Method for updating user equipment location and related device

Abstract

A method for updating a location of a user equipment (UE) in a radio resource control (RRC) inactive state performed by the UE is provided. The method includes determining whether a small data transmission (SDT) procedure is ongoing in case of an event triggering a location updating procedure; initiating the location updating procedure in case the SDT procedure is not ongoing.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit and priority of the national phase application of International Patent Application Serial No. PCT / CN2021 / 120316, filed on September 24, 2021, entitled “RADIO RESOURCE CONTROLMANAGEMENT FOR IDLE-MODE PACKET TRANSMISSION OF USER EQUIPMENT”, filed on September 25, 2020, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure generally relates to wireless communications, and more specifically, to a method and related apparatus for updating the location of a user equipment (UE) during a Radio Resource Control (RRC) inactive state. Background Technology

[0004] With the massive growth in the number of connected devices and the rapid increase in user / network traffic, various efforts have been made to improve different aspects of wireless communication systems, such as fifth-generation (5G) New Radio (NR) systems, by increasing data rates, latency, reliability, and mobility.

[0005] 5G NR systems are designed to provide flexibility and configurability to optimize network services and types and adapt to a variety of uses, such as enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable and low-latency communication (URLLC).

[0006] However, with the increasing demand for radio access, there is a need to further improve wireless communication in next-generation wireless communication systems. Summary of the Invention

[0007] This disclosure provides a method and related apparatus for updating the location of a user equipment (UE) during a Radio Resource Control (RRC) inactive state.

[0008] In one aspect of this application, a method is provided for updating the location of a user equipment (UE) in a radio resource control (RRC) inactive state. The method includes, after the UE receives a first RRC release message from the RAN instructing the UE to move to or remain in an RRC inactive state, performing a UE location update procedure with the radio access network (RAN) serving the UE, determining whether to suspend the UE location update procedure when the UE performs a first small data transmission (SDT) procedure with a first cell in the RAN while in an RRC inactive state, and determining whether to start or restart the UE location update procedure when the first SDT procedure terminates.

[0009] In another aspect of this application, a user equipment (UE) is provided for updating the location of the UE in a Radio Resource Control (RRC) inactive state. The UE includes a processor and a memory coupled to the processor, wherein the memory stores a computer-executable program that, when executed by the processor, causes the processor to perform the above-described method for updating the location of the UE in an RRC inactive state. Attached Figure Description

[0010] The aspects of this disclosure are best understood when read in conjunction with the accompanying drawings. The various features are not drawn to scale. For clarity of discussion, the dimensions of the various features may be increased or decreased arbitrarily.

[0011] Figure 1 This is a schematic diagram of the transmission sequence of a small data transmission (SDT) process provided according to an embodiment of this application.

[0012] Figure 2 This is a schematic diagram of a transmission sequence of an SDT process based on random access (RA) provided according to an embodiment of this application.

[0013] Figure 3 This is a schematic diagram of the transmission sequence of a configured grant (CG) SDT process provided according to an embodiment of this application.

[0014] Figure 4 This is a schematic diagram of the transmission sequence of the Notification Area Update (RNAU) process of a radio access network (RAN) according to an embodiment of this application.

[0015] Figure 5This is a flowchart illustrating a method for updating the location of a user equipment (UE) during a Radio Resource Control (RRC) inactive state, according to embodiments of this application.

[0016] Figure 6 This is a block diagram of a wireless communication node provided according to an embodiment of this application. Detailed Implementation

[0017] The following description contains specific information relating to the exemplary embodiments described herein. The accompanying drawings and detailed descriptions are for illustrative purposes only. However, this document is not limited to these exemplary embodiments. Other variations and embodiments will occur to those skilled in the art. Unless otherwise stated, the same or corresponding elements in the drawings are indicated by the same or corresponding reference numerals. Furthermore, the drawings and illustrations in this document are generally not drawn to scale and are not intended to correspond to actual relevant dimensions.

[0018] For the purposes of consistency and ease of understanding, the same features are indicated by reference numerals in the exemplary drawings (although not shown in some examples). However, features in different embodiments may differ in other respects, and therefore should not be narrowly limited to the features shown in the drawings.

[0019] The specification uses the phrases "in one embodiment" or "in some embodiments," which may each refer to one or more of the same or different embodiments. The term "coupled" is defined as a connection, either directly or indirectly through intermediate components, and is not necessarily limited to a physical connection. When the term "comprising" is used, it means "including but not limited to"; it specifically refers to open-ended inclusions or subordinate members in the described combinations, groups, series, and equivalents.

[0020] The term "and / or" simply describes the relationship between related objects, indicating that there are three possible relationships. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. "A and / or B and / or C" can mean: at least one of A, B, and C exists; A and B exist simultaneously; A and C exist simultaneously; B and C exist simultaneously; or A, B, and C exist simultaneously. Additionally, the character " / " used here generally indicates that the preceding and following related objects have an "OR" relationship.

[0021] Furthermore, any two or more of the following paragraphs, (sub)-bulls, points, actions, behaviors, terms, alternatives, examples, or claims in this application may be logically, reasonably, and appropriately combined to form a particular method. Any sentence, paragraph, (sub)-bulls, point, action, behavior, term, or claim in this application may be implemented independently and separately to form a particular method. Dependencies, such as “based on,” “more specifically,” “preferably,” “in one embodiment,” “in one implementation,” “in an alternative,” may refer only to a possible example in this application and do not limit the specific method.

[0022] For purposes of explanation and non-restriction, specific details such as functional entities, technologies, protocols, and standards are described to provide an understanding of the technologies being described. In other examples, detailed descriptions of well-known methods, technologies, systems, architectures, etc., are omitted to avoid unnecessary ambiguity.

[0023] Those skilled in the art will readily recognize that any network functions or algorithms described herein can be implemented by hardware, software, or a combination of software and hardware. The described functions may correspond to modules, which can be software, hardware, firmware, or any combination thereof. Software implementations may include computer-executable instructions stored on a computer-readable medium such as memory or other types of storage devices. For example, one or more microprocessors or general-purpose computers with communication processing capabilities may be programmed using the corresponding executable instructions to perform the described network functions or algorithms. These microprocessors or general-purpose computers may be formed from application-specific integrated circuits (ASICs), programmable logic arrays, and / or using one or more digital signal processors (DSPs). While several exemplary embodiments described herein are directed to software installed and executed on computer hardware, alternative exemplary embodiments implemented as firmware or hardware or a combination of hardware and software are also within the scope of this specification.

[0024] Computer-readable media include, but are not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, compact disc read-only memory (CD-ROM), magnetic tape, magnetic tape, disk storage, or any other equivalent medium capable of storing computer-readable instructions.

[0025] Wireless communication network architectures (e.g., Long-Term Evolution (LTE) systems, LTE-Advanced (LTE-Advanced, LTE-A) systems, LTE-Advanced Pro systems, or 5G New Radio (NR) radio access networks (RANs) typically include at least one base station (BS), at least one user equipment (UE), and one or more optional network elements providing connectivity to the network. The UE communicates with the network (e.g., Core Network (CN), Evolved Packet Core (EPC) network, Evolved Universal Terrestrial Radio Access Network (E-UTRAN), 5G Core (5GC)), or the Internet) through the RAN established by one or more base stations.

[0026] The UE in this application may include, but is not limited to, a mobile station, a mobile terminal or device, or a user communication wireless terminal. For example, the UE may be a portable wireless device, including but not limited to mobile phones, tablets, wearable devices, sensors, vehicles, or personal digital assistants (PDAs) with wireless communication capabilities. The UE is configured to receive signals through an air interface and transmit signals to one or more cells in a radio access network.

[0027] A BS may include, but is not limited to: Node B (NB) in UMTS, Evolved Node B (eNB) in LTE or LTE-A, Radio Network Controller (RNC) in UMTS, Base Station Controller (BSC) in GSM / GERAN, ng-eNB in ​​an Evolved Universal Terrestrial Radio Access (E-UTRA) BS connected to 5GC, Generation Node B (gNB) in 5G-RAN, and any other device capable of controlling wireless communications and managing radio resources within the cell. A BS can serve one or more UEs through a radio interface.

[0028] The BS can be configured to provide communication services based on at least one of the following radio access technologies (RATs): Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile Communications (GSM, commonly referred to as 2G), GSM Evolution of GSM Enhanced Data Rate Radio Access Network (GERAN), General Packet Radio Service (GPRS), Universal Mobile Telecommunication System (UMTS, commonly referred to as 3G) based on Basic Wideband Code Division Multiple Access (W-CDMA), High-Speed ​​Packet Access (HSPA), LTE, LTE-A, eLTE (evolved LTE, e.g., LTE connected to 5GC), NR (commonly referred to as 5G), and / or LTE-A Pro. However, the scope of this application should not be limited to the protocols mentioned above.

[0029] A BS is operable to provide radio coverage to a specific geographic area using multiple cells forming a radio access network. The BS supports cell operation. Each cell is operable to provide service to at least one UE within its radio coverage area. More specifically, each cell (often referred to as the serving cell) provides service to one or more UEs within its radio coverage area (e.g., each cell schedules downlink and optional uplink resources to at least one UE within its radio coverage area for downlink and optional uplink packet transmissions). The BS can communicate with one or more UEs in a radio communication system through multiple cells.

[0030] Cells can allocate sidelink (SL) resources to support Proximity Service (ProSe) or Vehicle to Everything (V2X) services. Each cell can have coverage areas overlapping with other cells. In Multi-RAT Dual Connectivity (MR-DC) scenarios, the master cell of a Master Cell Group (MCG) or Secondary Cell Group (SCG) can be referred to as a Special Cell (SpCell). A Primary Cell (PCell) can refer to the SpCell of an MCG. A Primary SCG Cell (PSCell) can refer to the SpCell of an SCG. An MCG can refer to the serving cell group associated with a Master Node (MN), including SpCells and optionally one or more Secondary Cells (SCells). An SCG can refer to the serving cell group associated with a Secondary Node (SN), including SpCells and optionally one or more Scells.

[0031] As discussed above, the frame structure for NR should support flexible configuration to adapt to various next-generation (e.g., 5G) communication requirements, such as Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC), Ultra-Reliable and Low-Latency Communication (URLLC), while meeting high reliability, high data rate, and low latency requirements. Orthogonal Frequency Division Multiplexing (OFDM) technology, agreed upon in the 3rd Generation Partnership Project (3GPP), can be used as a benchmark for NR waveforms. A scalable set of OFDM parameters, such as adaptive subcarrier spacing, channel bandwidth, and cyclic prefix (CP), can also be used. Additionally, two coding schemes are considered for NR: (1) Low-Density Parity-Check (LDPC) codes and (2) polar codes. Coding scheme adaptation can be configured based on channel conditions and / or service applications.

[0032] In addition, the following is also considered: within the transmission time interval (TX) of a single NR frame, at least downlink (DL) transmission data, a guard period, and uplink (UL) transmission data should be included. For example, based on the network dynamics of NR, the individual components of the DL transmission data, guard period, and UL transmission data should also be configurable. Furthermore, SL resources can be provided in the NR frame to support ProSe or V2X services.

[0033] Figure 1 This is a schematic diagram of the transmission sequence of a small data transmission (SDT) process provided according to an embodiment of this application. Figure 1This illustrates an SDT procedure with access control mechanisms when UE 11 initiates an SDT procedure with serving RAN 12. In step 101, UE 11 receives an SDT configuration from its serving cell, which is part of RAN 12 serving UE 11, while UE 11 remains in an RRC connected state. In some embodiments, the serving cell can transmit the SDT configuration via UE-specific Radio Resource Control (RRC) signals, such as an RRCReconfiguration message and / or an RRCRelease message (e.g., an RRC release message with a "pause configuration" IE, used to instruct UE 11 to move to an RRC inactive state). After UE 11 receives the SDT configuration, UE 11 can move to an RRC inactive state with the stored SDT configuration. In some embodiments, the SDT configuration may include any combination of the following:

[0034] (1) One or more random access resource configurations (e.g., the location of Physical Resource Blocks (PRBs) and / or the transmission of (selected) preambles by UE 11 and / or a specific set of preambles that UE 11 can select for multiplexed data and preamble sets transmitted to the serving cell during random access (RA)). In some embodiments, the random access resource configuration may include radio resource configurations for UE 11 to initiate a 2-step RA procedure and / or radio resource configurations for UE 11 to initiate a 4-step RA procedure.

[0035] In some embodiments, the random access resource configuration used for the SDT procedure is referred to as RA-SDT configuration, and therefore the SDT procedure implemented through a 2-step / 4-step RA procedure is referred to as an RA-SDT procedure. In some embodiments, UE 11 can receive UE-specific RA-SDT configurations by broadcasting system information (e.g., via SystemInformationBlock1 (SIB1) or by using SDT configuration-specific SIBs (e.g., SDT-specific SIBs, which may be configured by the serving cell as other SIs)). Furthermore, for SDT-specific SIBs that include RA-SDT configurations for the serving cell, UE 11 can receive the SDT-specific SIBs via a dedicated SIB request procedure (so the serving cell can reply to UE 11 with an SDT-specific SIB) or via a system information (SI) on-demand procedure (so the serving cell can reply to UE 11 with an SDT-specific SIB by broadcasting an SDT-specific SIB). In other embodiments, the UE can receive UE-specific RA-SDT configurations by receiving UE-specific control signaling from its serving cell.

[0036] (2) A configured grant (CG) configuration for one or more (Type 1) uplink (UL) configurations (e.g., a PRB location for UE 11 to transmit UL control signals with multiplexed data (e.g., an RRR CresumeRequest message) via a configured Type 1 UL-CG configuration). In some embodiments, the PRB for the UL-CG configuration may appear periodically in the time domain, so as once an available pending packet (e.g., or referred to herein as a small data, UL packet, (small) packet, or small packet) is available. In some embodiments, the Type 1 UL-CG configuration for the SDT procedure is also referred to as the CG-SDT configuration, and therefore the SDT procedure implemented via the Type 1 UL-CG configuration is also referred to as the CG-SDT procedure. In some embodiments, the UE may receive a UE-specific CG-SDT configuration by receiving UE-specific control signaling from its serving cell.

[0037] In some embodiments, the SDT configuration may further indicate that one or more logical channels are available / allowed / enabled for the SDT procedure. Therefore, when one or more packets arrive at Layer 2 (e.g., a Medium Access Control (MAC) entity), the MAC entity can identify which logical channels the arriving packets are associated with. If there are (at least) pending packets in one or more logical channels enabled / configured for the SDT procedure (e.g., when UE 11 is in an RRC inactive state), UE 11 can decide to initiate an SDT procedure. Conversely, when UE 11 is in an RRC inactive state, if there are (at least) pending packets in one or more logical channels where the SDT procedure is not enabled, UE 11 can initiate an RRC recovery procedure with its serving cell. In step 102, UE 11 may (optionally) initiate the execution of an access control mechanism (e.g., a unified access control (UAC) mechanism) for SDT after UE 11 observes one or more suspended packets in at least one logical channel enabled for the SDT procedure. If UE 11 passes the access control mechanism used for the SDT procedure (e.g., UAC result is pass and / or when the total pending uplink packets allowed for SDT are less than or equal to a given data threshold). Conversely, if UE 11 does not pass the access control mechanism, UE 11 may (temporarily) be unable to initiate the SDT procedure.

[0038] In step 103, if UE 11 is connected to the access control mechanism, UE 11 can initiate an SDT procedure with its serving cell. Note that UE 11 can perform step 103 in different ways. In some embodiments, UE 11 can initiate a CG-SDT procedure to transmit UL packets (with or without a multiplexed RRCresumeRequest message, which includes the UE-ID (e.g., an Inactive-Radio Network Temporary Identifier, I-RNTI)) by accessing (at least) one UL-CG physical resource. In some embodiments, UE 11 can initiate an RA-SDT procedure to transmit UL packets (with or without a multiplexed RRCresumeRequest message, which includes the UE-ID (e.g., an I-RNTI)) by accessing (at least) one RA physical resource. In some embodiments, the RA-SDT procedure can be implemented via a 4-step RA procedure (e.g., UE11 can send a UL packet with / without a multiplexed RRCResumeRequest message in MSG3 during the 4-step RA procedure), therefore step 103 is implemented via MSG3 transmission from UE11 to the serving cell. In some other embodiments, the RA-SDT procedure can be implemented via a two-step RA procedure (e.g., UE11 can send a UL packet with / without a multiplexed RRCResumeRequest message in MSGA during the two-step RA procedure), therefore step 103 is implemented via MSGA transmission from UE11 to the serving cell. After the serving cell receives the UL packet in step 103, the serving cell can send a Layer 1 ACK / NACK message (e.g., a HARQ ACK / NACK message) to notify UE1 whether the serving cell has successfully received the UL packet. In some embodiments, the serving cell may further configure dynamic DL assignment / UL authorization, which can be transmitted to UE 11 via Downlink Control Information (DCI) in the Physical Downlink Control Channels (PDCCH) to extend the ongoing SDT procedure. Therefore, during subsequent packet switching, UE 11 may receive a DL packet based on the received dynamic downlink assignment (via (at least) one DCI), and then UE 11 may reply to the serving cell with a HARQ ACK / NACK message (also based on the received DCI associated with the DL packet).Furthermore, during subsequent packet switching, UE 11 can send a UL packet based on the received dynamic UL grant (via (at least) a DCI), and then UE 11 can wait for the serving cell to reply with a HARQ ACK / UL packet NACK message (also based on the received DCI associated with the UL packet). Note that during the SDT procedure (and subsequent packet switching), UE 11 and the serving cell can further exchange Layer 2 ACK / NACK messages (e.g., ARQ ACK / NACK messages) for DL / UL packet switching.

[0039] In step 105, the serving cell may send at least one SDT termination message to UE 11 to terminate the running SDT procedure (which may or may not include the subsequent packet switching in step 104). In some embodiments, the serving cell may send an RRC release message (e.g., an RRCRelease message with a 'pause configuration' IE) to instruct UE 11 to complete the running SDT procedure and remain in an RRC inactive state. In some embodiments, the serving cell may send an RRC release message (e.g., an RRCRelease message without a 'pause configuration' IE) to instruct UE 11 to complete the running SDT procedure and move to an RRC idle state. In some other embodiments, the serving cell may send an RRC recovery message (or RRC rebuild message) to instruct UE 11 to end the running SDT procedure and move to an RRC connected state. In some further embodiments, the serving cell may send an RRC setup message to instruct UE 11 to complete the running SDT procedure and move to an RRC idle state to reconnect with the serving cell.

[0040] Please also note that UE 11 can... Figure 1During the SDT process, UE 11 reselects its serving cell within the serving RAN 12. In some embodiments, UE 11 may receive SDT configuration from serving cell #1 and then move and reselect another cell #2 as the UE's serving cell. In this case, UE 11 may perform access control mechanisms with serving cell #2 in step 102. In some embodiments, UE 11 may reselect another cell (e.g., cell #3) during the SDT process (or during subsequent packet switching). In some embodiments, UE 11 may interrupt the running SDT process (and subsequent packet switching) and remain in an RRC inactive state (and UE 11 may retain or not retain the stored SDT configuration after reselecting cell #3) if cell reselection is performed during the SDT process. In some embodiments, UE 11 may interrupt the running SDT process (and subsequent packet switching) and move to an RRC idle state (and the stored SDT configuration may not be retained by UE 11 after moving to an RRC idle state) if cell reselection is performed during the SDT process.

[0041] Please also note that the SDT process is as follows: Figure 1 As shown, it can be an RRC-embedded SDT process or an RRC-less SDT process, the difference being whether UE 11 generates an RRCResumeRequest message in step 103 and multiplexes it with the UL packet to be processed.

[0042] Figure 2This is a schematic diagram of the transmission sequence of an RA-based SDT procedure according to an embodiment of this application. First, after UE 21 receives an RRC release message from its serving cell, which is part of serving RAN 22, UE 21 can remain in an RRC inactive state using a stored SDT configuration. When UE 21, in its RRC inactive state, has UL data available for transmission and UE 21 passes the access control mechanism for the SDT procedure, UE 21 can initiate an RA-SDT procedure for transmitting the UL data (e.g., if the CG-SDT configuration is deemed invalid). UE 21 can select a 4-step RA type or a 2-step RA type for the RA-SDT procedure. Furthermore, the preamble / Physical Random Access Channel (PRACH) resources used for the RA-based SDT procedure (e.g., the RA preamble / PRACH resources configured for the SDT procedure) and those used for the normal RA procedure (e.g., without an RA preamble configured for the SDT procedure) can be different. Here, UE 21 can select the RA preamble (for MSG1 transmission, as shown in step 201) / PRACH resource configured for the RA-SDT procedure.

[0043] As shown in step 202, after UE 21 sends the RA preamble in step 201, when the RA-SDT procedure is executed, UE 21 may wait for a response from its serving cell (e.g., a Random Access Response (RAR) message) through a contention-based (CB) 4-step RA procedure. The RAR message received in step 202 (e.g., MSG2) may also include a UL dynamic grant for UE 21 to send MSG3 in step 203. In step 203, UE 21 may send an RRC message (e.g., common control channel) through MSG3 (when a 4-step RA type is selected for the RA-SDT procedure) or MSGA (when a 2-step RA type is selected for the RA-SDT procedure) message, MAC CE, and / or UL data. The RRC message may be an RRC Resume Request message. In addition to the RRC message, MAC CE (e.g., buffer status report) and UL data (e.g., data associated with the DRB / SRB used for the SDT procedure) may also be included in MSG3 / MSGA. Please also note that, as Figure 2 As shown, the two-step RA process (for the SDT process) is implemented by merging steps 201 and 203 in the PRACH resources pre-configured for the two-step RA process (therefore step 202 can be omitted in the two-step RA process).

[0044] Once MSG3 / MSGA is sent, UE 21 can monitor the temporary Cell-RNTI (C-RNTI) / C-RNTI / RA-RNTI / MSGB-RNTI / I-RNTI (as shown in step 204) for MSG4 / MSGB, which carries the contention resolution ID. Additionally, the RAN can send RRC messages for MSG4 (when the RA-SDT procedure selects the 4-step RA type) / MSGB (when the RA-SDT procedure selects the 2-step RA type). The RRC message can be an RRCRelease message (with suspendConfig IE) or an RRCResume message. If UE 21 receives the RRCRelease message (with suspendConfig IE), UE 21 can remain in an RRC inactive state, thus terminating the running RA-SDT procedure. In some embodiments, after UE 21 successfully receives MSG4 / MSGB, the RA-SDT procedure can be considered successfully completed (e.g., as an ACK message from the serving cell, indicating that the UL data in MSG3 / MSGA has been successfully received by the serving RAN). However, in some embodiments, as shown in step 205, the RA-SDT procedure can be further extended (or a new subsequent packet exchange procedure can be started after the RA-SDT procedure terminates). For example, in step 205, UE 21 can monitor a specific RNTI (e.g., C-RNTI) in a specific search space for subsequent packet exchange. In some embodiments, the serving cell can transmit one or more UL dynamic licenses in steps 204 / 205 for subsequent packet exchange. The subsequent packet exchange may be the transmission of multiple UL and / or DL ​​packets as part of the SDT procedure, and there is no transition to the RRC connected state (e.g., UE 21 is still in an RRC inactive state). UE 21 can monitor the PDCCH via a specific RNTI (e.g., C-RNTI) to receive dynamic scheduling for new UL and / or DL ​​transmissions and / or corresponding packet retransmissions (e.g., HARQ retransmissions and / or ARQ retransmissions). It should also be noted that in some embodiments, when UE 21 initiates a contention-based random access (CBRA) procedure for the SDT process, UE 21 may perform a contention resolution procedure in step 204. This is because physical RA resources (e.g., the PRB and preamble selected by UE 21 in steps 201 (for a contention-based 4-step RA procedure) / 203 (for a contention-based 2-step RA procedure)) may conflict with one or more other UEs served by the same RAN 22.Therefore, for the contention resolution process, UE 21 may further examine the response message from the serving RAN 22 in step 204 (e.g., by examining the UE-ID, such as C-RNTI / I-RNTI, or control information associated with the UE-ID of the target receiver indicated in MSG4 / MSGB). If UE 21 finds that the target receiver UE in MSG4 / MSGB is not UE 21, UE 21 will determine that a conflict / congestion event has occurred, and then UE 21 will consider the RA process to have failed. After the failure of the running CBRA process, UE 21 may consider initiating another (2-step / 4-step) RA process later for the SDT process. Conversely, if UE 21 finds that the UE-ID or control information associated with the target receiver's UE-ID indicated in MSG4 / MSGB matches UE 21's UE-ID, UE 21 will consider the CBRA process to have succeeded.

[0045] In step 206, the serving RAN 22 may send an RRRCRRelease (with suspendConfig IE) message to keep UE 21 in an RRC inactive state. Upon receiving the RRRCRRelease message (with suspendConfig IE), UE 21 may terminate the RA-SDT procedure based on the RRRCRRelease message, and / or stop monitoring C-RNTI, and remain in an RRC inactive state.

[0046] Please also note that, as Figure 2 The SDT process shown can be an RRC-embedded SDT process or an RRC-less SDT process. The difference lies in whether UE 21 generates an RRCResumeRequest message in step 203 and multiplexes it with the UL packet to be processed.

[0047] Figure 3 This is a schematic diagram of the transmission sequence of the CG-SDT process provided according to an embodiment of this application. In one embodiment, the serving RAN 32 can decide to move UE 31 to an RRC inactive state (e.g., in [location missing]) by sending an RRRRCRelease message (including suspendConfig IE) to UE 31. Figure 1In step 101). The RRCRelease message may include at least the UL-CG configuration to configure UL-CG resources for UE 31. The CG configuration may include, but is not limited to, the following information: CG period, transport block (TB) size, the maximum number of implicit releases of (unused / skipped) CG resources, CG timer, retransmission timer, the number of HARQ processes reserved for CG during SDT, the reference signal received power (RSRP) threshold (SSB) of the synchronization signal / PBCH block, the selection and association between SSB and CG resources, and time alignment (TA) related parameters (e.g., cg-SDT-TimeAlignmentTimer).

[0048] As shown in step 301, UE 31 can perform the CG-SDT procedure based on the configured CG resources, and UE 31 can wait for a response message from the serving RAN 32 in step 302 (e.g., a HARQ ACK / NACK message for the UL packet transmitted in step 301). In some embodiments, the serving cell of UE 31 (which is also part of the serving RAN 32) can send an RRRCelease message (with a "Pause Configuration" IE) to UE 31. After UE 31 receives the RRRCelease message in step 302, UE 31 can terminate the CG-SDT procedure.

[0049] In some embodiments, subsequent packet switching may be part of a CG-SDT process (e.g., UE 31 is still in an RRC inactive state). In step 303, UE 31 may receive dynamic scheduling of UL grants and / or DL ​​assignments and / or corresponding retransmissions (e.g., HARQ retransmissions and / or ARQ retransmissions) via specific RNTIs (e.g., C-RNTI, Configuration Scheduling-RNTI (CS-RNTI), and / or new RNTIs for the SDT process) in the search space (e.g., configured as part of an SDT-specific SDT configuration). UE 31 may monitor the PDCCH via specific RNTIs to receive dynamic scheduling for retransmitting packets transmitted via the stored UL-CG configuration. UE 31 may also perform subsequent data transmissions via CG resources according to the CG configuration (e.g., in...). Figure 1 (In step 101). In step 304, the serving RAN 32 may send an RRRRCRelease message (with suspendConfig IE) to keep UE 31 in an RRC inactive state. Once the RRRRCRelease message (with suspendConfig IE) is received, UE 31 may terminate the CG-SDT procedure based on the RRRRCRelease message.

[0050] Please also note that, as Figure 3 The SDT process shown can be an RRC-embedded SDT process or an RRC-less SDT process. The difference lies in whether UE 31 generates an RRCResumeRequest message in step 301 and multiplexes it with the UL packet to be processed.

[0051] Figure 4 This is a schematic diagram of the transmission sequence of a Notification Area Update (RNAU) process according to an embodiment of this application. In step 401, when the serving cell instructs UE 41 to move to an RRC inactive state (e.g., via an RRC Release message including the RNAU configuration), UE 41 can receive the RNAU configuration from the serving cell, which is part of the serving RAN 42. The RNAU configuration may include an (optional) T380 value and / or a RAN notification area configuration. In some embodiments, the RAN notification area configuration may consist of one or more cell identifiers and / or one or more tracking area codes. Furthermore, each cell identifier or tracking area code may also be associated with a network supported by the cell (e.g., PLMN, SNPN, or PNI-NPN). UE 41 can then move to an RRC inactive state with the stored RNAU configuration. Additionally, UE 41 can start counting a timer T380 to zero by configuring an initial value based on the stored RNAU configuration.

[0052] In some embodiments, UE 41 may be triggered to initiate an RNAU procedure if at least one event is met: (1) the ongoing T380 expires; or (2) UE 41 moves out of the RAN notification area configured by the stored RNAU configuration. As shown in step 402, UE 41 may first perform an access control mechanism for the initiated RNAU procedure, and then UE 41 may be allowed to trigger a random access procedure (e.g., a 2-step random access procedure or a 4-step random access procedure). For RNAU procedures initiated by UE 41 after access control mechanisms (e.g., a unified access control (UAC) mechanism as defined in 3GPP TS 38.331). In step 403, UE 41 sends an RNAU request message to the serving cell. In some embodiments, the RNAU request message may be implemented by UE 41 by sending an RRRCResumerequest message in the MSGA during a 2-step RA procedure. In some other embodiments, the RNAU request message may be implemented by UE 41 by sending an RRRCResumerequest message in the MSG3 during a 4-step RA procedure. Then, after the serving cell receives the RNAU request message from UE 41, the serving cell can reply with an RNAU response message (e.g., a DL RRC message, such as an RRCResume message / RRCSetup message / RRCReject message / RRRCLease message) to be transmitted by UE 41 via MSG4 during the 4-step RA process in step 404 or via MSGB during the 2-step RA process. Finally, UE 41 can determine whether to move to the RRC connected state / RRC idle state or remain in the RRC inactive state based on the RNAU response message from its serving cell. For example, UE 41 can receive an RRCRelease message from the serving cell indicating whether it has an updated RNAU configuration or not, which instructs UE 41 to remain in the RRC inactive state if it has an updated RNAU configuration or the same RNAU configuration stored by UE 41. In some other cases, UE 41 can receive an RRCRelease message from the serving cell instructing UE 41 to move to the RRC idle state, so UE 41 can release the stored RNAU configuration after UE 41 moves to the RRC idle state. In some other cases, UE 41 may receive an RRCResume message from the serving cell to instruct UE 41 to move to an RRC connected state for the restoration of the RRC connection between UE 41 and the serving RAN 42. In some other cases, UE 41 may receive an RRCReject message from the serving cell to reject the RNAU request, and UE 41 may remain in an RRC inactive state after receiving the RRCReject message from its serving cell.

[0053] The above SDT process (e.g., such as) Figure 1 , Figure 2 and Figure 3 (as shown) and RNAU processes (e.g., as shown) Figure 4 As shown, the SDT procedure can be optimized when the UE is able to perform it, and the UE is also requested to update its location via the RNAU procedure. For example, the UE may want to initiate the RNAU procedure, but the UE attempting to execute the RNAU procedure may be temporarily blocked by an access control mechanism (e.g., a UAC mechanism). Then, during the period when the RNAU procedure is blocked, the UE can also be triggered to initiate the SDT procedure. At the same time, the UE can execute the access control mechanism for the SDT procedure, and can be blocked by the UE attempting to execute the SDT procedure. In this case, if the UE initiates the SDT procedure to the serving RAN (e.g., when the UAC result of the SDT procedure is "passed" and the RNAU procedure is suspended / blocked on the UE side). However, in some embodiments, the RNAU procedure can only be removed / released / discarded if the SDT procedure is successfully executed (e.g., after the UE successfully sends the RRRCResumeRequest message to the serving cell, or after the UE receives the (HARQ)ACK message from the serving RAN for sending a UL packet during the SDT procedure). In this application, the RNAU procedure and the SDT procedure are considered together for the enhancement mechanism.

[0054] Idle Mode SDT can be sent by the UE to the RAN in the UL direction in the following two ways:

[0055] 1. UL-CG configuration; and

[0056] 2. RA process.

[0057] Idle modes can include NR RRC inactive state (or RRC_INACTIVE state), NR RRC idle state (or RRC_IDLE state), LTE RRC inactive state, and LTE RRC idle state (with a paused RRC configuration). Please note that the mechanisms / implementations in this application may not be limited to the previously listed RRC states.

[0058] The serving cell can pre-configure radio resources (e.g., UL-CG, physical resources, or preambles for the RA procedure) to the UE, enabling the UE to send UL packets indicating RRC inactivity to the serving cell while the UE is inactive. For example, the serving cell can send UL-CG configuration, preambles, or PRACH resources (e.g., via broadcast SI or RRC signals, such as RRCReconfiguration or RRCReconfiguration messages) for UL-direction SDT via downlink (DL) control signals.

[0059] In some embodiments, (small) packets can be multiplexed with RRC signals (e.g., RRC ResumeRequest or RRC ResumeRequest1 messages) in a TB within the MAC layer (or physical layer). The UE transmits the (small) packets to the RAN via an RA procedure (e.g., via MSG3 in a 4-step RA procedure or MSGA in a 2-step RA procedure) or via UL-CG configuration. Note that (small) packets multiplexed with RRC signals can be referred to as RRC-embedded packet transmissions in this application. On the other hand, the serving RAN (e.g., the UE's serving cell) can identify the source (e.g., the UE) of the received (small) packets by decoding the RRC signals. The serving cell can then decode the (small) packets received from the UE using an access stratum (AS) security key associated with the UE, which can be stored in both the serving RAN and the UE.

[0060] In some embodiments, (small) packets may not be multiplexed with RRC signals in the TB (e.g., RRCResumeRequest or RRCResumeRequest1 messages). The UE transmits the (small) packets to the RAN via the RA procedure (e.g., via MSG3 or MSGA) or via UL-CG configuration. Note that in this application, (small) packets not multiplexed with RRC signals may be referred to as RRC-less packet transmission. The serving RAN (e.g., the UE's serving cell) may transmit the UL (small) packets via other methods (e.g., based on the location of the UL-CG in the time / frequency domain or Random Access Channel (RACH) resources) or based on UE-specific identifiers (e.g., short I-RNTI, (full) I-RNTI, C-RNTI, CS-RNTI).

[0061] The UE can be configured to perform RRC-embedded / RRC-less packet transmission based on explicit instructions from the serving cell (e.g., via broadcast system information (SI) or UE-specific RRC signals, such as the 'pause configuration' IE included in the RRCRelease message). In some embodiments, the UE can be predefined / preconfigured / preinstalled / specified to perform RRC-less packet transmission when the UE applies the RA procedure for (small) packet transmission and is configured / preconfigured / specified to perform RRC-less packet transmission when a pre-configured UL authorization is applied for the SDT procedure. In some embodiments, when the RA procedure for the SDT procedure is allowed / configured / enabled to the UE, the UE can determine whether to perform RRC-embedded packet transmission or RRC-less packet transmission based on different conditions. For example, when the UE does not have a valid UE-specific identifier (e.g., short I-RNTI, (full) I-RNTI, C-RNTI, CS-RNTI), the UE can perform RRC-embedded packet transmission. For example, when the packet size is greater than or equal to a given or predefined threshold, the UE can perform RRC-less packet transmission.

[0062] In some embodiments, when a pre-configured UL license is allowed / configured for the SDT procedure, the UE can determine whether to perform RRC-embedded packet transmission or RRC-less packet transmission based on different conditions. For example, the UE can perform RRC-embedded packet transmission when it does not have a valid UE-specific identifier (e.g., short I-RNTI, (full) I-RNTI, C-RNTI, CS-RNTI). For example, the UE can perform RRC-less packet transmission when the packet size is greater than or equal to a given or predefined threshold.

[0063] In some embodiments, if both the RA procedure for the SDT procedure and the pre-configured UL license for the SDT procedure are allowed / configured / enabled, the UE can perform the SDT procedure only. In other words, the RRC-embedded packet transmission mechanism can be configured to have a higher priority than the RRC-less packet transmission mechanism. Furthermore, in some embodiments, the UE can fall back to the RRC-less packet transmission mechanism when a failure event occurs during RRC-embedded packet transmission.

[0064] In some embodiments, if the RA procedure for the SDT procedure and the pre-configured UL authorization for the SDT procedure are allowed / configured / enabled, the UE can perform RRC-less packet transmission for the SDT procedure. In other words, the RRC-less packet transmission mechanism can be configured to have a higher priority than the RRC-embedded packet transmission mechanism. Furthermore, in some embodiments, the UE can fall back to the RRC-embedded packet transmission mechanism when a failure event occurs during RRC-less packet transmission.

[0065] In some embodiments, the aforementioned "fallback" mechanism can be applied to scenarios where the UE is triggered to change the SDT procedure from an RRC-less packet transmission mechanism to an RRC-embedded packet transmission mechanism. In some implementations, the aforementioned "fallback" mechanism can be applied to scenarios where the UE is triggered to change the SDT procedure from an RRC-embedded packet transmission mechanism to an RRC-less packet transmission mechanism.

[0066] In some embodiments, the aforementioned "fallback" mechanism can be applied to scenarios where the UE is triggered to change the SDT procedure to the RA procedure via UL-CG configuration. In some embodiments, the aforementioned "fallback" mechanism can be applied to scenarios where the UE is triggered to change the SDT procedure to the UL-CG configuration via the RA procedure. Furthermore, in some embodiments, when the fallback mechanism is enabled for the UE (falling back from the UL-CG configuration to the RA procedure or vice versa), the UE may not be allowed to change packet transmissions after the RRC-embedded / RRC-less UE triggers the fallback mechanism (e.g., transmitting the same TB).

[0067] In some embodiments, if the UE performs RRC-less packet transmission through one or more RA procedures for the SDT procedure, the UE can still perform RRC-less packet transmission (e.g., by transmitting the same TB after the UE backs down to apply one or more UL-CGs to the SDT procedure, multiplexed in the MAC entity).

[0068] In some embodiments, if the UE performs RRC-embedded packet transmissions through one or more RA procedures for the SDT procedure, the UE can still perform RRC-embedded packet transmissions for the SDT procedure after the UE rolls back to apply one or more UL-CGs.

[0069] In some embodiments, if the UE performs RRC-less packet transmission for the SDT procedure via one or more UL-CGs, the UE can still perform RRC-less packet transmission for the SDT procedure after the UE falls back to initiate one or more RA procedures.

[0070] In some embodiments, if the UE performs RRC-embedded packet transmission for the SDT procedure via one or more UL-CGs, the UE can still perform RRC-embedded packet transmission for the SDT procedure after the UE falls back to initiate one or more RA procedures.

[0071] In some embodiments, the fallback mechanism may include an Information Element (IE) to explicitly configure the UE to perform RRC-embedded packet transmission or RRC-less packet transmission after the fallback mechanism is triggered. For example, if the fallback mechanism is allowed / configured / enabled for the UE (e.g., switching from UL-CG configuration for SDT procedures to RA procedures for SDT procedures), the UE can be configured to perform RRC-embedded packet transmission (by receiving an explicit indication to configure the UE to perform RRC-embedded packet transmission only via the RA procedure).

[0072] In some embodiments, the fallback mechanism can be triggered when the UE transmits the same TB. Alternatively, when the fallback mechanism is triggered, different mechanisms can be applied to transmit the same TB. In some embodiments, the fallback mechanism can be triggered when the UE transmits different TBs, thus different mechanisms can be applied to transmit different TBs when the fallback mechanism is triggered.

[0073] T380 counting mechanism

[0074] In the RRCRelease message (e.g., as Figure 4As shown in step 401, the UE can configure a timer T380 for performing a periodic RAN Notification Area Update (RNAU) procedure. As shown in Table 1, the UE can start counting T380 based on the configuration value (e.g., the T380 value) in the RRRRCRelease message instructing the UE to move to an RRC inactive state (e.g., when the UE receives an RRRRCRelease message with suspendConfig IE). The UE can initiate the RNAU procedure while in an RRC inactive state. For example, each time the UE receives an RRRRCRelease message with T380_Value, the UE can start counting T380 to zero (e.g., by setting the initial value of T380 to the configuration value (e.g., T380_Value) received by the UE in the RRRRCRelease message). Then, after the count T380 expires, the UE can trigger an RNAU procedure with the serving cell (or associated BS). The UE behavior during T380 counting is shown in Table 1. Furthermore, when the UE receives an RRC signal, such as an RRCRelease message, an RRCSetup message, or an RRCRelease message, it can stop the T380 count. In some embodiments, the UE receives an RRC signal and / or does not configure T380_Value in the received RRC signal (e.g., the UE receives an RRCRelease message without providing T380_Value, so the UE can stop counting T380 and then clear the stored value of T380). Note that in some embodiments, the UE may not configure timer T380 in the RRCRelease message (e.g., as...). Figure 4 (as shown in step 401) for the UE to perform a periodic RNAU procedure. In this case, the UE can stop T380 (in addition, if the UE has stored T380_value as part of the stored RNAU configuration, the originally stored T380_value will also be removed / released), and then the UE may not perform the periodic RNAU procedure. Also note that in some embodiments, the RRC Release message including the RNAU configuration (e.g., as shown in step 401) is used for the UE to perform a periodic RNAU procedure. Figure 4 Step 401 (as shown) may include SDT configuration (e.g., as shown) Figure 1 The same signal (e.g., the same RRC Release message) shown in step 101. In some other implementations, the UE can receive the RNAU configuration via a different RRC Release message (e.g., as shown in step 101). Figure 4 Step 401 is shown) and SDT configuration (e.g., as shown) Figure 1 (See step 101).

[0075] Table 1

[0076]

[0077] VarPendingRNA-Update

[0078] In some embodiments, the UE may perform the RNAU procedure when T380 expires or when the UE removes the stored RNA. However, the RNAU procedure may be pending or paused within the UE. Therefore, the parameter "VarPendingRNA-Update" (or pendingRNA-Update) may be applied to the UE.

[0079] VarPendingRNA-Update indicates whether the RNAU process is pending or paused in the UE. A Boolean variable set to true (e.g., VarPendingRNA-Update) means that the RNAU process is waiting or paused. More details about the “VarPendingRNA-Update” IE are shown in Table 2.

[0080] Table 2

[0081]

[0082] The UE can set the stored VarPendingRNA-Update to true / false during the conditions shown in Table 3.

[0083] Table 3

[0084]

[0085]

[0086] With the introduction of (RRC-embedded / RRC-less) packet transmission, the implementation related to VarPendingRNA-Update can improve the system efficiency of the UE. Detailed design is disclosed below.

[0087] VarRA-Report

[0088] In some embodiments, the UE can record RA-related information in VarRA-Report.

[0089] VarRA-Report includes RA-related information. More details about the “VarRA-Report” IE are shown in Table 4.

[0090] Table 4

[0091]

[0092]

[0093] In addition, the content of the 'ra-ReportList-r16' IE can (at least) include the following IEs as shown in Table 5.

[0094] Table 5

[0095]

[0096] On the other hand, the serving cell can query the VarRA-Report from the UE by sending a UEInformationRequest message to the UE (e.g., by including an IE (e.g., 'ra-ReportReq=true') in the UEInformationRequest message). Upon receiving the UEInformationRequest message (with ra-ReportReq=true), the UE can report the stored VarRA-Report to the serving cell in a UEInformationResponse message. Furthermore, the stored VarRA-Report can be discarded after the UEInformationResponse message, confirmed by a lower layer (e.g., the PHY layer), is successfully delivered (e.g., by the UE's RRC entity).

[0097] Because (RRC-embedded / RRC-less) packet transmission can be performed through the RA procedure, a method for using the SDT procedure designed with VarRA-Report is provided.

[0098] In this application, the RNAU procedure can be executed concurrently with the SDT procedure (or the UE may have a pending RNAU procedure when the UE is triggered to begin the SDT procedure). It is important to note that the purpose of a timer-based (e.g., T380) RNAU procedure is to provide a maximum time period so that the serving RAN can identify the UE's location after a certain period (e.g., T380_Value). Therefore, T380_Value can be considered as the maximum time period the RAN can tolerate the UE remaining in an RRC inactive state without any data (or signal) exchange. The serving RAN can identify the UE's state each time the UE re-establishes its RRC connection with the serving RAN.

[0099] However, from the RAN / UE perspective, a UE in an RRC inactive state may not need to count T380 (so that the UE does not trigger the RNAU procedure so frequently), because the UE can perform the SDT procedure while remaining in an RRC inactive state. Furthermore, the serving cell can identify the UE state when the UE sends (small) packets to the serving cell, regardless of whether the SDT procedure is performed via the RA procedure or via a pre-configured UL-CG. However, a timer-based RNAU procedure may still be necessary because the traffic patterns of (small) packet arrivals (for a UE in an RRC inactive state) can be unpredictable, thus triggering the UE to perform the RNAU procedure for a given time period threshold may be necessary.

[0100] In some embodiments (e.g., embodiment #1), this application provides a method for reducing unnecessary RNAU processes (in order to reduce unnecessary power consumption and signal overhead) when the UE performs the SDT process.

[0101] Furthermore, for timer-based RNAU procedures in the 3GPP technical specifications, the 'pendingRNA-Update'IE may affect the RNAU procedure. Therefore, the impact of pending RNA updates is considered in the SDT procedure. Related designs are disclosed in the following embodiments (e.g., Embodiment #3). To support RRC-embedded packet transmission, some detailed designs regarding the UE's selection of the RRCResumeRequest / RRRCResumeRequest1 message or a pre-configured UL-CG with (small) packets to be sent during the (2-step / 4-step) RA procedure are provided in the following embodiments (e.g., Embodiment #2). Additionally, optimizations regarding VarRA-Report are disclosed in the following embodiments (e.g., Embodiment #4).

[0102] Example #1: T380 Counting Mechanism

[0103] The T380 counting mechanism is shown in Table 6.

[0104] Table 6

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113] In some embodiments, the UE can be configured to enable or disable the serving cell from performing RRC-less packet transmission and / or RRC-embedded packet transmission. There are four methods for configuring RRC-less packet transmission and / or RRC-embedded packet transmission.

[0114] 1. UE-specific

[0115] In some embodiments, the configuration can be UE-specific. The UE can receive the configuration via a UE-specific RRC signal (e.g., an RRCReconfiguration or RRCRelease message). Furthermore, the configuration can be applied to packet transmissions via UL-CG or RA procedures.

[0116] 2. Resource-Related

[0117] In some embodiments, this configuration may be associated with a specific UL-CG configuration and / or RACH resource configuration.

[0118] 3. Residential Community - Specific

[0119] In some embodiments, the configuration may be cell-specific. Furthermore, the UE can receive the configuration via broadcast SI and / or via SI on-demand procedures.

[0120] 4. Region-Specific

[0121] In some embodiments, the configuration can be region-specific. For example, the UE can receive the configuration via broadcast SI and / or via an SI on-demand process associated with a system information region ID, which is broadcast by one or more cells in the serving RAN.

[0122] In some embodiments, the UE can perform RRC-less packet transmission or RRC-embedded packet transmission based on some standards and / or some implicit methods. For example, the UE can determine whether to perform RRC-embedded packet transmission or RRC-less packet transmission based on the size of the UL authorization. For example, the UE can determine whether to perform RRC-embedded packet transmission or RRC-less packet transmission based on whether the UE is configured with a specific UE identity (e.g., I-RNTI, C-RNTI, CS-RNTI, and / or a new RNTI for RRC-embedded or RRC-less packet transmission). For example, the UE can determine whether to perform RRC-embedded packet transmission or RRC-less packet transmission based on a new timer. The new timer can be used by the UE to periodically send RRC-embedded packet transmissions. When the new timer expires, the UE needs to perform RRC-embedded packet transmission (and the UE can restart the new timer (e.g., T380)).

[0123] Continuing, for the UE side, the UE location update mechanism previously mentioned in this application can be UE-specific (e.g., configured by UE-specific RRC signals, such as the RRCRelease message as part of the SDT configuration) / resource-related (e.g., configured as part of the CG-SDT configuration or RA-SDT configuration) / cell-specific (e.g., configured as part of the SDT configuration by cell-specific broadcast system information) / area-specific (e.g., configured by cell-specific broadcast system information with a specific system information area ID).

[0124] Note that the UE can perform different restart methods. In some embodiments, the UE can restart a counter / timer that has been stopped by the UE (e.g., T380 in Table 3) so that the count is zero when the UE restarts T380. In other embodiments, the UE can restart a counter / timer that is still counting to a configured value (e.g., an initial value, T380_Value, which is received by the UE from the serving cell in the Universal Subscriber Identity Module (USIM) via UE-specific control signals, broadcast SI, or pre-installed / configured). Then, after the UE sets T380 to the initial value, the UE can keep the T380 count at zero.

[0125] The UE can perform an RNAU procedure upon the expiration of T380. In some embodiments, the RNAU procedure (e.g., triggered by the expiration of T380) can be terminated by the UE when it receives SDT configuration from the serving cell. For example, after the UE receives SDT configuration from the serving cell, the count T380 can be released and the stored T380_Value can be removed by the UE. In some embodiments, the count T380 can be stopped when the UE receives SDT configuration from the serving cell. Then, if the stored SDT configuration becomes invalid (e.g., when the UE (re)selects to another serving cell or the UE moves out of the valid area of ​​the stored SDT configuration), the UE can restart T380. In some additional embodiments, if the serving RAN has already configured SDT configuration for the UE, the serving RAN may not configure T380_Value for the periodic RNAU for the UE (e.g., in other words, if the UE has SDT configuration, the UE may not expect to trigger a periodic RNAU / RNAU procedure).

[0126] Example #2: RRC recovery message transmission for RRC-embedded packet transmission

[0127] For UE requests to restore RRC connection with the serving RAN, two RRC signal formats, RRCResumeRequest1 and RRCResumeRequest messages, are designed. Furthermore, the UE can send RRC signals (e.g., RRCResumeRequest1 or RRCResumeRequest messages) to the serving cell via (small) packets. However, design details (e.g., the signals the UE can choose when requesting RRC connection restoration via the SDT procedure) are not explicitly disclosed. Therefore, in this application, details regarding the SDT method are described in Table 7 for RRC restoration messages with the SDT procedure.

[0128] Table 7

[0129]

[0130]

[0131]

[0132] Example #3: PendingRNA-Update Enhancement

[0133] When a UE is triggered to send an RNAU request message to the serving cell (e.g., when the UE moves out of a range defined in a stored RNA or T380 that has expired), the triggered RNAU request message may be suspended in the UE for some reason. However, there are some issues regarding how the UE configures pendingRNA-Update in different situations. For example, since the RRCresumeRequest message may or may not be transmitted through the SDT procedure (e.g., through the RA procedure or through a pre-assigned or pre-configured UL-CG), a "pending RNA-Update" modification is provided during the SDT procedure. Several mechanisms for the 'pendingRNA-Update' modification are described in Table 8 in this application.

[0134] Table 8

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141]

[0142]

[0143]

[0144]

[0145] Example #4: VarRA Report and VarUL-CG Report

[0146] VarRA Report

[0147] In some embodiments, when the RA procedure is triggered by the UE for the SDT procedure, some new IEs are provided in the VarRA-Report. Table 9 illustrates the available IEs included in the VarRA report.

[0148] Table 9

[0149]

[0150]

[0151] VarUL-CG Report

[0152] In some embodiments, if an SDT procedure fails on a corresponding UL-CG configuration, the UE can release or delete the SDT procedure through one (or more) UL-CG configurations (e.g., when a successive failure event is detected when the UE attempts to transmit pending packets on the corresponding UL-CG configuration). In some embodiments, the UE can report an identifier associated with the corresponding UL-CG configuration in a VarUL-CG-Report. The UE can transmit the VarUL-CG-Report via a UEAssistanceInformation transmission procedure or via a response from the serving cell (e.g., the VarUL-CG-Report can be included in a UEInformationResponse message sent back to the serving cell after receiving a UEInformationRequest message from the serving cell) after the UE restores its RRC connection with the serving cell. In some embodiments, when a packet transmission failure event occurs while the UE is performing an SDT procedure, the UE can be triggered to perform an RRC connection recovery procedure (e.g., by sending an RRCResumeRequest message with a recovery reason, such as 'ULpacketTx-Failure') to an RRC inactive state. Then, after the UE restores the RRC connection, the UE can report the availability of VarUL-CG-Report to the serving cell (e.g., by sending a 'VarUL-CG-Report available' indicator to the serving cell). After the serving cell receives the 'VarUL-CG Report available' indicator from the UE, the serving cell can request the UE to send a VarUL-CG-Report to the serving cell (e.g., by sending a UL-CG report request message via the DL RRC signal). After the UE receives the UL-CG report request message, the UE can report the stored VarUL-CG Report to the serving cell via the UL RRC signal. Furthermore, when the stored VarUL-CG Report is successfully delivered to the serving cell, the stored VarUL-CG Report can be released / removed.

[0153] More specifically, in some embodiments, when the UE is in the RRC_INACTIVE state, it can send the previously mentioned VarRA-Report / VarUL-CG-Report via MSG3, MSGA, and / or CG. In some embodiments, the VarRA-Report / VarUL-CG-Report can be triggered and / or transmitted periodically. In some embodiments, the VarRA-Report / VarUL-CG-Report can be triggered and / or transmitted when the UL license size of MSG3, MSGA, and / or CG is higher than (or equal to) a given threshold. In some embodiments, the UE can obtain the value of the given threshold by broadcasting SI or UE-specific RRC control signals. In some embodiments, the value of the given threshold can be predefined in the 3GPP technical specifications or pre-installed in the USIM.

[0154] Please also note that the above embodiments apply to NR protocols, 3GPP radio access technologies (e.g., E-UTRA), and non-3GPP RATs, but are not limited thereto. For example, the proposed mechanisms or implementations mentioned above can be applied to other RATs, such as E-UTRA, Wi-Fi, Bluetooth, or unlicensed NR bands, E-UTRA Licensed Assisted Access (LAA), NR SL operation (e.g., NR PC5 interface), LTE V2X service, LTE ProSe, and LTE SL operation (e.g., LTE PC5 interface).

[0155] Figure 5 This is a flowchart of a method 500 for updating a UE's location in an RRC inactive state, according to an embodiment of this application. In action 502, after the UE receives a first RRC release message (e.g., an RRC Release message) from the RAN instructing the UE to move to or remain in an RRC inactive state, the UE performs a UE location update procedure (e.g., an RNAU procedure) with the RAN serving the UE. In action 504, when the UE performs an SDT procedure (e.g., a CG-SDT / RA-SDT procedure) with the first cell in the RAN that is in an RRC inactive state, the UE determines whether to suspend the UE location update procedure. In action 506, when the SDT procedure (e.g., as...) is performed... Figure 2 The RA-SDT procedure shown and / or as follows Figure 3 When the CG-SDT procedure shown terminates, the UE determines whether to start or restart the UE location update procedure (e.g., regardless of whether the result of the SDT procedure is success, failure, or a fallback to a non-SDT procedure. In some embodiments, the non-SDT procedure may include an RRC recovery procedure and an RRC establishment procedure).

[0156] In some embodiments, the UE can pause the UE location update process while the UE is performing an SDT procedure, and can do so while the UE is performing an SDT procedure (e.g., CG-SDT / RA-SDT procedure), where the RNAU timer is started by the UE after the UE receives the first RRRCRelease message. Therefore, the UE can stop performing the UE location update process during the SDT procedure by stopping the RNAU timer.

[0157] In some embodiments, the UE can restart after the UE terminates the SDT process to count the stopped RNAU timer.

[0158] In some embodiments, the UE may continue to count the RNAU timer (e.g., T380) while the UE is performing the SDT procedure, wherein the UE starts the RNAU timer after receiving the first RRC release message, and the UE may pause the RNAU procedure when the RNAU timer times out during the SDT procedure.

[0159] In some embodiments, the UE can restart counting the RNAU timer after the UE terminates the SDT process.

[0160] In some embodiments, after the UE reselects to a second cell, when the UE restarts another SDT procedure with a second cell that does not belong to the RAN notification area stored in the UE, the UE may suspend the RNAU procedure RAN through the cell reselection procedure.

[0161] In some embodiments, the UE may update the RNAU configuration stored in the UE after the UE terminates the SDT procedure by receiving a second RRC release message including the RNAU configuration from the first cell, and may start an RNAU timer based on the updated RNAU configuration.

[0162] In some embodiments, the UE can perform the SDT procedure via a 2-step / 4-step random access procedure or via one or more UL-CG configurations stored in the UE.

[0163] In some embodiments, when the UE receives at least one of one or more DL and UL dynamic grants configured by the first cell during the SDT procedure, the UE may extend the SDT procedure.

[0164] In some embodiments, after the UE successfully sends an RRC recovery request message (e.g., RRCResumeRequest message or RRCResumeRequest1) to the first cell, the UE may set the pending RNA record (e.g., PendingRNA-Update) to a 'fake' SDT procedure.

[0165] In some embodiments, when the UE successfully receives an RRC rejection message (e.g., an RRCReject message) from the first cell during the SDT procedure, the UE can set the pending RNA record (e.g., PendingRNA-Update) to 'true'.

[0166] Figure 6 This is a block diagram of a node 600 implementing wireless communication according to an embodiment of this application.

[0167] like Figure 6 As shown, node 600 may include a transceiver 620, a processor 626, a memory 628, one or more presentation components 634, and at least one antenna 636. Node 600 may also include an RF spectrum band module, a BS communication module, a network communication module and a system communication management module, input / output (I / O) ports, I / O components, and a power supply. Figure 6 (Not explicitly shown in the text).

[0168] Each of these components can communicate with each other directly or indirectly via one or more buses 640. Node 600 can be an execution reference. Figure 5 The various functions of the UE or BS are publicly available.

[0169] A transceiver 620, having a transmitter 622 (e.g., transmitting / transmission circuitry) and a receiver 624 (e.g., receiving / reception circuitry), can be configured to transmit and / or receive time and / or frequency resource allocation information. In some embodiments, the transceiver 620 can be configured to transmit in different types of subframes and time slots, including but not limited to usable, unusable, and flexibly usable subframe and time slot formats. The transceiver 620 can be configured to receive data and control channels.

[0170] Node 600 may include various computer-readable media. Computer-readable media can be any available media accessible by Node 600, and includes both volatile and non-volatile media, and both removable and non-removable media. As an example and not a limitation, computer-readable media may include computer storage media and communication media. Computer storage media includes both volatile and non-volatile media, and both removable and non-removable media, implemented through any method or technology for storing information such as computer-readable instructions, data structures, program modules, or data.

[0171] Computer storage media include RAM, ROM, EEPROM, flash memory or other storage technologies, CD-ROM, Digital Versatile Disks (DVDs) or other optical disc storage devices, magnetic tapes, magnetic tapes, disk storage devices or other magnetic storage devices. Computer storage media do not contain transmitted data signals.

[0172] Communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals employing mechanisms such as carrier waves or other transmission mechanisms, and include any information transmission medium. The term "modulated data signal" refers to a signal whose characteristics are set or altered by encoding information into the signal. For example, and not as a limitation, communication media include wired media, such as wired networks or direct wired connections; and wireless media, such as acoustic, RF, infrared, and other wireless media. Any combination of the above should also be included within the scope of computer-readable media.

[0173] Memory 628 may include computer storage media in the form of volatile and / or non-volatile memory. Memory 628 may be removable, non-removable, or a combination thereof. Exemplary memories include solid-state memory, hard disk drives, optical disk drives, etc. Figure 6 As shown, memory 628 may store computer-readable, computer-executable instructions 632 (e.g., software code), which, when executed, cause processor 628 to perform, as illustrated herein by reference, for example. Figures 1 to 5 The various functions described herein. Alternatively, instruction 632 may not be executed directly by processor 626, but may be configured to cause node 600 (e.g., when compiled and executed) to perform the various functions described herein.

[0174] Processor 626 (e.g., having processing circuitry) may include intelligent hardware devices, such as a central processing unit (CPU), microcontroller, ASIC, etc. Processor 626 may include memory. Processor 626 can process data 630 and instructions 632 received from memory 628, as well as information transmitted via transceiver 620, baseband communication module, and / or network communication module. Processor 626 can also process information to be transmitted to transceiver 620 for transmission via antenna 636, and information to be transmitted to network communication module for transmission to the core network.

[0175] One or more presentation components 634 present data instructions to a person or other device. Exemplary presentation components 634 include display devices, speakers, printing components, vibrating components, etc.

[0176] It is evident from the above description that various techniques can be used to implement the concepts without departing from the scope of the concepts described in this application. Furthermore, although these concepts have been specifically described with reference to certain embodiments, those skilled in the art will recognize that changes in form and detail can be made without departing from the scope of those concepts. Therefore, the described embodiments are to be considered illustrative rather than restrictive in all respects. It should also be understood that this application is not limited to the specific embodiments described above, and many rearrangements, modifications, and substitutions are possible without departing from the scope of this disclosure.

Claims

1. A method of updating a location of a user equipment, UE, in a radio resource control, RRC, inactive state, performed by the UE, characterized in that, The method comprises: determining whether a small data transmission (SDT) procedure is ongoing in case of an event triggering a location update procedure; and initiating the location update procedure in case the SDT procedure is not ongoing.

2. The method of claim 1, wherein, The method further comprises: not initiating the location update procedure in case the SDT procedure is ongoing.

3. The method of claim 1, wherein the location update procedure comprises a radio access network (RAN) notification area update (RNAU) procedure; the event comprises at least one of (i) an RNAU timer expiry, or (ii) the UE moving out of a stored RAN notification area (RNA).

4. The method of claim 3, wherein, The method further comprises: starting the RNAU timer upon receiving a first value configured for the RNAU timer in a first RRC release message, wherein the first RRC release message indicates the UE changing to the RRC inactive state; and keeping the RNAU timer running in the ongoing SDT procedure.

5. The method of claim 3, wherein, The method further comprises: receiving a first RRC release message as a response of the ongoing SDT procedure; restarting the RNAU timer with a timer value configured for the RNAU timer in case the first RRC release message comprises the timer value; and stopping the RNAU timer in case the first RRC release message does not comprise the timer value.

6. The method of claim 3, wherein, The method further comprises: setting a parameter indicating whether the RNAU procedure is pending to "true" in case of both: the RNAU timer expiring; and the UE receiving a RRC reject message in the ongoing SDT procedure.

7. The method of claim 3, wherein, The method further comprises: setting the parameter indicating whether the RNAU procedure is pending to "false" in case the UE initiates the SDT procedure.

8. The method of claim 1, wherein the SDT procedure comprises one of an RRC-based SDT procedure or an RRC-less SDT procedure, the RRC-based SDT procedure comprises sending a first packet embedded in an RRC resume request message, the RRC-less SDT procedure comprises sending a second packet not embedded in an RRC resume request message.

9. The method of claim 1, wherein the location update procedure comprises a tracking area update (TAU) procedure in case the UE is configured to change to the RRC inactive state or an RRC idle state.

10. The method of claim 1, wherein the SDT procedure comprises one of a random access (RA) based SDT procedure or a configured grant (CG) based SDT procedure; and the SDT procedure is implemented over an evolved universal terrestrial radio access (E-UTRA) protocol or a new radio (NR) protocol.

11. A user equipment (UE) for updating the UE's location during Radio Resource Control (RRC) inactivity, characterized in that, The UE comprises: one or more processors; and at least one memory coupled to the processor, wherein the at least one memory stores computer-executable instructions that, when executed by at least one of the one or more processors, cause the UE to perform the method of any one of claims 1-10.

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