

[0377] 5>Use the encryption algorithm and the master key (K eNB / K gNB ) or secondary key (SK gNB / SK eNB ) associated with K UPencKey configuration PDCP entity, i.e., the ciphering configuration shall be applied to all subsequent PDCP PDUs received and transmitted by the UE;

[0378] 4> If the PDCP entity of the DRB is configured with integrityProtection:

[0379] 5> Configure the PDCP entity using the integrity protection algorithm according to securityConfig and apply the master key (K eNB / K gNB ) or secondary key (SK gNB ) associated with K UPint Key;

[0380] 3> If drb-ContinueROHC is included in pdcp-Config:

[0381] 4>Indicate to the lower layer that drb-ContinueROHC is configured;

[0382] 3> If drb-ContinueEHC-DL is included in pdcp-Config:

[0383] 4>Indicate to the lower layer that drb-ContinueEHC-DL is configured;

[0384] 3> If drb-ContinueEHC-UL is included in pdcp-Config:

[0385] 4>Indicate to the lower layer that drb-ContinueEHC-UL is configured;

[0386] 3> If drb-ContinueUDC is included in pdcp-Config:

[0387] 4>Indicate to the lower layer that drb-ContinueUDC is configured;

[0388] 3> Reestablish the PDCP entity of the DRB;

[0389] 2> Otherwise, if recoverPDCP is set:

[0390] 3> The PDCP entity that triggers the DRB performs data recovery;

[0391] 2> If pdcp-Config is included:

[0392] 3> Reconfigure the PDCP entity based on the received pdcp-Config.

[0393] 2> If sdap-Config is included:

[0394] 3>Reconfigure the SDAP entity according to the received sdap-Config;

[0395] 3> For each QFI value added to mappedQoS-FlowsToAdd, if the QFI value was previously configured, release the QFI value from the old DRB;

[0396] In response to the UE receiving the RRCReconfiguration, the UE may:

[0397] 1> Set the content of the RRCReconfigurationComplete message as follows:

[0398] 2> If RRCReconfiguration includes masterCellGroup or secondaryCellGroup (which contains masterKeyUpdate or sk-Counter that is not related to group security keys), and group security for subsequent mobility is deactivated due to masterKeyUpdate or sk-Counter:

[0399] 3> Include group security information to instruct the UE to maintain the group security configuration for the next subsequent mobility.

[0400] The present disclosure may have various beneficial effects.

[0401] For example, when performing subsequent mobility, the security reuse problem can be solved by cell group-based security information handling.

[0402] The beneficial effects obtained by the specific examples of this specification are not limited to the effects listed above. For example, there may be a variety of technical effects that can be understood or derived from this specification by a person of ordinary skill in the art. Therefore, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that can be understood or derived from the technical features of the present disclosure.

[0403] The claims in this disclosure can be combined in various ways. For example, the technical features in the method claims of this disclosure can be combined to be implemented or performed in a device, and the technical features in the device claims can be combined to be implemented or performed in a method. In addition, the technical features in the method claims and the device claims can be combined to be implemented or performed in a device. In addition, the technical features in the method claims and the device claims can be combined to be implemented or performed in a method. Other implementations are within the scope of the appended claims.

Claims

1. A method performed by a wireless device adapted to operate in a wireless communication system, the method comprising the steps of: receiving a security mode command including a security configuration from a network; considering access layer AS security to be activated based on the security configuration; receiving a mobility command for a target cell from the network; receiving information from the network informing whether the target cell belongs to a security group; performing mobility to the target cell based on the mobility command; as well as The target cell is notified based on the information that the target cell belongs to the security group, and the security configuration continues to be used.

2. The method according to claim 1, wherein: The information is received by being included in the group security information.

3. The method according to claim 2, wherein: The information corresponds to a list of cells to which the group security information can be applied.

4. The method according to claim 3, wherein: All mobility commands for all target cells included in the cell list include the same group security information.

5. The method according to claim 3, wherein: The list of cells to which the group security information can be applied is the same as the list of cells for subsequent mobility.

6. The method according to any one of claims 2 to 5, wherein: The group security information includes at least one of an encryption algorithm, an integrity algorithm, a key to be used, a Sk counter, a key set change indicator, or a next hop chaining count NCC.

7. The method according to any one of claims 2 to 6, wherein: The method further comprises the step of checking whether the target cell is in the security group and whether the wireless device is using the group security information in a source cell.

8. The method according to any one of claims 2 to 7, wherein: The step of continuing to use the security configuration includes maintaining current security information without requiring an AS security update.

9. The method according to any one of claims 2 to 7, wherein: The method further comprises the following steps: notifying the target cell that it does not belong to the security group based on the information, and updating the AS security according to a second security configuration.

10. The method according to claim 9, wherein: The second security configuration is received via the mobility command to the target cell.

11. The method according to claim 9 or 10, wherein: The method further includes the step of notifying the target cell that the wireless device has used the group security information in a source cell.

12. The method according to any one of claims 9 to 11, wherein: The method further includes the step of notifying the target cell that the wireless device maintains the group security information for next mobility.

13. The method according to any one of claims 1 to 12, wherein: The wireless device communicates with at least one of a mobile device other than the wireless device, a network, and / or an autonomous vehicle.

14. A wireless device adapted to operate in a wireless communication system, the wireless device comprising: at least one transceiver; at least one processor; as well as At least one memory, the at least one memory being operatively connectable to the at least one processor and storing instructions, the instructions being executed by the at least one processor to perform the method according to any one of claims 1 to 13.

15. A processing device adapted to control a wireless device in a wireless communication system, the processing device comprising: at least one processor; as well as at least one memory operatively connectable to the at least one processor, Wherein, the at least one processor is adapted to perform the method according to any one of claims 1 to 13.

16. A non-transitory computer readable medium (CRM) storing instructions for executing the method according to any one of claims 1 to 13 upon being executed by at least one processor.

17. A method performed by a base station adapted to operate in a wireless communication system, the method comprising the steps of: sending a security mode command including a security configuration to the wireless device, wherein access stratum AS security to be activated is considered based on the security configuration; sending a mobility command for a target cell to the wireless device; Sending information from the network notifying whether the target cell belongs to a security group, wherein mobility to the target cell is performed based on the mobility command, and Wherein, based on the information, the target cell is notified that it belongs to the security group and the security configuration continues to be used.

18. A base station serving a second serving cell adapted to operate in a wireless communication system, the base station comprising: at least one transceiver; at least one processor; as well as At least one memory is operatively connected to the at least one processor and stores instructions, the instructions performing the method according to claim 17 upon being executed by the at least one processor.

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