Communication device and method for early paging indication

Abstract

This distribution unit (DU) may comprise at least one processor. The at least one processor can be configured to: acquire, from a central unit (CU), a paging message including a paging cell list; determine whether the paging message includes at least one parameter for identifying a paging subgroup of a user equipment (UE) for paging; determine all bits of a paging indication field to be 1 according to a determination that the paging message does not include the at least one parameter; and transmit, to the UE, downlink control information (DCI) including the paging indication field.

Description

Communication device and method for early paging instruction

[0001] The following descriptions relate to a communication device and method for paging early indication (PEI).

[0002] To reduce power consumption, user equipment (UE) can operate in a radio resource control (RRC) inactive state. Paging messages can be used to transition the UE's RRC state from the inactive state to the connected state. However, in conventional paging procedures, the UE can decode paging messages for other UEs that share the paging occasion (PO) and paging-radio network temporary identifier (P-RNTI). Decoding for other UEs can increase the UE's power consumption.

[0003] The information described above may be provided as related art for the purpose of aiding understanding of the present disclosure. No claim or determination is made as to whether any of the foregoing may be applied as prior art related to the present disclosure.

[0004] A distributed unit (DU) is provided. The DU may include communication circuits. The DU may include memory that stores instructions and includes one or more storage media. The DU may include at least one processor that includes processing circuits. When the instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to obtain a paging message from a central unit (CU) that includes a paging early indication (PEI) subgrouping support indication. When the instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to determine whether the paging message includes at least one parameter for identifying a paging subgroup of user equipment (UE) for paging. When the above instructions are executed individually or collectively by the at least one processor, the DU may cause all bits of the paging indication field to be set to 1 upon the determination that the paging message does not include the at least one parameter. When the above instructions are executed individually or collectively by the at least one processor, the DU may cause downlink control information (DCI) containing the paging indication field to be transmitted to the UE.

[0005] A method performed by a DU is provided. The method may include the operation of obtaining a paging message from a central unit (CU) that includes a paging early indication (PEI) subgrouping support indication. The method may include the operation of determining whether the paging message includes at least one parameter for identifying a paging subgroup of a user equipment (UE) for paging. The method may include the operation of determining all bits of a paging indication field to 1 based on the determination that the paging message does not include the at least one parameter. The method may include the operation of transmitting downlink control information (DCI) including the paging indication field to the UE.

[0006] In relation to the description of the drawings, the same or similar reference numerals may be used for identical or similar components.

[0007] Figure 1 illustrates an example of a wireless communication system.

[0008] FIGS. 2A and FIGS. 2B illustrate examples of distributed network layouts.

[0009] Figure 3 illustrates the RRC modes of the UE.

[0010] Figures 4a and 4b illustrate examples of paging.

[0011] Figure 5 illustrates the components of the DU.

[0012] Figure 6 illustrates an example of signaling for early paging indication.

[0013] Figure 7 is a flowchart showing the operations of the DU for early paging indication.

[0014] Figure 8 illustrates an example of signaling for early paging indication.

[0015] Figure 9 illustrates an example of signaling for early paging instructions.

[0016] FIG. 10 illustrates a flowchart showing the operations of a DU for early paging indication.

[0017] FIG. 11 illustrates a flowchart showing the operations of a DU for early paging indication.

[0018] The terms used in this disclosure are used merely to describe specific embodiments and are not intended to limit the scope of other embodiments. A singular expression may include a plural expression unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as generally understood by those skilled in the art described in this disclosure. Terms used in this disclosure that are defined in a general dictionary may be interpreted as having the same or similar meaning as they have in the context of the relevant technology, and are not to be interpreted in an ideal or overly formal sense unless explicitly defined in this disclosure. In some cases, even terms defined in this disclosure are not to be interpreted to exclude the embodiments of this disclosure.

[0019] In the various embodiments of the present disclosure described below, a hardware-based approach is described as an example. However, since the various embodiments of the present disclosure include techniques using both hardware and software, the various embodiments of the present disclosure do not exclude a software-based approach.

[0020] Terms referring to signals used in the following description (e.g., packet, message, signal, information, signaling), terms referring to resources (e.g., section, symbol, slot, subframe, radio frame, subcarrier, RE (resource element), RB (resource block), BWP (bandwidth part), occasion)), terms for operation states (e.g., step, operation, procedure)), terms referring to data (e.g., packet, message, user stream, information, bit, symbol, codeword)), terms referring to channels, terms referring to network entities (DU (distributed unit), RU (radio unit), CU (central unit), CU-CP (control plane), CU-UP (user plane), O-DU (O-RAN (open radio access network) DU), O-RU (O-RAN RU), O-CU (O-RAN CU), Terms such as O-CU-UP (O-RAN CU-CP), O-CU-CP (O-RAN CU-CP), and terms referring to components of the device are examples provided for convenience of explanation. Accordingly, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used. Furthermore, terms such as '...part', '...device', '...object', '...body' used below may refer to at least one shape structure or a unit that processes a function.

[0021] Additionally, in this disclosure, expressions of "greater than" or "less than" may be used to determine whether a specific condition is satisfied or fulfilled; however, this is merely for the purpose of expressing an example and does not exclude descriptions of "greater than" or "less than." Conditions described as "greater than" may be replaced with "greater than," conditions described as "less than" may be replaced with "less than," and conditions described as "greater than and less than" may be replaced with "greater than and less than." Furthermore, "A" to "B" below refer to at least one of elements from A (including A) to B (including B). Below, "C" and / or "D" refers to including at least one of "C" or "D," i.e., {"C", "D", "C" and "D"}.

[0022] The present disclosure describes embodiments using terms used in some communication standards (e.g., 3GPP (3rd Generation Partnership Project) and / or O-RAN (open-radio access network)), but this is merely illustrative. The embodiments of the present disclosure may also be applied to other communication systems.

[0023] Figure 1 illustrates an example of a wireless communication system.

[0024] Referring to FIG. 1, a wireless communication system may include a base station (110) and a UE (user equipment) (120) as part of nodes utilizing a wireless channel. FIG. 1 illustrates a base station (110) and a UE (120), but this is merely an example and the present disclosure is not limited thereto. The wireless communication system may further include other base stations and other UEs.

[0025] A base station (110) is an infrastructure for providing wireless access to a UE (120). The base station (110) has coverage defined based on the distance over which it can transmit signals. In addition to being a base station, the base station (110) may be referred to as an 'access point (AP)', 'eNodeB (eNB)', '5G node (5th generation node)', 'next generation nodeB (gNB)', 'wireless point', 'transmission / reception point (TRP)', or other terms having an equivalent technical / functional meaning.

[0026] A UE (120) is a device used by a user and communicates with a base station (110) via a wireless channel. The link from the base station (110) to the UE (120) is referred to as a downlink (DL), and the link from the UE (120) to the base station (110) is referred to as an uplink (UL). In addition to UE (user equipment), the UE (120) may be referred to as a 'terminal', 'customer premises equipment' (CPE), 'mobile station', 'subscriber station', 'remote terminal', 'wireless terminal', 'electronic device', or 'user device', or any other term having an equivalent technical or functional meaning.

[0027] The base station (110) illustrated in FIG. 1 can be implemented using a central unit (CU), a distributed unit (DU), and a radio unit (RU). Below, a distributed deployment of the base station (110) implemented using a central unit (CU), a distributed unit (DU), and a radio unit (RU) is described in FIG. 2a and FIG. 2b.

[0028] FIGS. 2A and FIGS. 2B illustrate examples of distributed network layouts.

[0029] The communication system of FIG. 2a may include a central unit (CU) (210), a distributed unit (DU) (220), a radio unit (RU) (230), and a core network (CN) (240). For example, the CN (240) may include network functions (NF). For example, network functions may include an access and mobility management function (AMF) for performing registration management, reachability management, connection management, and mobility management, and / or a user plane function (UPF) for data transmission.

[0030] Referring to example (201) of FIG. 2a, the CU (210), DU (220), and RU (230) may be arranged independently. Referring to example (202) of FIG. 2a, the DU (220) and RU (230) may be implemented within a single device. Within that device, the DU (220) and RU (230) may be logically distinguishable. Referring to example (203) of FIG. 2a, the CU (210) and DU (220) may be implemented within a single device. Within that device, the CU (210) and DU (220) may be logically distinguishable. Referring to example (204) of FIG. 2a, the CU (210), DU (220), and RU (230) may be implemented within the device below. Within the device, CU (210), DU (220), and RU (230) can be logically distinguished.

[0031] In one embodiment, the base station (110) may be implemented using a CU (210), a DU (220), and an RU (230). For example, the CU (210) may be configured to perform functions of the upper layer of the protocol stack (e.g., the RRC (radio resource control) layer (211), the SDAP (service data adaptation protocol) layer (212)). For example, the DU (220) may be configured to perform functions of the lower layer of the protocol stack (e.g., the RLC (radio link control) layer (221), the MAC (medium access control) layer (222), the PHY (physical) layer (223)). For example, the RU (230) may be configured to perform some functions of the PHY layer (223). In the examples described above, the DU (220) may be configured to perform some functions (high PHY) of the PHY layer (223), and the RU (230) may be configured to perform the remaining functions (low PHY) of the PHY layer (223).

[0032] In one embodiment, the functions performed by the RRC layer (211) may include at least one of the following functions.

[0033] - Broadcasting system information related to AS (Access Stratum) and NAS

[0034] - Paging initiated by 5GC (5G Core) or NG-RAN (Next Generation-Radio Access network)

[0035] - Establishing, maintaining, and releasing the RRC connection between the UE and NG-RAN, including the following; more specifically, controlling the RLC, MAC, and PHY:

[0036] - Adding, modifying, and removing Carrier Aggregation

[0037] - Add, modify, and disable dual connectivity between NR or E-UTRA and NR.

[0038] - Security features including Key Management;

[0039] - Setup, configuration, maintenance, and release of SRB (Signaling Radio Bearer) and DRB (Data Radio Bearer)

[0040] - Movement functions including the following:

[0041] - Handover and context transfer;

[0042] - UE cell selection and re-selection and cell selection and re-selection control;

[0043] - Mobility between RATs.

[0044] - QoS (quality of service) management function;

[0045] - UE measurement reporting and control of reporting;

[0046] - Radio link failure detection and recovery

[0047] - Send messages from / to UE to / from NAS.

[0048] In one embodiment, the functions performed by the SDAP layer (212) may include at least one of the following functions.

[0049] - Mapping between QoS flow and data wireless bearer;

[0050] - Displays QoS flow ID (identifier) ​​(QFI) in both DL and UL packets.

[0051] In one embodiment, the functions performed by the PDCP layer (213) may include at least one of the following functions.

[0052] - Header compression and decompression features (ROHC only)

[0053] - User data transfer function (Transfer of user data)

[0054] - Sequential delivery function (In-order delivery of upper layer PDU (protocol data unit)s)

[0055] - Out-of-order delivery of upper layer PDUs

[0056] - Reordering function (PDCP PDU reordering for reception) (hereinafter, reordering)

[0057] - Duplicate detection function (Duplicate detection of lower layer SDUs)

[0058] - Retransmission of PDCP SDUs

[0059] - Encryption and decryption functions (Ciphering and deciphering)

[0060] - Timer-based SDU discard in uplink.

[0061] In one embodiment, the functions performed by the RLC layer (221) may include at least one of the following functions.

[0062] - Data transfer function (Transfer of upper layer PDUs)

[0063] - Sequential delivery function (In-sequence delivery of upper layer PDUs)

[0064] - Out-of-sequence delivery of upper layer PDUs

[0065] - ARQ function (Error Correction through ARQ)

[0066] - Concatenation, segmentation, and reassembly functions of RLC SDUs

[0067] - Re-segmentation function (Re-segmentation of RLC data PDUs)

[0068] - Reordering function (Reordering of RLC data PDUs)

[0069] - Duplicate detection

[0070] - Error detection function (Protocol error detection)

[0071] - RLC SDU discard function

[0072] RLC re-establishment function

[0073] In one embodiment, the functions performed by the MAC layer (222) may include at least one of the following functions.

[0074] - Mapping function between logical channels and transport channels

[0075] - Multiplexing and demultiplexing of MAC SDUs

[0076] - Scheduling information reporting function

[0077] Error correction through HARQ

[0078] - Priority handling between logical channels of one UE

[0079] - Priority handling between UEs by means of dynamic scheduling

[0080] - MBMS service identification

[0081] - Transport format selection function

[0082] - Padding

[0083] In one embodiment, the PHY layer (211) can perform channel coding and transmission of OFDM symbols over a wireless channel, or perform demodulation and channel decoding of OFDM symbols received over a wireless channel.

[0084] FIG. 3 illustrates the RRC modes of a UE. Referring to FIG. 3, the radio resource control (RRC) modes may include an RRC connected mode (310), an RRC inactive mode (320), and an RRC idle mode. However, the present disclosure is not limited thereto. For example, the RRC connected modes may include only some of the modes described above. In one example, the RRC connected mode (310) may be referred to as the RRC connected state or another term having an equivalent technical / functional meaning. In one example, the RRC inactive mode (320) may be referred to as the RRC inactive state or another term having an equivalent technical / functional meaning. In one example, the RRC idle mode (330) may be referred to as the RRC idle state or another term having an equivalent technical / functional meaning.

[0085] In one embodiment, a UE (user equipment) (120) in RRC connection mode may be configured with one or more signaling radio bearers (SRBs) and one or more data radio bearers (DRBs). For example, an SRB may be used to transmit signaling messages between the UE (120) and the base station (110). The signaling messages may belong to an RRC signaling protocol or a non-access stratum (NAS) signaling protocol. The base station (110) may use a next generation application protocol (NGAP) to provide NAS messages to an AMF or to obtain them from an AMF. For example, a DRB may be used to transmit application data between the UE (120) and the base station (110). The base station (110) can use a GTP-U (GRPS (general packet radio service) tunneling protocol-user plane) tunnel to provide application data to a UPF (user plane function) or to obtain application data from a UPF.

[0086] In one embodiment, a UE (120) in RRC connection mode (310) can switch to RRC inactive mode (320) using an RRC release procedure. An NG signaling connection between the AMF and the base station (110) can be maintained while the UE is in RRC inactive mode (320). A GTP-U tunnel between the UPF and the base station (110) can be maintained while the UE is in RRC inactive mode (320). The UE context can be maintained while the UE (120) is in RRC inactive mode (320). A UE (120) in RRC inactive mode (320) can switch to RRC connection mode (310) using an RRC resume procedure. Since the UE context is maintained in RRC inactive mode (320), the latency to switch to RRC connection mode (310) can be reduced compared to RRC idle mode (330). A UE (120) in RRC inactive mode (320) can reduce battery power consumption of the UE (120) compared to RRC connected mode (310) because it has a longer DRX (discontinuous reception) cycle and / or does not perform channel quality reporting.

[0087] FIGS. 4a and 4b illustrate examples of paging. FIG. 4a illustrates an example of a conventional paging procedure. FIG. 4b illustrates examples of a paging procedure for PEI (paging early indication).

[0088] Referring to the situation (410) of FIG. 4a, the UE (user equipment) (120) can receive a synchronization signal block (SSB) (411) from the base station (110). After receiving the SSB (411), the UE (120) can enter a light sleep mode according to the discontinuous reception (DRX). The UE (120) can receive an SSB (412) from the base station (110) in the next SSB cycle. After receiving the SSB (412), the UE (120) can enter a light sleep mode according to the DRX. The UE (120) can receive an SSB (413) from the base station (110) in the next SSB cycle. After receiving the SSB (413), the UE (120) can enter a light sleep mode. The UE (120) can monitor the paging DCI (downlink control information) transmitted from the base station (110) at the PO (paging occasion) (414). The paging DCI can be scrambled into a P-RNTI (paging-radio network temporary identifier). The UE (120) can decode the paging PDSCH (physical downlink shared channel) corresponding to the paging DCI. In the example illustrated in FIG. 4a, the UE (120) can identify that the paging DCI and the paging PDSCH are for a different UE based on the decoding of the paging PDSCH. Afterward, the UE (120) can enter deep sleep mode.

[0089] As described above, the paging DCI and paging PDSCH can be decoded by multiple terminals sharing the PO (414) and P-RNTI. The UE (120) may need to decode the paging DCI and paging PDSCH for other UEs. Decoding the paging DCI and paging PDSCH for other UEs may be referred to as a paging false alarm. A paging false alarm can increase the power consumption of the UE (120). To address the problem of increased power consumption of the UE (120), a paging early indication (PEI) is introduced to divide UEs monitoring the same PO into subgroups.

[0090] For example, the base station (110) may notify the UEs in advance, based on PEI, whether a paging message for the UEs included in the subgroup will be transmitted from the next PO. The paging subgroup may be based on CN (core network) controlled subgrouping and / or UE ID (identifier) ​​based subgrouping. For example, in CN controlled subgrouping, the CN subgroup ID representing the paging subgroup of the UE (120) may be assigned by the AMF (access and mobility management function). For example, in UE ID based subgrouping, the UE ID based subgroup ID representing the paging subgroup of the UE (120) may be determined (or calculated) by the UE (120) and CU (210) based on the UE identifier (e.g., extended UE identity index value or 5G-S-TMSI (5th generation-short-temporary mobile subscriber identity)).

[0091] Referring to the situation (420) of FIG. 4b, the UE (120) may receive an SSB (421) from the base station (110). After receiving the SSB (421), the UE (120) may receive a PEI DCI (422). For example, the PEI DCI may be in DCI format 2_7. For example, the PEI DCI may be scrambled into PEI-RNTI. For example, the PEI DCI may include a paging indication field. For example, the number of bits in the paging indication field may be determined based on the number of POs and the number of paging subgroups in the POs. For example, each bit of the paging indication field may be associated with one paging subgroup in the PO. For example, the paging indication field may indicate whether to call up to eight paging subgroups per PO. For descriptions of paging instruction fields, further reference may be made to the descriptions in Section 7.3.1.3.8 of 3GPP (3rd generation partnership project) TS (technical specification) 38.212.

[0092] In the example illustrated in situation (420), the bit corresponding to the subgroup ID of the UE (120) included in the paging instruction field may be '1'. Since the bit corresponding to the subgroup ID of the UE (120) indicates 1, the UE (120) can anticipate that a paging message for a subgroup including the UE (120) will be received in the next PO (425). The UE (120) can receive a paging message in the PO (425) after receiving the SSB (423) and SSB (424). After receiving the paging message, the UE (120) can perform a random access procedure (426).

[0093] Referring to the situation (430) of FIG. 4b, the UE (120) can receive an SSB (431) from the base station (110). After receiving the SSB (431), the UE (120) can receive a PEI DCI (432). In the example illustrated in the situation (430), the bit corresponding to the subgroup ID of the UE (120) included in the paging instruction field may be '0'. Since the bit corresponding to the subgroup ID of the UE (120) indicates 0, the UE (120) can anticipate that no paging message for the UE (120)'s subgroup will be received in the next PO (433). Therefore, the UE (120) can enter a deep sleep mode after receiving the PEI DCI (432). The UE (120) may not perform paging monitoring in the PO (433).

[0094] As described above, if the UE (120) does not receive SSB (423) and SSB (424) when paging for the subgroup to which the UE (120) is included is not indicated by the PEI DCI, the UE (120) may not monitor paging messages in the next PO. Therefore, power consumption of the UE (120) can be reduced depending on the PEI operation.

[0095] Figure 5 illustrates the components of the DU.

[0096] Referring to FIG. 5, a distributed unit (DU) (220) may include a processor (501), a memory (502), and a communication circuit (503). For example, the processor (501), the memory (502), and the communication circuit (503) may be electrically and / or operably coupled with each other by a communication bus. Operatably coupled hardware components may mean that a direct or indirect connection between hardware components is established via wire (or wirelessly) so that a second hardware component (e.g., memory (502) and / or communication circuit (503)) is controlled by a first hardware component (e.g., processor (501)). The hardware components illustrated in FIG. 5 are illustrated based on different blocks, but the present disclosure is not limited thereto. For example, at least a portion of the hardware components shown in FIG. 5 (e.g., processor (501), memory (502), and / or communication circuit (503)) may be included in a single integrated circuit such as a system on chip (SoC) or a system in package (SIP).

[0097] In one embodiment, the DU (220) may include a processor (501). The processor (510) may include a hardware component for processing data based on one or more instructions. The processor (501) may include various processing circuits and / or a number of processors. For example, the term “processor” as used herein, including in the claims, may include various processing circuits including at least one processor, and one or more of said at least one processor may be configured to perform the various functions described below in a distributed manner, individually and / or collectively. As used below, where “processor,” “at least one processor,” and “one or more processors” are described as being configured to perform various functions, these terms encompass, for example but not limited to, situations where one processor performs some of the cited functions and another processor(s) perform other parts of the cited functions, and also situations where one processor can perform all of the cited functions. Additionally, the at least one processor may include a combination of processors that perform various enumerated / disclosed functions, for example, in a distributed manner. The at least one processor may execute program instructions to achieve or perform various functions.

[0098] In one embodiment, the DU (220) may include a memory (502). The memory (502) may include a hardware component for storing data and / or instructions that are input to or output from the processor (501). For example, the memory (502) may include a volatile memory such as random-access memory (RAM) and / or a non-volatile memory such as read-only memory (ROM). The volatile memory may include, for example, at least one of dynamic RAM (DRAM), static RAM (SRAM), cache RAM, and pseudo SRAM (PSRAM). The non-volatile memory may include, for example, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), flash memory, a hard disk, a compact disk, and an embedded multimedia card (eMMC).

[0099] In one embodiment, one or more instructions (or commands) representing operations and / or operations performed by the processor (501) may be stored in the memory (502) of the DU (220). A set of one or more instructions may be referred to as a program, firmware, operating system, process, routine, sub-routine, and / or application. Hereinafter, the statement that an application is installed in the CU (210) may mean that one or more instructions provided in the form of an application are stored in the memory (502), and that one or more applications are stored in an executable format by the processor (501).

[0100] In one embodiment, the DU (220) may include a communication circuit (503). The communication circuit (503) may perform functions for transmitting and receiving signals in a wired communication environment. The communication circuit (503) may include a wired interface for controlling a direct connection between devices through a transmission medium (e.g., copper wire, optical fiber). For example, the communication circuit (503) may transmit an electrical signal to another device through a copper wire or perform conversion between an electrical signal and an optical signal. For example, the DU (220) may communicate with a central unit (CU) (210) through the communication circuit (503). For example, it may communicate with a radio unit (RU) (230) through the communication circuit (503). For example, a first part of a communication circuit (503) that performs the function of communicating with CU (210) and a second part of a communication circuit (530) that performs the function of communicating with RU (230) can be distinguished.

[0101] In one embodiment, the communication circuit (503) may perform functions for transmitting and receiving signals in a wireless communication environment. For example, the communication circuit (503) may perform a conversion function between a baseband signal and a bit sequence according to the physical layer specifications of the system. For example, when transmitting data, the communication circuit (503) generates complex symbols by encoding and modulating the transmitted bit sequence. Also, when receiving data, the communication circuit (503) restores the received bit sequence by demodulating and decoding the baseband signal. Additionally, the communication circuit (503) may include a plurality of transmission and reception paths. In one embodiment, the DU (220) is a base station (110) and may communicate with the UE (120) through a direct wireless access network.

[0102] The configuration of the DU (220) shown in FIG. 5 is merely an example, and the components of the DU (220) for carrying out embodiments of the present disclosure are not limited to the configuration shown in FIG. 5. In some embodiments, some components may be added, deleted, and / or changed.

[0103] FIG. 6 illustrates an example of signaling for early paging indication. FIG. 6 describes signaling for early paging indication for a UE (user equipment) (120) in an RRC (radio resource control) inactive mode. The operations described in FIG. 6 are described based on a CU (central unit) (210) and / or a DU (distributed unit) (220). In the following, at least one of the operations (e.g., operation 615 or operation 625) may be omitted.

[0104] Referring to FIG. 6, in operation 610, a central unit (CU) (210) according to one embodiment may obtain (or receive) core network assistance information from a network function (NF) of a core network (CN) (240). For example, the network function of the CN (240) for transmitting core network assistance information may be an access and mobility management function (AMF). For example, core network assistance information may be included in an initial context setup request, a UE context modification request, a handover request, or a path switch request acknowledge.

[0105] In one embodiment, the core network auxiliary information may provide auxiliary information for RRC disabled configuration. For example, the core network auxiliary information may include UE radio capability information for paging (611), PEIPS (paging early indication with paging subgrouping) auxiliary information (612), and / or extended UE identity index values. In one example, if the AMF supports RAN (radio access network) paging PEI (paging early indication), the core network auxiliary information may include PEIPS auxiliary information (612) and / or extended UE identity index values ​​(613). In another example, if the AMF does not support RAN paging PEI, the core network auxiliary information may not include PEIPS auxiliary information (612) and extended UE identity index values ​​(613).

[0106] For example, UE radio capability information for paging (611) may indicate whether the UE (120) supports PEI for a list of frequency bands. For example, PEIPS auxiliary information (612) may be associated with CN controlled subgrouping. PEIPS auxiliary information (612) may include a CN subgroup ID representing the paging subgroup of the UE (120). For example, an extended UE identity index value (613) may be associated with UE ID-based subgrouping. The extended UE identity index value may be used to determine (or calculate) a UE ID-based subgroup ID representing the paging subgroup of the UE (120).

[0107] In operation 620, according to one embodiment, the CU (210) may obtain (or receive) DL (downlink) UE associated signaling from the network function of the CN (240). For example, the network function of the CN (240) for transmitting DL UE associated signaling may be an AMF.

[0108] In operation 625, according to one embodiment, the CU (210) can obtain (or receive) DL data from the network function of the CN (240). For example, the network function of the CN (240) for transmitting DL data may be a user plane function (UPF).

[0109] In one embodiment, the CU (210) may send a paging message to the DU (distributed unit) (220) to request paging of the UE (120) in RRC inactive mode (320) in response to receiving DL UE-related signaling or DL ​​data.

[0110] In operation 630, a DU (220) according to one embodiment may obtain (or receive) a paging message from a CU (210). For example, the DU (220) may obtain (or receive) a paging message through an F1 interface between the CU (210) and the DU (220). For example, the paging message may be intended to request the DU (220) to page a UE (120). In one example, the paging message between the CU (210) and the DU (220) may be referred to as an F1 paging message or another term having an equivalent technical / functional meaning.

[0111] In one embodiment, the paging message may include a RAN (radio access network) UE paging identity (631), a paging cell list (632), PEIPS auxiliary information (633), and / or an extended UE identity index value (634). In one example, if the AMF and CU (210) support RAN paging PEI, the paging message may include PEIPS auxiliary information (633) and / or an extended UE identity index value (634). In another example, if at least one network element of the AMF or CU (210) does not support RAN paging PEI and the 5G-S-TMSI (5th generation-short-temporary subscriber identifier) ​​is not stored within the CU (210), the paging message may not include PEIPS auxiliary information (633) and an extended UE identity index value (634).

[0112] For example, the RAN UE paging identity (631) may include an inactive-radio network temporary identifier (I-RNTI) for identifying the UE (120) associated with paging.

[0113] For example, the paging cell list (632) may include a new radio (NR) cell global identifier (CGI) and / or a paging early indication (PEI) subgrouping support indication. For example, the NR CGI may indicate a cell associated with paging. For example, the PEI subgrouping support indication may indicate that the UE (120) supports PEI in the cell indicated by the NR CGI.

[0114] For example, the description of PEIPS auxiliary information (633) may refer to the description of PEIPS auxiliary information (612). For example, the description of the extended UE identity index value (634) may refer to the description of the extended UE identity index value (613).

[0115] In one embodiment, the DU (220) can identify that the UE (120) supports PEI in a cell associated with paging based on a PEI subgrouping support instruction. Based on the identification, the DU (220) can determine whether the paging message includes at least one parameter for identifying the paging subgroup of the UE (120). For example, the at least one parameter for identifying the paging subgroup of the UE (120) may include PEIPS auxiliary information associated with CN control subgrouping and an extended UE identity index value associated with UE ID-based subgrouping.

[0116] However, the AMF and / or CU (210) may not support RAN paging PEI. In one example, the AMF and / or CU (210) may not have updates to the RAN paging PEI (e.g., version mismatch). In one example, the AMF and / or CU (210) may have features for the RAN paging PEI disabled according to the PEI cell settings. For example, if the AMF does not support RAN paging PEI, the core network auxiliary information may not include PEIPS auxiliary information (612) and extended UE identity index values ​​(613). Since the core network auxiliary information (610) does not include PEIPS auxiliary information (612) and extended UE identity index values ​​(613), the paging message may not include PEIPS auxiliary information (633) and extended UE identity index values ​​(634). In another example, if the CU (210) does not support RAN paging PEI, the paging message may not include PEIPS auxiliary information (633) and an extended UE identity index value (634). In the examples described above, the PEIPS auxiliary information (633) and the extended UE identity index value (634) for identifying the paging subgroup of the UE (120) may not be transmitted to the DU (220). Since the DU (220) cannot obtain information for identifying the paging subgroup of the UE (120), the DU (220) cannot determine the paging subgroup ID to which the UE (120) is included. Since the DU (220) cannot determine the paging subgroup ID of the UE (120), the DU (220) may set all bits of the paging indication field to 0.

[0117] In operation 640, a DU (220) according to one embodiment may set all bits of a paging instruction field to 0 and then transmit downlink control information (DCI) containing the paging instruction field to a UE (120). For example, the DCI may be DCI format 2_7. For example, the DCI may be scrambled based on PEI-RNTI.

[0118] In operation 650, the DU (220) according to one embodiment may transmit a paging message at the next paging occasion. However, the UE (120) may not monitor the paging message at the next PO because the bit of the paging instruction field corresponding to the UE (120)'s paging subgroup indicates 0. Since the UE (120) does not monitor the paging message, paging for the UE (120) may fail.

[0119] As described above, paging for the UE (120) may fail because the parameter for identifying the paging subgroup of the UE (120) is not transmitted to the DU (220) due to version differences between network elements (e.g., AMF, CU (210), and / or DU (220)) and / or PEI cell settings. The failure of paging may cause a call release by the core network. Below, to resolve the aforementioned problems, a method performed by the DU (220) and the DU (220) to successfully perform PEI for the UE (120) while the parameter for identifying the paging subgroup of the UE (120) has not been obtained is described.

[0120] FIG. 7 is a flowchart illustrating the operations of a DU for paging early indication. The operations of FIG. 7 may be performed by the DU (distributed unit) (220) of FIG. 2a, FIG. 2b, FIG. 3, and FIG. 5. For example, at least some of the operations may be controlled by the processor (501) of the DU (220). In the following, each operation may be performed sequentially, but is not necessarily performed sequentially. For example, the order of each operation may be changed and / or at least two operations may be performed in parallel. FIG. 7 describes the operations of a DU (220) for performing paging early indication (PEI) in a cell that supports CN (core network) controlled subgrouping and / or UE (user equipment) ID (identifier) ​​based subgrouping.

[0121] Referring to FIG. 7, in operation 701, a DU (220) according to one embodiment may obtain (or receive) a paging message from a CU (210). For example, the DU (220) may obtain (or receive) a paging message from the CU (210) through an F1 interface between the CU (210) and the DU (220). For example, a paging message may be transmitted from the CU (210) to request the DU (220) to page the UE (120). In one example, the paging message between the CU (210) and the DU (220) may be referred to as an F1 paging message or another term having an equivalent technical / functional meaning.

[0122] In one embodiment, the paging message may include a RAN (radio access network) UE paging identity, a paging cell list, PEIPS (paging early indication with paging subgrouping) assistance information, and / or an extended UE identity index value. For example, the paging message may include only some of the parameters (or information elements (IE)) described above. In another example, the paging message may include all of the parameters described above.

[0123] In one embodiment, the RAN UE paging identity may include an inactive-radio network temporary identifier (I-RNTI) for identifying the UE (120) associated with paging.

[0124] In one embodiment, the paging cell list may include one or more NR CGIs (new radio global identifiers) and / or one or more PEI subgrouping support indications corresponding to one or more NR CGIs.

[0125] For example, NR CGI can display cells associated with paging. In one example, NR CGI may include a public land mobile network (PLMN) identity and an NR cell identity to globally identify the cell.

[0126] For example, the UE (120) may support PEI in only at least one of the multiple cells. Therefore, a PEI subgrouping support indicator may be used to indicate the at least one cell in which the UE (120) supports PEI. For example, the PEI subgrouping support indicator may be used to indicate whether the UE (120) supports PEI in a cell identified by an NR CGI. In one example, if the PEI subgrouping support indicator corresponding to the NR CGI is present in the paging message, the DU (220) may identify that the UE (120) supports PEI in the cell identified by the NR CGI. In another example, if the PEI subgrouping support indicator corresponding to the NR CGI is absent in the paging message, the DU (220) may identify that the UE (120) does not support PEI in the cell identified by the NR CGI.

[0127] In one embodiment, PEIPS auxiliary information may provide information related to a CN paging subgroup for the UE (120). For example, PEIPS auxiliary information may include a CN subgroup ID representing a paging subgroup of the UE (120). In one example, the CN subgroup ID may represent a paging subgroup of the UE (120) among a plurality of paging subgroups.

[0128] In one embodiment, the extended UE identity index value may provide information related to UE ID-based subgrouping. For example, the extended UE identity index value may be used to determine (or calculate) a UE ID-based subgroup ID representing a paging subgroup of the UE (120). In one example, the extended UE identity index value may be obtained from the AMF via the CU (210). In another example, the extended UE identity index value may be determined by the CU (210) based on the 5G-S-TMSI (5th generation-short-temporary mobile subscriber identity).

[0129] The parameters (or IEs) described above included in the paging message are merely examples and the present disclosure is not limited thereto. For example, the paging message may include further parameters. For the parameters included in the paging message, reference may be made to Section 9.2.6.1 of 3GPP (3rd generation partnership project) 38.473.

[0130] In operation 702, the DU (220) according to one embodiment can determine whether the paging message includes at least one parameter for identifying a paging subgroup of the UE (120).

[0131] In one embodiment, the DU (220) can identify that the UE (120) supports PEI in a cell associated with paging based on a PEI subgrouping support instruction. For example, the DU (220) can identify that the UE (120) supports PEI in a cell identified by an NR CGI corresponding to a PEI subgrouping support instruction based on the identification that a PEI subgrouping support instruction is included in a paging message. Based on the identification, the DU (220) can determine whether the paging message includes at least one parameter for identifying the paging subgroup of the UE (120).

[0132] In one embodiment, the cell may support only CN controlled subgrouping. Since the cell supports only CN controlled subgrouping, at least one parameter for identifying the paging subgroup of the UE (120) may be a CN subgroup ID. Therefore, the DU (220) can determine whether the paging message includes a CN subgroup ID when the cell supports only CN controlled subgrouping.

[0133] In one embodiment, the cell may support only UE ID-based subgrouping. Since the cell supports only UE ID-based subgrouping, at least one parameter for identifying the paging subgroup of the UE (120) may be an extended UE identity index value. Therefore, the DU (220) can determine whether the paging message contains an extended UE identity index value when the cell supports only UE ID-based subgrouping.

[0134] In one embodiment, the cell may support both CN control subgrouping and UE ID-based subgrouping. Since the cell supports both CN control subgrouping and UE ID-based subgrouping, at least one parameter for identifying a paging subgroup may include a CN subgroup ID and an extended UE identity index value. Therefore, the DU (220) can determine whether the paging message includes a CN subgroup ID and an extended UE identity index value when the cell supports both CN control subgrouping and UE ID-based subgrouping.

[0135] In operation 703, the DU (220) according to one embodiment may set (or determine) to 1 a bit corresponding to the paging subgroup of the UE (120) among the bits of the paging indication field, depending on the determination that the paging message includes at least one parameter for identifying the paging subgroup of the UE (120).

[0136] In one embodiment, the cell may support only CN control subgrouping. The DU (220) may determine whether the paging message includes a CN subgroup ID when the cell supports only CN control subgrouping. The DU (220) may determine the paging subgroup of the UE (120) corresponding to the CN subgroup ID among a plurality of paging subgroups based on the determination that the paging message includes a CN subgroup ID. The DU (220) may set (or determine) the bit corresponding to the paging subgroup of the UE (120) among the bits of the paging instruction field to 1.

[0137] In one embodiment, the cell may support only UE ID-based subgrouping. The DU (220) may determine whether the paging message contains an extended UE identity index value when the cell supports only UE ID-based subgrouping. The DU (220) may determine a UE ID-based subgroup ID based on the extended UE identity index value in accordance with the determination that the paging message contains an extended UE identity index value. The DU (220) may determine the paging subgroup of the UE (120) corresponding to the UE ID-based subgroup ID among a plurality of paging subgroups. The DU (220) may set (or determine) the bit corresponding to the paging subgroup of the UE (120) among the bits of the paging instruction field to 1.

[0138] In one embodiment, the cell may support both CN control subgrouping and UE ID-based subgrouping. If the cell supports both CN control subgrouping and UE ID-based subgrouping, the DU (220) may determine whether the paging message includes a CN subgroup ID and an extended UE identity index value.

[0139] In one example, the paging message may include only a CN subgroup ID. The DU (220) may determine the paging subgroup of the UE (120) corresponding to the CN subgroup ID among a plurality of paging subgroups. The DU (220) may set (or determine) the bit corresponding to the paging subgroup of the UE (120) among the bits of the paging instruction field to 1.

[0140] In one example, the paging message may include only the extended UE identity index value. The DU (220) may determine a UE ID-based subgroup ID based on the extended UE identity index value. The DU (220) may determine the paging subgroup of the UE (120) corresponding to the UE ID-based subgroup ID among a plurality of paging subgroups. The DU (220) may set (or determine) the bit corresponding to the paging subgroup of the UE (120) among the bits of the paging instruction field to 1.

[0141] In one example, the paging message may include both a CN subgroup ID and an extended UE identity index value. The DU (220) may use the CN subgroup ID to identify the paging subgroup of the UE (120) among the CN subgroup ID and the extended UE identity index value. For example, the DU (220) may determine the paging subgroup of the UE (120) corresponding to the CN subgroup ID among a plurality of paging subgroups. The DU (220) may set (or determine) the bit corresponding to the paging subgroup of the UE (120) among the bits of the paging instruction field to 1. In the description above, an example has been described in which the paging subgroup of the UE (120) is determined based on the CN subgroup ID when both the CN subgroup ID and the extended UE identity index value are included in the paging message. However, the present disclosure is not limited thereto. For example, DU (220) may determine the paging subgroup of the UE (120) based on the extended UE identity index value when both the CN subgroup ID and the extended UE identity index value are included in the paging message.

[0142] In operation 704, the DU (220) according to one embodiment may set (or determine) all bits of the paging instruction field to 1 based on the determination that the paging message does not include at least one parameter for identifying the paging subgroup of the UE (120).

[0143] In one embodiment, the cell may support only CN control subgrouping. The DU (220) may determine whether the paging message includes a CN subgroup ID if the cell supports only CN control subgrouping. The DU (220) may set (or determine) all bits of the paging instruction field to 1 based on the determination that the paging message does not include a CN subgroup ID.

[0144] In one embodiment, the cell may support only UE ID-based subgrouping. The DU (220) may determine whether the paging message contains an extended UE identity index value if the cell supports only UE ID-based subgrouping. The DU (220) may set (or determine) all bits of the paging instruction field to 1 based on the determination that the paging message does not contain an extended UE identity index value.

[0145] In one embodiment, the cell may support both CN control subgrouping and UE ID-based subgrouping. If the cell supports both CN control subgrouping and UE ID-based subgrouping, the DU (220) may determine whether the paging message includes a CN subgroup ID and an extended UE identity index value. The DU (220) may set (or determine) all bits of the paging instruction field to 1 based on the determination that the paging message does not include both a CN subgroup ID and an extended UE identity index value.

[0146] In operation 705, a DU (220) according to one embodiment may transmit downlink control information (DCI) including a paging instruction field to a UE (120). For example, the DCI may be in DCI format 2_7. For example, the DCI may be scrambled based on PEI-RNTI.

[0147] As described above, the DU (220) may not obtain at least one parameter from the CU (210) for identifying the paging subgroup of the UE (120). In this case, the DU (220) may perform PEI for the UE (120) by setting all bits of the paging instruction field of the DCI to 1. Since all bits of the paging instruction field of the DCI indicate 1, the UE (120) can receive a paging message transmitted from the DU (220) at the next paging occasion (PO). In one example, the paging message between the UE (120) and the DU (220) may be referred to as an RRC paging message or other terms having an equivalent technical / functional meaning.

[0148] Although not illustrated in FIG. 7, a UE (120) in RRC inactive mode (320) may send an RRC resume request to the DU (220) in response to a paging message. Subsequently, the UE (120), CU (210), DU (220), and / or AMF may cause the UE (120) to switch from inactive mode (320) to connected mode (310) by performing an RRC resume procedure. Thus, according to the descriptions above, call release caused by a failure of RAN paging can be prevented.

[0149] FIG. 8 illustrates an example of signaling for early paging indication. FIG. 8 describes signaling for early paging indication for a UE (user equipment) (120) in an RRC (radio resource control) inactive mode (320). The operations described in FIG. 8 are described based on a CU (central unit) (210) and / or a DU (distributed unit) (220). In the following, at least one of the operations (e.g., operation 815 or operation 825) may be omitted.

[0150] Referring to FIG. 8, in operation 810, a CU (210) according to one embodiment may obtain (or receive) core network assistance information from a network function of a CN (core network) (240). For example, the network function of the CN (240) for transmitting core network assistance information may be an access and mobility management function (AMF). For example, core network assistance information may be included in an initial context setup request, a UE context modification request, a handover request, or a path switch request acknowledge.

[0151] In one embodiment, the core network auxiliary information may provide auxiliary information for RRC disabled configuration. For example, the core network auxiliary information may include UE radio capability information for paging (811), PEIPS (paging early indication with paging subgrouping) auxiliary information (812), and / or an extended UE identity index value (813). In one example, if the AMF supports RAN paging PEI (paging early indication), the core network auxiliary information may include PEIPS auxiliary information (812) and / or an extended UE identity index value (813). In another example, if the AMF supports only CN paging PEI and does not support RAN paging PEI, the core network auxiliary information may not include PEIPS auxiliary information (812) and an extended UE identity index value (813).

[0152] For example, UE wireless capability information (811) for paging may indicate whether the UE (120) supports PEI for a list of frequency bands.

[0153] For example, PEIPS auxiliary information (812) may be associated with CN control subgrouping. In CN control subgrouping, a CN subgroup ID representing a paging subgroup of the UE (120) may be determined by an AMF. PEIPS auxiliary information (812) may include a CN subgroup ID.

[0154] For example, an extended UE identity index value may be associated with UE ID-based subgrouping. In UE ID-based subgrouping, the extended UE identity index value may be used to determine (or calculate) a UE ID-based subgroup ID representing a paging subgroup of the UE (120).

[0155] In one embodiment, the CU (210) may determine whether the 5G-S-TMSI (5th generation-short-temporary mobile subscriber identity) is stored within the CU (210) based on the determination that the core network auxiliary information obtained from the AMF does not contain an extended UE identity index value. If the CU (210) is the initial attach CU of the UE (120), the CU (210) may store the 5G-S-TMSI of the UE (120). The CU (210) may determine the extended UE identity index value based on the 5G-S-TMSI based on the determination that the 5G-S-TMSI is stored within the CU (210). In one example, the extended UE identity index value may be determined (or encoded) according to [Equation 1] below.

[0156]

[0157] In operation 815, according to one embodiment, the CU (210) may obtain (or receive) DL (downlink) UE associated signaling from the network function of the CN (240). For example, the network function of the CN (240) for transmitting DL UE associated signaling may be an AMF.

[0158] In operation 825, according to one embodiment, the CU (210) may obtain (or receive) DL data for the UE (120) from the network function of the CN (240). For example, the network function of the CN (240) for transmitting the DL data may be a user plane function (UPF).

[0159] In one embodiment, the CU (210) may send a paging message to the DU (distributed unit) (220) to request paging of the UE (120) in RRC inactive mode in response to receiving DL UE-related signaling or DL ​​data. The operations of the DU (220) related to the paging message are described below.

[0160] In operation 830, a DU (220) according to one embodiment may receive (or obtain) a paging message from a CU (210). For example, the DU (220) may obtain (or receive) a paging message from the CU (210) through an F1 interface between the CU (210) and the DU (220). For example, the paging message may be intended to request the DU (220) to page the UE (120). In one example, the paging message between the CU (210) and the DU (220) may be referred to as an F1 paging message or another term having an equivalent technical / functional meaning.

[0161] In one embodiment, the paging message may include a RAN (radio access network) UE paging identity (831), a paging cell list (832), PEIPS auxiliary information (833), and / or an extended UE identity index value (834). In one example, if the AMF and CU (210) support RAN paging PEI, the paging message may include PEIPS auxiliary information (833) and / or an extended UE identity index value (834). In another example, if at least one network element of the AMF or CU (210) does not support RAN paging PEI and the 5G-S-TMSI of the UE (120) is not stored within the CU (210), the paging message may not include PEIPS auxiliary information (833) and an extended UE identity index value (834).

[0162] For example, the RAN UE paging identity (831) may include an inactive-radio network temporary identifier (I-RNTI) for identifying the UE (120) associated with paging.

[0163] For example, the paging cell list (832) may include one or more NR CGIs (new radio cell global identifiers) and / or one or more PEI subgrouping support indications corresponding to one or more NR CGIs. For example, an NR CGI may indicate a cell associated with paging. For example, a PEI subgrouping support indication may indicate that the UE (120) supports PEI in the cell indicated by the NR CGI. In one example, the paging cell list (832) may correspond to UE radio capability information (811) for paging of core network auxiliary information (810).

[0164] For example, the description of PEIPS auxiliary information (833) may refer to the description of PEIPS auxiliary information (812). For example, the description of the extended UE identity index value (834) may refer to the description of the extended UE identity index value (813).

[0165] The parameters described above included in the paging message are merely examples and the present disclosure is not limited thereto. For example, the paging message may include other parameters further. For the parameters included in the paging message, reference may be made to Section 9.2.6.1 of 3GPP (3rd generation partnership project) TS (technical specification) 38.473. In other examples, the paging message may include only some of the parameters described above.

[0166] In one embodiment, the DU (220) can identify that the UE (120) supports PEI in a cell associated with paging based on a PEI subgrouping support instruction. For example, the DU (220) can identify that the UE (120) supports PEI in a cell identified by an NR CGI corresponding to a PEI subgrouping support instruction based on the identification that a PEI subgrouping support instruction is included in a paging message.

[0167] In one embodiment, the DU (220) may determine, based on the identification, whether the paging message includes at least one parameter for identifying the paging subgroup of the UE (120). For example, the at least one parameter for identifying the paging subgroup of the UE (120) may include PEIPS auxiliary information (833) related to CN controlled subgrouping and an extended UE identity index value (834) related to UE ID-based subgrouping. In one example, if the cell supports only CN controlled subgrouping, the at least one parameter for identifying the paging subgroup of the UE (120) may be a CN subgroup ID. In one example, if the cell supports only UE ID-based subgrouping, the at least one parameter for identifying the paging subgroup of the UE (120) may be an extended UE identity index value. In one example, if the cell supports both CN control subgrouping and UE ID-based subgrouping, at least one parameter for identifying the paging subgroup of the UE (120) may include a CN subgroup ID and an extended UE identity index value.

[0168] In the situation exemplified in FIG. 8, the AMF and / or CU (210) may not support RAN paging PEI and may not have 5G-S-TMSI stored within the CU (210). Since the AMF and / or CU (210) may not support RAN paging PEI and may not have 5G-S-TMSI stored within the CU (210), the paging message may not include parameter(s) for identifying a paging subgroup. The DU (220) may determine that the paging message does not include at least one parameter for identifying a paging subgroup of the UE (120). Based on the determination, the DU (220) may set (or determine) all bits of the paging instruction field to 1 to enable PEI for the UE (120).

[0169] In operation 840, a DU (220) according to one embodiment may set all bits of a paging instruction field to 1 and then transmit downlink control information (DCI) containing the corresponding paging instruction field to a UE (120). For example, the DCI may be DCI format 2_7. For example, the DCI may be scrambled based on PEI-RNTI.

[0170] In operation 850, a DU (220) according to one embodiment may transmit a paging message to the UE (120) at the next paging occasion. For example, the UE (120) may receive a paging message at the next PO because all bits of the paging indication field indicate 1. In one example, the paging message between the UE (120) and the DU (220) may be referred to as an RRC paging message or other terms having an equivalent technical / functional meaning. Based on the paging message, the UE (120) may transmit an RRC resume request to the DU (220). Subsequently, the UE (120), CU (210), DU (220), and / or AMF may cause the UE (120) to switch from inactive mode to connected mode by performing an RRC resume procedure. Therefore, according to the above descriptions, call cancellation caused by RAN paging failure can be prevented.

[0171] FIG. 9 illustrates an example of signaling for early paging indication. FIG. 9 describes signaling for early paging indication for a UE (user equipment) (120) when the UE (120) in RRC (radio resource control) inactive mode (320) moves from the coverage of a serving base station (901) into the coverage of a DU (220). The operations described in FIG. 9 are described based on the serving base station (901), the central unit (CU) (210), and the distributed unit (DU) (220). In the following, at least one of the operations (e.g., operation 915 or operation 925) may be omitted.

[0172] Referring to FIG. 9, in operation 910, the serving base station (901) may obtain (or receive) core network auxiliary information from a network function of the CN (core network) (240). For example, the network function of the CN (240) for transmitting core network auxiliary information may be an access and mobility management function (AMF). For example, core network auxiliary information may be included in an initial context setup request, a UE context modification request, a handover request, or a path switch request acknowledge.

[0173] In one embodiment, the core network auxiliary information may provide auxiliary information for RRC disabled configuration. For example, the core network auxiliary information may include UE radio capability information for paging (911), PEIPS (paging early indication with paging subgrouping) auxiliary information (912), and / or an extended UE identity index value (913). In the example illustrated in FIG. 9, since the AMF supports RAN (radio access network) paging PEI (paging early indication), the core network auxiliary information may include PEIPS auxiliary information (912) and / or an extended UE identity index value (913). However, the present disclosure is not limited thereto. For example, if the AMF does not support RAN paging PEI, the core network auxiliary information may not include PEIPS auxiliary information (912) and an extended UE identity index value (913).

[0174] For example, UE wireless capability information (911) for paging may indicate whether the UE (120) supports PEI for a list of frequency bands.

[0175] For example, PEIPS auxiliary information (912) may be associated with CN controlled subgrouping. In the CN controlled subgrouping, the CN subgroup ID representing the paging subgroup of the UE (120) may be determined by the AMF. PEIPS auxiliary information (912) may include the CN subgroup ID.

[0176] For example, the extended UE identity index value (913) may be associated with UE ID-based subgrouping. In UE ID-based subgrouping, the extended UE identity index value may be used to determine (or calculate) a UE ID-based subgroup ID representing a paging subgroup of the UE (120).

[0177] In operation 915, a serving base station (901) according to one embodiment may obtain (or receive) signaling associated with a DL (downlink) UE from a network function of a CN (core network) (240). For example, the network function of the CN (240) for transmitting the signaling associated with a DL UE may be an access and mobility management function (AMF).

[0178] In operation 925, a serving base station (901) according to one embodiment may obtain (or receive) DL data for the UE (120) from a network function of the CN (240). For example, the network function of the CN (240) for transmitting the DL data may be a user plane function (UPF).

[0179] In one embodiment, the CU (210) may send a RAN (radio access network) paging message to the CU (210) to request paging of the UE (120) in RRC inactive mode in response to receiving DL UE-related signaling or DL ​​data.

[0180] In one embodiment, the RAN paging message may include a UE RAN paging identity (931), UE radio capability information for paging (932), PEIPS auxiliary information (933), and / or an extended UE identity index value (934). In the example illustrated in FIG. 9, since the AMF and the serving base station (901) support RAN paging PEI, the RAN paging message may include PEIPS auxiliary information (933) and an extended UE identity index value (934). However, the present disclosure is not limited thereto. For example, if at least one network element of the AMF or the serving base station (901) does not support RAN paging PEI, the RAN paging message may not include PEIPS auxiliary information (933) and an extended UE identity index value (934).

[0181] For example, the UE RAN paging identity (931) may define a UE identity for a UE (120) in RRC inactive mode. The UE RAN paging identity (931) may include an I-RNTI (inactive-radio network temporary identifier) ​​for identifying the UE (120) associated with RAN paging.

[0182] For example, the description of UE radio capability information for paging (932) may refer to the description of UE radio capability information for paging (911). For example, the description of PEIPS auxiliary information (933) may refer to the description of PEIPS auxiliary information (912). For example, the description of the extended UE identity index value (934) may refer to the description of the extended UE identity index value (913).

[0183] In a non-limiting example, the RAN paging message may not contain an extended UE identity index value (934). The CU (210) may determine whether the 5G-S-TMSI (5th generation-short-temporary mobile subscriber identity) is stored within the CU (210) based on the determination that the RAN paging message obtained from the serving base station (901) does not contain an extended UE identity index value. If the CU (210) is the initial attach CU of the UE (120), the CU (210) may store the 5G-S-TMSI of the UE (120). If the 5G-S-TMSI is stored within the CU (210), the CU (210) may determine an extended identity index value based on the 5G-S-TMSI according to the above-described [Equation 1]. However, in the example illustrated in FIG. 9, since the CU (210) is not the initial attach CU of the UE (120), the 5G-S-TMSI of the UE (120) is not in the CU (210). Since the RAN paging message does not contain the extended UE identity index value (934) and the 5G-S-TMSI is not stored in the CU (210), the DU (220) may not be able to obtain the extended UE identity index value.

[0184] In one embodiment, the parameters described above included in the RAN paging message are merely examples and the present disclosure is not limited thereto. For example, the RAN paging message may include further parameters. For the parameters included in the RAN paging message, reference may be made to the contents of Section 9.1.1.7 of 3GPP TS 38.423. In another example, the RAN paging message may include only some of the parameters described above.

[0185] In operation 940, a DU (220) according to one embodiment may obtain (or receive) a paging message from a CU (210). For example, the DU (220) may obtain (or receive) a paging message from the CU (210) through an F1 interface between the CU (210) and the DU (220). For example, the paging message may be intended to request the DU (220) to page the UE (120). In one example, the paging message between the CU (210) and the DU (220) may be referred to as an F1 paging message or another term having an equivalent technical / functional meaning.

[0186] In one embodiment, the paging message may include a RAN (radio access network) UE paging identity (941), a paging cell list (942), PEIPS auxiliary information (943), and / or an extended UE identity index value (944). In the example illustrated in FIG. 9, the AMF and the serving base station (901) support RAN paging PEI, but at least one network element among the CU (210) or DU (220) may not support RAN paging PEI. Additionally, since the CU (210) is not the initial attach CU of the UE (120), the CU (210) does not have the 5G-S-TMSI of the UE (120). Therefore, the paging message may not include the PEIPS auxiliary information (943) and the extended UE identity index value (944).

[0187] For example, the RAN UE paging identity (941) may include an inactive-radio network temporary identifier (I-RNTI) for identifying the UE (120) associated with paging.

[0188] For example, the paging cell list (942) may include one or more NR CGIs (new radio cell global identifiers) and / or PEI subgrouping support indications corresponding to one or more NR CGIs. For example, the NR CGIs may indicate cells associated with paging. For example, the PEI subgrouping support indication may indicate that the UE (120) supports PEI in the cells indicated by the NR CGIs. In one example, the paging cell list (942) may correspond to UE radio capability information (911) for paging of core network auxiliary information (910) and / or UE radio capability information (932) for paging of RAN paging messages (930).

[0189] For example, the description of PEIPS auxiliary information (943) may refer to the description of PEIPS auxiliary information (911). For example, the description of the extended UE identity index value (944) may refer to the description of the extended UE identity index value (913). The parameters described above included in the paging message are merely examples and the present disclosure is not limited thereto. For example, the paging message may include other parameters further. The parameters included in the paging message may refer to the contents of Section 9.2.6.1 of 3GPP (3rd generation partnership project) TS (technical specification) 38.473. In other examples, the paging message may include only some of the parameters described above.

[0190] In one embodiment, the DU (220) may determine that the UE (120) supports PEI in a cell associated with paging based on a PEI subgrouping support instruction. For example, the DU (220) may determine that the UE (120) supports PEI in a cell identified by an NR CGI corresponding to a PEI subgrouping support instruction based on the identification that a PEI subgrouping support instruction is included in a paging message.

[0191] In one embodiment, the DU (220) may determine, based on the determination, whether the paging message includes at least one parameter for identifying a paging subgroup of the UE (120). For example, the at least one parameter for identifying a paging subgroup of the UE (120) may include PEIPS auxiliary information (943) related to CN control subgrouping and an extended UE identity index value (944) related to UE ID-based subgrouping.

[0192] In one example, if the cell supports only CN control subgrouping, at least one parameter for identifying the paging subgroup of the UE (120) may be PEIPS auxiliary information (943).

[0193] In one example, if the cell supports only UE ID-based subgrouping, at least one parameter for identifying the paging subgroup of the UE (120) may be an extended UE identity index value (944).

[0194] In one example, if the cell supports both CN control subgrouping and UE ID-based subgrouping, at least one parameter for identifying the paging subgroup of the UE (120) may include PEIPS auxiliary information (943) and an extended UE identity index value (944).

[0195] In the situation exemplified in FIG. 9, the AMF and the serving base station (901) support RAN paging PEI, but at least one network element among the CU (210) or DU (220) may not support RAN paging PEI. Additionally, since the CU (210) is not the initial attach CU of the UE (120), there is no 5G-S-TMSI in the CU (210). Therefore, the paging message may not include at least one parameter for identifying the paging subgroup of the UE (120).

[0196] In the situation illustrated in FIG. 9, the DU (220) may determine that the paging message does not include at least one parameter for identifying the paging subgroup of the UE (120). Based on the determination, the DU (220) may set (or determine) all bits of the paging instruction field to 1 to enable PEI for the UE (120).

[0197] In operation 950, a DU (220) according to one embodiment may set all bits of a paging instruction field to 1 and then transmit downlink control information (DCI) containing the corresponding paging instruction field to a UE (120). For example, the DCI may be DCI format 2_7. For example, the DCI may be scrambled based on PEI-RNTI.

[0198] In operation 960, according to one embodiment, the DU (220) may transmit a paging message to the UE (120) at the next paging occasion. For example, the UE (120) may receive the paging message at the next PO because all bits of the paging indication field indicate 1. In one example, the paging message between the UE (120) and the DU (220) may be referred to as an RRC paging message or other terms having an equivalent technical / functional meaning. Based on the paging message, the UE (120) may transmit an RRC resume request to the DU (220). Subsequently, the UE (120), CU (210), DU (220), and / or AMF may cause the UE (120) to switch from inactive mode (320) to connected mode (310) by performing an RRC resume procedure. Therefore, according to the above descriptions, call cancellation caused by RAN paging failure can be prevented.

[0199] FIG. 10 illustrates a flowchart showing the operations of a DU for early paging instructions. The operations of FIG. 10 may be performed by the DU (distributed unit) (220) of FIG. 2a, FIG. 2b, FIG. 3, and FIG. 5. For example, at least some of the operations may be controlled by the processor (501) of the DU (220). In the following, each operation may be performed sequentially, but is not necessarily performed sequentially. For example, the order of each operation may be changed and / or at least two operations may be performed in parallel.

[0200] FIG. 10 describes the operations of a DU (220) for performing PEI (paging early indication) in a cell that supports only CN (core network) controlled subgrouping and UE (user equipment) ID (identifier) ​​based subgrouping.

[0201] Referring to FIG. 10, in operation 1001, a DU (220) according to one embodiment may obtain (or receive) a paging message from a CU (central unit) (210). For example, the DU (220) may obtain (or receive) a paging message from the CU (210) through an F1 interface between the CU (210) and the DU (220). For example, the paging message may be intended to request the DU (220) to paging a UE (120). In one example, the paging message between the CU (210) and the DU (220) may be referred to as an F1 paging message or another term having an equivalent technical / functional meaning.

[0202] In operation 1002, the DU (220) according to one embodiment can determine whether the paging message includes a CN subgroup ID for identifying a paging subgroup of the UE (120).

[0203] In one embodiment, the paging message may include a RAN (radio access network) UE paging identity, a paging cell list, and / or PEIPS (paging early indication with paging subgrouping) auxiliary information.

[0204] For example, the RAN UE paging identity may include an inactive-radio network temporary identifier (I-RNTI) to identify the UE (120) associated with paging.

[0205] For example, the paging cell list may include one or more NR CGIs (new radio cell global identifiers) and / or PEI subgrouping support indications corresponding to one or more NR CGIs. For example, an NR CGI may indicate a cell associated with paging. For example, a PEI subgrouping support indication may indicate that the UE (120) supports PEI in the cell indicated by the NR CGI.

[0206] For example, PEIPS auxiliary information may include a CN subgroup ID representing a paging subgroup of the UE (120). The CN subgroup ID may be determined by an AMF.

[0207] The parameters described above included in the paging message are merely examples and the present disclosure is not limited thereto. For example, the paging message may include other parameters further. For the parameters included in the paging message, reference may be made to Section 9.2.6.1 of 3GPP (3rd generation partnership project) TS (technical specification) 38.473. In other examples, the paging message may include only some of the parameters described above.

[0208] In one embodiment, the DU (220) can identify that the UE (120) supports PEI in a cell associated with paging based on a PEI subgrouping support instruction. For example, the DU (220) can identify that the UE (120) supports PEI in a cell identified by an NR CGI corresponding to a PEI subgrouping support instruction based on the identification that a PEI subgrouping support instruction is included in a paging message. In the example of FIG. 10, the cell identified by the NR CGI may be configured to support only the CN control subgrouping among the CN control subgrouping and the UE ID-based subgrouping. Therefore, the parameter for identifying the paging subgroup of the UE (120) may be the CN subgroup ID.

[0209] In one embodiment, the DU (220) can determine whether a paging message includes a CN subgroup ID to identify a paging subgroup of the UE (120) based on the identification that the UE (120) supports PEI in a cell associated with paging and that the cell supports only CN control subgrouping.

[0210] In operation 1003, the DU (220) according to one embodiment may set (or determine) the bit corresponding to the CN subgroup ID among the bits of the paging indication field to 1, depending on the determination that the paging message includes a CN subgroup ID for identifying the paging subgroup of the UE (120).

[0211] In operation 1004, the DU (220) according to one embodiment may set (or determine) all bits of the paging instruction field to 1 based on the determination that the paging message does not include a CN subgroup ID for identifying the paging subgroup of the UE (120). For example, in a cell that supports only CN control subgrouping, if the CN subgroup ID is not included in the paging message, the DU (220) cannot determine the paging subgroup ID of the UE (120). Therefore, the DU (220) may set all bits of the paging instruction field to 1 to enable PEI for the UE (120).

[0212] In operation 1005, a DU (220) according to one embodiment may transmit downlink control information (DCI) including a paging instruction field to a UE (120). For example, the DCI may be in DCI format 2_7. For example, the DCI may be scrambled based on PEI-RNTI.

[0213] As described in FIG. 10, in a cell that supports CN control subgrouping, the DU (220) may not obtain a CN subgroup ID representing the paging subgroup of the UE (120). In this case, the DU (220) may set all bits of the paging instruction field to 1 and then transmit a DCI containing the paging instruction field to the UE (120).

[0214] According to the descriptions above, the UE (120) can receive a paging message (or RRC paging message) at the next paging occasion (PO) because all bits of the paging indication field of the DCI indicate 1. Based on the paging message, the UE (120) can send an RRC resume request to the DU (220). Subsequently, the UE (120), CU (210), DU (220), and / or AMF can cause the terminal to switch from inactive mode (320) to connected mode (310) by performing the RRC resume procedure. Therefore, according to the descriptions above, call release caused by a failure of RAN paging can be prevented.

[0215] FIG. 11 illustrates a flowchart showing the operations of a DU for early paging instructions. The operations of FIG. 11 may be performed by the DU (distributed unit) (220) of FIG. 2a, FIG. 2b, FIG. 3, and FIG. 5. For example, at least some of the operations may be controlled by the processor (501) of the DU (220). In the following, each operation may be performed sequentially, but is not necessarily performed sequentially. For example, the order of each operation may be changed and / or at least two operations may be performed in parallel.

[0216] FIG. 11 describes the operations of a DU (220) for performing PEI (paging early indication) in a cell that supports only UE ID-based subgrouping among CN (core network) controlled subgrouping and UE (user equipment) ID-based subgrouping.

[0217] Referring to FIG. 11, in operation 1101, a DU (220) according to one embodiment may obtain (or receive) a paging message from a CU (210). For example, the DU (220) may obtain (or receive) a paging message from the CU (210) through an F1 interface between the CU (210) and the DU (220). For example, the paging message may be intended to request the DU (220) to page a UE (120). In one example, the paging message between the CU (210) and the DU (220) may be referred to as an F1 paging message or another term having an equivalent technical / functional meaning.

[0218] In operation 1102, the DU (220) according to one embodiment can determine whether the paging message includes an extended UE identity index value.

[0219] In one embodiment, the paging message may include a RAN (radio access network) UE paging identity, a paging cell list, and / or an extended UE identity index value.

[0220] For example, the RAN UE paging identity may include an inactive-radio network temporary identifier (I-RNTI) to identify the UE (120) associated with paging.

[0221] For example, the paging cell list may include one or more NR CGIs (new radio cell global identifiers) and / or PEI subgrouping support indications corresponding to one or more NR CGIs. For example, an NR CGI may indicate a cell associated with paging. For example, a PEI subgrouping support indication may indicate that the UE (120) supports PEI in the cell indicated by the NR CGI.

[0222] For example, the extended UE identity index value may be used to determine (or calculate) a UE ID-based subgroup ID representing a paging subgroup of the UE (120). The UE ID-based subgroup ID may be determined from the UE (120) and the DU (220).

[0223] The parameters described above included in the paging message are merely examples and the present disclosure is not limited thereto. For example, the paging message may include other parameters further. For the parameters included in the paging message, reference may be made to Section 9.2.6.1 of 3GPP (3rd generation partnership project) TS (technical specification) 38.473. In other examples, the paging message may include only some of the parameters described above.

[0224] In one embodiment, the DU (220) can identify that the UE (120) supports PEI in a cell associated with paging based on a PEI subgrouping support instruction. For example, the DU (220) can identify that the UE (120) supports PEI in a cell identified by an NR CGI corresponding to a PEI subgrouping support instruction based on the identification that a PEI subgrouping support instruction is included in a paging message. In the example of FIG. 11, the cell identified by the NR CGI may be configured to support only the UE ID-based subgrouping among CN control subgrouping and UE ID-based subgrouping. Therefore, the parameter for identifying the paging subgroup of the UE (120) may be an extended UE identity index value.

[0225] In one embodiment, the DU (220) can determine whether the paging message contains an extended UE identity index value based on the identification that the UE (120) in the cell associated with paging supports PEI and that the cell supports only UE ID-based subgrouping.

[0226] In operation 1103, the DU (220) according to one embodiment may determine a UE ID-based subgroup ID based on an extended UE identity index value, depending on the determination that the paging message includes an extended UE identity index value.

[0227] In operation 1104, the DU (220) according to one embodiment may set (or determine) the bit corresponding to the UE ID-based subgroup ID among the bits of the paging indication field to 1.

[0228] In operation 1105, the DU (220) according to one embodiment may set (or determine) all bits of the paging instruction field to 1 based on the determination that the paging message does not contain an extended UE identity index value.

[0229] In operation 1106, a DU (220) according to one embodiment may transmit downlink control information (DCI) including a paging instruction field to a UE (120). For example, the DCI may be DCI format 2_7. For example, the DCI may be scrambled based on PEI-RNTI.

[0230] As described in FIG. 11, in a cell that supports UE ID-based subgrouping, the DU (220) may not be able to obtain an extended UE identity index value from the CU (210) that is used to determine the UE ID-based subgroup ID. For example, if at least one network element of the AMF or CU (210) does not support RAN paging PEI and 5G-S-TMSI is not stored in the CU (210), the DU (220) may not be able to obtain an extended UE identity index value from the CU (210). In this case, the DU (220) may set all bits of the paging instruction field to 1 and then transmit a DCI containing the paging instruction field to the UE (120).

[0231] According to the descriptions above, since the bit corresponding to the paging subgroup of the UE (120) among the bits of the paging instruction field of the DCI indicates 1, the UE (120) can receive a paging message (or an RRC paging message) at the next paging occasion. Based on the paging message, the UE (120) can send an RRC resume request to the DU (220). Subsequently, the UE (120), CU (210), DU (220), and / or AMF can cause the terminal to switch from inactive mode (320) to connected mode (310) by performing the RRC resume procedure. Therefore, according to the descriptions above, call release caused by a failure of RAN paging can be prevented.

[0232] The technical problems to be solved in this disclosure are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which this disclosure belongs.

[0233] A distributed unit (DU) as described above may include a communication circuit. The DU may include a memory that stores instructions and includes one or more storage media. The DU may include at least one processor that includes a processing circuit. When the instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to obtain a paging message from a central unit (CU) that includes a paging early indication (PEI) subgrouping support indication. When the instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to determine whether the paging message includes at least one parameter for identifying a paging subgroup of user equipment (UE) for paging. When the above instructions are executed individually or collectively by the at least one processor, the DU may cause all bits of the paging indication field to be set to 1 upon the determination that the paging message does not include the at least one parameter. When the above instructions are executed individually or collectively by the at least one processor, the DU may cause downlink control information (DCI) containing the paging indication field to be transmitted to the UE.

[0234] For example, when the instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to determine the paging subgroup of the UE based on the at least one parameter, in accordance with the determination that the paging message includes the at least one parameter. When the instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to determine the bit corresponding to the paging subgroup of the UE among the bits of the paging instruction field to be 1.

[0235] For example, if the cell for paging supports the CN (core network) controlled subgrouping among the CN (core network) controlled subgrouping and the UE ID (identifier) ​​based subgrouping, the at least one parameter may be a CN subgroup ID representing the paging subgroup of the UE. The CN subgroup ID may be determined by an access and mobility management function (AMF).

[0236] For example, when the above instructions are executed individually or collectively by the at least one processor, the DU may cause the bit corresponding to the CN subgroup ID among the bits of the paging instruction field to be determined to be 1, depending on the determination that the paging message includes the at least one parameter.

[0237] For example, if the cell for paging supports the UE ID-based subgrouping among the CN control subgrouping and the UE ID-based subgrouping, the at least one parameter may be an extended UE identity index value.

[0238] For example, when the instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to determine a UE ID-based subgroup ID representing a paging subgroup of the UE based on the extended UE identity index value, depending on the determination that the paging message includes the at least one parameter. When the instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to determine a bit corresponding to the UE ID-based subgroup ID among the bits of the paging instruction field to be 1.

[0239] For example, if the cell for paging supports both CN control subgrouping and UE ID-based subgrouping, the at least one parameter may include a CN subgroup ID and an extended UE identity index value.

[0240] For example, the paging message may further include a cell global identifier (CGI) indicating a cell associated with the paging. The PEI subgrouping support instruction may indicate that the cell identified by the CGI supports PEI.

[0241] For example, when the instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to send an RRC paging message to the UE that is in a radio resource control (RRC) inactive state at a paging occasion (PO) after sending the DCI. When the instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to receive an RRC resume request from the UE in response to the RRC paging message.

[0242] For example, at least one network element of the AMF associated with the paging or the CU may not support PEI. For example, the CU may not store 5G-S-TMSI (5th generation-short-temporary mobile subscriber identity).

[0243] A method performed by a DU as described above may include the operation of obtaining a paging message from a central unit (CU) that includes a paging early indication (PEI) subgrouping support indication. The method may include the operation of determining whether the paging message includes at least one parameter for identifying a paging subgroup of a user equipment (UE) for paging. The method may include the operation of determining all bits of a paging indication field to 1 based on the determination that the paging message does not include the at least one parameter. The method may include the operation of transmitting downlink control information (DCI) including the paging indication field to the UE.

[0244] For example, the above method may include an operation to determine the paging subgroup of the UE based on the at least one parameter according to a determination that the paging message includes the at least one parameter. The above method may include an operation to determine the bit corresponding to the paging subgroup of the UE among the bits of the paging instruction field to be 1.

[0245] For example, if the cell for paging supports the CN (core network) controlled subgrouping among the CN (core network) controlled subgrouping and the UE ID (identifier) ​​based subgrouping, the at least one parameter may be a CN subgroup ID representing the paging subgroup of the UE. The CN subgroup ID may be determined by an access and mobility management function (AMF).

[0246] For example, the above method may include an operation of determining to 1 a bit corresponding to the CN subgroup ID among the bits of the paging instruction field, depending on the determination that the paging message includes the at least one parameter.

[0247] For example, if the cell for paging supports the UE ID-based subgrouping among the CN control subgrouping and the UE ID-based subgrouping, the at least one parameter may be an extended UE identity index value.

[0248] For example, the method may include an operation of determining a UE ID-based subgroup ID representing a paging subgroup of the UE based on an extended UE identity index value, depending on a determination that the paging message includes at least one parameter. The method may include an operation of determining a bit corresponding to the UE ID-based subgroup ID among the bits of the paging instruction field to be 1.

[0249] For example, if the cell for paging supports both CN control subgrouping and UE ID-based subgrouping, the at least one parameter may include a CN subgroup ID and an extended UE identity index value.

[0250] For example, the paging message may further include a cell global identifier (CGI) indicating a cell associated with the paging. The PEI subgrouping support instruction may indicate that the cell identified by the CGI supports PEI.

[0251] For example, the above method may include the operation of transmitting an RRC paging message to the UE that is in a radio resource control (RRC) inactive state at a paging occasion (PO) after transmitting the DCI. The above method may include the operation of receiving an RRC resume request from the UE in response to the RRC paging message.

[0252] For example, at least one network element of the AMF associated with the paging or the CU may not support PEI. The CU may not store 5G-S-TMSI (5th generation-short-temporary mobile subscriber identity).

[0253] The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs.

[0254] For one or more embodiments, at least one of the components described in one or more of the prior art drawings may be configured to perform one or more operations, techniques, processes and / or methods as described in the present disclosure. For example, a processor (e.g., a baseband processor) described in the present disclosure in relation to one or more of the prior art drawings may be configured to operate according to one or more examples described in the present disclosure. As another example, circuits associated with user equipment (UE), a base station, a network element, etc., as described above in relation to one or more of the prior art drawings may be configured to operate according to one or more examples described herein.

[0255] Any of the embodiments described above may be combined with any other embodiment (or combination of embodiments) unless otherwise explicitly stated. The foregoing description of one or more embodiments is for illustrative and explanatory purposes only, and is not intended to limit or exhaust the scope of the embodiments in the exact form disclosed. Modifications and variations are possible in light of the foregoing teachings or may be obtained from the practice of various embodiments.

[0256] Methods according to the claims or embodiments described in the specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0257] When implemented in software, a computer-readable storage medium (e.g., a non-transient computer-readable storage medium) storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. One or more programs include instructions that cause the electronic device to execute methods according to the claims or embodiments described in the specification of this disclosure. The one or more programs may be provided as a computer program product. The computer program product may be traded between a seller and a buyer as a product. The computer program product may be distributed in the form of a device-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or distributed online (e.g., download or upload) through an application store (e.g., Play Store™) or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily created on a device-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or a relay server.

[0258] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic disc storage devices, compact disc-ROM (CD-ROM), digital versatile discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.

[0259] Additionally, the program may be stored on an attachable storage device that can be accessed via a communication network such as the Internet, Intranet, LAN (local area network), WAN (wide area network), or SAN (storage area network), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure through an external port. Additionally, a separate storage device on a communication network may be connected to a device performing an embodiment of the present disclosure.

[0260] In the specific embodiments of the present disclosure described above, the components included in the disclosure are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed of a singular form, and even if a component is expressed in the singular form, it may be composed of a plural form.

[0261] According to the embodiments, one or more of the aforementioned components or operations may be omitted, or one or more other components or operations may be added. Generally or additionally, a plurality of components (e.g., a module or a program) may be integrated into a single component. In this case, the integrated component may perform one or more functions of each of the plurality of components in the same or similar manner as those performed by the corresponding component among the plurality of components prior to the integration. According to the embodiments, operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0262] Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, it is understood that various modifications are possible within the scope of the present disclosure.

Claims

1. In the case of a DU (distributed unit), Communication circuit; Memory for storing instructions and including one or more storage media; and The DU comprises at least one processor including a processing circuit, wherein when the instructions are executed individually or collectively by the at least one processor, the DU A paging message containing a paging cell list is obtained from the CU (central unit), and Determining whether the above paging message includes at least one parameter for identifying a paging subgroup of a UE (user equipment) for paging, and Based on the determination that the above paging message does not include the at least one parameter, all bits of the paging indication field are determined to be 1, and Causing to transmit DCI (downlink control information) including the above paging instruction field to the UE, DU.

2. In Paragraph 1, When the above instructions are executed individually or collectively by the at least one processor, the DU, Based on the determination that the paging message includes the at least one parameter, the paging subgroup of the UE is determined based on the at least one parameter, and Causing to determine the bit corresponding to the paging subgroup of the UE among the bits of the above paging instruction field to be 1, DU.

3. In Paragraph 1, The above paging cell list includes an NR CGI (new radio cell global identifier) ​​and a PEI (paging early indication) subgrouping support indication corresponding to the NR CGI, DU.

4. In Paragraph 3, When the above instructions are executed individually or collectively by the at least one processor, the DU, Based on the above PEI subgrouping support instruction, it is identified that the UE supports PEI in the cell identified by the above NR CGI, and, Causing to identify whether the cell supports CN controlled subgrouping and UE ID (identifier) ​​based subgrouping, based on the identification that the UE supports the PEI in the cell identified by the above NR CGI. DU.

5. In Paragraph 4, When the above instructions are executed individually or collectively by the at least one processor, the DU, If the cell supports both the CN control subgrouping and the UE ID-based subgrouping, it causes to determine whether the paging message includes the at least one parameter having a CN subgroup ID and an extended UE identity index value, and The above CN subgroup ID is used to identify the paging subgroup of the UE in relation to the above CN control subgrouping, and The above extended UE identity index value is used to identify the paging subgroup of the UE in relation to the UE ID-based subgrouping, DU.

6. In Paragraph 4, When the above instructions are executed individually or collectively by the at least one processor, the DU, If the cell supports only the CN control subgrouping, causing to determine whether the paging message includes the at least one parameter having a CN subgroup ID, DU.

7. In Paragraph 4, When the above instructions are executed individually or collectively by the at least one processor, the DU, If the cell supports only the UE ID-based subgrouping, causing to determine whether the paging message includes the at least one parameter having an extended UE identity index value, DU.

8. In Paragraph 7, The above extended UE identity index value is determined by the AMF (access and mobility management function), or The above extended UE identity index value is determined by the CU based on 5G-S-TMSI (5th generation-short-temporary mobile subscriber identity), DU.

9. In Paragraph 1, When the above instructions are executed individually or collectively by the at least one processor, the DU, After transmitting the above DCI, transmit an RRC paging message to the UE that is in an RRC (radio resource control) inactive state at the PO (paging occasion), and, Causing to receive an RRC resume request from the UE in response to the above RRC paging message, DU.

10. In Paragraph 1, At least one network element among the AMF associated with the above paging, the CU, the serving base station of the UE, or the DU does not support RAN (radio access network) paging PEI, and The above CU does not store 5G-S-TMSI (5th generation-short-temporary mobile subscriber identity), DU.

11. In a method performed by a DU (distributed unit), An operation to obtain a paging message containing a paging cell list from a central unit (CU); An operation to determine whether the above paging message includes at least one parameter for identifying a paging subgroup of a UE (user equipment) for paging; An operation to determine all bits of a paging indication field to 1 based on the determination that the paging message does not include at least one parameter; and The operation of transmitting DCI (downlink control information) including the paging instruction field to the UE, method.

12. In Paragraph 11, An operation to determine the paging subgroup of the UE based on the at least one parameter, in accordance with the determination that the paging message includes the at least one parameter; and further comprising the operation of determining the bit corresponding to the paging subgroup of the UE among the bits of the paging instruction field as 1, method.

13. In Paragraph 11, The above paging cell list includes an NR CGI (new radio cell global identifier) ​​and a PEI (paging early indication) subgrouping support indication corresponding to the NR CGI, method.

14. In Paragraph 13, An operation to identify that the UE supports PEI in a cell identified by the NR CGI based on the above PEI subgrouping support instruction; and Further comprising an operation to identify whether the cell supports CN controlled subgrouping and UE ID (identifier) ​​based subgrouping, based on the identification that the UE supports the PEI in the cell identified by the NR CGI. method.

15. In paragraph 14, the operation of determining whether the paging message includes the at least one parameter is, If the cell supports both the CN control subgrouping and the UE ID-based subgrouping, the method includes an operation to determine whether the paging message includes at least one parameter having a CN subgroup ID and an extended UE identity index value, and The above CN subgroup ID is used to identify the paging subgroup of the UE in relation to the above CN control subgrouping, and The above extended UE identity index value is used to identify the paging subgroup of the UE in relation to the UE ID-based subgrouping, method.

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