Enhanced mechanisms for uu interface for mt sdt

Abstract

Methods and apparatuses for MT SDT are disclosed. A terminal device includes a processor; and a transceiver coupled to the processor, wherein the processor is configured to: receive, from a network device via the transceiver, a message for mobile terminated (MT) small data transmission (SDT) when the terminal device is in a radio resource control (RRC) non-connected state with the network device; and determine a DL data reception procedure for the MT SDT according to the message for the MT SDT.

Description

TECHNICAL FIELD

[0001] The subject matter disclosed herein relates to wireless communications, and more particularly to methods and apparatus for MT SDT. BACKGROUND

[0002] The following abbreviations are defined below in the Description: New Radio (NR), Very Large Scale Integration (VLSI), Random Access Memory (RAM), Read Only Memory (ROM), Erasable Programmable Read Only Memory (EPROM or Flash memory), Compact Disc Read Only Memory (CD-ROM), Local Area Network (LAN), Wide Area Network (WAN), User Equipment (UE), Evolved Node B (eNB), Next Generation Node B (gNB), Uplink (UL), Downlink (DL), Central Processing Unit (CPU), Graphics Processing Unit (GPU), Field Programmable Gate Array (FPGA), Orthogonal Frequency Division Multiplexing (OFDM), Radio Resource Control (RRC), User Entity / Equipment (Mobile Terminal), Transmitter (TX), Receiver (RX), Small Data Transmission (SDT), Configured Grant (CG), CG-based SDT (CG-SDT), Random Access Channel (RACH), RACH-based SDT (RA-SDT), Reference Signal Received Power (RSRP), Mobile Originated (MO), Mobile Terminated (MT), Radio Access Network (RAN), 5G Core (5GC), Physical Random Access Channel (PRACH), Time Alignment or Timing Advance or Timing Adjustment (TA), TA Timer (TAT), Timing Advance Group (TAG), Primary TAG (PTAG), Secondary TAG (STAG), Transmission- Reception Point (TRP), Physical Uplink Control Channel (PUCCH), Physical Uplink Shared Channel (PUSCH), Time Division Multiplexing (TDM), Control Resource Set (CORESET), Reference Signal (RS), Inter-Cell Beam Management (ICBM), Multiple Input Multiple Output (MIMO), Data Radio Bearer (DRB), Signaling Radio Bearer (SRB), Earthquake and Tsunami Warning System (ETWS), Commercial Mobile Alert System (CMAS), Radio Network Temporary Identifier (RNTI), Paging RNTI (P-RNTI), Physical Downlink Control Channel (PDCCH), Paging Control Channel (PCCH), Cyclic Redundancy Check (CRC), Reference Signal Received Power (RSRP), Information Element (IE), Access Stratum (AS), Packet Data Convergence Protocol (PDCP).

[0003] There are two RRC states for 4G LTE: RRC_IDLE and RRC_CONNECTED. 5G NR introduces a new RRC state, RRC_INACTIVE. Thus, in 5G NR, RRC has three different states: RRC_IDLE, RRC_CONNECTED, and RRC_INACTIVE.

[0004] RRC_IDLE: Upon power on, the UE enters the RRC_IDLE state. The UE can move to this state from the RRC_CONNECTED state or the RRC_INACTIVE state.

[0005] RRC_INACTIVE: The UE moves to this state from the RRC_CONNECTED state. It is a connected but inactive state for the UE. In this state, the UE maintains the RRC connection and at the same time minimizes signaling and power consumption.

[0006] RRC_CONNECTED: In this state, the UE keeps a connection with the 5G-RAN and 5GC.

[0007] In Figure 1 RRC state transition procedures are shown in.

[0008] The main principle of the RRC_INACTIVE state is that the UE is able to return to the RRC_CONNECTED state as quickly and efficiently as possible. When the UE transitions to the RRC_INACTIVE state, both the UE and the RAN store all information necessary for a quick recovery to the RRC_CONNECTED state.

[0009] When data or signaling needs to be transmitted, a UE in the RRC_INACTIVE state can initiate a resume procedure. In this case, the UE sends an RRC resume request including a UE identifier and a security token to verify the legitimacy of the resume request. After successfully retrieving the UE configuration, the target node (e.g., the base station receiving the RRC resume request) resumes the configuration stored at the UE and applies any necessary modifications, such as the configuration of measurements and addition or removal of bearers. The corresponding RRC resume message is integrity protected and encrypted using the security context stored in the network and the UE.

[0010] In the RRC_INACTIVE state, the UE is in a power saving sleep state, but still retains parts of the RAN context (security context, UE capability information, etc.) and is able to quickly wake up by a message to move from the RRC_INACTIVE state to the RRC_CONNECTED state. NR Release 17 supports direct transmission of small data transmissions (SDT) in the RRC_INACTIVE state.

[0011] The current SDT procedure is described as follows.

[0012] When the UE is released to the RRC_INACTIVE state, an SDT configuration (e.g., a CG-based SDT (CG-SDT) configuration) has been configured to the UE. In the CG-SDT configuration, a number of CG occasions (e.g., CG resources) for SDT are configured. Alternatively, a number of CG configurations for SDT are configured. When SDT data arrives, the UE initiates a selection between SDT and non-SDT, and if SDT is selected, also initiates a selection between a CG-SDT procedure and a RACH-based SDT (RA-SDT) procedure. Specifically, if the CG-SDT criteria are met, the UE selects CG-SDT and initiates the SDT procedure; otherwise, if the RA-SDT criteria are met: the UE selects RA-SDT and initiates the SDT procedure; otherwise, the UE initiates the non-SDT procedure. The CG-SDT criteria are considered to be met if 1) the amount of available data <= the data amount threshold and 2) the RSRP is greater than or equal to a configured threshold. The RA-SDT criteria are considered to be met if 1) the amount of available data <= the data amount threshold; 2) the RSRP is greater than or equal to a configured threshold; and 3) either 4-step RA-SDT resources are configured on the selected UL carrier and the criteria for selecting 4-step RA-SDT are met; or 2-step RA-SDT resources are configured on the selected UL carrier and the criteria for selecting 2-step RA-SDT are met.

[0013] A 4-step RACH procedure (which can be used as RA-SDT) includes: the UE sending a preamble (Msg1) to a network device (e.g., a gNB) on a PRACH; the network device sending a response to the preamble (Msg2); the UE sending uplink information (Msg3) in accordance with the response; and the network device sending a contention resolution message (Msg4) in accordance with the uplink information. A 2-step RACH procedure (which can be used as RA-SDT) includes transmission of MsgA and MsgB, where MsgA corresponds to a combination of Msg1 and Msg3, and MsgB corresponds to a combination of Msg2 and Msg4. It can be seen that RA-SDT (4-step RA-SDT or 2-step RA-SDT) allows SDT to use an uplink grant received via a random access procedure for SDT.

[0014] CG-SDT, on the other hand, allows SDT to use a configured grant without performing a random access procedure.

[0015] The above-described SDT (e.g., RA-SDT and CG-SDT) can be referred to as UL (uplink) SDT. In addition, the above-described SDT is initiated by the UE, which can be referred to as MO (mobile-originated) SDT.

[0016] In MO SDT initiated by a UE, a network device (e.g., gNB) can also transmit DL data (e.g., small data). Such DL small data transmission can be referred to as DL SDT. In addition, SDT can be initiated by a network device (e.g., gNB). SDT initiated by a gNB is referred to as MT (mobile terminated) SDT.

[0017] MT SDT procedure is initiated by a network device (e.g., gNB) for downlink (DL) data transmission.

[0018] TA, which can represent time alignment or timing advance or timing adjustment, is used to adjust uplink frame timing with respect to downlink frame timing. The TA value, which can be a timing adjustment amount, depends on the propagation delay of the signal from the gNB to the UE. Therefore, different UEs have different TA with respect to a gNB.

[0019] Traditionally, a UE can be served by multiple serving cells. Among the multiple serving cells, a group of cells using the same timing reference cell and the same TA value when configured with UL transmission belongs to a timing advance group (TAG). The TAG containing the SpCell is referred to as the primary TAG (PTAG), while each of the other TAGs is referred to as a secondary TAG (STAG).

[0020] A cell can have multiple (e.g., two) TRPs. A UE can transmit UL signals (e.g., PUSCH transmission and / or PUCCH transmission) to multiple TRPs. In NR Release 17, multiple TRPs are limited to two TRPs. In addition, a UE can transmit UL signals to two TRPs in a TDM manner (i.e., asynchronously, rather than simultaneously) using only, for example, two panels of the UE.

[0021] To extend cell coverage, multiple TRPs can be placed in different locations within a cell. In this case, the TA from a UE to one of the multiple TRPs and the TA from the UE to another of the multiple TRPs (e.g., two TRPs) will be significantly different. This means that the UE should transmit UL signals to one TRP of a cell by using one TA and transmit the same UL signals or another UL signal to another TRP of the cell by using another TA.

[0022] Therefore, a UE needs to manage at least two TAs for a cell having multiple (e.g., two) differently located TRPs. When the UE transmits UL signals to multiple (e.g., two) TRPs of a cell, the UE typically has multiple (e.g., two) panels, each of which is used to transmit UL signals to a different TRP. This can be referred to as a multi-panel multi-TRP scenario.

[0023] A link is defined such that different links are associated with different TAs. A link can be indicated as from a panel to a TRP. Multiple beams are transmitted from a panel. In addition, multiple beams for reception belong to a TRP. Thus, a beam or a beam set (or beam group) consisting of multiple beams can alternatively indicate a link.

[0024] In general, for a UE in a multi-panel multi-TRP scenario and served by multiple serving cells, beam configuration is related to how signals are transmitted between the UE and the base station, e.g., which panel of the UE establishes a link with which TRP of which cell. Each link is associated with a TA. Different links can be associated with different TAs or the same TA.

[0025] Configuration of inter-cell beam management (ICBM) (i.e., beam configuration) can be added to the configuration of a serving cell (e.g., ServingCellConfig).

[0026] The present disclosure is directed to issues related to MT SDT, e.g., response procedure, recovery timing of SDT resources, and configuration (e.g., beam configuration) to be recovered. SUMMARY

[0027] Methods and apparatuses for MT SDT are disclosed.

[0028] In one embodiment, a terminal device supporting a radio resource control (RRC) inactive state with a network device includes a processor; and a transceiver coupled to the processor, wherein the processor is configured to: receive, from the network device via the transceiver, a message for a mobile terminated (MT) small data transmission (SDT); and determine a DL data reception procedure for the MT SDT according to the message for the MT SDT.

[0029] In one embodiment, the message includes at least one of an intent indication, a response indication, and a DL data size indication, wherein the intent indication indicates that the message is intended for the MT SDT, the response indication indicates a procedure that can be used to respond to a page for the MT-SDT, and the DL data size indication indicates at least one of (1) a DL data size, (2) an RSRP threshold, (3) whether a data size is greater than or less than a data size threshold, and (4) whether DL data is a single transmission or multiple transmissions. In another embodiment, the message is one of a page message, a short message, a short message indicator, a new broadcast message, a new RRC message, and a new message on a Uu interface.

[0030] In one embodiment, one of the RA-SDT, CG-SDT, and legacy RACH procedure is determined as the DL data reception procedure for the MT SDT. In another embodiment, determining the DL data reception procedure for the MT SDT further includes determining a recovery occasion and / or a recovery configuration.

[0031] In some embodiments, the recovery occasion is one of: upon receiving a message for the MT SDT; upon the UL response procedure being initiated; upon the UL response message being sent; after the RRC resume request message has been successfully received; and after the UL transmission on the PUSCH has been acknowledged. The recovered configuration includes a beam configuration, and the beam configuration is recovered according to a configuration included in the message for the MT SDT from the network device, or the beam configuration is not allowed to be recovered. In some embodiments, only the beam configuration associated with a non-expired TAT can be recovered. In some embodiments, the recovered configuration can include a beam configuration, where the beam configuration is released when reselecting a neighboring cell to respond to the MT SDT.

[0032] In one embodiment, a network device includes: a processor; and a transceiver coupled to the processor, wherein the processor is configured to: send, via the transceiver, a message for a mobile terminated (MT) small data transmission (SDT) to a terminal device in a radio resource control (RRC) idle state; and receive, via the transceiver, an UL message to indicate a DL data reception procedure for the MT SDT.

[0033] In another embodiment, a method performed by a terminal device in a radio resource control (RRC) idle state with a network device includes: receiving a message for a mobile terminated (MT) small data transmission (SDT) from the network device; and determining a DL data reception procedure for the MT SDT according to the message for the MT SDT.

[0034] In yet another embodiment, a method can be performed by a network device and includes: sending a message for a mobile terminated (MT) small data transmission (SDT) to a terminal device in a radio resource control (RRC) idle state with the network device; and receiving an UL message to indicate a DL data reception procedure for the MT SDT. BRIEF DESCRIPTION OF DRAWINGS

[0035] A more particular description of the embodiments briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only some embodiments and are not therefore to be considered to be limiting of the scope, embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

[0036] Figure 1RRC states in NR are illustrated;

[0037] Figure 2 is a schematic flowchart illustrating one embodiment of a method;

[0038] Figure 3 is a schematic flowchart illustrating yet another embodiment of a method; and

[0039] Figure 4 is a schematic block diagram illustrating an apparatus according to an embodiment. DETAILED DESCRIPTION

[0040] As will be appreciated by those skilled in the art, certain aspects of embodiments can be embodied as a system, a device, a method or a program product. Accordingly, embodiments can take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that can all generally be referred to herein as a "circuit," "module" or "system." Furthermore, embodiments can take the form of a program product embodied in one or more computer readable storage devices storing machine-readable code, computer readable code, and / or program code, hereinafter "code". The storage devices can be tangible, non-transitory, and / or non-transmission. The storage devices can not embody signals. In a certain embodiment, the storage devices only employ signals for accessing code.

[0041] Certain of the functional units described in this specification can be labeled as "modules," in order to more particularly emphasize their independent implementation. For example, a module can be implemented as a hardware circuit comprising custom very-large-scale integration (VLSI) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module can also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.

[0042] Modules can also be implemented in code and / or software for execution by various types of processors. An identified module of code may, for instance, include one or more physical or logical blocks of executable code which may, for instance, be organized as an object, procedure or function. Nevertheless, the executables of an identified module need not be physically located together, but the module may

[0043] Indeed, a module of code can be a single instruction, or many instructions, and can even be distributed over several different code segments, in several different programs, and across several memory devices. Similarly, operational data can be identified and illustrated herein within modules, and can be embodied in any suitable form and organized within any suitable type of data structure. The operational data can be collected as a single data set, or can be distributed over different locations including over different computer readable storage devices. Where a module or portions of a module are implemented in software, the software portion is stored in one or more computer readable storage devices.

[0044] Any combination of one or more computer readable medium can be utilized. The computer readable medium can be a computer readable storage medium. The computer readable storage medium can be a storage device storing the code. The storage device can be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

[0045] A non-exhaustive list of more specific examples of the storage device would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium can be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

[0046] Code for carrying out operations for embodiments can be written in any combination of one or more programming languages, including an object oriented programming language such as Python, Ruby, Java, Smalltalk, C++, or the like, conventional procedural programming languages, such as the "C" programming language, assembly language of a computer or micro-processor, or a machine language of a computer or micro-processor. The code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0047] References in the specification to “one embodiment,” “an embodiment,” or similar language mean that a particular feature, structure, or characteristic described is included in at least one embodiment. Thus, unless expressly specified otherwise, the appearance of a phrase in several

[0048] Furthermore, the described features, structures, or characteristics of the various embodiments can be combined in any suitable manner. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of the embodiments. One skilled in the relevant art will recognize, however, that the embodiments can be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail in order to avoid obscuring aspects of the embodiments.

[0049] Aspects of the different embodiments can be described below with reference to schematic flowcharts and / or schematic block diagrams of methods, apparatuses, systems, and program products according to the embodiments. It will be understood that each block of the schematic flowcharts and / or schematic block diagrams, and combinations of blocks in the schematic flowcharts and / or schematic block diagrams, can be implemented by code. The code can be provided to a processor of a general purpose computer, a special purpose computer, or other programmable data processing apparatus to produce a machine, such that the code, when executed via the processor of the computer or other programmable data processing apparatus, creates means for implementing the functions specified in the schematic flowcharts and / or schematic block diagrams for one or more blocks.

[0050] The code can also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the storage device produce an article of manufacture including instructions which implement the function specified in the schematic flowcharts and / or schematic block diagrams for one or more blocks.

[0051] The code can also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the code which execute on the computer or other programmable apparatus provide processes for implementing the functions specified in the flowchart and / or block diagram block or blocks.

[0052] The flowcharts and / or block diagrams in the drawings illustrate the architecture, functionality, and operation of possible implementations of apparatuses, systems, methods and program products according to various embodiments. In this regard, each block in the flowcharts and / or block diagrams can represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical functions.

[0053] It should also be noted that in some alternative implementations, the functions noted in the blocks can occur out of the order noted in the figures. For example, two blocks noted in succession can in fact be executed substantially concurrently or can sometimes be executed in the reverse order, depending upon the functionality involved. Other steps and methods can be conceived that are equivalent in function, logic, or effect to those illustrated, with the scope of the present disclosure intended to include such equivalent steps and methods.

[0054] Although various arrow types and line types can be employed in the flowchart and / or block diagrams, these are understood to be the arrows or lines indicating the flow of logical operations, rather than actual record lines. For example, an arrow can indicate a waiting or monitoring period of time after a preceding block has been executed, but before a succeeding block is executed. It will also be noted that each block of the block diagrams and / or flowchart illustrations, and combinations of blocks in the block diagrams and / or flowchart illustrations, can be implemented by special purpose hardware-based systems that perform the specified functions or steps, or combinations of special purpose hardware and code.

[0055] The description of elements in each figure can refer to elements of a preceding figure. Like numbers refer to like elements in all figures.

[0056] Reference will now be made in detail to some embodiments of the present application, examples of which are illustrated in the accompanying drawings. Embodiments are provided under a new service scenario and a specific network architecture, such as 3GPP 5G, 3GPP LTE, 3GPP NR-U, NR radio access, and the like operating together with shared spectrum channel access, to facilitate understanding. It is foreseeable that all embodiments of the present application are also applicable to similar technical problems as the network architecture and new service scenario develop. In addition, the terms recorded in the present application can change, which should not affect the principles of the present application. Embodiments of the present disclosure can also be applied to unlicensed spectrum scenarios.

[0057] Not only SDT can be supported in RRC_INACTIVE state, but also SDT can be supported in RRC_IDLE state. RRC_INACTIVE state and RRC_IDLE state can be collectively referred to as RRC non-connected state. All embodiments apply to terminal devices (e.g., UEs) in RRC non-connected state.

[0058] In the following description, "paging for MT-SDT" means a message or indication for upcoming DL triggered small data transmission. The name of the expression "paging for MT-SDT" can be replaced by other names. However, the meaning of the expression does not change.

[0059] When downlink (DL) data arrives at a gNB and the size of the DL data meets a certain criterion (e.g., the size of the DL data is smaller than a predefined threshold), a base station (e.g., gNB), which can also be referred to as BS, network device, network node, etc., can send a paging for MT-SDT to a UE. When the paging for MT-SDT is received by a UE in RRC non-connected (e.g., RRC_IDLE or RRC_INACTIVE) state, the UE is expected to receive the DL data as SDT without transitioning to RRC_CONNECTED state.

[0060] In a first embodiment, it is assumed that a UE is in RRC non-connected state and is configured with SDT (e.g., the UE is configured with SDT DRB and / or SDT SRB and / or resources for SDT).

[0061] The paging for MT-SDT received by the UE can be contained in a message. The message can be a paging message, a short message, a short message indicator, or a new broadcast message, or a new RRC message, or a new message on Uu interface.

[0062] Paging allows the network to reach UEs in RRC_IDLE and in RRC_INACTIVE state through a paging message and to inform UEs in RRC_IDLE, RRC_INACTIVE and RRC_CONNECTED state of system information change and ETWS or CMAS indication through a short message. Both the paging message and the short message are addressed with P-RNTI on PDCCH, but while the former (paging message) is sent on PCCH, the latter (short message) is sent directly through PDCCH.

[0063] The short message can be sent on PDCCH using P-RNTI with or without an associated paging message using the short message field in DCI format 1_0.

[0064] In particular, the following information is transmitted by means of DCI format 1_0 with CRC scrambled by P-RNTI: short message indicator (2 bits), short message (8 bits), etc.

[0065] The paging for MT-SDT includes at least one of the following indications:

[0066] (1) intention indication, for indicating the intention or cause of the paging for MT-SDT is arrival of DL data that can be transmitted as SDT, e.g., MT SDT.

[0067] (2) response indication, for indicating the procedure that can be used to respond to the paging for MT-SDT. In a first example, the response indication can indicate which one of RA-SDT, CG-SDT and legacy RACH procedure the UE should utilize to respond. In addition, in the first example, the response indication can provide additional selection depending on UE implementation to determine which procedure to respond to the paging for MT-SDT. The indication depending on UE implementation can be explicit or implicit. For example, when the response indication is absent, it implicitly means the response depends on UE implementation. In a second example, the response indication can indicate whether the UE is allowed to respond with CG-SDT. For example, a new IE can be used to indicate whether the UE is allowed to respond with CG-SDT. The response indication can be specified or predefined as, for example, “allowed”. That is, the absence of the response indication means the UE is allowed to respond with CG-SDT. Alternatively, the response indication can explicitly indicate “allowed” or “not allowed”.

[0068] (3) DL data size indication. The DL data size indication can include at least one of the following information: (3-1) DL data size; (3-2) DL data size (or DL data amount) is greater than or less than a data size threshold; (3-3) RSRP threshold (T1), where the UE can compare the RSRP of the UE with the RSRP threshold; (3-4) DL data is single transmission or multiple transmissions.

[0069] Upon the UE receiving the message including the paging for MT-SDT, the UE can determine how to respond to the paging for MT-SDT according to the indications contained in the paging for MT-SDT. For example, the UE determines which procedure to use to respond to the paging for MT-SDT, e.g., can use MO SDT procedure (e.g., RA-SDT or CG-SDT) or legacy RACH procedure to respond to the paging for MT-SDT. Upon the UE initiating the procedure to respond to the paging for MT-SDT, the resume cause is set to MT-SDT.

[0070] The UE also determines a resume occasion (to be discussed in the second embodiment) at which the configured SDT DRBs and / or SDT SRBs and / or resources for SDT are resumed, and / or part or all of the UE-inactive AS context is restored (e.g., RRC configuration, RoHC state, stored QoS flow to DRB mapping rules, and K gNB and K RRCint keys) are restored, and / or the PDCP entity for SRB1 is re-established, and / or determines how to resume stored configuration (e.g., beam configuration) when transitioning to RRC inactive state (to be discussed in the third embodiment).

[0071] The second embodiment relates to the resume occasion.

[0072] According to the second embodiment, the UE determines the resume occasion. The following different occasion candidates are provided:

[0073] Occasion candidate 1: when a message (e.g., “paging for MT-SDT”) is received by the UE. Occasion candidate 1 applies to all potential responding procedures (e.g., MO SDT procedure or legacy RACH procedure).

[0074] Occasion candidate 2: after the gNB has successfully received the RRC resume request message. For example, after the UE’s contention resolution is successful, or after the UE’s UL transmission on PUSCH has been acknowledged. Occasion candidate 2 applies to all potential responding procedures.

[0075] Occasion candidate 3: when initiating the UL responding procedure. For example, when MO SDT (e.g., RA-SDT or CG-SDT) is used as the UL responding procedure, the resume occasion is when the RRC resume procedure for SDT initiation is initiated. For another example, if legacy RACH procedure is used to respond to “paging for MT-SDT”, the resume occasion is when the RRC resume procedure is initiated.

[0076] Occasion candidate 4: when the UL responding message is sent.

[0077] Occasion candidate 5: after the UE’s UL transmission on PUSCH has been acknowledged.

[0078] The third embodiment relates to beam configuration.

[0079] In a third embodiment, the UE is assumed to be configured with a beam configuration. The beam configuration can include, but is not limited to, at least one of inter-cell configuration based on beam, multi-TRP configuration, multi-panel configuration, and MIMO configuration. In addition, other configurations are possible. For example, a panel corresponds to a set of reference signals (which can be referred to as a RS set). Thus, the beam configuration can further include a RS set configuration. For another example, a TRP corresponds to a pool of CORESETs with the same CORESETPoolIndex. Thus, the beam configuration can further include a CORESET pool configuration. In addition, the UE is configured with a SDT (e.g., the UE is configured with a SDT DRB and / or a SDT SRB and / or resources for SDT). When the UE is transitioned to the RRC inactive state, the UE has stored the beam configuration.

[0080] When the UE in the RRC inactive state receives a paging for MT-SDT, the UE determines whether to resume (i.e., revert) the stored beam configuration according to any one of the following options:

[0081] Option 1: The gNB managing the cell from which the paging for MT-SDT is sent can configure the UE to resume the stored beam configuration. If the gNB managing the cell from which the paging for MT-SDT is sent does not configure the UE to resume the stored beam configuration, the UE releases the stored beam configuration. “Resume” the stored beam configuration means “revert” or “use” the stored beam configuration.

[0082] Option 2: The UE is not allowed (i.e., not) to resume the stored beam configuration. For example, it can be specified that the UE is not allowed to resume the stored beam configuration; or it is a default configuration that the UE is not allowed to resume the stored beam configuration; or it is predefined that the UE is not allowed to resume the stored beam configuration. “Not allowed” the UE to resume the stored beam configuration means “prohibited” the UE to resume the stored ICBM configuration.

[0083] Option 3: The UE determines whether to restore the stored beam configurations or not depending on an RSRP threshold and / or a data size threshold. For example, if the RSRP of the UE is greater than a first threshold (T1) and / or the data size for the MT SDT is smaller than a second threshold (T2), only some of the beam configurations are restored. For example, if the beam configurations include a multi-TRP configuration or a multi-panel configuration or a multi-beam configuration, only a one-TRP configuration or a one-panel configuration or a one-beam configuration can be restored. Otherwise, for example, if the RSRP of the UE is smaller than the first threshold (T1) and / or the data size for the MT-SDT is greater than the second threshold (T2), all stored beam configurations are restored. By the way, the RSRP threshold can be included in the DL data size indication. If the data size for the MT SDT is included in the DL data size indication, the data size threshold, i.e. the second threshold (T2), can be a pre-defined value. Alternatively, the DL data size indication can include whether the data size for the MT SDT is smaller or greater than the second threshold (T2).

[0084] If the UE reselects a neighbor cell and initiates a response procedure using this neighbor cell, the UE releases all stored beam configurations. If the UE reselects a neighbor cell but does not initiate a response procedure using this neighbor cell, the UE neither restores nor releases the stored beam configurations. This means that the beam configurations are still stored.

[0085] Each beam is associated with a TA and each TA is associated with a TA timer (TAT). When a TAT expires, the beam configuration related to the beam associated with this TAT, i.e. the beam configuration associated with the TA associated with this TAT, is released by the UE. This means that when restoring all or part of the beam configurations, only the beam configurations associated with the TATs that are not expired can be restored. Alternatively, when a TAT expires, neither the beam configuration related to the beam associated with this TAT is restored nor released (this implies that the beam configuration related to the beam associated with the expired TAT is still stored and can be reused when the TAT is re-running).

[0086] The fourth embodiment relates to beam configurations without SDT.

[0087] In the fourth embodiment, it is assumed that the UE is configured with beam configurations.

[0088] If storing beam configuration in the UE is allowed when the UE transitions to the RRC non-connected state, the serving cell that releases the UE to the RRC non-connected state indicates the state transition of the UE (e.g., from the RRC connected state to the RRC non-connected state) to the neighboring cell. This means that the information exchange between the cells can be performed within the gNB (if the serving cell and the neighboring cell belong to the same gNB) or between the gNBs (if the serving cell and the neighboring cell belong to different gNBs).

[0089] If storing beam configuration in the UE is allowed when the UE transitions to the RRC non-connected state, the UE stores the beam configuration when it is released to the RRC non-connected state. Otherwise (i.e., when storing beam configuration in the UE is not allowed when the UE transitions to the RRC non-connected state), the UE releases the beam configuration when it is released to the RRC non-connected state.

[0090] When the UE is resumed to the RRC connected state, the UE applies the stored beam configuration (if stored) or the default beam configuration (if the default beam configuration is configured). When initiating the RRC connection, the stored or default beam configuration can be applied.

[0091] If the UE reselects a neighboring cell and initiates a response procedure (e.g., RRC procedure) using the neighboring cell, the UE releases all stored beam configurations. If the UE reselects a neighboring cell but does not initiate a response procedure using the neighboring cell, the UE neither resumes nor releases the stored beam configuration. This means that the beam configuration is still stored.

[0092] When the TAT expires, the beam configuration related to the beam associated with the TAT, i.e., the beam configuration associated with the TA associated with the TAT, is released by the UE. This means that when resuming all or part of the beam configuration, only the beam configuration associated with the TAT that does not expire can be resumed.

[0093] The above description of the present disclosure is made from the perspective of a terminal device (e.g., UE). From the perspective of a network device (e.g., gNB), the gNB transmits a message (e.g., one of a paging message, a short message, a short message indicator, a new broadcast message, a new RRC message, and a new message on a Uu interface) including a paging for an MT-SDT. Thereafter, one of a RA-SDT, a CG-SDT, and a legacy RACH procedure is determined as a DL data reception procedure for the MT SDT depending on the determination of the UE. Accordingly, the gNB receives a first message of one of the RA-SDT, the CG-SDT, and the legacy RACH procedure, wherein the first message indicates which one of the RA-SDT, the CG-SDT, and the legacy RACH procedure is determined as the DL data reception procedure for the MT SDT.

[0094] Figure 2 is a schematic flow chart illustrating one embodiment of a method 200 according to the present application. In some embodiments, the method 200 is performed by an apparatus such as a remote unit (UE). In certain embodiments, the method 200 can be performed by a processor executing program code, for example a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.

[0095] The method 200 can be performed by a terminal device supporting a radio resource control (RRC) non-connected state with a network device, and includes: 202 receiving, from the network device, a message for a mobile terminated (MT) small data transmission (SDT); and 204 determining, from the message for the MT SDT, a DL data reception procedure for the MT SDT.

[0096] In one embodiment, the message includes at least one of an intent indication, a response indication, and a DL data size indication, where the intent indication indicates that the message is intended for the MT SDT, the response indication indicates a procedure that can be used to respond to a page for the MT-SDT, the DL data size indication indicates at least one of: (1) a DL data size, (2) an RSRP threshold, (3) whether a data size is greater than or less than a data size threshold, and (4) whether the DL data is a single transmission or multiple transmissions.

[0097] In another embodiment, the message is one of a paging message, a short message, a short message indicator, a new broadcast message, a new RRC message, and a new message on a Uu interface.

[0098] In some embodiments, one of a RA-SDT, a CG-SDT, and a legacy RACH procedure is determined as the DL data reception procedure for the MT SDT.

[0099] In some embodiments, determining the DL data reception procedure for the MT SDT further includes determining a resume occasion and / or a resumed configuration. The resume occasion is one of: upon receiving the message for the MT SDT; upon the UL response procedure being initiated; upon the UL response message being sent; after the RRC resume request message has been successfully received; and after the UL transmission on PUSCH has been acknowledged. The resumed configuration includes a beam configuration, and the beam configuration is resumed according to a configuration included in the message for the MT SDT from the network device, or the beam configuration is not allowed to be resumed. In some embodiments, only a beam configuration associated with a non-expired TAT can be resumed. The resumed configuration can include a beam configuration, where the beam configuration is released when reselecting a neighboring cell to respond to the MT SDT.

[0100] Figure 3is a schematic flow chart illustrating yet another embodiment of a method 300 according to the present application. In some embodiments, the method 300 is performed by a device such as a base unit. In certain embodiments, the method 300 can be performed by a processor executing program code, for example a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

[0101] The method 300 can be performed by a network device and comprises: 302 transmitting, to a terminal device in a radio resource control (RRC) non-connected state with the network device, a message for a mobile terminated (MT) small data transmission (SDT); and 304 receiving an UL message to indicate a DL data reception procedure for the MT SDT.

[0102] In one embodiment, the message comprises at least one of an intent indication, a response indication, and a DL data size indication, wherein the intent indication indicates that the message is intended for the MT SDT, the response indication indicates a procedure that can be used to respond to a paging for the MT-SDT, the DL data size indication indicates at least one of (1) a DL data size, (2) an RSRP threshold, (3) whether a data size is greater than or less than a data size threshold, and (4) whether the DL data is a single transmission or multiple transmissions.

[0103] In another embodiment, the message is one of a paging message, a short message, a short message indicator, a new broadcast message, a new RRC message, and a new message on a Uu interface.

[0104] In some embodiments, the UL message indicates one of a RA-SDT, a CG-SDT, and a legacy RACH procedure as the DL data reception procedure for the MT SDT.

[0105] Figure 4 is a schematic block diagram illustrating an apparatus according to one embodiment.

[0106] Reference is made to Figure 4 , a UE (i.e., a remote unit or terminal device) comprises a processor, a memory, and a transceiver. The processor implements the functions, procedures, and / or methods presented in Figure 2 .

[0107] A terminal device in a radio resource control (RRC) non-connected state with a network device comprises: a processor; and a transceiver coupled to the processor, wherein the processor is configured to: receive, from the network device via the transceiver, a message for a mobile terminated (MT) small data transmission (SDT); and determine, from the message for the MT SDT, a DL data reception procedure for the MT SDT.

[0108] In one embodiment, the message includes at least one of an intent indication, a response indication, and a DL data size indication, where the intent indication indicates that the message is intended for MT SDT, the response indication indicates a procedure that can be used to respond to a page for MT-SDT, and the DL data size indication indicates at least one of (1) a DL data size, (2) an RSRP threshold, (3) whether the data size is greater than or less than a data size threshold, and (4) whether the DL data is a single transmission or multiple transmissions.

[0109] In another embodiment, the message is one of a paging message, a short message, a short message indicator, a new broadcast message, a new RRC message, and a new message on Uu interface.

[0110] In some embodiments, one of RA-SDT, CG-SDT, and a legacy RACH procedure is determined as the DL data reception procedure for MT SDT.

[0111] In some embodiments, determining the DL data reception procedure for MT SDT further includes determining a recovery occasion and / or a recovered configuration. The recovery occasion is one of: upon receiving the message for MT SDT; upon the UL response procedure being initiated; upon the UL response message being sent; upon the RRC resume request message having been successfully received; and upon the UL transmission on PUSCH having been acknowledged. The recovered configuration includes a beam configuration, and the beam configuration is recovered according to a configuration contained in the message for MT SDT from the network device, or the beam configuration is not allowed to be recovered. In some embodiments, only the beam configuration associated with a non-expired TAT can be recovered. The recovered configuration can include a beam configuration, where the beam configuration is released when reselecting a neighboring cell to respond to the MT SDT.

[0112] Reference Figure 4 A gNB (i.e., a base unit or a network device) includes a processor, a memory, and a transceiver. The processor implements the functions, procedures, and / or methods presented in Figure 3 .

[0113] A network device includes: a processor; and a transceiver coupled to the processor, where the processor is configured to: transmit, via the transceiver, a message for mobile terminated (MT) small data transmission (SDT) to a terminal device in a radio resource control (RRC) non-connected state; and receive, via the transceiver, an UL message to indicate a DL data reception procedure for MT SDT.

[0114] In one embodiment, the message includes at least one of an intent indication, a response indication, and a DL data size indication, where the intent indication indicates that the message is intended for MT SDT, the response indication indicates a procedure that can be used to respond to a paging for MT-SDT, and the DL data size indication indicates at least one of (1) a DL data size, (2) an RSRP threshold, (3) whether a data size is greater than or less than a data size threshold, and (4) whether DL data is a single transmission or multiple transmissions.

[0115] In another embodiment, the message is one of a paging message, a short message, a short message indicator, a new broadcast message, a new RRC message, and a new message on a Uu interface.

[0116] In some embodiments, the UL message indicates one of a RA-SDT, a CG-SDT, and a legacy RACH procedure as a DL data reception procedure for MT SDT.

[0117] Layers of the radio interface protocol can be implemented by the processor. The memory is connected with the processor to store various information for driving the processor. The transceiver is connected with the processor to transmit and / or receive a radio signal. It is obvious that the transceiver can be implemented as the transmitter for transmitting a radio signal and the receiver for receiving a radio signal.

[0118] The memory can be positioned inside or outside the processor and connected with the processor by various well-known means.

[0119] In the above-described embodiments, components and features of the embodiments are combined in a predetermined form. Each component or feature should be considered as an option unless explicitly stated otherwise. Each component or feature can be implemented as not associated with other components or features. Also, a certain embodiment can be configured by associating some components and / or features. The order of operations described in the embodiments can be changed. Some components or features of any embodiment can be included in another embodiment or replaced with components and features corresponding to another embodiment. It is obvious that claims not explicitly cited in the claims are combined to form embodiments or included in new claims.

[0120] The embodiments can be implemented by hardware, firmware, software, or a combination thereof. In the case of hardware implementation, according to the hardware implementation, the exemplary embodiments described herein can be implemented by using one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, etc.

[0121] Embodiments can be practiced in other specific forms. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the application is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. A user equipment (UE) for wireless communication, comprising: At least one memory; as well as At least one processor, coupled to the at least one memory and configured such that the UE: The UE receives a message for Mobile Termination of Small Data Transmission (MT) SDT from the network device, and the UE supports a Radio Resource Control (RRC) disconnected state with the network device. as well as Based on the message used for MT SDT, determine the downlink DL data reception procedure for MT SDT. The at least one processor is further configured to cause the UE to determine the DL data reception process for the MT SDT by determining the recovery timing and / or the recovered configuration.

2. The UE according to claim 1, wherein, The message includes at least one of an intent indication, a response indication, and a DL data size indication, wherein the intent indication indicates that the intent of the message is MT SDT, the response indication indicates a process that can be used to respond to a paging for MT-SDT, and the DL data size indication indicates at least one of the following: DL data size, a Reference Signal Received Power (RSRP) threshold, whether the DL data size is greater than or less than a data size threshold, and whether the DL data is transmitted in a single transmission or multiple transmissions.

3. The UE according to claim 1, wherein, The message is one of the following: paging message, short message, short message indicator, new broadcast message, new RRC message, and new message on the Uu interface.

4. The UE according to claim 1, wherein, One of the following procedures—RACH-based SDT, RA-SDT-based SDT-configured licensed CG-SDT, and conventional RACH-based random access channel—was identified as the DL data reception procedure for MT SDT.

5. The UE according to claim 1, wherein, The recovery timing is one of the following: Upon receiving the message for MT SDT; When the uplink UL response process is initiated; When the UL response message is sent; After the RRC recovery request message has been successfully received; and After the UL transmission on the physical uplink shared channel PUSCH has been confirmed.

6. The UE according to claim 1, wherein, The restored configuration includes the beam configuration, and The beam configuration may be restored according to the configuration contained in the message for MT SDT from the network device, or the beam configuration may not be allowed to be restored.

7. The UE according to claim 6, wherein, Only beam configurations associated with unexpired timing adjustment timers (TATs) can be restored.

8. The UE according to claim 1, wherein, The restored configuration includes the beam configuration, and The beam configuration is released when a neighboring cell is reselected in response to the MT SDT.

9. A processor for wireless communication, the processor comprising: At least one controller, coupled to at least one memory and configured such that the processor: The processor receives a message for Mobile Termination Small Data Transmission (MT) SDT from a network device in a Radio Resource Control (RRC) disconnected state, wherein the processor supports the RRC disconnected state of the network device. as well as Based on the message used for MT SDT, determine the downlink DL data reception procedure for MT SDT. The at least one controller is further configured to cause the processor to determine the DL data reception process for the MT SDT by determining the recovery timing and / or the recovered configuration.

10. The processor according to claim 9, wherein, The message includes at least one of an intent indication, a response indication, and a DL data size indication, wherein the intent indication indicates that the intent of the message is MT SDT, the response indication indicates a process that can be used to respond to a paging for MT-SDT, and the DL data size indication indicates at least one of the following: DL data size, a Reference Signal Received Power (RSRP) threshold, whether the DL data size is greater than or less than a data size threshold, and whether the DL data is transmitted in a single transmission or multiple transmissions.

11. The processor according to claim 9, wherein, The message is one of the following: paging message, short message, short message indicator, new broadcast message, new RRC message, and new message on the Uu interface.

12. The processor according to claim 9, wherein, The UL message indicates one of the following procedures for the DL data reception process: SDTRA-SDT based on random access channel RACH, licensed CG-SDT based on SDT configuration, and conventional random access channel RACH.

13. A method performed by a user equipment (UE), the method comprising: The UE receives a message for Mobile Termination Small Data Transmission (MT) SDT from a network device that is in a Radio Resource Control (RRC) disconnected state, and the UE supports the Radio Resource Control (RRC) disconnected state with the network device. as well as Based on the message used for MT SDT, determine the downlink DL data reception procedure for MT SDT. The method further includes determining the DL data reception process for the MT SDT by determining the recovery timing and / or the recovered configuration.

14. The method according to claim 13, wherein, The message includes at least one of an intent indication, a response indication, and a DL data size indication, wherein the intent indication indicates that the intent of the message is MT SDT, the response indication indicates a process that can be used to respond to a paging for MT-SDT, and the DL data size indication indicates at least one of the following: DL data size, a Reference Signal Received Power (RSRP) threshold, whether the DL data size is greater than or less than a data size threshold, and whether the DL data is transmitted in a single transmission or multiple transmissions.

Images