Full configuration procedure in subsequent mobility

Abstract

The present disclosure is related to full configuration procedure in subsequent mobility in wireless communications. According to an embodiment of the present disclosure, a method performed by a communication device comprises: receiving a subsequent mobility configuration for a first candidate cell, wherein the subsequent mobility configuration comprises a list of execution conditions for a subsequent mobility, and a list of candidate cells related to a full configuration procedure; after performing a mobility to the first candidate cell, performing a subsequent mobility to a second candidate cell based on one or more execution conditions for the second candidate cell in the list of execution conditions being satisfied; determining whether to perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the list of candidate cells related to the full configuration procedure; and performing the full configuration procedure for the subsequent mobility to the second candidate cell based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.

Description

FULL CONFIGURATION PROCEDURE IN SUBSEQUENT MOBILITY

[0001] The present disclosure is related to full configuration procedure in subsequent mobility in wireless communications.

[0002] 3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) is a technology for enabling high-speed packet communications. Many schemes have been proposed for the LTE objective including those that aim to reduce user and provider costs, improve service quality, and expand and improve coverage and system capacity. The 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of a frequency band, a simple structure, an open interface, and adequate power consumption of a terminal as an upper-level requirement.

[0003] Work has started in International Telecommunication Union (ITU) and 3GPP to develop requirements and specifications for New Radio (NR) systems. 3GPP has to identify and develop the technology components needed for successfully standardizing the new RAT timely satisfying both the urgent market needs, and the more long-term requirements set forth by the ITU Radio communication sector (ITU-R) International Mobile Telecommunications (IMT)-2020 process. Further, the NR should be able to use any spectrum band ranging at least up to 100 GHz that may be made available for wireless communications even in a more distant future.

[0004] The NR targets a single technical framework addressing all usage scenarios, requirements and deployment scenarios including enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC), Ultra-Reliable and Low Latency Communications (URLLC), etc. The NR shall be inherently forward compatible.

[0005] In wireless communications, a user equipment (UE) may perform a full configuration procedure based on a full configuration flag in a radio resource control (RRC) reconfiguration message. The UE may determine whether to perform the full configuration procedure based on the full configuration flag, when receiving the RRC reconfiguration message or applying the RRC reconfiguration message for a mobility, including a subsequent mobility.

[0006] An aspect of the present disclosure is to provide method and apparatus for full configuration procedure in a subsequent mobility in a wireless communication system.

[0007] According to an embodiment of the present disclosure, a method performed by a communication device comprises: receiving a subsequent mobility configuration for a first candidate cell, wherein the subsequent mobility configuration comprises a list of execution conditions for a subsequent mobility, and a list of candidate cells related to a full configuration procedure; after performing a mobility to the first candidate cell, performing a subsequent mobility to a second candidate cell based on one or more execution conditions for the second candidate cell in the list of execution conditions being satisfied; determining whether to perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the list of candidate cells related to the full configuration procedure; and performing the full configuration procedure for the subsequent mobility to the second candidate cell based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.

[0008] According to an embodiment of the present disclosure, a method performed by a network node comprises: transmitting, to a user equipment (UE), a subsequent mobility configuration for a first candidate cell, wherein the subsequent mobility configuration comprises a list of execution conditions for a subsequent mobility, and a list of candidate cells related to a full configuration procedure, wherein the UE is configured to perform operations comprising: after performing a mobility to the first candidate cell, performing a subsequent mobility to a second candidate cell based on one or more execution conditions for the second candidate cell in the list of execution conditions being satisfied; determining whether to perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the list of candidate cells related to the full configuration procedure; and performing the full configuration procedure for the subsequent mobility to the second candidate cell based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.

[0009] According to various embodiments, apparatuses to implement the above methods are provided.

[0010] The present disclosure may have various advantageous effects.

[0011] For example, the UE receives and manages a separate full configuration cell list provided from the network for subsequent mobility for each candidate cell, thereby minimizing data interruption by performing full configuration only when the full configuration is actually needed.

[0012] Advantageous effects which can be obtained through specific embodiments of the present disclosure are not limited to the advantageous effects listed above. For example, there may be a variety of technical effects that a person having ordinary skill in the related art can understand and / or derive from the present disclosure. Accordingly, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that may be understood or derived from the technical features of the present disclosure.

[0013] FIG. 1 shows an example of a communication system to which implementations of the present disclosure is applied.

[0014] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure is applied.

[0015] FIG. 3 shows an example of UE to which implementations of the present disclosure is applied.

[0016] FIGs. 4 and 5 show an example of protocol stacks in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.

[0017] FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.

[0018] FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure is applied.

[0019] FIG. 8 shows an example of a conditional mobility procedure according to an embodiment of the present disclosure.

[0020] FIG. 9 shows an example of a method performed by a UE according to an embodiment of the present disclosure.

[0021] FIG. 10 shows an example of a signal flow between a UE and a network node according to an embodiment of the present disclosure.

[0022] FIG. 11 shows an example of a subsequent CPAC scenario according to an embodiment of the present disclosure.

[0023] FIG. 12 shows an example of a method for full configuration decision when performing subsequent CPAC according to an embodiment of the present disclosure.

[0024] The following techniques, apparatuses, and systems may be applied to a variety of wireless multiple access systems. Examples of the multiple access systems include a Code Division Multiple Access (CDMA) system, a Frequency Division Multiple Access (FDMA) system, a Time Division Multiple Access (TDMA) system, an Orthogonal Frequency Division Multiple Access (OFDMA) system, a Single Carrier Frequency Division Multiple Access (SC-FDMA) system, and a Multi Carrier Frequency Division Multiple Access (MC-FDMA) system. CDMA may be embodied through radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may be embodied through radio technology such as Global System for Mobile communications (GSM), General Packet Radio Service (GPRS), or Enhanced Data rates for GSM Evolution (EDGE). OFDMA may be embodied through radio technology 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 a part of a 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 employs OFDMA in downlink (DL) and SC-FDMA in uplink (UL). Evolution of 3GPP LTE includes LTE-Advanced (LTE-A), LTE-A Pro, and / or 5G New Radio (NR).

[0025] For convenience of description, implementations of the present disclosure are mainly described in regards 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 3GPP based wireless communication system are applicable to other mobile communication systems.

[0026] For terms and technologies which are not specifically described among the terms of and technologies employed in the present disclosure, the wireless communication standard documents published before the present disclosure may be referenced.

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

[0028] In the present disclosure, slash ( / ) or comma (,) may mean "and / or". For example, "A / B" may mean "A and / or B". Accordingly, "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 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] Also, parentheses 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, "control information" in the present disclosure is not limited to "PDCCH", and "PDCCH" may be proposed as an example of "control information". In addition, even when shown as "control information (i.e., PDCCH)", "PDCCH" may be proposed as an example of "control information".

[0032] Technical features that are separately described in one drawing in the present disclosure may be implemented separately or simultaneously.

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

[0034] Hereinafter, the present disclosure will be described in more detail with reference to drawings. 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 unless otherwise indicated.

[0035] FIG. 1 shows an example of a communication system to which implementations of the present disclosure is applied.

[0036] The 5G usage scenarios shown in FIG. 1 are only exemplary, and the technical features of the present disclosure can be applied to other 5G usage scenarios which are not shown in FIG. 1.

[0037] Three main requirement categories for 5G include (1) a category of enhanced Mobile BroadBand (eMBB), (2) a category of massive Machine Type Communication (mMTC), and (3) a category of Ultra-Reliable and Low Latency Communications (URLLC).

[0038] Referring to FIG. 1, the communication system 1 includes wireless devices 100a to 100f, Base Stations (BSs) 200, and a network 300. Although FIG. 1 illustrates a 5G network as an example of the network of the communication system 1, the implementations of the present disclosure are not limited to the 5G system, and can be applied to the future communication system beyond the 5G system.

[0039] The BSs 200 and the network 300 may be implemented as wireless devices and a specific wireless device may operate as a BS / network node with respect to other wireless devices.

[0040] The wireless devices 100a to 100f represent devices performing communication using Radio Access Technology (RAT) (e.g., 5G NR or LTE) and may be referred to as communication / radio / 5G devices. The wireless devices 100a to 100f may include, without being limited to, a robot 100a, vehicles 100b-1 and 100b-2, an eXtended Reality (XR) device 100c, a hand-held device 100d, a home appliance 100e, an Internet-of-Things (IoT) device 100f, and an Artificial Intelligence (AI) device / server 400. For example, the vehicles may include a vehicle having a wireless communication function, an autonomous driving vehicle, and a vehicle capable of performing communication between vehicles. The vehicles 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) mounted in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, etc. The hand-held device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch or a smartglasses), and a computer (e.g., a notebook). The home appliance may include a TV, a refrigerator, and a washing machine. The IoT device may include a sensor and a smartmeter.

[0041] In the present disclosure, the wireless devices 100a to 100f may be called User Equipments (UEs). A UE may include, for example, a cellular phone, a smartphone, a laptop computer, a digital broadcast terminal, a Personal Digital Assistant (PDA), a Portable Multimedia Player (PMP), a navigation system, a slate Personal Computer (PC), a tablet PC, an ultrabook, a vehicle, a vehicle having an autonomous traveling function, a connected car, an 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 / environment device, a device related to a 5G service, or a device related to a fourth industrial revolution field.

[0042] The wireless devices 100a to 100f may be connected to the network 300 via the BSs 200. An 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 beyond-5G network. Although the wireless devices 100a to 100f may communicate with each other through the BSs 200 / network 300, the wireless devices 100a to 100f may perform direct communication (e.g., sidelink communication) with each other without passing through the BSs 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). The 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 / connections 150a, 150b and 150c may be established between the wireless devices 100a to 100f and / or between wireless device 100a to 100f and BS 200 and / or between BSs 200. Herein, the wireless communication / connections 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. The wireless devices 100a to 100f and the BSs 200 / the wireless devices 100a to 100f may transmit / receive radio signals to / from each other through the wireless communication / connections 150a, 150b and 150c. For example, the wireless communication / connections 150a, 150b and 150c may transmit / receive signals through various physical channels. To this end, at least a part of various configuration information configuring processes, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, and resource mapping / de-mapping), and resource allocating processes, for transmitting / receiving radio signals, may be performed based on the various proposals of the present disclosure.

[0044] NR supports multiples numerologies (and / or multiple Sub-Carrier Spacings (SCS)) to support various 5G services. For example, if SCS is 15 kHz, wide area can be supported in traditional cellular bands, and if SCS is 30 kHz / 60 kHz, dense-urban, lower latency, and wider carrier bandwidth can be supported. If SCS is 60 kHz or higher, bandwidths greater than 24.25 GHz can be supported to overcome phase noise.

[0045] The NR frequency band may be defined as two types of frequency range, i.e., Frequency Range 1 (FR1) and Frequency Range 2 (FR2). The numerical value of the frequency range may be changed. For example, the frequency ranges of the two types (FR1 and FR2) may be as shown in Table 1 below. For ease of explanation, in the frequency ranges used in the NR system, FR1 may mean "sub 6 GHz range", FR2 may mean "above 6 GHz range," and may be referred to as millimeter Wave (mmW).

[0046] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0047] As mentioned above, the numerical value of the frequency range of the NR system may be changed. For example, FR1 may include a frequency band of 410MHz to 7125MHz as shown in Table 2 below. That is, FR1 may include a frequency band of 6GHz (or 5850, 5900, 5925 MHz, etc.) or more. For example, a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or more included in FR1 may include an unlicensed band. Unlicensed bands may be used for a variety of purposes, for example for communication for vehicles (e.g., autonomous driving).

[0048] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0049] Here, the radio communication technologies implemented in the wireless devices 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 Low Power Wide Area Network (LPWAN) technology, may be implemented in specifications such as LTE Cat NB1 and / or LTE Cat NB2, and may not be limited to the above-mentioned names. Additionally and / or alternatively, the radio communication technologies implemented in the wireless devices in the present disclosure may communicate based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and be called by various names such as enhanced MTC (eMTC). For example, LTE-M technology may be implemented in at least one of the 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-mentioned names. Additionally and / or alternatively, the radio communication technologies implemented in the wireless devices in the present disclosure may include at least one of ZigBee, Bluetooth, and / or LPWAN which take into account low-power communication, and may not be limited to the above-mentioned names. For example, ZigBee technology may generate Personal Area Networks (PANs) associated with small / low-power digital communication based on various specifications such as IEEE 802.15.4 and may be called various names.FIG. 2 shows an example of wireless devices to which implementations of the present disclosure is applied.

[0050] In FIG. 2, The first wireless device 100 and / or the second wireless device 200 may be implemented in various forms according to use cases / services. For example, {the first wireless device 100 and the second wireless device 200} may correspond to at least one of {the wireless device 100a to 100f and the BS 200}, {the wireless device 100a to 100f and the wireless device 100a to 100f} and / or {the BS 200 and the BS 200} of FIG. 1. The first wireless device 100 and / or the second wireless device 200 may be configured by various elements, devices / parts, and / or modules.

[0051] The first wireless device 100 may include at least one transceiver, such as a transceiver 106, at least one processing chip, such as a processing chip 101, and / or one or more antennas 108.

[0052] The processing chip 101 may include at least one processor, such a processor 102, and at least one memory, such as a memory 104. Additional and / or alternatively, the memory 104 may be placed outside of the processing chip 101.

[0053] The processor 102 may control the memory 104 and / or the transceiver 106 and may be adapted to implement the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts described in the present disclosure. For example, the processor 102 may process information within the memory 104 to generate first information / signals and then transmit radio signals including the first information / signals through the transceiver 106. The processor 102 may receive radio signals including second information / signals through the transceiver 106 and then store information obtained by processing the second information / signals in the memory 104.

[0054] The memory 104 may be operably connectable to the processor 102. The memory 104 may store various types of information and / or instructions. The memory 104 may store a firmware and / or a software code 105 which implements codes, commands, and / or a set of commands that, when executed by the processor 102, perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. For example, the firmware and / or the software code 105 may implement instructions that, when executed by the processor 102, perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. For example, the firmware and / or the software code 105 may control the processor 102 to perform one or more protocols. For example, the firmware and / or the software code 105 may control the processor 102 to perform one or more layers of the radio interface protocol.

[0055] Herein, the processor 102 and the memory 104 may be a part of a communication modem / circuit / chip designed to implement 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 transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be interchangeably used with Radio Frequency (RF) unit(s). In the present disclosure, the first wireless device 100 may represent a communication modem / circuit / chip.

[0056] The second wireless device 200 may include at least one transceiver, such as a transceiver 206, at least one processing chip, such as a processing chip 201, and / or one or more antennas 208.

[0057] The processing chip 201 may include at least one processor, such a processor 202, and at least one memory, such as a memory 204. Additional and / or alternatively, the memory 204 may be placed outside of the processing chip 201.

[0058] The processor 202 may control the memory 204 and / or the transceiver 206 and may be adapted to implement the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts described in the present disclosure. For example, the processor 202 may process information within the memory 204 to generate third information / signals and then transmit radio signals including the third information / signals through the transceiver 206. The processor 202 may receive radio signals including fourth information / signals through the transceiver 106 and then store information obtained by processing the fourth information / signals in the memory 204.

[0059] The memory 204 may be operably connectable to the processor 202. The memory 204 may store various types of information and / or instructions. The memory 204 may store a firmware and / or a software code 205 which implements codes, commands, and / or a set of commands that, when executed by the processor 202, perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. For example, the firmware and / or the software code 205 may implement instructions that, when executed by the processor 202, perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. For example, the firmware and / or the software code 205 may control the processor 202 to perform one or more protocols. For example, the firmware and / or the software code 205 may control the processor 202 to perform one or more layers of the radio interface protocol.

[0060] Herein, the processor 202 and the memory 204 may be a part of a communication modem / circuit / chip designed to implement 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 transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be interchangeably used with RF unit. In the present disclosure, the second wireless device 200 may represent a communication modem / circuit / chip.

[0061] Hereinafter, hardware elements of the wireless devices 100 and 200 will be described more specifically. One or more protocol layers may be implemented by, without being limited to, one or more processors 102 and 202. For example, the one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as Physical (PHY) layer, Media 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). The one or more processors 102 and 202 may generate one or more Protocol Data Units (PDUs), one or more Service Data Unit (SDUs), messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. The one or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure and provide the generated signals to the one or more transceivers 106 and 206. The one or more processors 102 and 202 may receive the signals (e.g., baseband signals) from the one or more transceivers 106 and 206 and acquire the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure.

[0062] The one or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The 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 the one or more processors 102 and 202. For example, the one or more processors 102 and 202 may be configured by a set of a communication control processor, an Application Processor (AP), an Electronic Control Unit (ECU), a Central Processing Unit (CPU), a Graphic Processing Unit (GPU), and a memory control processor.

[0063] The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, code, instructions, and / or commands. 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, non-volatile memory, hard drive, register, cash memory, computer-readable storage medium, and / or combinations thereof. The one or more memories 104 and 204 may be located at the interior and / or exterior of 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 connection.

[0064] The one or more transceivers 106 and 206 may transmit user data, control information, and / or radio signals / channels, mentioned in the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure, to one or more other devices. The one or more transceivers 106 and 206 may receive user data, control information, and / or radio signals / channels, mentioned in the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure, from one or more other devices. For example, the one or more transceivers 106 and 206 may be connected to the one or more processors 102 and 202 and transmit and receive radio signals. For example, the one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may transmit user data, control information, or radio signals to one or more other devices. The one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may receive user data, control information, or radio signals from one or more other devices.

[0065] The one or more transceivers 106 and 206 may be connected to the one or more antennas 108 and 208. Additionally and / or alternatively, the one or more transceivers 106 and 206 may include one or more antennas 108 and 208. The 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, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure, through the one or more antennas 108 and 208. In the present disclosure, the one or more antennas 108 and 208 may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports).

[0066] The one or more transceivers 106 and 206 may convert received user data, control information, radio signals / channels, etc., from RF band signals into baseband signals in order to process 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 the base band signals into the 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 can up-convert OFDM baseband signals to OFDM signals by 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 OFDM signals at a carrier frequency and down-convert the OFDM signals into OFDM baseband signals by their (analog) oscillators and / or filters under the control of the one or more processors 102 and 202.

[0067] Although not shown in FIG. 2, the wireless devices 100 and 200 may further include additional components. The additional components 140 may be variously configured according to types 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., audio I / O port, video I / O port), a driving 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 a wired or wireless connection.

[0068] In the implementations of the present disclosure, a UE may operate as a transmitting device in Uplink (UL) and as a receiving device in Downlink (DL). In the implementations of the present disclosure, a BS may operate as a receiving device in UL and as a transmitting device in DL. Hereinafter, for convenience of description, it is mainly assumed that the first wireless device 100 acts as the UE, and the second wireless device 200 acts as the BS. For example, the processor(s) 102 connected to, mounted on or launched in the first wireless device 100 may be adapted to perform the UE behavior according to an implementation of the present disclosure or control the transceiver(s) 106 to perform the UE behavior according to an implementation of the present disclosure. The processor(s) 202 connected to, mounted on or launched in the second wireless device 200 may be adapted to perform the BS behavior according to an implementation of the present disclosure or control the transceiver(s) 206 to perform the BS behavior according to an implementation of the present disclosure.

[0069] In the present disclosure, a BS is also referred to as a node B (NB), an eNode B (eNB), or a gNB.

[0070] FIG. 3 shows an example of UE to which implementations of the present disclosure is applied.

[0071] Referring to FIG. 3, a UE 100 may correspond to the first wireless device 100 of FIG. 2.

[0072] A 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 Identification Module (SIM) card 145, a speaker 146, and a microphone 147.

[0073] The processor 102 may be adapted to implement the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. The processor 102 may be adapted to control one or more other components of the UE 100 to implement the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. Layers of the radio interface protocol may be implemented in the processor 102. The processor 102 may include ASIC, other chipset, logic circuit and / or data processing device. The processor 102 may be an application processor. The processor 102 may include at least one of DSP, CPU, GPU, a modem (modulator and demodulator). An example of the processor 102 may be found in SNAPDRAGONTMseries of processors made by Qualcomm®, EXYNOSTMseries of processors made by Samsung®, A series of processors made by Apple®, HELIOTMseries of processors made by MediaTek®, ATOMTMseries of processors made by Intel®or a corresponding next generation processor.

[0074] The memory 104 is operatively coupled with the processor 102 and stores a variety of information to operate the processor 102. The memory 104 may include ROM, RAM, flash memory, memory card, storage medium and / or other storage device. When the embodiments are implemented in software, the techniques described herein can be implemented with modules (e.g., procedures, functions, etc.) that perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present 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 external to the processor 102 in which case those can be communicatively coupled to the processor 102 via various means as is known in the art.

[0075] The transceiver 106 is operatively coupled with the processor 102, and transmits and / or receives a radio signal. The transceiver 106 includes a transmitter and a receiver. The transceiver 106 may include baseband circuitry to process radio frequency signals. The transceiver 106 controls the one or more antennas 108 to transmit and / or receive a radio signal.

[0076] The power management module 141 manages power for the processor 102 and / or the transceiver 106. The battery 142 supplies power to the power management module 141.

[0077] The display 143 outputs results processed by the processor 102. The keypad 144 receives inputs to be used by the processor 102. The keypad 144 may be shown on the display 143.

[0078] The SIM card 145 is an　integrated circuit　that is intended to　securely store the　International Mobile Subscriber Identity　(IMSI) number and its related　key, which are used to identify and authenticate subscribers on　mobile telephony　devices (such as　mobile phones　and　computers). It is also possible to store contact information on many SIM cards.

[0079] The speaker 146 outputs sound-related results processed by the processor 102. The microphone 147 receives sound-related inputs to be used by the processor 102.

[0080] FIGs. 4 and 5 show an example of protocol stacks in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.

[0081] In particular, FIG. 4 illustrates an example of a radio interface user plane protocol stack between a UE and a BS and FIG. 5 illustrates an example of a radio interface control plane protocol stack between a UE and a BS. The control plane refers to a path through which control messages used to manage call by a UE and a network are transported. The user plane refers to a path through which data generated in an application layer, for example, voice data or Internet packet data are transported. Referring to FIG. 4, the user plane protocol stack may be divided into Layer 1 (L1, for example PHY layer) and Layer 2 (L2, for example MAC / RLC / PDCP layer). Referring to FIG. 5, the control plane protocol stack may be divided into Layer 1 (L1, for example PHY layer), Layer 2 (L2, for example MAC / RLC / PDCP layer), Layer 3 (L3, for example an RRC layer), and a non-access stratum (NAS) layer. Layer 1, Layer 2 and Layer 3 are referred to as an access stratum (AS).

[0082] In the 3GPP LTE system, the Layer 2 is split into the following sublayers: MAC, RLC, and PDCP. In the 3GPP NR system, the Layer 2 is split into the following sublayers: MAC, RLC, PDCP and SDAP. The PHY layer offers to the MAC sublayer transport channels, the MAC sublayer offers to the RLC sublayer logical channels, the RLC sublayer offers to the PDCP sublayer RLC channels, the PDCP sublayer offers to the SDAP sublayer radio bearers. The SDAP sublayer offers to 5G core network quality of service (QoS) flows.

[0083] In the 3GPP NR system, the main services and functions of the MAC sublayer include: mapping between logical channels and transport channels; multiplexing / de-multiplexing of MAC SDUs belonging to one or different logical channels into / from transport blocks (TB) delivered to / from the physical layer on transport channels; scheduling information reporting; error correction through hybrid automatic repeat request (HARQ) (one HARQ entity per cell in case of carrier aggregation (CA)); priority handling between UEs by means of dynamic scheduling; priority handling between logical channels of one UE by means of logical channel prioritization; padding. A single MAC entity may support multiple numerologies, transmission timings and cells. Mapping restrictions in logical channel prioritization control which numerology(ies), cell(s), and transmission timing(s) a logical channel can use.

[0084] Different kinds of data transfer services are offered by MAC. To accommodate different kinds of data transfer services, multiple types of logical channels are defined, i.e., each supporting transfer of a particular type of information. Each logical channel type is defined by what type of information is transferred. Logical channels are classified into two groups: control channels and traffic channels. Control channels are used for the transfer of control plane information only, and traffic channels are used for the transfer of user plane information only. Broadcast control channel (BCCH) is a downlink logical channel for broadcasting system control information, paging control channel (PCCH) is a downlink logical channel that transfers paging information, system information change notifications and indications of ongoing public warning service (PWS) broadcasts, common control channel (CCCH) is a logical channel for transmitting control information between UEs and network and used for UEs having no RRC connection with the network, and dedicated control channel (DCCH) is a point-to-point bi-directional logical channel that transmits dedicated control information between a UE and the network and used by UEs having an RRC connection. Dedicated traffic channel (DTCH) is a point-to-point logical channel, dedicated to one UE, for the transfer of user information. A DTCH can exist in both uplink and downlink. In downlink, the following connections between logical channels and transport channels exist: BCCH can be mapped to broadcast channel (BCH); BCCH can be mapped to downlink shared channel (DL-SCH); PCCH can be mapped to 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 uplink, the following connections between logical channels and transport channels exist: CCCH can be mapped to uplink shared channel (UL-SCH); DCCH can be mapped to UL-SCH; and DTCH can be mapped to UL-SCH.

[0085] The RLC sublayer supports three transmission modes: transparent mode (TM), unacknowledged mode (UM), and acknowledged node (AM). The RLC configuration is per logical channel with no dependency on numerologies and / or transmission durations. In the 3GPP NR system, the main services and functions of the RLC sublayer depend on the transmission mode and include: transfer of upper layer PDUs; sequence numbering independent of the one 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 SDU (AM and UM); duplicate detection (AM only); RLC SDU discard (AM and UM); RLC re-establishment; protocol error detection (AM only).

[0086] 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); transfer of user data; reordering and duplicate detection; in-order delivery; PDCP PDU routing (in case of split bearers); retransmission of PDCP SDUs; ciphering, deciphering and integrity protection; PDCP SDU discard; PDCP re-establishment and data recovery for RLC AM; PDCP status reporting for RLC AM; duplication of PDCP PDUs 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; transfer of control plane data; reordering and duplicate detection; in-order delivery; duplication of PDCP PDUs and duplicate discard indication to lower layers.

[0087] In the 3GPP NR system, the main services and functions of SDAP include: mapping between a QoS flow and a data radio bearer; marking QoS flow ID (QFI) in both DL and UL packets. A single protocol entity of SDAP is configured for each individual PDU session.

[0088] 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 5GC or NG-RAN; establishment, maintenance and release of an RRC connection between the UE and 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 the reporting; detection of and recovery from radio link failure; NAS message transfer to / from NAS from / to UE.

[0089] FIG. 6 shows a frame structure in a 3GPP based wireless communication system to which implementations of the present disclosure is applied.

[0090] The frame structure shown in FIG. 6 is purely exemplary and the number of subframes, the number of slots, and / or the number of symbols in a frame may be variously changed. In the 3GPP based wireless communication system, OFDM numerologies (e.g., subcarrier spacing (SCS), transmission time interval (TTI) duration) may be differently configured between a plurality of cells aggregated for one UE. For example, if a UE is configured with different SCSs for cells aggregated for the cell, an (absolute time) duration of a time resource (e.g., a subframe, a slot, or a TTI) including the same number of symbols may be different among the aggregated cells. Herein, symbols may include OFDM symbols (or CP-OFDM symbols), SC-FDMA symbols (or discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbols).

[0091] Referring to FIG. 6, downlink and uplink transmissions are organized into frames. Each frame has Tf= 10ms duration. Each frame is divided into two half-frames, where each of the half-frames has 5ms duration. Each half-frame consists of 5 subframes, where the duration Tsfper subframe is 1ms. Each subframe is divided into slots and the number of slots in a subframe depends on a subcarrier spacing. Each slot includes 14 or 12 OFDM symbols based on a cyclic prefix (CP). In a normal CP, each slot includes 14 OFDM symbols and, in an extended CP, each slot includes 12 OFDM symbols. The numerology is based on exponentially scalable subcarrier spacing βf = 2u*15 kHz.

[0092] Table 3 shows the number of OFDM symbols per slot Nslotsymb, the number of slots per frameNframe,uslot, and the number of slots per subframe Nsubframe,uslotfor the normal CP, according to the subcarrier spacing βf = 2u*15 kHz.

[0093] uNslotsymbNframe,uslotNsubframe,uslot01410111420221440431480841416016

[0094] Table 4 shows the number of OFDM symbols per slot Nslotsymb, the number of slots per frameNframe,uslot, and the number of slots per subframe Nsubframe,uslotfor the extended CP, according to the subcarrier spacing βf = 2u*15 kHz.

[0095] uNslotsymbNframe,uslotNsubframe,uslot212404

[0096] A slot includes plural symbols (e.g., 14 or 12 symbols) in the time domain. For each numerology (e.g., subcarrier spacing) and carrier, a resource grid ofNsize,ugrid,x*NRBscsubcarriers andNsubframe,usymbOFDM symbols is defined, starting at common resource block (CRB)Nstart,ugridindicated by higher-layer signaling (e.g., RRC signaling), whereNsize,ugrid,xis the number of resource blocks (RBs) in the resource grid and the subscript x is DL for downlink and UL for uplink.NRBscis the number of subcarriers per RB. In the 3GPP based wireless communication system,NRBscis 12 generally. There is one resource grid for a given antenna portp, subcarrier spacing configurationu, and transmission direction (DL or UL). The carrier bandwidthNsize,ugridfor subcarrier spacing configurationuis given by the higher-layer parameter (e.g., RRC parameter). Each element in the resource grid for the antenna portpand the subcarrier spacing configurationuis referred to as a resource element (RE) and one complex symbol may be mapped to each RE. Each RE in the resource grid is uniquely identified by an indexkin the frequency domain and an indexlrepresenting a symbol location relative to a reference point in the time domain. In the 3GPP based wireless communication system, an RB is defined by 12 consecutive subcarriers in the frequency domain. As shown in FIG. 6, as SCS doubles, the slot length and symbol length are halved. For example, when SCS is 15kHz, the slot length is 1ms, which is the same as the subframe length. When SCS is 30kHz, the slot length is 0.5ms (=500us), and the symbol length is half of that when the SCS is 15kHz. When SCS is 60kHz, the slot length is 0.25ms (=250us), and the symbol length is half of that when the SCS is 30kHz. When SCS is 120kHz, the slot length is 0.125ms (=125us), and the symbol length is half of that when the SCS is 60kHz. When SCS is 240kHz, the slot length is 0.0625ms (=62.5us), and the symbol length is half of that when the SCS is 120kHz.

[0097] In the 3GPP NR system, RBs are classified into CRBs and physical resource blocks (PRBs). CRBs are numbered from 0 and upwards in the frequency domain for subcarrier spacing configurationu. The center of subcarrier 0 of CRB 0 for subcarrier spacing configurationucoincides with 'point A' which serves as a common reference point for resource block grids. In the 3GPP NR system, PRBs are defined within a bandwidth part (BWP) and numbered from 0 toNsizeBWP,i-1, where i is the number of the bandwidth part. The relation between the physical resource block nPRBin the bandwidth part i and the common resource block nCRBis as follows: nPRB= nCRB+NsizeBWP,i, whereNsizeBWP,iis the common resource block where bandwidth part starts relative to CRB 0. The BWP includes a plurality of consecutive RBs. A carrier may include a maximum of N (e.g., 5) BWPs. A UE may be configured with one or more BWPs on a given component carrier. Only one BWP among BWPs configured to the UE can active at a time. The active BWP defines the UE's operating bandwidth within the cell's operating bandwidth.

[0098] In the present disclosure, the term "cell" may refer to a geographic area to which one or more nodes provide a communication system, or refer to radio resources. A "cell" as a geographic area may be understood as coverage within which a node can provide service using a carrier and a "cell" as radio resources (e.g., time-frequency resources) is associated with bandwidth which is a frequency range configured by the carrier. The "cell" associated with the radio resources is defined by a combination of downlink resources and uplink resources, for example, a combination of a DL component carrier (CC) and a UL CC. The cell may be configured by downlink resources only, or may be configured by downlink resources and uplink resources. Since DL coverage, which is a range within which the node is capable of transmitting a valid signal, and UL coverage, which is a range within which the node is capable of receiving the valid signal from the UE, depends upon a carrier carrying the signal, the coverage of the node may be associated with coverage of the "cell" of radio resources used by the node. Accordingly, the term "cell" may be used to represent service coverage of the node sometimes, radio resources at other times, or a range that signals using the radio resources can reach with valid strength at other times.

[0099] In CA, two or more CCs are aggregated. A UE may simultaneously receive or transmit on one or multiple CCs depending on its capabilities. CA is supported for both contiguous and non-contiguous CCs. When CA is configured, the UE only has one RRC connection with the network. At RRC connection establishment / re-establishment / handover, one serving cell provides the NAS mobility information, and at RRC connection re-establishment / handover, one serving cell provides the security input. This cell is referred to as the primary cell (PCell). The PCell is a cell, operating on the primary frequency, in which the UE either performs the initial connection establishment procedure or initiates the connection re-establishment procedure. Depending on UE capabilities, secondary cells (SCells) can be configured to form together with the PCell a set of serving cells. An SCell is a cell providing additional radio resources on top of special cell (SpCell). The configured set of serving cells for a UE therefore always consists of one PCell and one or more SCells. For dual connectivity (DC) operation, the term SpCell refers to the PCell of the master cell group (MCG) or the primary SCell (PSCell) of the secondary cell group (SCG). An SpCell supports PUCCH transmission and contention-based random access, and is always activated. The MCG is a group of serving cells associated with a master node, comprised of the SpCell (PCell) and optionally one or more SCells. The SCG is the subset of serving cells associated with a secondary node, comprised of the PSCell and zero or more SCells, for a UE configured with DC. For a UE in RRC_CONNECTED not configured with CA / DC, there is only one serving cell comprised of the PCell. For a UE in RRC_CONNECTED configured with CA / DC, the term "serving cells" is used to denote the set of cells comprised of the SpCell(s) and all SCells. In DC, two MAC entities are configured in a UE: one for the MCG and one for the SCG.

[0100] FIG. 7 shows a data flow example in the 3GPP NR system to which implementations of the present disclosure is applied.

[0101] Referring to FIG. 7, "RB" denotes a radio bearer, and "H" denotes a header. Radio bearers are categorized into two groups: DRBs for user plane data and SRBs for control plane data. The MAC PDU is transmitted / received using radio resources through the PHY layer to / from an external device. The MAC PDU arrives to the PHY layer in the form of a transport block.

[0102] In the PHY layer, the uplink transport channels UL-SCH and random access channel (RACH) are mapped to their physical channels physical uplink shared channel (PUSCH) and physical random access channel (PRACH), respectively, and the downlink transport channels DL-SCH, BCH and PCH are mapped to physical downlink shared channel (PDSCH), physical broadcast channel (PBCH) and PDSCH, respectively. In the PHY layer, uplink control information (UCI) is mapped to physical uplink control channel (PUCCH), and downlink control information (DCI) is mapped to physical downlink control channel (PDCCH). A MAC PDU related to UL-SCH is transmitted by a UE via a PUSCH based on an UL grant, and a MAC PDU related to DL-SCH is transmitted by a BS via a PDSCH based on a DL assignment.

[0103] Hereinafter, contents regarding mobility are described.

[0104] The mobility may comprise PCell change, PSCell change (or, secondary node (SN) change), and / or PSCell addition (or, SN addition).

[0105] In the present disclosure, the term "handover (HO)" may mean PCell change, or may be a broad concept that includes not only PCell change but also PSCell change / addition.

[0106] In the present disclosure, the terms "handover" and "mobility" can be used interchangeably.

[0107] In the present disclosure, the description regarding handover can also be applied to other mobility procedures (e.g., PSCell change / addition).

[0108] There may be at least two types of mobility: network-controlled mobility (or, legacy mobility) and UE-based mobility (or, conditional mobility).

[0109] The network-controlled mobility (or, legacy mobility) is a mobility where the network determines a target cell for mobility, and configures UE with the target cell. The network may transmit, to the UE, anRRCReconfigurationmessage comprising a configuration of the target cell. The UE may execute a mobility to the target cell and / or apply the configuration of the target cell, upon receiving the configuration of the target cell.

[0110] The UE-based mobility (or, conditional mobility) is a mobility where the network configures the UE with a plurality of candidate cells, and the UE determines a target cell which satisfies a mobility execution condition among the plurality of candidate cells. The conditional mobility may comprise at least one of a conditional PCell change / conditional handover (CHO) or a conditional PSCell mobility. The conditional PSCell mobility may comprise conditional PSCell addition / change (CPAC), including conditional PSCell addition (CPA) and / or conditional PSCell change (CPC). The network may transmit, to the UE, anRRCReconfigurationmessage comprisingConditionalReconfigurationinformation element (IE)(or, conditional mobility configuration), which comprises a list of candidate configurations for conditional mobility related to the plurality of candidate cells. A candidate configuration for conditional mobility may comprise an identifier of the candidate configuration, a mobility execution condition for the related candidate cell, and a configuration of the related candidate cell. The UE may evaluate the mobility execution conditions for the plurality of candidate cells, and when a mobility execution condition for a candidate cell is satisfied, the UE may consider the candidate cell as a target cell, and execute a mobility to the target cell and / or apply the configuration of the target cell.

[0111] According to various embodiments, the mobility execution condition may be satisfied / met when an entry condition (or, entering condition) for the mobility execution condition is satisfied / met for at least a time-to-trigger (TTT) for the mobility execution condition. The entry condition / entering condition may mean that the mobility execution condition is initially met. Once the entry condition is met, the mobility execution condition will be considered to be met if the entry condition is met for time duration TTT continuously.

[0112] In the present disclosure, subsequent mobility (e.g., subsequent CHO, subsequent CPAC (SCPAC)) is described. The subsequent mobility may refer to a mobility that is done by repeating a mobility execution / completion after each mobility execution / completion based on a corresponding candidate configuration without releasing other candidate configurations. That is, the subsequent mobility may refer to a mobility that is performed without reconfiguration and / or re-initialization on the mobility preparation from a network after a previous mobility. For example, when a UE has received a plurality of candidate configurations, after the UE performs a mobility based on a corresponding candidate configuration, the UE does not release other candidate configurations, and may perform a subsequent mobility based on a corresponding candidate configuration among the already received plurality of candidate configurations without reconfiguration and / or re-initialization on the mobility preparation from the network (or, without receiving new candidate configurations from the network). This results in a reduction of the signalling overhead and / or interrupting time for mobility.

[0113] FIG. 8 shows an example of a conditional mobility procedure according to an embodiment of the present disclosure.

[0114] In FIG. 8:

[0115] - the serving BS may be related to a PCell, which may be a source PCell for CHO;

[0116] - the serving BS may be an MN associated with an SN in DC, where the SN may be related to a source PSCell for CPC; and

[0117] - the target cell may be a target PCell for CHO, or a target PSCell for CPA / CPC.

[0118] Referring to FIG. 8, in step S801, UE may receive, from the serving BS, anRRCReconfigurationmessage comprising a conditional reconfiguration information element (IE) (i.e.,CondidtionalReconfiguration). The conditional reconfiguration IE may comprise a list of candidate configurations for conditional mobility related to candidate cells including the target cell. Each candidate configuration in the list may be related to the corresponding candidate cell, and comprises i) an identifier of the corresponding candidate configuration (i.e.,condReconfigId), ii) one or more execution conditions for the related candidate cell (i.e.,condExecutionCond), and / or iii) RRC reconfiguration for the related candidate cell (i.e.,condRRCReconfig) including a configuration of the related candidate cell. The one or more execution conditions may comprise CHO execution condition(s), CPA execution condition(s), and / or CPC execution condition(s).

[0119] The IEs in theConditionalReconfigurationare shown in table 5:

[0120] ConditionalReconfiguration-r16 ::= SEQUENCE {attemptCondReconfig-r16 ENUMERATED {true} OPTIONAL, -- Cond CHOcondReconfigToRemoveList-r16 CondReconfigToRemoveList-r16 OPTIONAL, -- Need NcondReconfigToAddModList-r16 CondReconfigToAddModList-r16 OPTIONAL, -- Need N...,[[scpac-ReferenceConfiguration-r18 SetupRelease (SCPAC-ReferenceConfiguration-r18) OPTIONAL, -- Need MservingSecurityCellSetId-r18 SecurityCellSetId-r18 OPTIONAL, -- condInitialSCPACsk-CounterConfiguration-r18 SK-CounterConfiguration-r18 OPTIONAL -- Need M]]}SCPAC-ReferenceConfiguration-r18 ::= OCTET STRING (CONTAINING RRCReconfiguration)SK-CounterConfiguration-r18 ::= SEQUENCE {sk-CounterConfigToReleaseList-r18 SK-CounterConfigToReleaseList-r18 OPTIONAL, -- Need Nsk-CounterConfigToAddModList-r18 SK-CounterConfigToAddModList-r18 OPTIONAL -- Need N}SK-CounterConfigToAddModList-r18 ::= SEQUENCE (SIZE (1..maxSecurityCellSet-r18)) OF SK-CounterConfigToAddMod-r18SK-CounterConfigToAddMod-r18 ::= SEQUENCE {securityCellSetId-r18 SecurityCellSetId-r18sk-CounterList-r18 SK-CounterList-r18}SecurityCellSetId-r18 ::= INTEGER (1.. maxSecurityCellSet-r18)SK-CounterList-r18 ::= SEQUENCE (SIZE (1..maxSK-Counter)) OF SK-Countersk-CounterConfigToRemoveList-r16 ::= SEQUENCE (SIZE (1.. maxSecurityCellSet-r18)) OF SecurityCellSetId-r18CondReconfigToRemoveList-r16 ::= SEQUENCE (SIZE (1.. maxNrofCondCells-r16)) OF CondReconfigId-r16

[0121] In table 5:-attemptCondReconfig: If present, the UE shall perform conditional reconfiguration if selected cell is a target candidate cell and it is the first cell selection after failure;

[0122] -condReconfigToAddModList: List of the configurations of candidate SpCells (i.e., list of candidate configurations) to be added or modified for CHO, CPA or CPC;

[0123] -condReconfigToRemoveList: List of the configurations of candidate SpCells (i.e., list of candidate configurations) to be removed;

[0124] -scpac-ReferenceConfiguration: Includes the reference configuration for the candidate supporting subsequent CPAC;

[0125] -securityCellSetId: This field is used to determine whether UE should perform security update when conditional reconfiguration containingsubsequentCondReconfigis executed. If the fieldservingSecurityCellSetIdis configured, this field is configured for all the candidate configurations for subsequent CPAC;

[0126] -servingSecurityCellSetId: This field identifies the security cell set for serving PSCell. The network does not provide this field for the conditional reconfiguration(s) generated by the SN; and

[0127] -sk-counterConfiguration: Includes a list ofsk-Counterfrom which the UE should select thesk-counterused to derive S-KgNB for inter-SN subsequent CPAC. The network does not provide this field for the conditional reconfiguration(s) generated by the SN.

[0128] The IEs in thecondReconfigToAddModListare shown in table 6:

[0129] CondReconfigToAddModList-r16 ::= SEQUENCE (SIZE (1.. maxNrofCondCells-r16)) OF CondReconfigToAddMod-r16CondReconfigToAddMod-r16 ::= SEQUENCE {condReconfigId-r16 CondReconfigId-r16,condExecutionCond-r16 SEQUENCE (SIZE (1..2)) OF MeasId OPTIONAL, -- Need McondRRCReconfig-r16 OCTET STRING (CONTAINING RRCReconfiguration) OPTIONAL, -- Cond condReconfigAdd...,[[condExecutionCondSCG-r17 OCTET STRING (CONTAINING CondReconfigExecCondSCG-r17) OPTIONAL -- Need M]][[subsequentCondReconfig-r18 SubsequentCondReconfig-r18 OPTIONAL -- Need MsecurityCellSetId-r18 SecurityCellSetId-r18 OPTIONAL -- Need M]]}CondReconfigExecCondSCG-r17 ::= SEQUENCE (SIZE (1..2)) OF MeasIdSubsequentCondReconfig-r18 ::= SEQUENCE {condExecutionCondToReleaseList-r18 CondExecutionCondToReleaseList-r18 OPTIONAL, -- Need NcondExecutionCondToAddModList-r18 CondExecutionCondToAddModList-r18 OPTIONAL -- Need N}CondExecutionCondToAddModList-r18 ::= SEQUENCE (SIZE (1.. maxNrofCondCells-r16)) OF CondExecutionCondToAddMod-r18CondExecutionCondToAddMod-r18 ::= SEQUENCE {condReconfigId-r16 CondReconfigId-r16,condExecutionCond-r16 ::= SEQUENCE (SIZE (1..2)) OF MeasId OPTIONAL, -- Need MCondReconfigExecCondSCG-r17 ::= SEQUENCE (SIZE (1..2)) OF MeasId OPTIONAL -- Need M}CondExecutionCondToReleaseList-r18 ::= SEQUENCE (SIZE (1.. maxNrofCondCells-r16)) OF condReconfigId-r16

[0130] In table 6:-condExecutionCond: The execution condition that needs to be fulfilled in order to trigger the execution of a conditional reconfiguration for CHO, CPA, intra-SN CPC without MN involvement, MN initiated inter-SN CPC or SN initiated intra-SN subsequent CPAC without MN involvement. When configuring 2 triggering events (Meas Ids) for a candidate cell, the network ensures that both refer to the samemeasObject.For CHO, if the network configurescondEventD1orcondEventT1for a candidate cell, the network configures a second triggering eventcondEventA3, condEventA4orcondEventA5for the same candidate cell. The network does not configure bothcondEventD1andcondEventT1for the same candidate cell. For CHO in terrestrial networks, the network does not indicate aMeasIdassociated withcondEventA4. For CPA and for MN-initiated inter-SN CPC, the network only indicatesMeasId(s) associated withcondEventA4. For intra-SN CPC and intra-SN subsequent CPAC, the network only indicatesMeasId(s) associated withcondEventA3orcondEventA5;

[0131] -condExecutionCondSCG: Contains execution condition that needs to be fulfilled in order to trigger the execution of a conditional reconfiguration for SN initiated inter-SN CPC or SN initiated inter-SN subsequent CPAC, SN initiated intra-SN subsequent CPAC with MN involvement or MN initiated inter-SN subsequent CPAC. The Meas Ids refer to themeasConfigassociated with the SCG. When configuring 2 triggering events (Meas Ids) for a candidate cell, network ensures that both refer to the samemeasObject. For eachcondReconfigId, the network always configures eithercondExecutionCondorcondExecutionCondSCG(not both). The network only indicatesMeasId(s) associated withcondEventA3orcondEventA5;

[0132] -condRRCReconfig: TheRRCReconfigurationmessage to be applied when the condition(s) are fulfilled. TheRRCReconfigurationmessage contained incondRRCReconfigcannot contain the fieldconditionalReconfigurationor the fielddaps-Config;

[0133] -subsequentCondReconfig: Contains the execution conditions for subsequent CPAC execution. If the field is present, the configuration of candidate PSCells for subsequent CPAC is supported. The subsequent execution condition is used for conditional reconfiguration evaluation for other candidate cells when theRRCReconfigurationmessage contained incondRRCReconfighas been applied;

[0134] -subsequentCondExecutionCond: The execution condition that needs to be fulfilled in order to trigger the subsequent execution of a conditional reconfiguration for SN initiated intra-SN subsequent CPAC without MN involvement. When configuring 2 triggering events (Meas Ids) for a candidate cell, the network ensures that both refer to the samemeasObject. The network only indicatesMeasId(s) associated withcondEventA3orcondEventA5; and

[0135] -subsequentCondExecutionCondSCG:Contains execution condition that needs to be fulfilled in order to trigger the subsequent execution of a conditional reconfiguration for SN initiated inter-SN subsequent CPAC, SN initiated intra-SN subsequent CPAC with MN involvement, or MN initiated subsequent CPAC. The Meas Ids refer to themeasConfigassociated with the SCG. When configuring 2 triggering events (Meas Ids) for a candidate cell, network ensures that both refer to the samemeasObject. The network only indicatesMeasId(s) associated withcondEventA3orcondEventA5.

[0136] In step S803, the UE may start evaluating the one or more execution conditions for the candidate cells.

[0137] In step S805, if the target cell satisfies the corresponding execution condition(s), the UE may execute the conditional mobility towards the target cell and / or apply the RRC reconfiguration for the target cell including a configuration of the target cell. When / upon executing the conditional mobility and / or applying the RRC reconfiguration (e.g.,RRCReconfigurationincludingReconfigurationWithSync) for the target cell, the UE may start a timer (e.g., T304 timer). The timer value of the T304 timer (i.e., T304 timer value) for the target cell may be included in theReconfigurationWithSyncinRRCReconfigurationfor the target cell.

[0138] While the timer is running, the UE may perform DL synchronization and / or UL synchronization (e.g., random access) towards the target cell. The UE may skip the random access towards the target cell if timing advance (TA) information for the target cell is available.

[0139] In step S807, the UE, serving BS and / or BS related to the target cell may perform actions related to conditional mobility completion. For example, upon successful completion of the random access on the corresponding target cell, the UE may stop the timer (e.g., T304 timer).

[0140] Hereinafter, detailed procedure of the conditional reconfiguration / mobility is described.

[0141] The network configures the UE with one or more candidate target SpCells in the conditional reconfiguration. The UE evaluates the condition of each configured candidate target SpCell. The UE applies the conditional reconfiguration associated with one of the target SpCells which fulfils associated execution condition. The network provides the configuration parameters for the target SpCell in thecondRRCReconfig.

[0142] In NR-DC, the UE may receive two independentconditionalReconfiguration:

[0143] - aconditionalReconfigurationassociated with MCG, that is included in theRRCReconfigurationmessage received via SRB1; and

[0144] - aconditionalReconfiguration, associated with SCG, that is included in theRRCReconfigurationmessage received via SRB3, or, alternatively, included within aRRCReconfigurationmessage embedded in aRRCReconfigurationmessage received via SRB1.

[0145] In this case:

[0146] - the UE maintains two independentVarConditionalReconfig, one associated with eachconditionalReconfiguration;

[0147] - the UE independently performs all the conditional reconfiguration procedures for eachconditionalReconfigurationand the associatedVarConditionalReconfig, unless explicitly stated otherwise;

[0148] - the UE performs the measurement procedures for theVarConditionalReconfigassociated with the same cell group like themeasConfig.

[0149] In EN-DC, theVarConditionalReconfigis associated with the SCG.

[0150] In NE-DC and when no SCG is configured, theVarConditionalReconfigis associated with the MCG.

[0151] The UE performs the following actions based on a receivedConditionalReconfigurationIE:

[0152] 1> if theConditionalReconfigurationcontains thecondReconfigToRemoveList:

[0153] 2> sperform conditional reconfiguration removal procedure;

[0154] 1> if theConditionalReconfigurationcontains thecondReconfigToAddModList:

[0155] 2> perform conditional reconfiguration addition / modification;

[0156] 1> if theConditionalReconfigurationcontains thescpac-ReferenceConfiguration:

[0157] 2> perform reference configuration addition / removal;

[0158] 1> if theConditionalReconfigurationcontains thesk-CounterConfiguration:

[0159] 2> performsk-CounterListaddition / modification / removal;

[0160] 1> if theConditionalReconfigurationcontains theservingSecurityCellSetId:

[0161] 2> if the currentVarServingSecurityCellSetIDincludesservingSecurityCellSetId:

[0162] 3> replace theservingSecurityCellSetIdvalue withinVarServingSecurityCellSetIDwith the receivedservingSecurityCellSetID;

[0163] 2> else:

[0164] 3> store the receivedservingSecurityCellSetIdwithinVarServingSecurityCellSetID.

[0165] I. Conditional reconfiguration removal

[0166] The UE shall:

[0167] 1> for eachcondReconfigIdvalue included in thecondReconfigToRemoveListthat is part of the current UE conditional reconfiguration inVarConditionalReconfig:

[0168] 2> remove the entry with the matchingcondReconfigIdfrom theVarConditionalReconfig;

[0169] The UE does not consider the message as erroneous if thecondReconfigToRemoveListincludes any condReconfigIdvalue that is not part of the current UE configuration.

[0170] II. Conditional reconfiguration addition / modification

[0171] For eachcondReconfigIdreceived in thecondReconfigToAddModListIE the UE shall:

[0172] 1> if an entry with the matchingcondReconfigIdexists in thecondReconfigToAddModListwithin theVarConditionalReconfig:

[0173] 2> if the entry incondReconfigToAddModListincludes ancondExecutionCondorcondExecutionCondSCG;

[0174] 3> replacecondExecutionCondorcondExecutionCondSCGwithin theVarConditionalReconfigwith the value received for thiscondReconfigId;

[0175] 2> if the entry incondReconfigToAddModListincludessubsequentCondReconfigcontainingcondExecutionCondToAddModList:

[0176] 3> for eachcondReconfigIdreceived incondExecutionCondToAddModList:

[0177] 4> if there is an entry with the matchingcondReconfigIdexists in thecondExecutionCondToAddModList;

[0178] 5> replace the entry with the value received for thiscondReconfigId;

[0179] 4> else:

[0180] 5> add a new entry for the receivedcondReconfigIdto thecondExecutionCondToAddModList;

[0181] 3> for eachcondReconfigIdreceived incondExecutionCondToReleaseListthat is part of current storedcondExecutionCondToAddModList:

[0182] 4> remove the entry with the matchingcondReconfigIdfrom thecondExecutionCondToAddModList;

[0183] 2> if the entry incondReconfigToAddModListincludes ancondRRCReconfig;

[0184] 3> replacecondRRCReconfigwithin theVarConditionalReconfigwith the value received for thiscondReconfigId;

[0185] 1> else:

[0186] 2> add a new entry for thiscondReconfigIdwithin theVarConditionalReconfig;

[0187] 1> perform conditional reconfiguration evaluation.

[0188] The UE does not consider the message as erroneous if thecondExecutionCondToReleaseListincludes anycondReconfigIdvalue that is not part of the current UE configuration.

[0189] III. Conditional reconfiguration evaluation

[0190] The UE shall:

[0191] 1> for eachcondReconfigIdwithin theVarConditionalReconfig:

[0192] 2> if theRRCReconfigurationwithincondRRCReconfigincludes themasterCellGroupincluding thereconfigurationWithSync:

[0193] 3> consider the cell which has a physical cell identity matching the value indicated in theServingCellConfigCommonincluded in thereconfigurationWithSyncwithin themasterCellGroupin the receivedcondRRCReconfigto be applicable cell;

[0194] 2> else if theRRCReconfigurationwithincondRRCReconfigincludes thesecondaryCellGroupincluding thereconfigurationWithSync:

[0195] 3> if the cell which has a physical cell identity matching the value indicated in theServingCellConfigCommonincluded in thereconfigurationWithSyncwithin thesecondaryCellGroupwithin the receivedcondRRCReconfigis not the PSCell:

[0196] 4> consider the cell to be applicable cell;

[0197] 2> ifcondExecutionCondSCGis configured:

[0198] 3> in the remainder of the procedure, consider eachmeasIdindicated in thecondExecutionCondSCGas ameasIdin theVarMeasConfigassociated with the SCGmeasConfig;

[0199] 2> ifcondExecutionCondis configured:

[0200] 3> if it is configured via SRB3 or configured withinnr-SCGor withinnr-SecondaryCellGroupConfigvia SRB1:

[0201] 4> in the remainder of the procedure, consider eachmeasIdindicated in thecondExecutionCondas ameasIdin theVarMeasConfigassociated with the SCGmeasConfig;

[0202] 3> else:

[0203] 4> in the remainder of the procedure, consider eachmeasIdindicated in thecondExecutionCondas ameasIdin theVarMeasConfigassociated with the MCGmeasConfig;

[0204] 2> for eachmeasIdincluded in themeasIdListwithinVarMeasConfigindicated in thecondExecutionCondorcondExecutionCondSCGassociated tocondReconfigId:

[0205] 3> if thecondEventIdis associated withcondEventT1, and if the entry condition applicable for this event associated with thecondReconfigId, i.e. the event corresponding with thecondEventId(s)of the correspondingcondTriggerConfigwithinVarConditionalReconfig, is fulfilled for the applicable cell; or

[0206] 3> if thecondEventIdis associated withcondEventD1, and if the entry conditions applicable for this event associated with thecondReconfigId, i.e. the event corresponding with thecondEventId(s)of the correspondingcondTriggerConfigwithinVarConditionalReconfig, is fulfilled for the applicable cell during the correspondingtimeToTriggerdefined for this event within theVarConditionalReconfig; or

[0207] 3> if thecondEventIdis associated withcondEventA3,condEventA4orcondEventA5, and if the entry condition(s) applicable for this event associated with thecondReconfigId, i.e. the event corresponding with thecondEventId(s)of the correspondingcondTriggerConfigwithinVarConditionalReconfig, is fulfilled for the applicable cells for all measurements after layer 3 filtering taken during the correspondingtimeToTriggerdefined for this event within theVarConditionalReconfig:

[0208] 4> consider the event associated to thatmeasIdto be fulfilled;

[0209] 3> if themeasIdfor this event associated with thecondReconfigIdhas been modified; or

[0210] 3> if thecondEventIdis associated withcondEventT1, and if the leaving condition applicable for this event associated with thecondReconfigId, i.e. the event corresponding with thecondEventId(s)of the correspondingcondTriggerConfigwithinVarConditionalReconfig, is fulfilled for the applicable cell; or

[0211] 3> if thecondEventIdis associated withcondEventD1, and if the leaving condition(s) applicable for this event associated with thecondReconfigId, i.e. the event corresponding with thecondEventId(s)of the correspondingcondTriggerConfigwithinVarConditionalReconfig, is fulfilled for the applicable cell during the correspondingtimeToTriggerdefined for this event within theVarConditionalReconfig; or

[0212] 3> if thecondEventIdis associated withcondEventA3,condEventA4orcondEventA5, and if the leaving condition(s) applicable for this event associated with thecondReconfigId, i.e. the event corresponding with thecondEventId(s)of the correspondingcondTriggerConfigwithinVarConditionalReconfig, is fulfilled for the applicable cells for all measurements after layer 3 filtering taken during the correspondingtimeToTriggerdefined for this event within theVarConditionalReconfig:

[0213] 4> consider the event associated to thatmeasIdto be not fulfilled;

[0214] 2> if event(s) associated to allmeasId(s) withincondTriggerConfigfor the applicable cell are fulfilled:

[0215] 3> consider the applicable cell, associated to thatcondReconfigId, as a triggered cell;

[0216] 3> initiate the conditional reconfiguration execution;

[0217] Up to 2MeasIdcan be configured for eachcondReconfigId.The conditional reconfiguration event of the 2MeasIdmay have the same or different event conditions, triggering quantity, time to trigger, and triggering threshold.

[0218] IV. Conditional reconfiguration evaluation of SN initiated inter-SN CPC for EN-DC

[0219] The UE shall:

[0220] 1> for eachcondReconfigurationIdwithin theVarConditionalReconfiguration:

[0221] 2> for eachmeasIdincluded in themeasIdListwithinVarMeasConfigindicated in theCondReconfigExecCondSCGcontained in thetriggerConditionSNassociated to thecondReconfigurationId:

[0222] 3> if the entry condition(s) applicable for the event associated with thatmeasId, is fulfilled for the applicable cells for all measurements after layer 3 filtering taken during the correspondingtimeToTriggerdefined for this event associated with thatmeasId:

[0223] 4> consider this event to be fulfilled;

[0224] 3> if themeasIdfor this event has been modified; or

[0225] 3> if the leaving condition(s) applicable for this event associated with thatmeasId, is fulfilled for the applicable cells for all measurements after layer 3 filtering taken during the correspondingtimeToTriggerdefined for this event associated with thatmeasId:

[0226] 4> consider this event associated to thatmeasIdto be not fulfilled;

[0227] 2> if trigger conditions for all events associated with themeasId(s)indicated in theCondReconfigExecCondSCGcontained in thetriggerConditionSN, are fulfilled:

[0228] 3> consider the target cell candidate within theRRCReconfigurationmessage contained innr-SecondaryCellGroupConfigin theRRCConnectionReconfigurationmessage contained in the storedcondReconfigurationToApply, associated to thatcondReconfigurationIdas a triggered cell;

[0229] 3> initiate the conditional reconfiguration execution,;

[0230] V. Conditional reconfiguration execution

[0231] The UE shall:

[0232] 1> if more than one triggered cell exists:

[0233] 2> select one of the triggered cells as the selected cell for conditional reconfiguration execution;

[0234] 1> else:

[0235] 2> consider the triggered cell as the selected cell for conditional reconfiguration execution;

[0236] 1> for the selected cell of conditional reconfiguration execution:

[0237] 2> apply the storedcondRRCReconfigof the selected cell and perform the actions as specified in 5.3.5.3;

[0238] If multiple NR cells are triggered in conditional reconfiguration execution, it is up to UE implementation which one to select, e.g. the UE considers beams and beam quality to select one of the triggered cells for execution.

[0239] VI. Reference configuration addition / removal

[0240] The UE shall:

[0241] 1> if thescpac-ReferenceConfigurationis set tosetup:

[0242] 2> ifSCPAC-ReferenceConfigurationexists within theVarConditionalReconfig:

[0243] 3> replace theSCPAC-ReferenceConfigurationwithin theVarConditionalReconfig;

[0244] 2> else:

[0245] 3> store theSCPAC-ReferenceConfigurationwithin theVarConditionalReconfig;

[0246] 1> else:

[0247] 2> remove theSCPAC-ReferenceConfigurationwithin theVarConditionalReconfig;

[0248] VII. sk-Counter configuration addition / modification / removal

[0249] The UE shall:

[0250] 1> for eachsecurityCellSetIdreceived in thesk-CounterConfigToAddModListIE:

[0251] 2> if an entry with the matchingsecurityCellSetIdexists in thesk-CounterConfigToAddModListwithin theVarConditionalReconfig:

[0252] 3> replace thesk-CounterListwithin theVarConditionalReconfigwith the value received for thissecurityCellSetId;

[0253] 2> else:

[0254] 3> add a new entry for thissecurityCellSetIdwithin theVarConditionalReconfig;

[0255] 1> for eachsecurityCellSetIdvalue included in thesk-CounterConfigToRemoveListthat is part of the currentsk-CounterConfigToAddModListinVarConditionalReconfig:

[0256] 2> remove the entry with the matchingsecurityCellSetIdfrom thesk-CounterConfigToAddModList.

[0257] VIII. Subsequent CPAC execution

[0258] Upon the conditional reconfiguration execution for subsequent CPAC, the UE shall:

[0259] 1> if the selected subsequent CPAC candidate configuration is stored in MCGVarConditionalReconfig:

[0260] 2> for each SRB / DRB in current UE configuration:

[0261] - keep the associated RLC, PDCP and SDAP entities, their state variables, buffers and timers;

[0262] - release all fields related to the SRB / DRB configuration except forsrb-Identity,drb-Identity, andsecurityConfig;

[0263] 2> release / clear all current dedicated radio configuration except for the following:

[0264] - the MCG C-RNTI;

[0265] - the AS security configurations associated with the master key and the secondary key;

[0266] - thelogicalChannelIdentityandlogicalChannelIdentityExtof RLC bearers configured in RLC-BearerConfig and the associated RLC entities, their state variables, buffers, and timers;

[0267] - the bh-LogicalChannelIdentityof BH RLC channels configured inBH-RLC-ChannelConfigand the associated RLC entities, their state variables, buffers, and timers;

[0268] - the UE variablesVarConditionalReconfigandVarServingSecurityCellSetID;

[0269] - the logged measurement configuration.

[0270] 2> release / clear all current common radio configuration;

[0271] 2> apply the default MAC Cell Group configuration for MCG MAC and SCG MAC;

[0272] 2> use the default values for timers T310, T311 and constants N310, N311, where T310, N310, and N311 are for both MCG and SCG, and T311 is only for the MCG;

[0273] 2> apply the default L1 parameter values for the MCG and SCG;

[0274] 1> else:

[0275] 2> for each SRB / DRB in current UE configuration:

[0276] - keep the associated PDCP and SDAP entities, their state variables, buffers and timers;

[0277] - release all fields related to the SRB / DRB configuration except forsrb-Identity,drb-Identity, andsecurityConfig;

[0278] 2> release / clear all current dedicated radio configuration associated with the SCG except for the following:

[0279] - the AS security configurations associated with the secondary key;

[0280] - the UE variablesVarConditionalReconfig.

[0281] 2> release / clear all current common radio configuration associated with the SCG;

[0282] 2> apply the default MAC Cell Group configuration for the SCG MAC;

[0283] 2> use the default values for timer T310 and constants N310 and N311 for the SCG;

[0284] 2> apply the default L1 parameter values as specified in corresponding physical layer specifications for the SCG;

[0285] 1> if thesecurityCellSetIdis included in the entry inVarConditionalReconfigcontaining theRRCReconfigurationmessage:

[0286] 2> ifservingSecurityCellSetIdis not included withinVarServingSecurityCellSetID; or

[0287] 2> if the value of thesecurityCellSetIdis not equal to the value ofservingSecurityCellSetIdwithinVarServingSecurityCellSetID:

[0288] 3> consider the firstsk-Countervalue in thesk-CounterListassociated with thesecurityCellSetIdwithin theVarConditionalReconfigas the selectedsk-Countervalue, and perform security key update procedure;

[0289] 3> remove the selectedsk-Countervalue from thesk-CounterListassociated with thesecurityCellSetIdwithin theVarConditionalReconfig;

[0290] 3> if the currentVarServingSecurityCellSetIDincludesservingSecurityCellSetId:

[0291] 4> replace the value ofservingSecurityCellSetIdwithinVarServingSecurityCellSetIDwith the value ofsecurityCellSetIdassociated with the selected cell;

[0292] 3> else:

[0293] 4> store theservingSecurityCellSetIdwithinVarServingSecurityCellSetIDwith the value ofsecurityCellSetIdassociated with the selected cell;

[0294] 1> if the selected subsequent CPAC candidate configuration is stored in the SCGVarConditionalReconfig:

[0295] 2> for eachdrb-Identityvalue included in eachRadioBearerConfigin the selected subsequent CPAC candidate configuration that is part of the current UE configuration, the UE shall perform the following actions after the end of this procedure:

[0296] 3> if the bearer is an AM DRB:

[0297] 4> trigger the PDCP entity of the bearer to perform PDCP data recovery;

[0298] 3> re-establish the corresponding RLC entity;

[0299] 1> else:

[0300] 2> for eachdrb-Identityvalue included in eachRadioBearerConfigin the selected subsequent CPAC candidate configuration that is part of the current UE configuration, the UE shall perform the following actions after the end of this procedure:

[0301] 3> if thekeyToUsein theRadioBearerConfigis different from thekeyToUsein the current UE configuration; or

[0302] 3> if the bearer is associated with the secondary key (S-KgNB) as indicated bykeyToUsein the current UE configuration and a newsk-Countervalue has been selected due to the conditional reconfiguration execution for subsequent CPAC:

[0303] 4> if the PDCP entity of this DRB is not configured withcipheringDisabled:

[0304] 5> configure the PDCP entity with the ciphering algorithm and KUPenc key associated with the master key (KgNB) or the secondary key (S-KgNB), as indicated inkeyToUse, i.e., the ciphering configuration shall be applied to all subsequent PDCP PDUs received and sent by the UE;

[0305] 4> if the PDCP entity of this DRB is configured withintegrityProtection:

[0306] 5> configure the PDCP entity with the integrity protection algorithms according tosecurityConfigand apply the KUPint key associated with the master key (KgNB) or the secondary key (S-KgNB) as indicated inkeyToUse;

[0307] 4> ifdrb-ContinueROHCis included inpdcp-Config:

[0308] 5> indicate to lower layer thatdrb-ContinueROHCis configured;

[0309] 4> ifdrb-ContinueEHC-DLis included inpdcp-Config:

[0310] 5> indicate to lower layer thatdrb-ContinueEHC-DLis configured;

[0311] 4> ifdrb-ContinueEHC-ULis included inpdcp-Config:

[0312] 5> indicate to lower layer thatdrb-ContinueEHC-ULis configured;

[0313] 4> ifdrb-ContinueUDCis included inpdcp-Config:

[0314] 5> indicate to lower layer thatdrb-ContinueUDCis configured;

[0315] 4> re-establish the corresponding RLC entity;

[0316] 4> trigger the PDCP entity of the bearer to perform PDCP re-establishment;

[0317] 3> else:

[0318] 4> if there is an associated SCG RLC bearer in the selected subsequent CPAC candidate configuration that is part of the current UE configuration:

[0319] 5> re-establish the SCG RLC entity;

[0320] 4> if the RLC entity of the associated RLC bearer(s) is re-established; or

[0321] 4> if an associated RLC bearer is released in the selected subsequent CPAC candidate configuration:

[0322] 5> if the bearer is an AM DRB:

[0323] 6> trigger the PDCP entity of the bearer to perform PDCP data recovery;

[0324] 2> for eachsrb-Identityincluded inRadioBearerConfigthat is part of the current UE configuration and if the radio bearer is SRB3 or SRB5, the UE shall perform the following actions after the end of this procedure:

[0325] 3> if a newsk-Countervalue has been selected due to the conditional reconfiguration execution for subsequent CPAC:

[0326] 4> configure the PDCP entity to apply the integrity protection algorithm and KRRCint key associated with the secondary key (S-KgNB) as indicated inkeyToUse, i.e. the integrity protection configuration shall be applied to all subsequent messages received and sent by the UE, including the message used to indicate the successful completion of the procedure;

[0327] 4> configure the PDCP entity to apply the ciphering algorithm and KRRCenc key associated with the secondary key (S-KgNB) as indicated inkeyToUse, i.e. the ciphering configuration shall be applied to all subsequent messages received and sent by the UE, including the message used to indicate the successful completion of the procedure;

[0328] 4> trigger the PDCP entity of SRB to perform PDCP re-establishment;

[0329] 3> else:

[0330] 4> trigger the PDCP entity of SRB to perform SDU discard;

[0331] 3> re-establish the corresponding RLC entity;

[0332] 1> ifscpac-ConfigCompleteis not included within theVarConditionalReconfigfor the selected cell:

[0333] 2> if the subsequent CPAC candidate cell configuration is stored in MCGVarConditionalReconfig:

[0334] 3> considerscpac-ReferenceConfigurationin MCGVarConditionalReconfigto be the current UE configuration;

[0335] 2> else:

[0336] 3> considerscpac-ReferenceConfigurationin SCGVarConditionalReconfigto be the current SCG configuration;

[0337] When the UE considers the reference configuration to be the current UE configuration, the UE should store fields and configurations that are part of the reference configuration but should not execute any actions or procedures triggered by the reception of anRRCReconfigurationmessage.

[0338] 1> apply the storedcondRRCReconfigof the selected cell(s) and perform actions upon reception ofRRCReconfigurationmessage;

[0339] 1> release the radio bearer(s) and the associated logical channel(s) that are part of the current UE configuration but not part of the subsequent CPAC candidate configuration for the selected cell, or the subsequent CPAC reference configuration (in case the subsequent CPAC candidate configuration does not includescpac-ConfigComplete).

[0340] Whenscpac-ConfigCompleteis not included for the selected cell, before a subsequent CPAC execution, a UE implementation may generate and store an RRC reconfiguration message by applying the received subsequent CPAC candidate configuration on top of the subsequent CPAC reference configuration, and the stored RRC reconfiguration message is applied for subsequent CPAC execution. The UE needs to ensure that the RRC reconfiguration applied at the time of subsequent CPAC execution is in accordance with the latest receivedscpac-ReferenceConfigurationandcondRRCReconfigfor the subsequent CPAC configuration.

[0341] Hereinafter, full configuration procedure is described.

[0342] The UE shall perform the following actions upon reception of theRRCReconfiguration,upon execution of the conditional reconfiguration (CHO, CPA, CPC, or subsequent CPAC) (i.e., upon / based on applyingRRCReconfigurationaccording to the execution of the conditional reconfiguration), or upon execution of an LTM cell switch (i.e., upon / based on applyingRRCReconfigurationaccording to the execution of the LTM cell switch):

[0343] 1> if theRRCReconfigurationincludes thefullConfig(i.e., full configuration flag):

[0344] 2> perform the full configuration procedure (i.e., applyRRCReconfigurationas a full configuration).

[0345] When performing the full configuration procedure, the UE shall:

[0346] 1> release / clear all current dedicated radio configurations except for the following:

[0347] - the MCG C-RNTI;

[0348] - the AS security configurations associated with the master key;

[0349] - the SRB1 / SRB2 configurations and DRB / multicast MRB configurations as configured byradioBearerConfigorradioBearerConfig2.

[0350] Radio configuration is not just the resource configuration but includes other configurations likeMeasConfig. Radio configuration also includes the RLC bearer configurations as configured byRLC-BearerConfig, PC5 Relay RLC channel as configured bySL-RLC-ChannelConfig, and Uu Relay RLC channel as configured byUu-RelayRLC-ChannelConfig. In case NR-DC or NE-DC is configured, this also includes the entire NR or E-UTRA SCG configuration which are released according to the MR-DC release procedure.

[0351] To establish the RLC bearer of SRB(s) after release due tofullConfig, the network can include thesrb-Identitywithinsrb-ToAddModList(i.e. the UE applies RLC default configuration) and / or providerlc-BearerToAddModListof concerned SRB(s) explicitly.

[0352] - the logged measurement configuration;

[0353] - thesuccessHO-Config;

[0354] - thesuccessPSCell-Config.

[0355] 1> if thespCellConfigin themasterCellGroupincludes thereconfigurationWithSync:

[0356] 2> release / clear all current common radio configurations;

[0357] 2> ifsl-PathSwitchConfigwas included inreconfigurationWithSync:

[0358] 3> use the default values for timer T311;

[0359] 2> else:

[0360] 3> use the default values for timers T310, T311 and constants N310, N311;

[0361] 1> else (full configuration after re-establishment or during RRC resume):

[0362] 2> if the UE is acting as L2 U2N Remote UE:

[0363] 3> use value for timer T311, as included inue-TimersAndConstantsreceived inSIB1;

[0364] 2> else:

[0365] 3> use values for timers T301, T310, T311 and constants N310, N311, as included inue-TimersAndConstantsreceived inSIB1;

[0366] 1> if nomeasConfigAppLayerIdis included:

[0367] 2> inform upper layers about the release of all application layer measurement configurations;

[0368] 2> release all application layer measurement configurations including their fields in the UE variablesVarAppLayerIdleConfigandVarAppLayerPLMN-ListConfig, if stored;

[0369] 2> discard any received application layer measurement reports from upper layers;

[0370] 2> consider itself not to be configured to send application layer measurement reports;

[0371] 1> if the UE is acting as L2 U2N Remote UE at the target side during reconfiguration with sync, or after re-establishment, or during RRC resume:

[0372] 2> apply the default configuration of SL-RLC1 as specified and associate it with the SRB1;

[0373] 1> else:

[0374] 2> apply the default L1 parameter values as specified in corresponding physical layer specifications except for the following:

[0375] - parameters for which values are provided inSIB1;

[0376] 2> apply the default MAC Cell Group configuration;

[0377] 2> for eachsrb-Identityvalue included in thesrb-ToAddModList(SRB reconfiguration):

[0378] 3> establish an RLC entity for the corresponding SRB;

[0379] 3> apply the default SRB configuration for the corresponding SRB;

[0380] This is to get the SRBs (SRB1 and SRB2 for reconfiguration with sync and SRB2 for resume and reconfiguration after re-establishment) to a known state from which the reconfiguration message can do further configuration.

[0381] 1> for eachpdu-Sessionthat is part of the current UE configuration:

[0382] 2> release the SDAP entity;

[0383] 2> release each DRB associated to thepdu-Session;

[0384] This will retain thepdu-Sessionbut remove the DRBs includingdrb-identityof these bearers from the current UE configuration. Thepdu-Sessionacts as the anchor for associating the released and re-setup DRB. In the AS the DRB re-setup is equivalent with a new DRB setup (including new PDCP and logical channel configurations).

[0385] 1> for eachmbs-SessionIdthat is part of the current UE configuration and associated to a multicast MRB:

[0386] 2> release the SDAP entity;

[0387] 2> release each multicast MRB associated to thembs-SessionId;

[0388] This will retain thembs-SessionIdbut remove the multicast MRBs includingmrb-identityof these bearers from the current UE configuration. Thembs-SessionIdacts as the anchor for associating the released and re-setup multicast MRB. In the AS the multicast MRB re-setup is equivalent with a new multicast MRB setup (including new PDCP and logical channel configurations).

[0389] 1> for eachpdu-Sessionthat is part of the current UE configuration but not added with samepdu-Sessionin thedrb-ToAddModList:

[0390] 2> if the procedure was triggered due to reconfiguration with sync:

[0391] 3> indicate the release of the user plane resources for thepdu-Sessionto upper layers after successful reconfiguration with sync;

[0392] 2> else:

[0393] 3> indicate the release of the user plane resources for thepdu-Sessionto upper layers immediately;

[0394] 1> for eachmbs-SessionIdthat is part of the current UE configuration but not added with the samembs-SessionIdin themrb-ToAddModList:

[0395] 2> if the procedure was triggered due to reconfiguration with sync:

[0396] 3> indicate the release of the user plane resources for thembs-SessionIdto upper layers after successful reconfiguration with sync;

[0397] 2> else:

[0398] 3> indicate the release of the user plane resources for thembs-SessionIdto upper layers immediately.

[0399] Meanwhile, candidate cells for subsequent CPA / CPC need to perform consecutive SN mobility. Consequently, specific candidate cells may require a change of some SCG data bearers based on where the source cell (i.e., which was one of the candidate cells) was, and / or when the target cell's capability varies from that of the source cell. In such cases, the UE shall perform a full configuration procedure.

[0400] Conversely, for some other specific candidate cells, there may not be a need to perform the full configuration procedure, even if some SCG data bearers need to be modified based on the source cell / source cell configuration. In such scenarios, the UE doesn't need to perform the full configuration procedure based on the complete configuration generated with the reference configuration.

[0401] The full configuration flag (i.e.,fullConfig) that mandates the full configuration procedure may be included in a configuration of each candidate (i.e.,RRCReconfigurationfor each candidate). Consequently, the UE may be required to perform the full configuration procedure regardless of which candidate cell was the source cell. Alternatively, the UE may not perform the full configuration procedure even though the target cell requires the full configuration procedure. This may lead to problems in data bearer re-establishment and / or potential data transmission failures, causing data interruptions.

[0402] Therefore, the present disclosure provides various embodiments for determining whether to perform a full configuration procedure when performing mobility (e.g., subsequent CPAC (SCPAC)).

[0403] FIG. 9 shows an example of a method performed by a UE according to an embodiment of the present disclosure.

[0404] Referring to FIG. 9, in step S901, the UE may receive a subsequent mobility configuration (e.g.,SubsequentCondReconfig) for a first candidate cell. The subsequent mobility configuration may comprise a list of execution conditions for a subsequent mobility (e.g.,condExecutionCondToAddModList), and a list of candidate cells related to a full configuration procedure.

[0405] In step S903, the UE may perform a mobility to the first candidate cell.

[0406] In step S905, the UE may perform a subsequent mobility to a second candidate cell based on one or more execution conditions for the second candidate cell in the list of execution conditions being satisfied.

[0407] In step S907, the UE may determine whether to perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the list of candidate cells related to the full configuration procedure.

[0408] In step S909, the UE may perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.

[0409] According to various embodiments, the list of candidate cells related to the full configuration procedure may comprise one or more first candidate cells for which full configuration flag (e.g.,fullConfig) is set to true indicating that the full configuration procedure needs to be performed.

[0410] According to various embodiments, the list of candidate cells related to the full configuration procedure may comprise a list of full configuration flags set to true for the list of candidate cells.

[0411] According to various embodiments, the UE may receive a mobility configuration (e.g.,condReconfigToAddMod) for the first candidate cell and a mobility configuration for the second candidate cell. The mobility configuration for the first candidate cell may comprise a radio resource control (RRC) reconfiguration for the first candidate cell and the subsequent mobility configuration for the first candidate cell. The mobility configuration for the second candidate cell may comprise an RRC reconfiguration for the second candidate cell and a subsequent mobility configuration for the second candidate cell.

[0412] According to various embodiments, the UE may apply the RRC reconfiguration for the first candidate cell in the mobility configuration for the first candidate cell, to perform the mobility to the first candidate cell.

[0413] According to various embodiments, the subsequent mobility configuration for the first candidate cell may comprise an identity (ID) of the mobility configuration for the second candidate cell (e.g.,subsequentCondReconfigId / CondReconfigId). The UE may apply the RRC reconfiguration for the second candidate cell in the mobility configuration for the second candidate cell identified by the ID.

[0414] According to various embodiments, the UE may apply the RRC reconfiguration for the second candidate cell as a full configuration for performing the full configuration procedure, based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.

[0415] According to various embodiments, the UE may apply the RRC reconfiguration for the second candidate cell as a delta configuration, based on the second candidate cell being not included in the list of candidate cells related to the full configuration procedure.

[0416] According to various embodiments, the RRC reconfiguration for the second candidate cell may comprise a full configuration flag for the second candidate cell. The list of candidate cells related to the full configuration flag may be separately configured from the full configuration flag without being included in the RRC reconfiguration for the second candidate cell.

[0417] According to various embodiments, the UE may determine whether to perform the full configuration procedure for the second candidate cell based on the list of candidate cells, while ignoring a full configuration flag for the second candidate cell in the RRC reconfiguration for the second candidate cell.

[0418] According to various embodiments, the list of candidate cells may comprise the second candidate cell for which full configuration flag is set to true. To ignore the full configuration flag in the RRC reconfiguration for the second candidate cell, the UE may apply the RRC reconfiguration for the second candidate cell as a full configuration based on the list of candidate cells, while the full configuration flag for the second candidate cell in the RRC reconfiguration for the second candidate cell is set to false.

[0419] According to various embodiments, the list of candidate cells does not comprise the second candidate cell for which full configuration flag is set to false. To ignore the full configuration flag in the RRC reconfiguration for the second candidate cell, the UE may apply the RRC reconfiguration for the second candidate cell as a delta configuration based on the list of candidate cells, while the full configuration flag for the second candidate cell in the RRC reconfiguration for the second candidate cell is set to true.

[0420] According to various embodiments, the subsequent mobility comprises a subsequent conditional primary secondary cell (PSCell) addition / change (CPAC).

[0421] According to various embodiments, the UE may receive a subsequent mobility configuration for one or more candidate cells from a network. The subsequent mobility configuration may provide a configuration of each candidate cell and one or more execution conditions for each candidate cell to the UE. The subsequent mobility configuration may provide one or more cell lists for each candidate cell to the UE. The UE may determine whether the UE performs a full configuration procedure based on the one or more cell lists for a candidate cell when the one or more execution conditions are met for the candidate cell. The UE may ignore a full configuration flag included in the configuration of the candidate cell. The UE may perform a full configuration procedure when the candidate cell is in the one or more cell lists when performing the subsequent mobility to the candidate cell. The UE may send an RRC reconfiguration complete message to the network after the subsequent mobility is successfully completed.

[0422] FIG. 10 shows an example of a signal flow between a UE and a network node according to an embodiment of the present disclosure.

[0423] Referring to FIG. 10, in step S1001, the network node may transmit, to the UE, a subsequent mobility configuration (e.g.,SubsequentCondReconfig) for a first candidate cell. The subsequent mobility configuration may comprise a list of execution conditions for a subsequent mobility (e.g.,condExecutionCondToAddModList), and a list of candidate cells related to a full configuration procedure.

[0424] In step S1003, the UE may perform a mobility to the first candidate cell.

[0425] In step S1005, the UE may perform a subsequent mobility to a second candidate cell based on one or more execution conditions for the second candidate cell in the list of execution conditions being satisfied.

[0426] In step S1007, the UE may determine whether to perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the list of candidate cells related to the full configuration procedure.

[0427] Hereinafter, detailed implementations regarding determining whether to perform a full configuration procedure when performing mobility (e.g., subsequent CPAC (SCPAC)) are described.

[0428] According to implementations of the present disclosure, when the UE performs a subsequent CPA / CPC (i.e., CPAC) to a candidate cell based on applying a configuration of the candidate cell (i.e.,RRCReconfigurationfor the candidate cell), the UE may ignore a full configuration flag (i.e.,fullConfig) in the configuration of the candidate cell but perform the full configuration procedure based on a list of full configuration flags which is included outside (or, not included in) the configuration of the candidate cell. For example, the list of full configuration flags may be separately included insubsequentCondReconfigIE (i.e., not in the configuration of the candidate cell). For the list of full configuration flags, when the network configures a subsequent CPA / CPC configuration to the UE, the network may include the list of full configuration flags for all candidate cells outside of each configuration of candidate cell in RRC dedicated message (i.e.,RRCReconfigurationmessage).

[0429] The list of full configuration flags may comprise at least one of:

[0430] - one or more full configuration flags set to 'true' for one or more candidate cell to indicate that a full configuration procedure needs to be performed after / upon a subsequent mobility to the one or more candidate cells; or

[0431] - one or more full configuration flags set to 'false' for one or more candidate cells to indicate that a full configuration procedure does not need to be performed after / upon a subsequent mobility to the one or more candidate cells.

[0432] The full configuration flag set to 'true' may mean that the full configuration flag is included / present in the subsequent mobility configuration (e.g.,subsequentCondReconfig).

[0433] The full configuration flag set to 'false' may mean that the full configuration flag is not included and / or is absent in the subsequent mobility configuration (e.g.,subsequentCondReconfig).

[0434] Alternatively, the list of full configuration flags may comprise at least one of:

[0435] - a list of candidate cells related to a full configuration procedure (i.e., a full configuration procedure needs to be performed after / upon a subsequent mobility to one of the candidate cells); or

[0436] - a list of candidate cells not related to a full configuration procedure (i.e., a full configuration procedure does not need to be performed after / upon a subsequent mobility to one of the candidate cells).

[0437] The list of candidate cells related to a full configuration procedure may be and / or may correspond to a list of candidate cells for which full configuration flag is set to 'true'.

[0438] The list of candidate cells not related to a full configuration procedure may be and / or may correspond to a list of candidate cells for which full configuration flag is set to 'false'.

[0439] For the list of full configuration flags, a separatefullConfiginformation (i.e., separate list of full configuration flags) for subsequent CPA / CPC may be provided to the UE. The UE may ignore thefullConfiginformation contained in the configuration of candidate cell (or,RRCReconfigurationfor the candidate cell) when performing a subsequent CPA / CPC (i.e., CPAC) to the candidate cell, but the UE may use the (separate)fullConfiginformation provided outside the configuration of candidate cell (or,RRCReconfigurationfor the candidate cell). The UE may determine whether the full configuration procedure depending on the relationship between the source cell and the next target cell is needed, based on the list of full configuration flags.

[0440] The network may includefullConfiginformation (or, the list of full configuration flags) determined appropriately based on the relationship between candidate cells, in thesubsequentCondReconfigIE. The current execution conditions for subsequent CPA / CPC may have been already configured and included appropriately for the relationship between candidate cells, in thesubsuequentCondReconfigIE.

[0441] When the network configures the list of full configuration flags to the UE, the network may inform the UE whether a full configuration procedure is needed for each candidate target cell with 1 bit information. For this case, the full configuration procedure may be performed only for a candidate target cell with the information indicated as 1 bit. Alternatively, the network may also configure differently such that the full configuration procedure may not be performed only for a candidate target cell with the information indicated as 1 bit.

[0442] FIG. 11 shows an example of a subsequent CPAC scenario according to an embodiment of the present disclosure.

[0443] Referring to FIG. 11, when performing a subsequent CPAC from cell 1 to cell 2, a full configuration flag for this case may indicate that a full configuration procedure is not needed. When performing a subsequent CPAC from cell 1 to cell 3, a full configuration flag for this case may indicate that a full configuration procedure is needed. When performing a subsequent CPAC from cell 1 to cell 4, a full configuration flag for this case may indicate that a full configuration procedure is needed.

[0444] When performing a subsequent CPAC from cell 2 to cell 1, a full configuration flag for this case may indicate that a full configuration procedure is not needed. When performing a subsequent CPAC from cell 2 to cell 3, a full configuration flag for this case may indicate that a full configuration procedure is needed. When performing a subsequent CPAC from cell 2 to cell 4, a full configuration flag for this case may indicate that a full configuration procedure is needed.

[0445] When performing a subsequent CPAC from cell 3 to cell 1, a full configuration flag for this case may indicate that a full configuration procedure is needed. When performing a subsequent CPAC from cell 3 to cell 2, a full configuration flag for this case may indicate that a full configuration procedure is needed. When performing a subsequent CPAC from cell 3 to cell 4, a full configuration flag for this case may indicate that a full configuration procedure is not needed.

[0446] When performing a subsequent CPAC from cell 4 to cell 1, a full configuration flag for this case may indicate that a full configuration procedure is needed. When performing a subsequent CPAC from cell 4 to cell 2, a full configuration flag for this case may indicate that a full configuration procedure is needed. When performing a subsequent CPAC from cell 4 to cell 3, a full configuration flag for this case may indicate that a full configuration procedure is not needed.

[0447] In the subsequent CPAC scenario as FIG. 11, the UE may perform steps as shown in FIG. 12.

[0448] FIG. 12 shows an example of a method for full configuration decision when performing subsequent CPAC according to an embodiment of the present disclosure.

[0449] Referring to FIG. 12, in step S1201, the UE may receive a subsequent CPAC configuration from a network. The network may configure 4 configurations of candidate cells (i.e., cell 1, cell 2, cell 3, cell 4) and 4 or more execution conditions for the candidate cells. The network may configure execution conditions for initial mobility and execution conditions for subsequent mobility / CPAC separately. Additionally, the network may provide a list of full configuration flags for the candidate cells in the subsequent CPAC configuration. The list of full configuration flags may be configured outside the 4 configurations of the candidate cells (i.e., outside theRRCReconfigurationfor each candidate cell). The list of full configuration flags may indicate an association indicating whether the full configuration procedure is required or not for all the candidate cells. The list of full configuration flags may be a single bitmap, or a list of 1 or 2 bit information flags to be set by true or false.

[0450] In step S1203, the UE may start evaluation of the candidate cells based on the subsequent CPAC configuration. The UE may evaluate the candidate cells based on the received execution conditions. The UE may evaluate the execution conditions for initial mobility if they are configured separately from the execution conditions for subsequent mobility / CPAC.

[0451] In step S1205, the UE may decide to perform a CPAC (e.g., initial CPAC) to cell 1 when at least one of the execution conditions for cell 1 is met. The UE may apply a configuration of cell 1 (i.e.,RRCReconfigurationfor cell 1). If there is a reference configuration in the subsequent CPAC configuration (e.g.,scpac-ReferenceConfiguration), the UE may firstly generate a complete configuration for cell 1 based on the reference configuration and the configuration of cell 1. In the configuration of cell 1, if full configuration flag is set to true, the UE may perform full configuration procedure for the initial mobility / CPAC to cell 1.

[0452] In step S1207, after the initial CPAC is successfully completed, the UE may maintain the subsequent CPAC configuration and the UE may start evaluation for other candidate cells (e.g., cell 2, cell 3, cell 4) based on the execution conditions for subsequent mobility.

[0453] In step S1209, the UE may decide to perform another CPAC (i.e., subsequent CPAC) to cell 2 when at least one of the execution conditions for cell 2 is met. The UE may apply a configuration of the cell 2 (i.e.,RRCReconfigurationfor cell 2). If there is a reference configuration in the subsequent CPAC configuration (e.g.,scpac-ReferenceConfiguration), the UE may firstly generate a complete configuration for cell 2 based on the reference configuration and the configuration of cell 2. However, even if full configuration flag is set to true in the configuration of cell 2, the UE may ignore the full configuration flag and determine whether to perform the full configuration procedure based on the list of full configuration flags configured separately in the subsequent CPAC configuration. Since the list of full configuration flags indicates not to perform the full configuration procedure when the UE performs a subsequent mobility / CPAC from cell 1 to cell 2, the UE doesn't perform the full configuration procedure - that is, the UE may apply the configuration of cell 2 as delta configuration.

[0454] In step S1211, after the subsequent CPAC is successfully completed, the UE may maintain the subsequent CPAC configuration and the UE may start evaluation for other candidate cells (e.g., cell 1, cell 3, cell 4) based on the execution conditions for subsequent mobility.

[0455] In step S1213, the UE may decide to perform another CPAC (i.e., subsequent CPAC) to cell 3 when at least one of the execution conditions for cell 3 is met. The UE apply a configuration of cell 3 (i.e.,RRCReconfigurationfor cell 3). If there is a reference configuration (e.g.,scpac-ReferenceConfiguration) in the subsequent CPAC configuration, the UE may firstly generate a complete configuration for cell 3 based on the reference configuration and the configuration of cell 3. However, even if full configuration flag is set to false in the configuration of cell 3, the UE may ignore the full configuration flag and determine to perform the full configuration procedure based on the list of full configuration flags configured separately in the subsequent CPAC configuration. Since the list of full configuration flags indicates to perform the full configuration procedure when the UE performs a subsequent mobility / CPAC from cell 2 to cell 3, the UE may perform the full configuration procedure.

[0456] Furthermore, the method in perspective of the UE described in the present disclosure (e.g., in FIG. 9) may be performed by the first wireless device 100 shown in FIG. 2 and / or the UE 100 shown in FIG. 3.

[0457] More specifically, the UE comprises at least one transceiver, at least processor, and at least one computer memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations.

[0458] The operations comprise: receiving a subsequent mobility configuration for a first candidate cell, wherein the subsequent mobility configuration comprises a list of execution conditions for a subsequent mobility, and a list of candidate cells related to a full configuration procedure; after performing a mobility to the first candidate cell, performing a subsequent mobility to a second candidate cell based on one or more execution conditions for the second candidate cell in the list of execution conditions being satisfied; determining whether to perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the list of candidate cells related to the full configuration procedure; and performing the full configuration procedure for the subsequent mobility to the second candidate cell based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.

[0459] Furthermore, the method in perspective of the UE described in the present disclosure (e.g., in FIG. 9) may be performed by a software code 105 stored in the memory 104 included in the first wireless device 100 shown in FIG. 2.

[0460] More specifically, at least one computer readable medium (CRM) stores instructions that, based on being executed by at least one processor, perform operations comprising: receiving a subsequent mobility configuration for a first candidate cell, wherein the subsequent mobility configuration comprises a list of execution conditions for a subsequent mobility, and a list of candidate cells related to a full configuration procedure; after performing a mobility to the first candidate cell, performing a subsequent mobility to a second candidate cell based on one or more execution conditions for the second candidate cell in the list of execution conditions being satisfied; determining whether to perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the list of candidate cells related to the full configuration procedure; and performing the full configuration procedure for the subsequent mobility to the second candidate cell based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.

[0461] Furthermore, the method in perspective of the UE described in the present disclosure (e.g., in FIG. 9) may be performed by control of the processor 102 included in the first wireless device 100 shown in FIG. 2 and / or by control of the processor 102 included in the UE 100 shown in FIG. 3.

[0462] More specifically, an apparatus configured to / adapted to operate in a wireless communication system (e.g., communication device / UE) comprises at least processor, and at least one computer memory operably connectable to the at least one processor. The at least one processor is configured to / adapted to perform operations comprising: receiving a subsequent mobility configuration for a first candidate cell, wherein the subsequent mobility configuration comprises a list of execution conditions for a subsequent mobility, and a list of candidate cells related to a full configuration procedure; after performing a mobility to the first candidate cell, performing a subsequent mobility to a second candidate cell based on one or more execution conditions for the second candidate cell in the list of execution conditions being satisfied; determining whether to perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the list of candidate cells related to the full configuration procedure; and performing the full configuration procedure for the subsequent mobility to the second candidate cell based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.

[0463] Furthermore, the method in perspective of a network node described in the present disclosure (e.g., in FIG. 10) may be performed by the second wireless device 200 shown in FIG. 2. The network node may be related to a serving cell.

[0464] More specifically, the network node comprises at least one transceiver, at least processor, and at least one computer memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations.

[0465] The operations comprise: transmitting, to a user equipment (UE), a subsequent mobility configuration for a first candidate cell, wherein the subsequent mobility configuration comprises a list of execution conditions for a subsequent mobility, and a list of candidate cells related to a full configuration procedure, wherein the UE is configured to perform operations comprising: after performing a mobility to the first candidate cell, performing a subsequent mobility to a second candidate cell based on one or more execution conditions for the second candidate cell in the list of execution conditions being satisfied; determining whether to perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the list of candidate cells related to the full configuration procedure; and performing the full configuration procedure for the subsequent mobility to the second candidate cell based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.

[0466] The present disclosure may have various advantageous effects.

[0467] For example, the UE receives and manages a separate full configuration cell list provided from the network for subsequent mobility for each candidate cell, thereby minimizing data interruption by performing full configuration only when the full configuration is actually needed.

[0468] Advantageous effects which can be obtained through specific embodiments of the present disclosure are not limited to the advantageous effects listed above. For example, there may be a variety of technical effects that a person having ordinary skill in the related art can understand and / or derive from the present disclosure. Accordingly, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that may be understood or derived from the technical features of the present disclosure.

[0469] Claims in the present disclosure can be combined in a various way. For instance, technical features in method claims of the present disclosure can be combined to be implemented or performed in an apparatus, and technical features in apparatus claims can be combined to be implemented or performed in a method. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in an apparatus. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in a method. Other implementations are within the scope of the following claims.

Claims

1.A method comprising:receiving a subsequent mobility configuration for a first candidate cell,wherein the subsequent mobility configuration comprises a list of execution conditions for a subsequent mobility, and a list of candidate cells related to a full configuration procedure;after performing a mobility to the first candidate cell, performing a subsequent mobility to a second candidate cell based on one or more execution conditions for the second candidate cell in the list of execution conditions being satisfied;determining whether to perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the list of candidate cells related to the full configuration procedure; andperforming the full configuration procedure for the subsequent mobility to the second candidate cell based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.2.The method of claim 1, wherein the list of candidate cells related to the full configuration procedure comprises one or more first candidate cells for which full configuration flag is set to true indicating that the full configuration procedure needs to be performed.3.The method of claim 1, wherein the list of candidate cells related to the full configuration procedure comprises a list of full configuration flags set to true for the list of candidate cells.4.The method of claim 1, wherein the receiving of the subsequent mobility configuration comprises receiving a mobility configuration for the first candidate cell and a mobility configuration for the second candidate cell,wherein the mobility configuration for the first candidate cell comprises a radio resource control (RRC) reconfiguration for the first candidate cell and the subsequent mobility configuration for the first candidate cell, andwherein the mobility configuration for the second candidate cell comprises an RRC reconfiguration for the second candidate cell and a subsequent mobility configuration for the second candidate cell.5.The method of claim 4, wherein the performing of the mobility to the first candidate cell comprises applying the RRC reconfiguration for the first candidate cell in the mobility configuration for the first candidate cell.6.The method of claim 4, wherein the subsequent mobility configuration for the first candidate cell comprises an identity (ID) of the mobility configuration for the second candidate cell, andwherein the performing of the subsequent mobility to the second candidate cell comprises applying the RRC reconfiguration for the second candidate cell in the mobility configuration for the second candidate cell identified by the ID.7.The method of claim 4 or 6, wherein the performing of the full configuration procedure comprises applying the RRC reconfiguration for the second candidate cell as a full configuration, based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.8.The method of claim 4 or 6, further comprising applying the RRC reconfiguration for the second candidate cell as a delta configuration, based on the second candidate cell being not included in the list of candidate cells related to the full configuration procedure.9.The method of claim 4, wherein the RRC reconfiguration for the second candidate cell comprises a full configuration flag for the second candidate cell, andwherein the list of candidate cells related to the full configuration flag is separately configured from the full configuration flag without being included in the RRC reconfiguration for the second candidate cell.10.The method of claim 4, wherein the determining of whether to perform the full configuration procedure comprises determining whether to perform the full configuration procedure for the second candidate cell based on the list of candidate cells, while ignoring a full configuration flag for the second candidate cell in the RRC reconfiguration for the second candidate cell.11.The method of claim 10, wherein the list of candidate cells comprises the second candidate cell for which full configuration flag is set to true, andwherein the ignoring of the full configuration flag comprises applying the RRC reconfiguration for the second candidate cell as a full configuration based on the list of candidate cells, while the full configuration flag for the second candidate cell in the RRC reconfiguration for the second candidate cell is set to false.12.The method of claim 10, wherein the list of candidate cells does not comprise the second candidate cell for which full configuration flag is set to false, andwherein the ignoring of the full configuration flag comprises applying the RRC reconfiguration for the second candidate cell as a delta configuration based on the list of candidate cells, while the full configuration flag for the second candidate cell in the RRC reconfiguration for the second candidate cell is set to true.13.The method of claim 1, wherein the subsequent mobility comprises a subsequent conditional primary secondary cell (PSCell) addition / change (CPAC).14.A user equipment (UE) comprising:at least one transceiver;at least one processor; andat least one memory operatively coupled to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising:receiving a subsequent mobility configuration for a first candidate cell,wherein the subsequent mobility configuration comprises a list of execution conditions for a subsequent mobility, and a list of candidate cells related to a full configuration procedure;after performing a mobility to the first candidate cell, performing a subsequent mobility to a second candidate cell based on one or more execution conditions for the second candidate cell in the list of execution conditions being satisfied;determining whether to perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the list of candidate cells related to the full configuration procedure; andperforming the full configuration procedure for the subsequent mobility to the second candidate cell based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.15.An apparatus comprising:at least processor; andat least one memory operatively coupled to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising:receiving a subsequent mobility configuration for a first candidate cell,wherein the subsequent mobility configuration comprises a list of execution conditions for a subsequent mobility, and a list of candidate cells related to a full configuration procedure;after performing a mobility to the first candidate cell, performing a subsequent mobility to a second candidate cell based on one or more execution conditions for the second candidate cell in the list of execution conditions being satisfied;determining whether to perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the list of candidate cells related to the full configuration procedure; andperforming the full configuration procedure for the subsequent mobility to the second candidate cell based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.16.A non-transitory computer readable medium (CRM) having stored thereon a program code implementing instructions that, based on being executed by at least one processor, perform operations comprising:receiving a subsequent mobility configuration for a first candidate cell,wherein the subsequent mobility configuration comprises a list of execution conditions for a subsequent mobility, and a list of candidate cells related to a full configuration procedure;after performing a mobility to the first candidate cell, performing a subsequent mobility to a second candidate cell based on one or more execution conditions for the second candidate cell in the list of execution conditions being satisfied;determining whether to perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the list of candidate cells related to the full configuration procedure; andperforming the full configuration procedure for the subsequent mobility to the second candidate cell based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.17.A method comprising:transmitting, to a user equipment (UE), a subsequent mobility configuration for a first candidate cell,wherein the subsequent mobility configuration comprises a list of execution conditions for a subsequent mobility, and a list of candidate cells related to a full configuration procedure,wherein the UE is configured to perform operations comprising:after performing a mobility to the first candidate cell, performing a subsequent mobility to a second candidate cell based on one or more execution conditions for the second candidate cell in the list of execution conditions being satisfied;determining whether to perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the list of candidate cells related to the full configuration procedure; andperforming the full configuration procedure for the subsequent mobility to the second candidate cell based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.18.A network node comprising:at least one transceiver;at least one processor; andat least one memory operatively coupled to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising:transmitting, to a user equipment (UE), a subsequent mobility configuration for a first candidate cell,wherein the subsequent mobility configuration comprises a list of execution conditions for a subsequent mobility, and a list of candidate cells related to a full configuration procedure,wherein the UE is configured to perform operations comprising:after performing a mobility to the first candidate cell, performing a subsequent mobility to a second candidate cell based on one or more execution conditions for the second candidate cell in the list of execution conditions being satisfied;determining whether to perform the full configuration procedure for the subsequent mobility to the second candidate cell based on the list of candidate cells related to the full configuration procedure; andperforming the full configuration procedure for the subsequent mobility to the second candidate cell based on the second candidate cell being included in the list of candidate cells related to the full configuration procedure.19.The network node of claim 18, wherein the performing of the subsequent mobility to the second candidate cell comprises applying a radio resource control (RRC) reconfiguration for the second candidate cell,wherein the RRC reconfiguration for the second candidate cell comprises a full configuration flag for the second candidate cell, andwherein the list of candidate cells related to the full configuration flag is separately configured from the full configuration flag without being included in the RRC reconfiguration for the second candidate cell.20.The method of claim 19, wherein the determining of whether to perform the full configuration procedure comprises determining whether to perform the full configuration procedure for the second candidate cell based on the list of candidate cells, while ignoring a full configuration flag for the second candidate cell in the RRC reconfiguration for the second candidate cell.

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