Supporting two timing advances in serving cell of wireless system

Abstract

Some aspects relate to apparatuses and methods for a wireless system supporting two timing advances for a user equipment (UE) to communicate with two different transmit receive points (TRPs) in a serving cell. The UE may: determine, based on a configuration received from a base station, that a first timing advance (TA) group (TAG) and a second TAG are configured for a serving cell; and further determining a first timing advance command (TAC) based on a first TA adjustment value and a second TA adjustment value based on a second TAC. The UE may select, from the first TAC or the second TAC, a TAC to be applied to an uplink transmission. The UE may also: select a TAG from the first TAG or the second TAG based on the selected TAC; and transmitting the uplink transmission according to the selected TAC and the selected TAG.

Description

[0001] Related patent applications

[0002] This application claims priority to U.S. patent application No. 18 / 394,212, filed on December 22, 2023, which claims the benefit of U.S. Provisional Patent Application No. 63 / 439,943, filed on January 19, 2023, the contents of both applications being incorporated herein by reference in their entirety. Background Art Technical Field

[0003] The described aspects relate generally to wireless communications, including supporting two timing advances for user equipment (UE) in a serving cell of a wireless system.

[0004] Related fields

[0005] Wireless communication systems may include fifth-generation (5G) systems, new radio (NR) systems, long-term evolution (LTE) systems, non-terrestrial wireless networks (NTNs), combinations thereof, or some other wireless systems. Furthermore, wireless communication systems may support a wide range of use cases, such as enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), ultra-reliable and low-latency communications (URLLC), enhanced vehicle-to-everything communications (eV2X), and more. Wireless systems may include multiple transmit / receive points (TRPs) for communicating with user equipment (UEs). Coordination of multiple TRPs may be desirable. Summary of the Invention

[0006] Some aspects of the present disclosure relate to apparatus and methods for implementing mechanisms for supporting two timing advances in a serving cell of a wireless system, enabling better coordination of user equipment (UE) communicating with two different transmit-receive points (TRPs). The techniques presented herein may be applicable when the timing synchronization error between the two TRPs is large, or when the distance between different panels or different TRPs is large (e.g., greater than a cyclic prefix (CP)).

[0007] Some aspects of the present disclosure relate to a UE. The UE may include a transceiver and a processor communicatively coupled to the transceiver. The transceiver may be configured to implement wireless communication with a base station in a wireless system. The processor of the UE may determine, based on a configuration received from the base station, that a first timing advance (TA) group (TAG) and a second TAG are configured for a serving cell. In some embodiments, a first time alignment timer for the first TAG is different from a second time alignment timer for the second TAG. The processor may also determine a first TA adjustment value based on a first timing advance command (TAC) and determine a second TA adjustment value based on a second TAC.

[0008] In addition, the processor may select a TAC to be applied to the uplink transmission from the first TAC or the second TAC. In some embodiments, when the UE is communicating with a first transmit reception point (TRP) of the wireless system, the selected TAC is the first TAC, and when the UE is communicating with a second TRP of the wireless system, the selected TAC is the second TAC. The processor may also select a TAG from the first TAG or the second TAG based on the selected TAC, and transmit the uplink transmission according to the selected TAC and the selected TAG.

[0009] In some embodiments, the first TAC and the second TAC are received from the base station in a random access response (RAR) message during a random access channel (RACH) procedure initiated by the UE to the base station. The RAR message includes an indication of a selected TAG for indicating the selected TAC for the uplink transmission scheduled by the RAR message. The first TAC is applied to the first TAG associated with a physical random access channel (PRACH) transmission, and the second TAC is applied to the second TAG not associated with the PRACH transmission. The first TAC and the second TAC may have different lengths resulting from differential encoding applied to the first TAC and the second TAC. The RAR message may be message B of a 2-step random access channel (RACH) procedure or message 2 of a 4-step RACH procedure.

[0010] In some embodiments, when the UE is in connected mode with the base station, an indication of the first TAC and the second TAC may be received from the base station in a medium access control-control element (MAC-CE) sent to the UE. The first TAC or the second TAC may be an absolute TAC carrying an absolute TA adjustment value or a relative TAC carrying a relative TA adjustment value. The MAC-CE may also include a TAG identifier corresponding to the first TAC or the second TAC.

[0011] This disclosure is provided for the purpose of illustrating some aspects only, so as to provide an understanding of the subject matter described herein. Therefore, the above features are merely examples and should not be construed as narrowing the scope or essence of the subject matter of this disclosure. Other features, aspects, and advantages of the present disclosure will become apparent from the following detailed description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and enable one skilled in the relevant art to make and use the present disclosure.

[0013] Figures 1A to 1CA wireless system for supporting two timing advances for a user equipment (UE) communicating with two transmit reception points (TRPs) in a serving cell is illustrated according to some aspects of the present disclosure.

[0014] Figure 2 A block diagram illustrating a UE for performing the functions described herein according to some aspects of the present disclosure is illustrated.

[0015] Figure 3 Illustrated are example procedures performed by a UE to support two timing advances in a serving cell for the UE to communicate with two TRPs in accordance with some aspects of the present disclosure.

[0016] Figure 4 is an exemplary computer system for implementing some aspects or portions of the disclosure provided herein.

[0017] The present disclosure is described with reference to the accompanying drawings. In the drawings, generally, like reference numerals indicate identical or functionally similar elements. Additionally, generally, the leftmost digit of a reference numeral identifies the drawing in which the reference numeral first appears. DETAILED DESCRIPTION

[0018] In wireless systems, user equipment (UE) can transmit and receive data on one or more component carriers (CCs) using coordinated multi-point (CoMP) transmission. In traditional cellular networks, a UE is connected to only a single transmit receive point (TRP) of the network at a time, and each TRP makes independent scheduling, precoding, and resource allocation decisions. With CoMP, multiple TRPs collaborate and coordinate their transmissions, allowing a UE to receive transmissions from multiple TRPs simultaneously, increasing the UE's throughput.

[0019] In some wireless systems, it can be assumed that the various uplink (UL) and downlink (DL) transmissions from different TRPs (e.g., physical downlink shared channel (PDSCH), physical downlink control channel (PDCCH), physical uplink control channel (PUCCH), and physical uplink shared channel (PUSCH)) can be synchronized at the UE receiver so that the maximum receive timing difference (MRTD) is less than the cyclic prefix (CP). However, in practice, from the perspective of the UE receiver, the MRTD between different TRPs may be larger than the CP. In some wireless systems, the timing synchronization error between two TRPs may be larger than the CP, or the distance between different panels or different TRPs may be larger than the CP.

[0020] In some wireless systems, timing advance (TA) is used to control the uplink transmission timing of individual UEs. The TA can be a command (notification) from the base station to the UE, enabling the UE to adjust its uplink transmission timing. The TA can help ensure that the uplink transmissions from all UEs are synchronized when received by the base station. A timing advance group (TAG) can include one or more serving cells with the same uplink TA and the same downlink timing reference cell. Each TAG contains at least one serving cell with a configured uplink, and the mapping of each serving cell to the TAG can be configured by a radio resource control (RRC) message.

[0021] The embodiments herein propose a mechanism for supporting two TAs in a serving cell of a wireless system so that UEs communicating with two different TRPs can be better coordinated. The two TAs may indicate two different UL timing adjustments applied to PUSCH, PUCCH, and Sounding Reference Signal (SRS) transmitted by the UE, respectively. In some embodiments, a first TA may be used to communicate with PUSCH, PUCCH, or SRS of a first TRP, and a second TA may be used to communicate with PUSCH, PUCCH, or SRS of a second TRP.

[0022] The embodiments herein may support two TAs and two TAGs for the same serving cell. The UE may determine, based on a configuration received from a base station, that a first TAG and a second TAG are configured for the serving cell, and may also determine a first TA adjustment value based on a first timing advance command (TAC) and a second TA adjustment value based on a second TAC. Furthermore, the UE may: select a TAC to be applied to an uplink transmission from the first TAC or the second TAC; further select a TAG from the first TAG or the second TAG based on the selected TAC; and transmit the uplink transmission according to the selected TAC and the selected TAG.

[0023] In some embodiments, the first TAC and the second TAC may be received from the base station in a random access response (RAR) message during a random access channel (RACH) procedure initiated by the UE to the base station. In some embodiments, an indication of the first TAC and the second TAC may be received from the base station in a medium access control-control element (MAC-CE) sent to the UE when the UE is in connected mode with the base station.

[0024] Figures 1A to 1CA wireless system 100 is illustrated for supporting two TAs in a serving cell for a UE to communicate with two Transition Relay Protocols (TRPs) in accordance with some aspects of the present disclosure. Wireless system 100 is provided for illustration purposes only and is not intended to limit the disclosed aspects. Wireless system 100 may include, but is not limited to, UE 101, base station 103, base station 105, and base station 107, all of which are communicatively coupled to core network 110. UE 101 communicates with base station 103 via communication link 121, with base station 105 via communication link 123, and with base station 107 via communication link 125. Each base station may be a TRP. For example, base station 105 or base station 107 may be a TRP.

[0025] In some examples, the wireless system 100 may include one or more of an NR system, an LTE system, a 5G system, or some other wireless system. Other network entities not shown may exist, such as a network controller, a relay station. The wireless system 100 may support a wide range of use cases, such as enhanced mobile broadband (eMBB), massive machine type communications (mMTC), ultra-reliable and low-latency communications (URLLC), and enhanced vehicle-to-everything communications (eV2X).

[0026] According to some aspects, base station 103, base station 105, and base station 107 can be fixed stations or mobile stations. Base station 103, base station 105, and base station 107 can also be referred to by other names, such as base transceiver system (BTS), access point (AP), TRP, evolved Node B (eNB), next generation Node B (gNB), 5G Node B (NB), or some other equivalent terminology. In some examples, base station 103 can be a gNB, and base station 105 and base station 107 can be gNB, eNB, or TRP. In some examples, base station 103, base station 105, and base station 107 can be interconnected with each other and / or interconnected to other base stations or network nodes in the network via various types of backhaul interfaces (such as direct physical connections, virtual networks, etc.) not shown.

[0027] According to some aspects, UE 101 can be stationary or mobile. UE 101 can be a cellular phone (e.g., a smartphone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a desktop computer, a cordless phone, a wireless local loop station, a wireless sensor, a tablet computer, a camera, a video surveillance camera, a gaming device, a netbook, an ultrabook, a medical device or equipment, a biometric sensor or device, a wearable device (e.g., a smart watch, smart clothing, smart glasses, a smart wristband, smart jewelry such as a smart ring or smart bracelet), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicle component, a smart meter, industrial manufacturing equipment, a global positioning system device, an Internet of Things (IoT) device, a machine type communication (MTC) device, an evolved or enhanced machine type communication (eMTC) device, or any other suitable device configured to communicate via a wireless medium. For example, MTC and eMTC devices may include robots, drones, location tags, etc.

[0028] According to some aspects, base station 103, base station 105, and base station 107 may be communicatively coupled to core network 110. Base station 103 may serve cell 102, base station 105 may serve cell 104 contained within cell 102, and base station 107 may serve cell 106 contained within cell 102 and overlapping with cell 104. In some other embodiments, cell 102 may partially overlap with cell 104 or cell 106. Cells 102, 104, and 106 may be macrocells, picocells, femtocells, and / or another type of cell. In contrast, a macrocell may cover a relatively large geographic area, e.g., several kilometers in radius, a femtocell may cover a relatively small geographic area, e.g., a home, and a picocell may cover an area smaller than the area covered by a macrocell but larger than the area covered by a femtocell. For example, cell 102 may be a macrocell, while cells 104 and 106 may be picocells or femtocells. Furthermore, cell 102 may be a picocell, while cells 104 and 106 may be femtocells. In some examples, the geographic area of ​​the cells may move depending on the location of the mobile base station.

[0029] According to some aspects, base station 103 may be a serving base station, a primary node (PN), and cell 102 may be a serving cell or a primary cell (PCell). Base station 105 and base station 107 may be neighboring base stations for UE 101, which may be secondary nodes (SNs). Cell 104 and cell 106 may be secondary cells (SCells) or primary secondary cells (PScells). Additional secondary cells for UE 101 may exist, not shown. Data for UE 101 may be transmitted simultaneously between UE 101 and core network 110 via one or more component carriers between UE 101 and base station 103 at communication link 121, one or more component carriers between UE 101 and base station 105 at communication link 123, and one or more component carriers between UE 101 and base station 107 at communication link 125. UE 101 may communicate with a serving base station, such as base station 103, using a first frequency band and communicate with a neighboring base station, such as base station 105 or base station 107, using a second frequency band different from the first frequency band. In some embodiments, cell 102, being a PCell, may be referred to as an anchor cell, which provides a radio resource control (RRC) connection to UE 101. In some examples, the PCell (cell 102) and the SCell (e.g., cell 104) may be co-located (e.g., different TRPs are in the same location).

[0030] In some embodiments, one or more SCells in the SCell (such as cell 104 or cell 106) may be activated or added to cell 102 as a PCell to form a serving cell serving UE 101. Each serving cell corresponds to one or more CCs. The CC of a PCell (e.g., cell 102) may be referred to as a primary CC (PCC), and the CC of an SCell (e.g., cell 104 or cell 106) may be referred to as a secondary CC (SCC). The PCell (cell 102) and one or more SCells (cell 104 or cell 106) may be served by corresponding base stations 103, 105, and 107. The coverage of the PCell and the SCell may be different because component carriers in different frequency bands may experience different path losses. In some embodiments, the PCell (cell 102) may add or remove one or more SCells (cell 104 or cell 106) to improve the reliability of the connection to the UE 101 and / or increase the data rate.

[0031] In some embodiments, UE 101 may be served by base station 103 (which may be a PN) and one or more secondary nodes (e.g., base station 105 and / or base station 107). A master cell group (MCG) is associated with base station 103 and one or more SCells (cell 104 and / or cell 106) in the PCell. A secondary cell group (SCG) may be associated with the SCell. Different examples may include different numbers of SCells. The PN (base station 103) may select a first SCG or a second SCG and further select one of the SCells as the PSCell of the SCG.

[0032] According to some aspects, UE 101 may include a memory 112, a processor 114 communicatively coupled to the memory, and a transceiver, such as Figure 2 The memory 112 may be configured to store various data and operations described below.

[0033] In some embodiments, the processor 114 may be configured to determine that the first TAG 115 and the second TAG 117 are configured for the serving cell based on the configuration 113 received from the base station 103. In some embodiments, the first time alignment timer for the first TAG 115 may be different from the second time alignment timer for the second TAG 117. The processor 114 may also determine a first TA adjustment value 131 based on the first TAC 135 and a second TA adjustment value 133 based on the second TAC 137. The processor 114 may select or determine a selected TAC 141 to be applied to the uplink transmission 122 from the first TAC or the second TAC. In some embodiments, when the UE 101 is communicating with a first TRP (e.g., the base station 105), the selected TAC 141 may be the first TAC 135, and when the UE 101 is communicating with a second TRP (e.g., the base station 107), the selected TAC 141 may be the second TAC 137. The processor 114 may further select or determine a selected TAG 139 from the first TAG 115 or the second TAG 117 based on the selected TAC 141 ; and transmit the uplink transmission 122 according to the selected TAC 141 and the selected TAG 139 .

[0034] In some embodiments, further details of the example uplink transmission 122 may be found in Figure 1B The process 170 shown or Figure 1C 180 is shown. In some embodiments, uplink transmission 122 may be PUCCH transmission 145. Process 170 or process 180 may also be referred to as a random access (RA) process or a RACH process. System 100 may support two types of RA processes, namely, contention-based RA processes and contention-free RA processes. Figure 1B 1 shows a contention-based RA with a 4-step message exchange process 170 between UE 101 and BS 103, and Figure 1C A contention-free mechanism using only a 2-step message exchange process 180 is shown.

[0035] In some embodiments, as Figure 1B As shown, at time window 151, UE 101 may be allocated a RA opportunity (RAO), which may be derived from a configuration index. When a RAO is present, UE 101 may transmit a random access preamble to base station 103 in message 1 using a physical random access channel (PRACH). At time window 161, base station 103 may estimate the round trip time (RTT) of UE 101 based on the time of arrival (ToA) of the preamble received in message 1. Base station 103 may use the ToA estimate to determine the timing advance (TA) to be applied by UE 101. Accordingly, UE 101 may send a dedicated preamble for the UE to the base station in a 4-step random access channel (RACH) procedure or a 2-step RACH procedure.

[0036] Base station 103 may continuously check for preamble reception at RAO, and if it detects a preamble reception, base station 103 may respond with a random access response (RAR), referred to as message 2. The RAR contains the TA parameter, as well as scheduling information (which points to the radio resources that UE 101 must use for subsequent uplink data transmission) and the modulation and coding scheme (MCS). UE 101 receives message 2 during time window 153 and further processes message 2 at time window 155.

[0037] UE 101 may send Message 3 to initiate a connection request, during which UE 101 is introduced to the network with a unique ID. This phase is also known as the contention resolution phase during time window 163. Base station 103 may then transmit Physical Downlink Shared Channel (PDSCH) Message 4 back to UE 101, which includes a confirmation of the selected temporary identifier. This temporary identifier will serve as the user's permanent ID for all future message exchanges. Similar to receiving Message 2, in this case, UE 101 will also wait for Message 4 during time window 157 until the contention resolution timer expires. If this timer expires, UE 101 may retry the RA process at another RAO. The Hybrid Automatic Repeat Request (HARQ) protocol is used for the transmission of Messages 3 and 4, with a PUCCH transmission 145 including HARQ being sent from UE 101 to base station 103. HARQ may include additional information indicating whether a packet was received (ACK or NACK). In the case of a NACK, the same packet must be retransmitted.

[0038] In some embodiments, Figure 1C In the case of the contention-free RA process shown, skip Figure 1B Messages 3 and 4 are sent because the user is already uniquely identified in this case. Figure 1C As shown, message A and PDSCH message B are sent between UE 101 and base station 103. These messages are similar to Figure 1B Message 1 and Message 2.

[0039] In some embodiments, during a RACH procedure initiated by the UE 101 to the base station 103, the first TAC 135 and the second TAC 137 are received from the base station 103 in a RAR message 124 (which is message 2 of the procedure 170). The RAR message may include an indication of a selected TAG 139 indicating a selected TAC 141 for the uplink transmission scheduled by the RAR message. The first TAC 135 is applied to a first TAG 115 associated with a physical random access channel (PRACH) transmission, and the second TAC 137 is applied to a second TAG 117 not associated with a PRACH transmission. The first TAC 135 and the second TAC 137 may have different lengths resulting from differential encoding applied to the first TAC 135 and the second TAC 137. The RAR message may be a 2-step RACH procedure ( Figure 1C Message B or 4-step RACH procedure ( Figure 1B Message 2 of process 170) shown.

[0040] In some embodiments, when the UE 101 is in connected mode with the base station 103, an indication of the first TAC 135 and the second TAC 137 may be received from the base station 103 in a medium access control-control element (MAC-CE) 128 sent to the UE 101. The first TAC 135 or the second TAC 137 may be an absolute TAC carrying an absolute TA adjustment value or a relative TAC carrying a relative TA adjustment value. The MAC-CE may also include a TAG identifier corresponding to the first TAC or the second TAC.

[0041] Figure 2The block diagram illustrates a UE 101 having an antenna panel 217, which includes one or more antenna elements, such as antenna element 219, coupled to a transceiver 203 and controlled by a processor 114. Specifically, the transceiver 203 may include radio frequency (RF) circuitry 216, baseband transmit circuitry 212, and baseband receive circuitry 214. The RF circuitry 216 may include multiple parallel RF chains for one or more of transmit and receive functions, each RF chain connected to one or more antenna elements of the antenna panel. The transceiver 203 enables wireless communication between the UE 101 and base stations 103, 105, and 107 via the antenna panel 217. Furthermore, the processor 114 may be communicatively coupled to the memory 112, which is further coupled to the transceiver 203.

[0042] In some examples, the RF circuit 216 is used by the UE 101 to perform measurements of reference signals, and to send and receive data in the serving cell. The memory 112 may store the configuration 113, the first TAG 115, the second TAG 117, the first TA adjustment value 131, the second TA adjustment value 133, the first TAC 135, the second TAC 137, the selected TAG 139, and the selected TAC 141. The memory 112 may include instructions that, when executed by the processor 114, perform the functions described herein, including supporting two TAs in the serving cell communicating with two different TRPs as described herein. Alternatively, the processor 114 may be "hard coded" to perform the functions described herein, including supporting two TAs in the serving cell communicating with two different TRPs as described herein.

[0043] Figure 3 An example process 300 is illustrated for a UE to support two timing advances in a serving cell for the UE to communicate with two TRPs according to some aspects of the present disclosure. The process 300 may be performed as shown in FIG. Figure 2 UE 101 is shown performing.

[0044] At 302, UE 101 may determine that a first TAG 115 and a second TAG 117 are configured for a serving cell based on configuration 113 received from base station 103. Configuration 113 may be sent via RAR message 124 or MAC-CE 128.

[0045] In some current systems, a single TAG is configured for each serving cell. In some implementations, to support two TAs or TAGs for a serving cell, an additional TAG identifier (Id) may be configured in the configuration parameter ServingCellConfig:

[0046] ServingCellConfig::=SEQUENCE{

[0047] tdd-UL-DL-ConfigurationDedicated TDD-UL-DL-ConfigDedicated

[0048] OPTIONAL,--Cond TDD initialDownlinkBWP BWP-DownlinkDedicated

[0049] OPTIONAL,--Need M

[0050] …

[0051] crossCarrierSchedulingConfig CrossCarrierSchedulingConfig OPTIONAL,--

[0052] Need M tag-Id

[0053] TAG-Id,

[0054] tag-Id2-r18 TAG-Id OPTIONAL,

[0055] …

[0056] }

[0057] In some embodiments, when two TAGs are configured in the same parameter ServingCellConfig, it is expected that the parameter TimeAlignmentTimer of the two TAGs is the same. In some other embodiments, the parameter TimeAlignmentTimer in the two TAGs may be different.

[0058] In some embodiments, when two TAGs are configured in the same ServingCellConfig, for intra-band carrier aggregation (CA), such as when two serving cells are located in the same frequency band, the UE 101 may expect to configure the same TAG for both the first TAG and the second TAG in the two ServingCellConfigs. In some embodiments, the UE 101 may report whether the UE 101 supports configuring different TAGs for the first TAG and the second TAG in the two ServingCellConfigs.

[0059] In some embodiments, when two TAGs are configured in the same ServingCellConfig, the maximum number of TAGs for each cell group (CG) may be increased from 4 to, for example, 6 or 8. UE 101 may also report the maximum number of TAGs supported to base station 103. This maximum number of TAGs may be reported for each CG. Additionally or alternatively, this maximum number of TAGs may be reported across two CGs.

[0060] At 304 , the UE 101 may determine a first TA adjustment value 131 based on the first TAC 135 and a second TA adjustment value 133 based on the second TAC 137 .

[0061]

[0062] In some embodiments, when two TAGs are configured in the same parameter ServingCellConfig, for RAR, the enhanced MAC RAR may be considered to support two TACs, namely TAC 1 and TAC 2, as shown in the example above.

[0063] As shown above, TAC 1 is the TAC of the first TAG occupying 12 bits, and TAC 2 is the TAC of the second TAG occupying 12 bits. The UL grant of the uplink grant field may have 27 bits, and the field R is a reserved bit, which is set to 0. The temporary C-RNTI is a temporary C-RNTI field that occupies 16 bits and indicates a temporary identity used by the MAC entity during random access. The above structure is applicable to the RAR for the 4-step RACH MSG1 and / or the fallback RAR for the 2-step RACH MSG B, as shown in FIG. Figures 1B to 1C shown.

[0064] At 306 , the UE 101 may select a TAC to apply to the uplink transmission 122 from the first TAC 135 or the second TAC 137 , eg, determine the selected TAC 141 .

[0065] In some embodiments, when two TACs are configured in the same RAR message, to determine the TAC to use for an UL grant, such as a scheduled msg3 transmission, the selected TAC 141 may be hard-coded in the specification, e.g., to use the first TAC. Additionally or alternatively, the base station 103 may first indicate in the RAR message whether the first TAC or the second TAC may be used for the msg3 transmission scheduled by the RAR message.

[0066] At 308 , the UE 101 may select a selected TAG 139 from the first TAG 115 or the second TAG 117 based on the selected TAC 141 .

[0067] In some embodiments, when two TACs are configured in the same RAR message, various options may be implemented with respect to mapping the TACs to TAGs. In some embodiments, it may be hard-coded in the specification that the first TAC 135 applies to the first TAG 115, and the second TAC 137 applies to the second TAG 117. In some other embodiments, a PRACH transmission may be associated with a TAG. The first TAC 135 applies to the TAG associated with the PRACH transmission, and the second TAC 137 applies to a TAG not associated with the PRACH transmission.

[0068] In some embodiments, when two TACs are configured in the same RAR message, differential encoding may be considered to reduce the number of bits required for the two TACs. In some embodiments, the first TAC 135 may still be encoded in 12 bits, and the second TAC 137 may be encoded in fewer than 12 bits based on the difference from the first TAC.

[0069] Similarly, for Figure 1C The successful RAR of the 2-step RACH MSG B shown in the figure can configure two TACs. Compared with the existing successful RAR message, the following fields are added:

[0070] Timing Advance Command 2: Timing Advance Command for the second TAG, 12 bits;

[0071] TAG ID 1: TAC 1 should be used for the identification of UL's tag;

[0072] TAG ID 2: TAC 2 should be used for the identification of the UL tag.

[0073] In some embodiments, the mapping of TAC to PUCCH transmission, the mapping of TAC to TAG, and the encoding of two TACs to TAG may follow a similar approach as described above.

[0074]

[0075] In some embodiments, the enhanced MAC-CE may be considered to allow the application

[0076]

[0077] Different absolute TACs. As shown below, the MAC-CE indicates the absolute TAC and the TAG ID to which the TAC should apply. The TAG ID field indicates the identity of the TAG to which the indicated TAC applies. For legacy schemes, this field is 2 bits, but for Rel-18, this field can have more bits. In addition, the Timing Advance Command field can indicate the absolute timing advance with 12 bits.

[0078] In some embodiments, the MAC-CE may indicate two absolute TACs. As shown below, the first TAC applies to the first TAG and the second TAC applies to the second TAG. In some embodiments, different encodings may be considered to reduce the bit width, especially for the second TAC.

[0079]

[0080] In some embodiments, for legacy absolute TAC, only a single 12-bit TAC is configured in the MAC-CE. The first TAC is applied to the TAG associated with the PRACH transmission. The associated TAG may be configured in the PRACH configuration or in the PDCCH order that triggers the PRACH transmission.

[0081] In some embodiments, a single MAC-CE can be used to change the TA of more than one TAG. This can be an enhancement of the relative TAC and / or absolute TAC. For example, as shown below, the TAG ID field can include the identifier of the TAG to which the indicated TAC applies. The Timing Advance Command field can include a 6-bit relative timing advance. In some embodiments, differential encoding can be used to reduce the TAC bit width.

[0082]

[0083] At 310 , UE 101 may send the uplink transmission according to the selected TAC and the selected TAG. In some implementations, UE 101 may send uplink transmission 122 according to the selected TAC 141 and the selected TAG 139 .

[0084] Various aspects may be implemented, for example, using one or more computer systems such as Figure 4 The computer system 400 shown in FIG. 4 is implemented. The computer system 400 may be capable of performing the functions described herein to implement the UE 101 or the like. Figure 3 Any computer operating as described in the process 300 shown, such as shown in FIG. 1 and Figure 2UE 101, base station 103, base station 105, and base station 107 are shown. Computer system 400 includes one or more processors (also known as central processing units or CPUs), such as processor 404. Processor 404 is connected to a communication infrastructure 406 (e.g., a bus). Computer system 400 also includes user input / output devices 403, such as a monitor, keyboard, pointing device, etc., that communicate with communication infrastructure 406 through user input / output interface 402. Computer system 400 also includes main memory or primary storage 408, such as random access memory (RAM). Main memory 408 may include one or more levels of cache. Main memory 408 has stored therein control logic (e.g., computer software) and / or data.

[0085] The computer system 400 may also include one or more secondary storage devices or memories 410. The secondary storage 410 may include, for example, a hard drive 412 and / or a removable storage device or drive 414. The removable storage drive 414 may be a floppy disk drive, a tape drive, an optical drive, an optical storage device, a tape backup device, and / or any other storage device / drive.

[0086] The removable storage drive 414 can interact with a removable storage unit 418. The removable storage unit 418 includes a computer-usable or readable storage device having computer software (control logic) and / or data stored thereon. The removable storage unit 418 can be a floppy disk, a magnetic tape, an optical disk, a DVD, an optical storage disk, and / or any other computer data storage device. The removable storage drive 414 reads from and / or writes to the removable storage unit 418 in a well-known manner.

[0087] According to some aspects, secondary memory 410 may include other components, tools, or other methods for allowing computer system 400 to access computer programs and / or other instructions and / or data. Such components, tools, or other methods may include, for example, a removable storage unit 422 and an interface 420. Examples of removable storage unit 422 and interface 420 may include a program cartridge and a cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM or PROM) and an associated socket, a memory stick and a USB port, a memory card and an associated memory card slot, and / or any other removable storage unit and an associated interface.

[0088] In some examples, the main memory 408, the removable storage unit 418, and the removable storage unit 422 may store instructions that, when executed by the processor 404, cause the processor 404 to perform operations for a UE or a base station (e.g., as shown in FIG. 1 and FIG. 2 ). Figure 2UE 101, base station 103, base station 105, base station 107) to implement the operation for UE 101 or as shown Figure 3 The operations described by process 300 are shown.

[0089] The computer system 400 may also include a communication or network interface 424. The communication interface 424 enables the computer system 400 to communicate and interact with any combination of remote devices, remote networks, remote entities, etc. (individually and collectively referenced by reference numeral 428). For example, the communication interface 424 may allow the computer system 400 to communicate with the remote device 428 via a communication path 426, which may be wired and / or wireless and may include any combination of a LAN, a WAN, the Internet, etc. Control logic and / or data may be sent to and from the computer system 400 via the communication path 426. The operations of the communication interface 424 may be performed by a wireless controller and / or a cellular controller. The cellular controller may be a separate controller to manage communications according to different wireless communication technologies. The operations in the aforementioned aspects may be implemented in various configurations and architectures. Thus, some or all of the operations in the aforementioned aspects may be performed in hardware, software, or both. In some aspects, a tangible, non-transitory device or article of manufacture includes a tangible, non-transitory computer-usable or readable medium having control logic (software) stored thereon, also referred to herein as a computer program product or program storage device. This includes, but is not limited to, computer system 400, main memory 408, secondary memory 410, and removable storage units 418 and 422, as well as tangible articles of manufacture embodying any combination of the foregoing. Such control logic, when executed by one or more data processing devices (such as computer system 400), causes such data processing devices to operate as described herein.

[0090] Based on the teachings contained in this disclosure, it will be apparent to those skilled in the relevant art how to use Figure 4 Various aspects of the present disclosure may be implemented and used with data processing devices, computer systems, and / or computer architectures other than those shown. In particular, various aspects may operate with software, hardware, and / or operating system implementations other than those described herein.

[0091] It should be understood that the Detailed Description section, and not the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary aspects of the present disclosure as contemplated by the inventor(s), and thus, are not intended to limit the present disclosure or the appended claims in any way.

[0092] Although the present disclosure has been described herein with reference to exemplary aspects of exemplary fields and applications, it should be understood that the present disclosure is not limited thereto. Other aspects and modifications are possible and are within the scope and essence of the present disclosure. For example, and without limiting the generality of this paragraph, the various aspects are not limited to the software, hardware, firmware and / or entities illustrated in the figures and / or described herein. In addition, the various aspects (whether or not explicitly described herein) have significant practicality for fields and applications beyond the examples described herein.

[0093] Various aspects have been described herein with reference to functional building blocks illustrating specific implementations of specific functions and relationships thereof. For ease of description, the boundaries of these functional building blocks have been arbitrarily defined herein. Alternative boundaries may be defined so long as the specified functions and relationships (or their equivalents) are appropriately performed. Additionally, alternative aspects may perform functional blocks, steps, operations, methods, etc., in an order different from that described herein.

[0094] References herein to "one embodiment," "an embodiment," "an example embodiment," or similar phrases indicate that the described embodiment may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Furthermore, such phrases are not necessarily referring to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is within the knowledge of those skilled in the relevant art to incorporate such feature, structure, or characteristic into other aspects, whether or not explicitly mentioned or described herein.

[0095] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary aspects, but should be defined only in accordance with the following claims and their equivalents.

[0096] For one or more embodiments or examples, at least one of the components described in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, and / or methods described below in the Examples section. For example, circuitry associated with a thread device, router, network element, or the like as described above in conjunction with one or more of the preceding figures may be configured to operate according to one or more of the examples set forth below in the Examples section.

[0097] This disclosure anticipates that entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will adhere to robust privacy policies and / or privacy practices. Specifically, such entities should implement and adhere to privacy policies and practices that are recognized as meeting or exceeding industry or government requirements for maintaining the privacy and security of personal information data. Such policies should be easily accessible to users and updated as changes occur in the collection and / or use of data. Personal information from users should be collected for legitimate and reasonable entity purposes and should not be shared or sold outside of those legitimate purposes. Furthermore, such collection / sharing should only be conducted with the user's informed consent. Additionally, such entities should consider taking any necessary steps to protect and safeguard access to such personal information data and ensure that other entities with access to personal information data comply with the other entity's privacy policies and procedures. Furthermore, such entities may subject themselves to third-party assessments to demonstrate compliance with widely accepted privacy policies and practices. Furthermore, policies and practices should be tailored to the specific type of personal information data collected and / or accessed, as well as to applicable laws and standards, including jurisdictional considerations. For example, in the United States, the collection or access of certain health data may be governed by federal and / or state laws, such as the Health Insurance Portability and Accountability Act (HIPAA); whereas health data in other countries may be subject to other regulations and policies and should be handled accordingly. Therefore, different privacy measures should be advocated for different types of personal data in each country.

Claims

1. A user equipment (UE), comprising: a transceiver configured to implement wireless communication with a base station in a wireless system; and a processor communicatively coupled to the transceiver and configured to: determining, based on a configuration received from the base station, that a first timing advance (TA) group (TAG) and a second TAG are configured for a serving cell; determining a first timing advance command (TAC) adjustment value based on a first TA adjustment value and determining a second TA adjustment value based on a second TAC; selecting a TAC to be applied to uplink transmission from the first TAC or the second TAC; selecting a TAG from the first TAG or the second TAG based on the selected TAC; as well as The uplink transmission is sent according to the selected TAC and the selected TAG. 2 . The UE of claim 1 , wherein a first time alignment timer for the first TAG is different from a second time alignment timer for the second TAG.

3. The UE of claim 1 , wherein when the UE communicates with a first transmit receive point (TRP) of the wireless system, the selected TAC is the first TAC, and when the UE communicates with a second TRP of the wireless system, the selected TAC is the second TAC.

4. The UE of claim 1 , wherein the first TAC and the second TAC are received from the base station in a random access response (RAR) message during a random access channel (RACH) procedure initiated by the UE to the base station. 5 . The UE of claim 4 , wherein the RAR message includes an indication of a selected TAG for indicating a selected TAC for the uplink transmission scheduled by the RAR message.

6. The UE of claim 4, wherein the first TAC is applied to the first TAG associated with a physical random access channel (PRACH) transmission, and the second TAC is applied to the second TAG not associated with the PRACH transmission. 7 . The UE of claim 4 , wherein the first TAC and the second TAC have different lengths resulting from differential encoding applied to the first TAC and the second TAC.

8. The UE of claim 4, wherein the RAR message is message B of a 2-step Random Access Channel (RACH) procedure or message 2 of a 4-step RACH procedure.

9. The UE of claim 1 , wherein the indication of the first TAC and the second TAC is received from the base station in a Medium Access Control-Control Element (MAC-CE) sent to the UE when the UE is in connected mode with the base station. 10 . The UE according to claim 9 , wherein the first TAC or the second TAC is an absolute TAC carrying an absolute TA adjustment value or a relative TAC carrying a relative TA adjustment value.

11. The UE according to claim 9, wherein: The MAC-CE further includes a TAG identifier corresponding to the first TAC or the second TAC.

12. A method for a user equipment (UE), the method comprising: determining, based on a configuration received from the base station, that a first timing advance (TA) group (TAG) and a second TAG are configured for a serving cell; determining a first timing advance command (TAC) adjustment value based on a first TA adjustment value and determining a second TA adjustment value based on a second TAC; selecting a TAC to be applied to uplink transmission from the first TAC or the second TAC; selecting a TAG from the first TAG or the second TAG based on the selected TAC; as well as The uplink transmission is sent according to the selected TAC and the selected TAG. 13 . The method of claim 12 , wherein a first time alignment timer for the first TAG is different from a second time alignment timer for the second TAG.

14. The method of claim 12, wherein when the UE communicates with a first transmit receive point (TRP) of the wireless system, the selected TAC is the first TAC, and when the UE communicates with a second TRP of the wireless system, the selected TAC is the second TAC.

15. The method of claim 12, wherein the first TAC and the second TAC are received from the base station in a random access response (RAR) message during a random access channel (RACH) procedure initiated by the UE to the base station.

16. The method of claim 15, wherein the RAR message includes an indication of a selected TAG indicating a selected TAC for the uplink transmission scheduled by the RAR message.

17. The method of claim 15, wherein the first TAC is applied to the first TAG associated with a physical random access channel (PRACH) transmission, and the second TAC is applied to the second TAG not associated with the PRACH transmission.

18. The method of claim 15, wherein the RAR message is message B of a 2-step random access channel (RACH) procedure or message 2 of a 4-step RACH procedure.

19. A non-transitory computer-readable medium storing instructions that, when executed by a processor of a user equipment (UE), cause the UE to perform operations comprising: determining, based on a configuration received from the base station, that a first timing advance (TA) group (TAG) and a second TAG are configured for a serving cell; determining a first timing advance command (TAC) adjustment value based on a first TA adjustment value and determining a second TA adjustment value based on a second TAC; selecting a TAC to be applied to uplink transmission from the first TAC or the second TAC; selecting a TAG from the first TAG or the second TAG based on the selected TAC; as well as The uplink transmission is sent according to the selected TAC and the selected TAG.

20. The non-transitory computer-readable medium of claim 19, wherein the first TAC and the second TAC are received from the base station in a random access response (RAR) message during a random access channel (RACH) procedure initiated by the UE to the base station.

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