Timing Advance Group Notification

Abstract

Embodiments of the present disclosure relate to devices, methods, apparatus and computer-readable storage media for notifying timing advance groups (TAGs). The method includes receiving a flag from a network device during a random access procedure, which is mappable to a timing advance group identifier (TAG ID) associated with a serving cell of the terminal device, wherein the terminal device has two TAGs associated with a serving cell, and the TAG ID is associated with one of the two TAGs; and determining the TAG ID based at least on a mapping between the index value of the flag and the index value of the TAG ID.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the field of telecommunications, and more particularly to a device, method, apparatus, and computer-readable storage medium for notifying a Timing Advance Group (TAG).

Background Art

[0002] The main objectives in enhancing Multi-Input Multi-Output (MIMO) include beam management, multi-transmit receive point (mTRP) for ultra-reliable low-latency communication (URLLC), mTRP for enhanced mobile broadband (eMBB), and the interoperability of time division duplex (TDD) / frequency division duplex (FDD).

Summary of the Invention

[0003] In a first aspect, a device is provided. The device includes at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the device to perform at least receiving a flag that can be mapped to a Timing Advance Group Identifier (TAG ID) associated with the serving cell of the device during at least a random access procedure, where two TAGs associated with the serving cell are set in the device and the TAG ID is associated with one of the two TAGs, and determining at least the TAG ID based on a mapping between the flag index value and the TAG ID index value.

[0004] In a second embodiment, the apparatus is provided. The apparatus comprises at least one processor and at least one memory which stores instructions that, when executed by at least one processor, cause the apparatus to perform, during a random access procedure, send a flag that is mappable to a TAG ID associated with a serving cell of the apparatus, to at least one terminal device, wherein the terminal device is set to two TAGs associated with the serving cell, and the TAG ID is associated with one of the two TAGs.

[0005] A third embodiment of the method is provided. The method includes receiving a flag from a network device during a random access procedure, which is mappable to a timing advance group identifier (TAG ID) associated with a serving cell of the terminal device, wherein the terminal device has two TAGs associated with a serving cell, and the TAG ID is associated with one of the two TAGs; and determining at least the TAG ID based on a mapping between the index value of the flag and the index value of the TAG ID.

[0006] In a fourth embodiment, a method is provided, which includes transmitting a flag from a network device to a terminal device during a random access procedure, which is mappable to a timing advance group identifier (TAG ID), such that the terminal device has two TAGs associated with a serving cell, and the TAG ID is associated with one of the two TAGs.

[0007] In a fifth embodiment, an apparatus is provided. The apparatus comprises means for receiving a flag during a random access procedure that is mappable to a timing advance group identifier (TAG ID) associated with a serving cell of the apparatus, wherein the apparatus has two TAGs associated with the serving cell, and the TAG ID is associated with one of the two TAGs; and means for determining the TAG ID based at least on a mapping between the index value of the flag and the index value of the TAG ID.

[0008] In a sixth embodiment, the apparatus is provided. The apparatus comprises means for transmitting a flag to a terminal device during a random access procedure, which is mappable to a timing advance group identifier (TAG ID) associated with a serving cell of the apparatus, wherein the terminal device has two TAGs associated with the serving cell, and the TAG ID is associated with one of the two TAGs.

[0009] In the seventh embodiment, a computer-readable medium is provided which, when executed by at least one processor of the apparatus, causes the apparatus to perform the method according to the third or fourth embodiment.

[0010] Other features and advantages of the embodiments of this disclosure will become apparent from the following description of specific embodiments, in conjunction with the accompanying drawings that exemplify the principles of the embodiments of this disclosure. [Brief explanation of the drawing]

[0011] The embodiments described herein are presented for illustrative purposes only, and their advantages will be described in more detail below with reference to the accompanying drawings. [Figure 1] Figure 1 shows an example of an environment in which the embodiments of this disclosure may be implemented. [Figure 2] Figure 2 is a signaling chart illustrating an example of the process according to some embodiments of the present disclosure. [Figure 3]Figure 3 shows an example of a message format that may include a flag to indicate a TAG, according to some embodiments of the present disclosure. [Figure 4] Figure 4 is a flowchart illustrating an example of a method for notifying a TAG according to some embodiments of this disclosure. [Figure 5] Figure 5 is a flowchart showing an example of a method for notifying a TAG according to some embodiments of this disclosure. [Figure 6] Figure 6 shows a simplified block diagram of an apparatus suitable for carrying out an embodiment of the present disclosure. [Figure 7] Figure 7 is a block diagram showing an example of a computer-readable medium according to an embodiment of the present disclosure. Throughout the drawings, the same or similar reference numerals may indicate the same or similar elements. [Modes for carrying out the invention]

[0012] The principles of this specification will be explained with reference to several examples. These examples are not intended to limit the scope of this specification, but are provided solely for illustrative purposes to help those skilled in the art understand and implement this specification. The examples described herein may be carried out in various ways other than those described below.

[0013] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by a person ordinary in the art to which this disclosure belongs.

[0014] In this specification, descriptions such as “one embodiment,” “embodiment,” and “exemplary embodiment” indicate that the described embodiment may include a particular function, structure, or feature, but not all embodiments are required to include such a particular function, structure, or feature. Furthermore, these expressions do not necessarily refer to the same embodiment. In addition, if a particular function, structure, or characteristic is described in relation to an embodiment, it is assumed that any influence of that function, structure, or characteristic in relation to other embodiments, whether explicitly stated or not, is within the knowledge of those skilled in the art.

[0015] While terms such as "first" and "second" may be used to describe various elements, these elements are not limited by these terms. These terms are simply used to distinguish between elements. For example, referring to the first element as the second element, or similarly referring to the second element as the first element, does not depart from the scope of the examples. In this specification, the term "and / or" encompasses any combination of one or more of the terms described.

[0016] In this specification, when "at least one of the following: <list of two or more elements>" and "list of at least one or more elements" and similar expressions refer to lists of two or more elements connected by "and" or "or", it means at least one of any two elements, at least two or more elements, or at least all of the elements.

[0017] In this specification, unless expressly stated otherwise, performing a step "in response to A" does not mean that the step is performed immediately after the occurrence of "A," and that one or more steps may be included in between.

[0018] The terms used in this specification are for the sole purpose of describing particular embodiments and are not intended to limit the exemplary embodiments. Unless otherwise indicated by context, the singular forms "a", "an", and "the" used in this specification are intended to include the plural forms as well. Further, the terms "comprise", "comprising", "include", "including", "have", and / or "having" as used in this specification identify the presence of the described features, elements, and / or components, etc., but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0019] In the present application, the term "circuit" refers to (a) only hardware circuit implementations (such as implementations by only analog circuits and / or digital circuits), (b) combinations of hardware circuits and software, for example (where applicable), (i) combinations of analog and / or digital hardware circuits and software / firmware, and (ii) combinations of a part of a hardware processor and software (including a digital signal processor), software, and memory, which cooperate to cause various functions to be executed in a device such as a mobile phone or a server, (c) hardware circuits and / or processors (such as a microprocessor or a part of a microprocessor) that require software (such as firmware) for operation and may not have software when not required for operation, and may refer to any one or more or all of the above.

[0020] This definition of "circuit" applies to all uses of this term in this application, i.e., to all claims. For further examples, the term "circuit" as used in this application includes not only a hardware circuit or processor (or multiple processors), but also a part of a hardware circuit or processor and its associated software and / or firmware implementation. The term "circuit" also includes, for example, a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network, or other computing system, where applicable to the elements of a particular claim.

[0021] In this specification, the term “communication network” refers to a network that conforms to any appropriate communication standard, such as New Radio (NR), Long-Term Evolution (LTE), LTE-Advanced (LTE-A), Broadband Code Division Multiple Access (WCDMA®), High-Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), and Enhanced Machine Communication (eMTC). Furthermore, communication between terminal devices and network devices in a communication network includes, but is not limited to, first-generation (1G), second-generation (2G), 2.5G, 2.75G, third-generation (3G), fourth-generation (4G), 4.5G, fifth-generation (5G), and sixth-generation (6G) communication protocols, and / or other protocols currently known or to be developed in the future. Embodiments of this disclosure are applicable to a variety of communication systems. Given the rapid development of communication technologies, there will naturally be future communication technologies and systems to which this disclosure will be embodied. The scope of this disclosure is not limited to the aforementioned systems.

[0022] As used herein, the terms "network device", "wireless network device" and / or "wireless access network device" refer to nodes within a communication network through which a terminal device accesses the network and receives services therefrom. Network devices include, for example, base stations (BSs), access points (APs), Node Bs (NBs), evolved Node Bs (eNBs), NR Node Bs (also referred to as gNBs), remote radio units (RRUs), remote radio heads (RRHs), relays, integrated access backhaul (IAB) nodes, low-power nodes such as femtos and picos, non-terrestrial networks (NTNs) or non-terrestrial network devices (such as satellite network devices, low-earth orbit (LEO) satellites, geostationary orbit (GEO) satellites), aircraft network devices, etc., which vary depending on the terms and technologies applied. In some embodiments, the low-earth orbit (RAN) split architecture includes a central unit (CU) and a distributed unit (DU). In other embodiments, part or all of the wireless access network may be mounted on an aircraft-mounted or space-mounted non-terrestrial network (NTN) vehicle.

[0023] The term "terminal device" refers to any terminal device capable of wireless communication. While these are merely examples, terminal devices may also be called communication equipment, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). Terminal devices include mobile phones, mobile phone terminals, smartphones, VoIP phones, wireless local loop phones, tablet devices, wearable devices, PDAs, portable computers, desktop computers, digital cameras and other image capture devices, game consoles, music storage and playback devices, in-vehicle wireless terminals, wireless endpoints, mobile stations, laptop computers (LEE), laptop computers (LME), USB dongles, smart devices, wireless customer premises equipment (CPE), Internet of Things (IoT) devices, watches and other wearables, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain environments), consumer electronics, devices operating on commercial and / or industrial wireless networks, and similar items. Terminal devices may also correspond to the mobile termination (MT) portion of IAB nodes (such as relay nodes). In the following explanation, the terms "terminal device," "communication device," "terminal," "user equipment," and "UE" may be used interchangeably.

[0024] In this specification, “resource,” “transmit resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” refers to any resource for performing communication, such as resources for communication between terminal equipment and network equipment, and includes time-domain resources, frequency-domain resources, spatial-domain resources, code-domain resources, or other resources that enable communication. Hereinafter, unless otherwise specified, some embodiments of this specification will use resources in both the frequency-domain and time-domain as examples of transmit resources. It should be noted that the embodiments of this specification are similarly applicable to other resources in other domains.

[0025] In this specification, the term “Transmit / Receive Point (TRP)” may refer to an antenna port or antenna array (having one or more antenna elements) available to a network device located at a specific geographical location. For example, a network device may be connected to multiple TRPs at different geographical locations to achieve better coverage. Alternatively, or additionally, multiple TRPs may be incorporated into a network device; in other words, a network device may contain multiple TRPs. The term “TRP” may also be referred to as a cell, such as a macrocell, small cell, picocell, femtocell, remote radiohead, or relay node. It should be understood that the term “TRP” may refer to a logical concept that is physically implemented in various ways. For example, a TRP may refer to or correspond to a Physical Cell Identifier (PCI) or a Control Resource Set (CORESET) pool index (i.e., CORESETPoolIndex). In the embodiments herein, the term “TRP” may be used interchangeably with the terms “PCI” or “CORESETPoolIndex”.

[0026] Figure 1 shows an example of a communication network 100 in which embodiments of the present disclosure may be implemented. As shown in Figure 1, the communication network 100 may include terminal devices 110. Hereinafter, terminal devices 110 may also be referred to as UEs.

[0027] The communication network 100 further includes a network device 120 that provides a serving cell 102 for terminal devices. The terminal devices 110 communicate with the network device 120 within the coverage area of ​​the serving cell 102.

[0028] In some scenarios, a serving cell may have multiple TRPs (MTRPs), such as a first TRP and a second TRP. When terminal device 110 communicates with network device 120 within serving cell 102, terminal device 110 can communicate with either or both of the first and second TRPs. For example, terminal device may be permitted to send and / or receive control information and data from both the first and second TRPs.

[0029] The number of network devices and terminal devices shown in Figure 1 is for illustrative purposes only and does not imply any limitation. The communication network 100 may include any appropriate number of network devices and terminal devices.

[0030] In some embodiments, the link from network device 120 to terminal device 110 is called a downlink (DL), and the link from terminal device 110 to network device 120 is called an uplink (UL). In a DL, network device 120 is a transmitting (TX) device (or transmitter), and terminal device 110 is a receiving (RX) device (or receiver). In a UL, terminal device 110 is a TX device (or transmitter), and network device 120 is an RX device (or receiver).

[0031] Communication in communication environment 100 is implemented according to an appropriate communication protocol, which includes, but is not limited to, cellular communication protocols such as first generation (1G), second generation (2G), third generation (3G), fourth generation (4G), fifth generation (5G), and sixth generation (6G), wireless local network communication protocols such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11, and / or other protocols currently known or to be developed in the future. Furthermore, communication may optionally utilize appropriate wireless communication technologies, which include, but is not limited to, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), frequency division duplexing (FDD), time division duplexing (TDD), multiple input multiple output (MIMO), orthogonal frequency division multiplexing (OFDM), discrete Fourier transform spread OFDM (DFT-s-OFDM), and other technologies currently known or to be developed in the future.

[0032] As mentioned above, MIMO is widely used in current wireless communication systems. Specifically, MIMO is one of the key technologies in NR systems and has been successfully deployed commercially. 3GPP® releases 15 / 16 / 17 investigate and define MIMO functionality for both frequency division duplex (FDD) and time division duplex (TDD) systems, with the main part relating to downlink MIMO operation.

[0033] In 3GPP® Release 18, it is important to identify and specify the enhancements required for uplink MIMO, while at the same time, the necessary enhancements for downlink MIMO that facilitate the use of large antenna arrays, not only in frequency band (FR) 1 but also in FR2, must continue to be introduced to meet the evolving requirements of NR deployment. This includes the following enhancement areas:

[0034] Firstly, in commercial deployments, particularly in multi-user MIMO (MU-MIMO) scenarios, significant performance degradation has been observed in high-speed / medium-speed UEs. This performance degradation is partly due to outdated channel status information (CSI), and therefore, mitigating this degradation by strengthening CSI acquisition is beneficial.

[0035] Secondly, the unified Transmit Configuration Indicator (TCI) framework introduced in Release 17 streamlines multibeam operations targeting FR2. Since Release 17 focuses on single TRP use cases, extending the unified TCI framework to focus on multi-TRP use cases would be beneficial.

[0036] Thirdly, the increasing demand for multiplexing capacity of downlink and uplink demodulated reference signals (DMRS) across various use cases necessitates an increase in the number of orthogonal ports for DMRS.

[0037] Fourth, release 16 / 17 introduced features to facilitate multi-TRP deployments focused on non-coherent co-transmission (NC-JT). Coherent co-transmission (CJT) improves coverage and average throughput in commercial deployments through high-performance backhaul and synchronization, and enhanced CSI acquisition for FDD and TDD targeting FR1 is beneficial in expanding the usefulness of multi-TRP deployments.

[0038] Fifth, as the importance of advanced UEs (e.g., CPE, fixed wireless access (FWA), vehicles, and industrial equipment) increases, improvements in UL coverage and average throughput can be achieved by introducing the necessary enhancements to support 8 antenna ports and 4-layer or higher uplink (UL) transmission.

[0039] Sixth, the UL panel selection feature introduced in Release 17 allows advanced UEs (e.g., CPE, FWA, vehicles, industrial equipment) to benefit from improved UL coverage and average throughput through simultaneous UL multi-panel transmission. Finally, further enhancements to facilitate UL multi-TRP deployments via two TAs, along with enhanced UL power control, enable additional UL performance improvements.

[0040] Furthermore, Release 18 is expected to include further enhancements for multi-TRP scenarios. For example, for FR1, enhancements to the CSI reporting function for high / medium speed UEs utilizing time-domain correlation / Doppler domain information are being considered. Specifically, this involves improving the Type II codebook from Release 16 / 17 without changing the spatial and frequency domain basis, and having the UE report time-domain channel characteristics measured by CSI-RS for tracking purposes.

[0041] As another example, it is anticipated that we will consider extending the unified TCI framework in Release 17 to focus on multi-TRP use cases and to represent multiple DL and ULTCI states.

[0042] As another example, specifically focusing on CP-OFDM, it is hoped that more orthogonal DMRS ports will be studied for downlink and uplink MU-MIMO (without increasing DM-RS overhead). Specifically, the aim is to create a common design between DL and UL DMRS, supporting up to 24 orthogonal DMRS ports, doubling the maximum number of orthogonal ports for both single-symbol and dual-symbol DMRS in each applicable DMRS type.

[0043] As yet another example, it is expected that improvements to CJT CSI acquisition targeting FR1 and up to four TRPs will be considered, assuming synchronization with an ideal backhaul and the same number of antenna ports between TRPs, by applying the improvements in the Release 16 / 17 Type II codebook to CJT multi-TRP (FDD target) and related CSI reporting, while considering the trade-off between throughput and overhead.

[0044] There are SRS augmentation techniques for managing inter-TRP cross-SRS interference targeting TDD CJT by improving SRS capacity and / or randomizing interference, with the constraints that 1) no additional resources are consumed by the SRS, 2) existing SRS comb structures are reused, and 3) no new SRS route sequences are introduced.

[0045] Furthermore, the maximum number of CSI-RS ports per resource remains the same as in Release 17, i.e., 32.

[0046] As another example, in UL for CPE / FWA / vehicle / industrial equipment, it is expected that enhancements to UL DMRS, SRS, SRI, and Transmit Pre-Coded Matrix Index (TPMI) (including codebooks) will be considered to enable 8Tx UL operation, which supports four or more layers per UE.

[0047] As yet another example, for CPE / FWA / vehicles / industrial equipment (where applicable), assuming up to two TRPs and up to two panels, focusing on FR2 and multi-TRP, the following items are expected to be considered to facilitate simultaneous multi-panel UL transmission for higher UL throughput / reliability. This is a UL precoding instruction for PUSCH, and no new codebook will be introduced for simultaneous multi-panel transmission. The total number of layers across all panels will be a maximum of 4, and the total number of codewords across all panels will be a maximum of 2, considering multi-TRP operation based on single DCI and multiple DCIs. UL beam instruction in physical uplink control channels (PUCCH) / physical uplink shared channels (PUSCH) is assumed to be an extension of the unified TCI framework, considering single downlink control information (DCI) and multiple TRP operations based on multiple DCIs. In the case of multi-DCI-based multi-TRP operations, only combinations of PUSCH and PUSCH, or PUCCH and PUCCH, are transmitted between two panels within the same component carrier (CC).

[0048] As yet another example, it is expected that power control for two TAs for UL multi-DCI in multi-TRP operation, and for UL single DCI in multi-TRP operation assuming the unified TCI framework extension in Objective 2, will be investigated and documented if deemed justifiable.

[0049] In summary, the technical focus is on operation under multi-TRP scenarios. This specification proposes solutions for relevant transmissions in scenarios where at least two TA values ​​are set for UEs within a serving cell. Relevant technical implementation examples are shown below.

[0050] In some embodiments, an extension of two TAs for UL multi-DCI in multi-TRP operation is supported. Furthermore, the network may advertise two TACs, or the network may advertise one TAC and the UE may derive a second TA.

[0051] In some embodiments, the extension of two TAs is supported for both intra-cell and inter-cell multi-DCI multi-TRP scenarios. Furthermore, the extension of two TAs for UL multi-DCI for multi-TRP operation is applicable to both FR1 and FR2.

[0052] In some embodiments, the extension of two TAs to uplink multi-DCI-based multi-TRP operation is applicable to at least TDM-based multi-DCI uplink transmission and simultaneous multi-DCI uplink transmission (if simultaneous uplink multi-DCI transmission is supported).

[0053] In some embodiments, it is conceivable that alternative approaches would be considered in multi-DCI multi-TRP operation using two TAs, such as considering two reference timings (i.e., DL reception timing) and considering one reference timing.

[0054] In some embodiments, multi-DCI multi-TRP operation using two TAs may support either one n-TimingAdvanceOffset value per serving cell or two n-TimingAdvanceOffset values ​​per serving cell.

[0055] In some embodiments, in multi-DCI-based multi-TRP operation, one of two options is selected: setting up two TAGs within a serving cell, or considering two TAs within a single TAG in a serving cell.

[0056] In some embodiments, in multi-DCI-based multi-TRP operation with two TAs, several solutions can be used for the overlapping portion of two UL transmissions related to the two TAs, such as introducing scheduling restrictions on the overlapping portion, introducing drop rules, or allowing overlapping transmissions if the UE supports STxMP transmissions.

[0057] In some embodiments, it is possible to configure two TAGs belonging to a single serving cell in a multi-DCI-based multi-TRP operation using two TAs.

[0058] In some embodiments, it is possible to support up to two n-TimingAdvanceOffset values ​​per serving cell in multi-DCI multi-TRP operation using two TAs.

[0059] In some embodiments, multi-DCI-based multi-TRP operation using two TAs is applicable to RACH triggered by the Physical Downlink Control Channel (PDCCH) order in the case of intra-cell MTRP, RACH triggered by the PDCCH order in the case of inter-cell MTRP, and UE RACH triggered by competition-based RA (CBRA) or competition-free RA (CFRA) in radio resource control (RRC) connection modes.

[0060] In some embodiments, one of the following options is selected to associate a TAG with a target UL channel / signal in multi-DCI-based multi-TRP operation. Option 1: Associate TAGs with TCI state / spatial relationships. Option 2: Associate the TAG with CORESETPoolIndex. Option 3: Associate the TAG with a DL reference signal (RS) group. In a UL transmission, the UE adopts the TAG associated with the DL RS group to which the PL RS of the UL transmission belongs. Option 4: Discuss how to directly associate TAGs with semi-static UL channels / RS (e.g., periodic CSI PUCCH, periodic SRS, setting grant (CG) PUSCH), and how to further associate TAGs with dynamic UL channels / RS (e.g., additionally associating TAGs with CORESETPoolIndex).

[0061] In some embodiments, multi-DCI multi-TRP operation using two TAs within a CC supports two DL reference timings, with each DL reference timing associated with one TAG. Furthermore, as a basic assumption, the receive timing difference between the two DL reference timings does not exceed the CP length, although an optional UE function can be assumed to accommodate cases where the receive timing difference between the two DL reference timings exceeds the CP length.

[0062] In some embodiments, in inter-cell multi-DCI-based multi-TRP operation with two TA extensions, the Physical Downlink Control Channel (PDCCH) scheduling RAR is always received from the serving cell, thus eliminating the need for additional Type 1 Common Search Space (CSS) configuration for each additional PCI. Furthermore, in addition to the PDCCH scheduling Random Access Response (RAR) being received from the service cell, the reception of PDCCH scheduling RARs from the TRP corresponding to the additional PCI is supported, which is due to the RACH procedure associated with the additional PCI, i.e., it is necessary to support an additional Type 1 CSS configuration for each additional PCI.

[0063] In some embodiments, a multi-DCI-based inter-cell multi-TRP operation with two TA extensions supports a physical random access channel (PRACH) configuration associated with an additionally configured PCI that is different from the PCI of the serving cell.

[0064] In some embodiments, a mechanism is supported to determine the PRACH configuration (i.e., the RACH configuration corresponding to the serving cell PCI or additional PCI) to be used in a RACH procedure triggered by a PDCCH order in a multi-DCI-based inter-cell multi-TRP operation with two TA extensions.

[0065] In some embodiments, two TA extensions in multi-DCI-based multi-TRP operation support either 1) a PDCCH order sent by one TRP is not allowed to trigger a RACH procedure for the same TRP, and a PDCCH order sent by one TRP is not allowed to trigger a RACH procedure for another TRP, or 2) alternative 2: a PDCCH order sent by one TRP triggers a RACH procedure for either the same TRP or another TRP, and it is possible to further support PDCCH orders that trigger two RACH procedures for two TRPs.

[0066] In some embodiments, four options are adjusted as follows to associate a TAG with a target UL channel / signal in multi-DCI based multi-TRP operation: Option 1: Associate the TAG with a TCI state / spatial relationship. Additionally, set the TAG ID (ID) as part of the UL / joint TCI state or spatial relationship, and use the TAG ID associated with the UL / joint TCI state or spatial relationship when sending ULs. Option 2: Associate the TAG with the CORESET pool index. Furthermore, for dynamically scheduled / activated PUSCHs, the TAG associated with the CORESET pool index of the CORESET sending the scheduled / activated PDCCH is used for UL transmission. Specifically, for Type 1 CG, P / SP-SRS, and P / SP-PUCCH, the CORESET pool index is set in RRC. Option 3: Associate the TAG with an SSB group. In UL transmissions, the UE adopts the TAG associated with the SSB group. Specifically, if the PL RS is SSB, the UE adopts the TAG associated with the SSB group to which the UL transmission's path loss (PL) RS belongs. If the PL RS is CSI-RS, the UE adopts the TAG associated with the SSB group to which the PL RS's QCL source SSB belongs. Option 4: TAG association is performed as follows: For dynamically scheduled / activated channels / signals, the TAG associated with the CORESET pool index of the CORESET that sends the scheduled PDCCH is used for UL transmission. For P / SPUL channels / signals that are not scheduled or activated by DCI, the TAG ID is set in RRC.

[0067] In some embodiments, enhanced support is provided for notification of TAG IDs via absolute TA commands in multi-DCI-based multi-TRP operation with two TA extensions.

[0068] In some embodiments, in multi-DCI-based multi-TRP operation with two TA extensions, it cannot always be assumed that both TRPs are aware of the overlapping region between transmissions corresponding to the two TAs. Furthermore, even if the TRPs are not aware of the overlapping region, the network may still impose scheduling restrictions.

[0069] In some embodiments, in intra-cell multi-DCI-based multi-TRP operation with two TA extensions, at least one of the following options is supported: Option 1: Notify the TAG ID as part of the TA command in RAR. Option 2: Notify the TAG ID as part of the PDCCH order. Option 3: Divide the SSB into two groups and assign one to each TRP. If the SSB associated with the RACH procedure belongs to the nth group (n=1,2), the TA obtained in the RACH procedure corresponds to the nth TRP. Option 4: Divide the RACH resources into two groups. In a RACH procedure, if the corresponding RACH resource belongs to the nth group (n=1,2), the TA obtained via the RACH procedure corresponds to the nth TRP. Option 5: Divide the preamble into two groups. In the RACH procedure, if the corresponding preamble belongs to the nth group (n=1,2), the TA obtained in the RACH procedure corresponds to the nth TRP. Option 6: The TAG ID is associated with the CORESETPoolIndex, and the TAG ID is determined based on the CORESETPoolIndex of the PDCCH order. Option 7: Each TCI state is associated with a TAG ID, and the TAG ID corresponding to a RACH triggered by a PDCCH order is determined based on the TCI state used to receive the PDCCH order.

[0070] In some embodiments, a multi-DCI-based inter-cell multi-TRP operation with two TA extensions supports one additional PRACH setting for each configured additional PCI. Furthermore, this additional PRACH setting is used in a RACH procedure triggered by a PDCCH order for the corresponding configured additional PCI.

[0071] In some embodiments, multi-DCI-based multi-TRP operation with two TA extensions supports CFRA triggered by PDCCH orders for both intra-cell and inter-cell cases.

[0072] In some embodiments, in multi-DCI-based multi-TRP operation with two TA extensions, at least in the case of inter-cell multi-DCI, it supports cases where a PDCCH order sent by one TRP triggers a RACH procedure for either the same TRP or a different TRP.

[0073] In some embodiments, there is no agreement to support CBRA enhancements triggered by PDCCH orders in multi-DCI-based multi-TRP operation with two TA extensions.

[0074] In some embodiments, regarding TAG association to target UL channels / signals in multi-DCI-based multi-TRP operation, it is supported that TAGs are associated with TCI states, TAG IDs are associated with UL / joint TCI states, UL transmissions utilize TAG IDs associated with UL / joint TCI states, and, as a basic operation, the UE expects that one (activated) UL / joint TCI state (UL signal / channel) associated with one CORESET pool index corresponds to one TAG. The UE can report that it supports one (activated) UL / joint TCI state (UL signal / channel) associated with one CORESET pool index corresponding to both TAGs.

[0075] In some embodiments, in multi-DCI-based inter-cell multi-TRP operation with two TA extensions, one additional PRACH setting is supported for each configured additional PCI, and this additional PRACH setting is used in a RACH procedure triggered by a PDCCH order for the corresponding configured additional PCI.

[0076] In some embodiments, in multi-DCI-based multi-TRP operation with two TA extensions, if the UE does not support ULSTxMP transmission, select at least one of the following: A time gap X is introduced between two UL transmissions associated with different TA values. In this case, the X symbol in the slot corresponding to the two UL transmissions remains unused. Reduce the overlap period of one of the two UL transmissions. Apply scheduling restrictions to prevent the UE from expecting duplicate UL transmissions.

[0077] Basically, two CBRA procedures are supported: a four-step random access procedure (i.e., RACH) and a two-step random access procedure.

[0078] For example, in a 4-step RACH, the UE sends message 1 (MSG1) to the gNB via a physical random access channel (PRACH). This message uses a specific resource called a RACH opportunity (RO) and sends a specific probe. The gNB responds with a Random Access Response (RAR) message, also known as message 2 (MSG2). MSG2 contains the detected preamble ID, time advance command, temporary cell radio network temporary identifier (TC-RNTI), and a UL grant for sending MSG3 over the physical uplink shared channel (PUSCH). The UE then responds to MSG2 via a scheduled PUSCH with a collision resolution ID for a radio resource control (RRC) request. This is also known as MSG3. The gNB sends a collision resolution message with a collision resolution ID for RRC setup. This is also known as message 4 (MSG4).

[0079] Upon receiving MSG4, the UE may send an ACK on the physical uplink control channel (PUCCH) if its collision resolution ID is included in MSG4. This completes the four-step RACH. Furthermore, prior to MSG1, there is a preliminary step of a synchronization signal block (SSB) transmitted by the gNB and received by the UE. This includes a DL beam sweep and is not part of the formal RACH procedure. As a result of this preliminary step, the UE selects the index of the preferred SSB beam and decodes the associated physical broadcast channel (PBCH) to obtain the Master Information Block (MIB), System Information Block (SIB), etc. This index is also used by the UE to identify a suitable RO for the preamble transmission (i.e., MSG1) based on the SSB-RO mapping transmitted in SIB1. The gNB may use the SSB beam index selected by the UE in the MSG2 transmission.

[0080] In the two-step random access procedure, MSG1 and MSG3 are combined into MSGA and sent without waiting for feedback from the gNB (traditionally MSG2). Similarly, the gNB can combine MSG2 and MSG4 into message B (MSGB).

[0081] Conflict resolution is specified for 4-step and 2-step RA procedures, and MSGB reception and conflict resolution in the 2-step RA type are specified as follows:

[0082] In some embodiments, once the MSGA preamble is sent, the MAC entity must initiate the msgB-ResponseWindow on the occasion of the PDCCH, regardless of the possibility of a measurement gap occurring.

[0083] In some embodiments, once the MSGA preamble is sent, regardless of the possibility of measurement gaps occurring, the MAC entity monitors the SpCell's PDCCH while the msgB-ResponseWindow is running to detect random access responses identified by the MSGB-RNTI.

[0084] In some embodiments, when an MSGA preamble is sent, and the MSGA contains a C-RNTI MAC CE, regardless of the possibility of measurement gaps occurring, the MAC entity monitors the SpCell's PDCCH for random access responses identified by the C-RNTI during the execution of the msgB-ResponseWindow.

[0085] In some embodiments, after the MSGA preamble has been transmitted, if a SpCell PDCCH transmit / receive notification is received from a lower layer regardless of the possibility of a measurement gap, and the MSGA contains a C-RNTI MAC CE, the MAC entity considers the reception of this random access response successful, stops the msgB-ResponseWindow, and considers this random access procedure to have completed successfully. However, this is only the case if the random access procedure was initiated for SpCell beam fault recovery, or for beam fault recovery of both the SpCell and PDCCH transmit BFD-RS sets, and the PDCCH transmit is destined for C-RNTI. Otherwise, the timeAlignmentTimer associated with the PTAG is operating.

[0086] In some embodiments, after the MSGA preamble has been sent, and regardless of the possibility of a measurement gap occurring, if a PDCCH transmit / receive notification for a SpCell is received from a lower layer, and the C-RNTI MAC CE is included in the MSGA, and the CG-SDT procedure is in progress with the cg-SDT-TimeAlignmentTimer running, the MAC entity considers the receipt of this random access response to be successful, stops the msgB-ResponseWindow, and considers this random access procedure to be successfully completed, provided that the PDCCH transmission is addressed to C-RNTI and includes a UL grant for a new transmission.

[0087] In some embodiments, after the MSGA preamble has been transmitted, if a SpCell PDCCH transmit / receive notification is received from a lower layer regardless of the possibility of a measurement gap occurring, and the MSGA contains a C-RNTI MAC CE, and a downlink assignment is received on the C-RNTI PDCCH, and the received TB is successfully decoded, the MAC entity processes the received timing advance command, considers the reception of this random access response successful, stops the msgB-ResponseWindow, considers this random access procedure to have been successfully completed, and terminates the disassembly and demultiplexing of the MAC PDU, provided that the MAC PDU contains an absolute timing advance command MAC CE.

[0088] In some embodiments, if an MSG3 transmission (initial transmission or HARQ retransmission) is scheduled in a type A PUSCH repeat after an MSG3 has been transmitted, the MAC entity starts or restarts the ra-ContentionResolutionTimer at the first symbol after +UE-gNBRTT has finished all repetitions of the MSG3 transmission have finished, if the MSG3 was transmitted over a non-terrestrial network. Otherwise, the ra-ContentionResolutionTimer starts or restarts at the first symbol after all repetitions of the MSG3 transmission have finished.

[0089] In some embodiments, if an MSG3 transmission (i.e., initial transmission or HARQ retransmission) is transmitted over a non-terrestrial network after an MSG3 transmission has been sent, the MAC entity starts or restarts the ra-ContentionResolutionTimer with the first symbol incremented by UE-gNBRTT after the completion of the MSG3 transmission.

[0090] In some embodiments, if, after an MSG3 is transmitted, no further MSG3 transmissions (initial transmission or HARQ retransmission) are scheduled in a Type A PUSCH repeat, and no further MSG3 transmissions (initial transmission or HARQ retransmission) are transmitted on a non-terrestrial network, the MAC entity must start or restart the ra-ContentionResolutionTimer in the first symbol after the completion of the MSG3 transmission.

[0091] In some embodiments, the MAC entity monitors the PDCCH while the ra-ContentionResolutionTimer is running, even if a measurement gap may occur after MSG3 is sent.

[0092] In some embodiments, after MSG3 is transmitted, if a PDCCH transmit / receive notification for the SpCell is received from a lower layer and MSG3 contains a C-RNTI MAC CE, the MAC entity considers this collision resolution successful, stops the ra-ContentionResolutionTimer, discards TEMPORARY_C-RNTI, and considers this random access procedure to have completed successfully, provided that the random access procedure is initiated for SpCell beam fault recovery or for beam fault recovery of both the BFD-RS set of the SpCell and the PDCCH transmission is destined for C-RNTI, or that the random access procedure is initiated by a PDCCH order and the PDCCH transmission is destined for C-RNTI. Otherwise, the random access procedure is initiated by the MAC sublayer itself or the RRC sublayer, the PDCCH transmission is destined for C-RNTI, and includes a UL grant for a new transmission.

[0093] As mentioned above, extensions to the two TAs for UL multi-DCI in multi-TRP operation are expected to be further discussed and developed in Release 18. While the current TAG ID space is four, if it is expanded to, for example, eight as a result of mTRP work, the method of notifying TAG IDs in random access procedures may still require discussion.

[0094] The solution of this disclosure proposes a mechanism for identifying TAGs. In this solution, if terminal device 100 has two TAGs associated with the serving cell of the terminal device set during a random access procedure, the network device sends a flag to the terminal device that can be mapped to a TAG ID associated with the serving cell, and that TAG ID is associated with one of the two TAGs. The terminal device 110 then determines the TAG ID at least based on a mapping between the index value of the flag and the index value of the TAG ID.

[0095] In this way, the serving cell's TAG ID is notified with a 1-bit flag that can indicate information about the TAG ID with lower overhead. Furthermore, this flag, like the DCI / UL grant, can be included in the RAR / MSGB / fallbackRAR with lower overhead.

[0096] Embodiments of this disclosure will be described in detail below with reference to the attached drawings.

[0097] Refer to Figure 2. Figure 2 shows a signaling chart 200 for communication according to some embodiments of the present disclosure. As shown in Figure 2, the signaling chart 200 includes terminal equipment 110 and network equipment 120. For convenience of explanation, the signaling chart 200 will be described with reference to Figure 1.

[0098] In the scenario related to Figure 2, the serving cell 102 managed by the network device 120 can provide services to the terminal device 110. The terminal device 110 may have two TAGs associated with the serving cell 102.

[0099] As shown in Figure 2, the network device 120 can send a flag (202) that can be mapped to a TAG ID associated with the serving cell.

[0100] In some embodiments, a flag is introduced to indicate a distinction between TAG IDs (e.g., two TAG IDs) associated with the serving cell 102 to which the PRACH preamble is sent. In other words, the flag can indicate which TAG ID within the serving cell to which the sent PRACH preamble corresponds.

[0101] For example, a flag can be a 1-bit instruction; that is, the flag functions as a 1-bit flag. Currently, a TAG ID occupies 2 bits (4 indices / values), but due to multi-TRP operations, it may expand to a larger value (e.g., 8), so a single reserved bit cannot indicate the exact TAG ID. Therefore, a 1-bit flag can be used to indicate the TAG ID of a serving cell with a specific index value.

[0102] In some embodiments, a flag indicating a first value can be mapped to a TAG ID having the lowest index value among the TAG IDs associated with the serving cell, and a flag indicating a second value can be mapped to a TAG ID having the lowest index value among the TAG IDs associated with the serving cell.

[0103] For example, the lowest index of a flag (i.e., "0") corresponds to the TAG ID of a serving cell with a lower index value (e.g., "0", "1", or "2"), and the highest index of a flag (i.e., "1") corresponds to the TAG ID of a serving cell with a higher index value (e.g., "1", "2", or "3"). Or vice versa.

[0104] In some embodiments, the flag is communicated via RAR or message B. Alternatively, the RAR used here may also be called a fallback RAR. In some embodiments, flags are indicated by reserved bits in the RAR or message B. For example, a 1-bit flag can replace a reserved bit in the RAR or MSGB.

[0105] In some embodiments, the flag is included in the UL grant field of the media access control (MAC) payload for RAR. For example, a 1-bit flag may be indicated by a first bit of the MAC payload for RAR, or by a first bit of the MAC payload for message B.

[0106] In some embodiments, the flag is included in the downlink control information (DCI) for scheduling RAR or MSGB. For example, the flag is included in the DCI for scheduling MAC protocol data units (PDUs) for RAR or MAC PDUs for message B.

[0107] In this case, each RAR MAC PDU is restricted to advertising only RARs associated with the same TRP (therefore, for each terminal device, the RAR is associated with the TAG ID corresponding to this TRP).

[0108] In some other embodiments, this flag is included in the DCI for scheduling UL grants for successful collision resolution or successful completion of a random access procedure. For example, a 1-bit flag is used for successful collision resolution or successful completion of an RA procedure (i.e., "PDCCH transmission is destined for C-RNTI and includes a UL grant for a new transmission"), or for DL ​​assignments (e.g., during beam fault recovery (BFR) or during a two-step RA using absolute timing advance command (TAC) MAC CE).

[0109] As shown in Figure 2, the terminal device 110 determines the TAG ID to be used for subsequent UL transmission based on the received flag and, for example, the correspondence between the flag's index value and the TAG ID's index value (204). That is, the received flag is mapped to the index value TAG ID based on this correspondence.

[0110] Subsequently, the terminal device 110 uses a timing advance corresponding to the TAG ID to perform a subsequent uplink (UL) transmission to the network device (204).

[0111] The impact on the specifications based on the solutions proposed in this specification can be listed as follows: [Table 1]

[0112] Figure 3 shows an example of a message format that may include a flag indicating a TAG, according to one embodiment of the present disclosure.

[0113] In some embodiments, a flag that can be mapped to a TAG ID may be included in the TI field 301 of the MAC payload for RAR. For example, the lowest index of the flag (i.e., "0") corresponds to a TAG ID of a serving cell with a lower index value (e.g., "0", "1", or "2"), and the highest index of the flag (i.e., "1") corresponds to a TAG ID of a serving cell with a higher index value (e.g., "1", "2", or "3").

[0114] In some examples, a flag that can be mapped to a TAG ID may be included in the UL grant field of the MAC payload for RAR.

[0115] Figure 4 is a flowchart showing examples of Method 400 for indicating a TAG according to some embodiments of the present disclosure. Method 400 is implemented in terminal device 110 as shown in Figure 1. For convenience of explanation, Method 400 will be described with reference to Figure 1.

[0116] In 410, the terminal device 110 receives a flag during a random access procedure that can be mapped to a timing advance group identifier (TAG ID) associated with the device's serving cell, and the device is configured with two TAGs associated with the serving cell, and the TAG ID is associated with one of those two TAGs.

[0117] In step 420, the terminal device 110 determines the TAG ID based at least on the mapping between the flag index value and the TAG ID index value.

[0118] In some embodiments, the flag is a 1-bit instruction.

[0119] In some embodiments, a flag indicating a first value can be mapped to the TAG ID with the lowest index value among the TAG IDs associated with the serving cell, and a flag indicating a second value can be mapped to the TAG ID with the lowest index value among the TAG IDs associated with the serving cell.

[0120] In some embodiments, the flag is notified in a Random Access Response (RAR) or message B.

[0121] In some embodiments, the flag is indicated by a first bit in the Media Access Control (MAC) payload of the RAR, or by a first bit in the MAC payload of message B.

[0122] In some embodiments, the flag is included in the uplink grant field of the Random Access Response (RAR).

[0123] In some embodiments, the flag is included in the downlink control information (DCI) for scheduling a Medium Access Control (MAC) protocol data unit (PDU) for a Random Access Response (RAR), or for scheduling a MAC PDU for Message B.

[0124] In some embodiments, the flag is included in the downlink control information (DCI) for scheduling uplink grants for successful collision resolution or successful completion of random access procedures.

[0125] Figure 5 is a flowchart showing examples of Method 500 for indicating a TAG according to some embodiments of the present disclosure. Method 500 is implemented in a network device 120 as shown in Figure 1. For convenience of explanation, Method 500 will be described with reference to Figure 1.

[0126] In step 510, the network device 120 sends a flag to the terminal device that can be mapped to a timing advance group identifier (TAG ID) associated with the device's serving cell during the random access procedure, and the terminal device is configured with two TAGs associated with the serving cell, and the TAG ID is associated with one of the two TAGs.

[0127] In some embodiments, this flag is a 1-bit instruction.

[0128] In some embodiments, a flag indicating a first value can be mapped to the TAG ID with the lowest index value among the TAG IDs associated with the serving cell, and a flag indicating a second value can be mapped to the TAG ID with the lowest index value among the TAG IDs associated with the serving cell.

[0129] In some embodiments, the flag is notified in a Random Access Response (RAR) or message B.

[0130] In some embodiments, the flag is indicated by a first bit in the Media Access Control (MAC) payload of the RAR, or by a first bit in the MAC payload of message B.

[0131] In some embodiments, the flag is included in the uplink grant field of the Random Access Response (RAR).

[0132] In some embodiments, the flag is included in the downlink control information (DCI) for scheduling a Medium Access Control (MAC) protocol data unit (PDU) for a Random Access Response (RAR), or for scheduling a MAC PDU for Message B.

[0133] In some embodiments, the flag is included in the downlink control information (DCI) for scheduling uplink grants for successful collision resolution or successful completion of random access procedures.

[0134] In some embodiments, an apparatus capable of performing Method 400 (for example, implemented in a terminal device 110) may include means for performing each step of Method 400. These means can be implemented in any suitable form. For example, these means can be implemented as a circuit or a software module.

[0135] In some embodiments, the apparatus includes means for receiving a flag during a random access procedure that is mappable to a timing advance group identifier (TAG ID) associated with a serving cell of the apparatus, wherein the apparatus has two TAGs associated with the serving cell, and the TAG ID is associated with one of the two TAGs; and means for determining the TAG ID based at least on a mapping between a flag index value and a TAG ID index value.

[0136] In some embodiments, the flag is represented by a single bit.

[0137] In some embodiments, a flag indicating a first value can be mapped to the TAG ID having the lowest index value of the TAG ID associated with the serving cell, and a flag indicating a second value can be mapped to the TAG ID having the lowest index value of the TAG ID associated with the serving cell.

[0138] In some embodiments, the flag is notified in a Random Access Response (RAR) or message B.

[0139] In some embodiments, the flag is indicated by a first bit in the Media Access Control (MAC) payload of the RAR, or by a first bit in the MAC payload of message B.

[0140] In some embodiments, the flag is included in the uplink grant field of the Random Access Response (RAR).

[0141] In some embodiments, the flag is included in the downlink control information (DCI) for scheduling a Medium Access Control (MAC) protocol data unit (PDU) for a Random Access Response (RAR), or for scheduling a MAC PDU for Message B.

[0142] In some embodiments, the flag is included in the downlink control information (DCI) for scheduling uplink grants for successful collision resolution or successful completion of random access procedures.

[0143] In some embodiments, an apparatus capable of performing Method 500 (for example, implemented on TRP120) may include means for performing each step of Method 500. These means can be implemented in any suitable form. For example, these means may be implemented as a circuit or a software module.

[0144] In some embodiments, the device includes means for sending a flag to a terminal device during a random access procedure that can be mapped to a timing advance group identifier (TAG ID) associated with the device's serving cell, the terminal device being configured with two TAGs associated with the serving cell, and the TAG ID being associated with one of the two TAGs.

[0145] In some embodiments, the flag is represented by a single bit.

[0146] In some embodiments, a flag indicating a first value can be mapped to the TAG ID with the lowest index value among the TAG IDs associated with the serving cell, and a flag indicating a second value can be mapped to the TAG ID with the lowest index value among the TAG IDs associated with the serving cell.

[0147] In some embodiments, the flag is notified in a Random Access Response (RAR) or message B.

[0148] In some embodiments, the flag is indicated by a first bit in the Media Access Control (MAC) payload of the RAR, or by a first bit in the MAC payload of message B.

[0149] In some embodiments, the flag is included in the uplink grant field of the Random Access Response (RAR).

[0150] In some embodiments, the flag is included in the downlink control information (DCI) for scheduling a Medium Access Control (MAC) protocol data unit (PDU) for a Random Access Response (RAR), or for scheduling a MAC PDU for Message B.

[0151] In some embodiments, the flag is included in the downlink control information (DCI) for scheduling uplink grants for successful collision resolution or successful completion of random access procedures.

[0152] Figure 6 is a simplified block diagram of a device 600 suitable for implementing an embodiment of the present disclosure. The device 600 is provided for implementing a communication device such as the first terminal device 110 or the second terminal device 120 shown in Figure 1. As shown in the figure, the device 600 comprises one or more processors 610, one or more memories 620 connected to the processors 610, and one or more communication modules 640 connected to the processors 610.

[0153] The communication module 640 is for bidirectional communication. The communication module 640 has one or more communication interfaces to facilitate communication with other modules or devices. The communication interfaces can represent any interfaces necessary for communication with other network elements. In some embodiments, the communication module 640 may include at least one antenna.

[0154] The processor 610 can be any type suitable for a local technology network and may include, for example, a general-purpose computer, a dedicated computer, a microprocessor, a digital signal processor (DSP), or a processor based on a multi-core processor architecture. The device 600 may have multiple processors, such as application-specific integrated circuit chips that are time-dependent to a clock that synchronizes the main processor.

[0155] Memory 620 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 624, electrically rewritable read-only memory (EPROM), flash® memory, hard disks, compact discs (CDs), digital video discs (DVDs), optical discs, laser discs, and other magnetic and / or optical storage devices. Examples of volatile memories include random-access memory (RAM) 622 and other volatile memories that cannot retain data during power-off periods.

[0156] The computer program 630 includes computer-executable instructions that are executed by the associated processor 610. The instructions in program 630 may include instructions for performing operations / actions in some embodiments of this disclosure. Program 630 may be stored in memory, for example, ROM 624. The processor 610 can perform any appropriate operations and processes by loading program 630 into RAM 622.

[0157] Exemplary embodiments of this disclosure may be implemented by program 630, thereby enabling the device 600 to perform any of the operations of this disclosure described with reference to Figures 2 to 6. Exemplary embodiments of this disclosure may also be implemented by hardware, or by a combination of software and hardware.

[0158] In some embodiments, the program 630 may be tangibly stored in a computer-readable medium built into the device 600 (for example, in memory 620) or in another storage device accessible to the device 600. The device 600 can load the program 630 from the computer-readable medium into RAM 622 and execute it. In some embodiments, the computer-readable medium may include any type of non-temporary storage medium, such as ROM, EPROM, flash® memory, hard disk, CD, DVD, etc. The term “non-temporary” here refers to the medium itself (i.e., a tangible medium rather than a signal) and not to the persistence of data storage (e.g., RAM vs. ROM).

[0159] Figure 8 shows an example of a computer-readable medium 800 that can take the form of a CD, DVD, or other optical storage disc. The computer-readable medium 800 stores a program 630.

[0160] Generally, various embodiments of this disclosure can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some features may be implemented in hardware, while others may be implemented in firmware or software executable by a controller, microprocessor, or other computing device. Various aspects of the embodiments described herein are illustrated using block diagrams, flowcharts, or other graphic representations, but it should be understood that the blocks, devices, systems, techniques, or methods described herein can be implemented, in non-limiting examples, in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or a combination thereof.

[0161] One example of an embodiment of this disclosure also provides at least one computer program product physically recorded on a computer-readable medium, such as a non-temporary computer-readable medium. This computer program product includes computer-executable instructions, such as those contained in a program module, and is executed on a device on a target physical or virtual processor, performing one of the methods described above. Generally, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc., that perform a specific task or implement a specific abstract data type. The functionality of program modules may be combined or divided among program modules as needed in various embodiments. The machine-executable instructions for a program module may be executed in a local or distributed device. In a distributed device, the program module may reside on both local and remote storage media.

[0162] Program code for carrying out the methods of this disclosure is written in any combination of one or more programming languages. The program code is provided to a processor or controller of a general-purpose computer, a dedicated computer, or other programmable data processing device, and when executed by the processor or controller, it implements the functions / operations specified in the flowcharts and / or block diagrams. The program code may run entirely on the machine, partially on the machine, run as a standalone software package, partially on the machine and partially on a remote machine, or run entirely on a remote machine or server.

[0163] In the context of this disclosure, computer program code or related data may be carried by any suitable medium to enable a device, apparatus, or processor to perform various processes and operations as described above. Examples of such mediums include signals and computer-readable media.

[0164] Computer-readable media may be computer-readable signal media or computer-readable storage media. Computer-readable media include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, and semiconductor systems, apparatus, devices, or appropriate combinations thereof. More specific examples of computer-readable storage media include electrical connections with one or more wires, portable computer floppy disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash® memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or appropriate combinations thereof.

[0165] Furthermore, while the operations are shown in a specific order, this does not mean that the operations must be performed in a specific or sequential order shown to obtain the desired results, or that all illustrated operations must be performed. In certain situations, multitasking or parallel processing may be advantageous. Similarly, the above description includes some specific implementation details, which should not be interpreted as limitations on the scope of this disclosure, but rather as descriptions of features specific to particular embodiments. Unless expressly stated, certain features described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless expressly stated, various features described in the context of a single embodiment may also be implemented individually or in any appropriate partial combination in multiple embodiments.

[0166] While this disclosure is described in a language specific to structural features and / or methodological actions, the disclosure as defined in the attached claims is not necessarily limited to the specific functions or actions described above. Rather, the specific functions or actions described above are disclosed as exemplary forms of implementing the claims.

Claims

1. It is a device, At least one processor, When executed by the at least one processor, the device has at least, During a random access procedure, the device receives a flag that can be mapped to a timing advance group identifier (TAG ID) associated with a serving cell, wherein the device has two TAGs associated with the serving cell, and the TAG ID is associated with one of the two TAGs. The TAG ID is determined at least based on a mapping between the index value of the flag and the index value of the TAG ID, At least one memory to store instructions to execute, A device equipped with the following features.

2. The apparatus according to claim 1, wherein the flag is represented by one bit.

3. The flag indicating the first value is mappable to the TAG ID having the lowest index value among the TAG IDs associated with the serving cell, and the flag indicating the second value is mappable to the TAG ID having the lowest index value among the TAG IDs associated with the serving cell. The apparatus according to claim 1 or 2.

4. The apparatus according to any one of claims 1 to 3, wherein the flag is notified by a random access response (RAR) or message B.

5. The apparatus according to claim 4, wherein the flag is indicated by a first bit of the media access control (MAC) payload of the RAR, or by a first bit of the MAC payload of message B.

6. The apparatus according to any one of claims 1 to 3, wherein the flag is included in the uplink grant field of the random access response (RAR).

7. The apparatus according to any one of claims 1 to 3, wherein the flag is included in a media access control (MAC) protocol data unit (PDU) for random access responses (RARs) or in downlink control information (DCI) for scheduling a MAC PDU for message B.

8. The apparatus according to any one of claims 1 to 3, wherein the flag is included in downlink control information (DCI) for scheduling uplink grants for successful collision resolution or successful completion of a random access procedure.

9. It is a device, At least one processor, When executed by the at least one processor, the device has at least, Sending a flag to a terminal device during a random access procedure that can be mapped to a timing advance group identifier (TAG ID) associated with a serving cell of the terminal device, wherein the terminal device has two TAGs associated with the serving cell, and the TAG ID is associated with one of the two TAGs. At least one memory to store instructions to execute, A device equipped with the following features.

10. The apparatus according to claim 9, wherein the flag is represented by one bit.

11. The apparatus according to claim 9 or 10, wherein the flag indicating a first value is mappable to a TAG ID having the lowest index value in the TAG IDs associated with the serving cell, and the flag indicating a second value is mappable to a TAG ID having the lowest index value in the TAG IDs associated with the serving cell.

12. The apparatus according to any one of claims 9 to 11, wherein the flag is notified by a random access response (RAR) or message B.

13. The apparatus according to claim 12, wherein the flag is indicated by a first bit of the media access control (MAC) payload of the RAR, or by a first bit of the MAC payload of message B.

14. The apparatus according to any one of claims 9 to 11, wherein the flag is included in the uplink grant field of the random access response (RAR).

15. The apparatus according to any one of claims 9 to 11, wherein the flag is included in a media access control (MAC) protocol data unit (PDU) for random access responses (RARs), or in downlink control information (DCI) for scheduling a MAC PDU for message B.

16. The apparatus according to any one of claims 9 to 11, wherein the flag is included in downlink control information (DCI) for scheduling an uplink grant for successful collision resolution or completion of a successful random access procedure.

17. In a terminal device, during a random access procedure, the terminal device receives a flag from a network device that can be mapped to a timing advance group identifier (TAG ID) associated with the serving cell of the terminal device, wherein the terminal device has two TAGs associated with the serving cell, and the TAG ID is associated with one of the two TAGs. The TAG ID is determined at least based on a mapping between the index value of the flag and the index value of the TAG ID, Methods that include...

18. The network device transmits a flag to a terminal device during a random access procedure that can be mapped to a timing advance group identifier (TAG ID) associated with a serving cell of the network device, wherein the terminal device has two TAGs associated with the serving cell, and the TAG ID is associated with one of the two TAGs. Methods that include...

19. It is a device, Means for receiving a flag during a random access procedure that can be mapped to a timing advance group identifier (TAG ID) associated with a serving cell of the device, wherein the device has two TAGs associated with the serving cell, and the TAG ID is associated with one of the two TAGs, Means for determining the TAG ID, at least based on a mapping between the index value of the flag and the index value of the TAG ID, A device equipped with the following features.

20. It is a device, Means for transmitting a flag to a terminal device during a random access procedure, which is mappable to a timing advance group identifier (TAG ID) associated with a serving cell of the device, wherein the terminal device has two TAGs associated with the serving cell, and the TAG ID is associated with one of the two TAGs. A device equipped with the following features.

21. A computer-readable medium, when executed by a device, containing instructions that cause the device to perform at least the method of claim 17 or the method of claim 18.

Images