WO2023150957A1

WO2023150957A1 - Enhanced absolute timing advance command for uplink multiple transmission reception point operation

Info

Publication number: WO2023150957A1
Application number: PCT/CN2022/075797
Authority: WO
Inventors: Shaozhen GUO; Mostafa KHOSHNEVISAN; Fang Yuan; Yan Zhou; Jing Sun; Xiaoxia Zhang; Tao Luo
Original assignee: Qualcomm Incorporated
Priority date: 2022-02-10
Filing date: 2022-02-10
Publication date: 2023-08-17

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit a msgA of a two-step random access channel (RACH) procedure to a network node on a serving cell, wherein the serving cell is associated with a first timing advance group (TAG) and a second TAG. The UE may receive, from the network node on the serving cell, an absolute timing advance (TA) command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to the first TAG or the second TAG. Numerous other aspects are described.

Description

ENHANCED ABSOLUTE TIMING ADVANCE COMMAND FOR UPLINK MULTIPLE TRANSMISSION RECEPTION POINT OPERATION

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for an enhanced absolute timing advance (TA) command for uplink multiple transmission reception point (mTRP) operation.

BACKGROUND

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, or the like) . Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE) . LTE/LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP) .

A wireless network may include one or more base stations that support communication for a user equipment (UE) or multiple UEs. A UE may communicate with a base station via downlink communications and uplink communications. “Downlink” (or “DL” ) refers to a communication link from the base station to the UE, and “uplink” (or “UL” ) refers to a communication link from the UE to the base station.

The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different UEs to communicate on a municipal, national, regional, and/or global level. New Radio (NR) , which may be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the 3GPP. NR is designed to better support mobile broadband internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the downlink, using CP-OFDM and/or single-carrier frequency division multiplexing (SC-FDM) (also known as discrete Fourier transform spread OFDM (DFT-s-OFDM) ) on the uplink, as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. As the demand for mobile broadband access continues to increase, further improvements in LTE, NR, and other radio access technologies remain useful.

SUMMARY

Some aspects described herein relate to a user equipment (UE) for wireless communication. The UE may include a memory and one or more processors coupled to the memory. The one or more processors may be configured to transmit a msgA of a two-step random access channel (RACH) procedure to a network node on a serving cell, wherein the serving cell is associated with a first timing advance group (TAG) and a second TAG. The one or more processors may be configured to receive, from the network node on the serving cell, an absolute timing advance (TA) command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to the first TAG or the second TAG.

Some aspects described herein relate to a network node for wireless communication. The network node may include a memory and one or more processors coupled to the memory. The one or more processors may be configured to receive, from a UE, a msgA of a two-step RACH procedure on a serving cell. The one or more processors may be configured to transmit, to the UE on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to a first TAG associated with the serving cell or a second TAG associated with the serving cell.

Some aspects described herein relate to a method of wireless communication performed by a UE. The method may include transmitting a msgA of a two-step RACH procedure to a network node on a serving cell, wherein the serving cell is associated with a first TAG and a second TAG. The method may include receiving, from the network node on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to the first TAG or the second TAG.

Some aspects described herein relate to a method of wireless communication performed by a network node. The method may include receiving, from a UE, a msgA of a two-step RACH procedure on a serving cell. The method may include transmitting, to the UE on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to a first TAG associated with the serving cell or a second TAG associated with the serving cell.

Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a UE. The set of instructions, when executed by one or more processors of the UE, may cause the UE to transmit a msgA of a two-step RACH procedure to a network node on a serving cell, wherein the serving cell is associated with a first TAG and a second TAG. The set of instructions, when executed by one or more processors of the UE, may cause the UE to receive, from the network node on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to the first TAG or the second TAG.

Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a network node. The set of instructions, when executed by one or more processors of the network node, may cause the network node to receive, from a UE, a msgA of a two-step RACH procedure on a serving cell. The set of instructions, when executed by one or more processors of the network node, may cause the network node to transmit, to the UE on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to a first TAG associated with the serving cell or a second TAG associated with the serving cell.

Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for transmitting a msgA of a two-step RACH procedure to a network node on a serving cell, wherein the serving cell is associated with a first TAG and a second TAG. The apparatus may include means for receiving, from the network node on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to the first TAG or the second TAG.

Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for receiving, from a UE, a msgA of a two-step RACH procedure on a serving cell. The apparatus may include means for transmitting, to the UE on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to a first TAG associated with the serving cell or a second TAG associated with the serving cell.

Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, network node, wireless communication device, and/or processing system as substantially described herein with reference to and as illustrated by the drawings and specification.

The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages, will be better understood from the following description when considered in connection with the accompanying figures. Each of the figures is provided for the purposes of illustration and description, and not as a definition of the limits of the claims.

While aspects are described in the present disclosure by illustration to some examples, those skilled in the art will understand that such aspects may be implemented in many different arrangements and scenarios. Techniques described herein may be implemented using different platform types, devices, systems, shapes, sizes, and/or packaging arrangements. For example, some aspects may be implemented via integrated chip embodiments or other non-module-component based devices (e.g., end- user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, and/or artificial intelligence devices) . Aspects may be implemented in chip-level components, modular components, non-modular components, non-chip-level components, device-level components, and/or system-level components. Devices incorporating described aspects and features may include additional components and features for implementation and practice of claimed and described aspects. For example, transmission and reception of wireless signals may include one or more components for analog and digital purposes (e.g., hardware components including antennas, radio frequency (RF) chains, power amplifiers, modulators, buffers, processors, interleavers, adders, and/or summers) . It is intended that aspects described herein may be practiced in a wide variety of devices, components, systems, distributed arrangements, and/or end-user devices of varying size, shape, and constitution.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects. The same reference numbers in different drawings may identify the same or similar elements.

Fig. 1 is a diagram illustrating an example of a wireless network, in accordance with the present disclosure.

Fig. 2 is a diagram illustrating an example of a base station in communication with a user equipment (UE) in a wireless network, in accordance with the present disclosure.

Fig. 3 is a diagram illustrating an example disaggregated base station architecture, in accordance with the present disclosure.

Fig. 4 is a diagram illustrating an example of transmission reception point (TRP) differentiation at a UE based at least in part on a control resource set (CORESET) pool index, in accordance with the present disclosure.

Fig. 5 is a diagram illustrating an example of a two-step random access procedure, in accordance with the present disclosure.

Figs. 6A-6B are diagrams illustrating examples associated with an enhanced absolute timing advance (TA) command for uplink multi-TRP (mTRP) operation, in accordance with the present disclosure.

Figs. 7-8 are diagrams illustrating example processes associated with an enhanced absolute TA command for uplink mTRP operation, in accordance with the present disclosure.

Figs. 9-10 are diagrams of example apparatuses for wireless communication, in accordance with the present disclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. One skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

Several aspects of telecommunication systems will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, or the like (collectively referred to as “elements” ) . These elements may be implemented using hardware, software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

While aspects may be described herein using terminology commonly associated with a 5G or New Radio (NR) radio access technology (RAT) , aspects of the present disclosure can be applied to other RATs, such as a 3G RAT, a 4G RAT, and/or a RAT subsequent to 5G (e.g., 6G) .

Fig. 1 is a diagram illustrating an example of a wireless network 100, in accordance with the present disclosure. The wireless network 100 may be or may include elements of a 5G (e.g., NR) network and/or a 4G (e.g., Long Term Evolution (LTE) ) network, among other examples. The wireless network 100 may include one or more base stations 110 (shown as a BS 110a, a BS 110b, a BS 110c, and a BS 110d) , a user equipment (UE) 120 or multiple UEs 120 (shown as a UE 120a, a UE 120b, a UE 120c, a UE 120d, and a UE 120e) , and/or other network entities. A base station 110 is an entity that communicates with UEs 120. A base station 110 (sometimes referred to as a BS) may include, for example, an NR base station, an LTE base station, a Node B, an eNB (e.g., in 4G) , a gNB (e.g., in 5G) , an access point, and/or a transmission reception point (TRP) . Each base station 110 may provide communication coverage for a particular geographic area. In the Third Generation Partnership Project (3GPP) , the term “cell” can refer to a coverage area of a base station 110 and/or a base station subsystem serving this coverage area, depending on the context in which the term is used.

A base station 110 may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs 120 with service subscriptions. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs 120 with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs 120 having association with the femto cell (e.g., UEs 120 in a closed subscriber group (CSG) ) . A base station 110 for a macro cell may be referred to as a macro base station. A base station 110 for a pico cell may be referred to as a pico base station. A base station 110 for a femto cell may be referred to as a femto base station or an in-home base station. In the example shown in Fig. 1, the BS 110a may be a macro base station for a macro cell 102a, the BS 110b may be a pico base station for a pico cell 102b, and the BS 110c may be a femto base station for a femto cell 102c. A base station may support one or multiple (e.g., three) cells.

In some examples, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a base station 110 that is mobile (e.g., a mobile base station) . In some examples, the base stations 110 may be interconnected to one another and/or to one or more other base stations 110 or network nodes (not shown) in the wireless network 100 through various types of backhaul interfaces, such as a direct physical connection or a virtual network, using any suitable transport network.

The wireless network 100 may include one or more relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (e.g., a base station 110 or a UE 120) and send a transmission of the data to a downstream station (e.g., a UE 120 or a base station 110) . A relay station may be a UE 120 that can relay transmissions for other UEs 120. In the example shown in Fig. 1, the BS 110d (e.g., a relay base station) may communicate with the BS 110a (e.g., a macro base station) and the UE 120d in order to facilitate communication between the BS 110a and the UE 120d. A base station 110 that relays communications may be referred to as a relay station, a relay base station, a relay, or the like.

The wireless network 100 may be a heterogeneous network that includes base stations 110 of different types, such as macro base stations, pico base stations, femto base stations, relay base stations, or the like. These different types of base stations 110 may have different transmit power levels, different coverage areas, and/or different impacts on interference in the wireless network 100. For example, macro base stations may have a high transmit power level (e.g., 5 to 40 watts) whereas pico base stations, femto base stations, and relay base stations may have lower transmit power levels (e.g., 0.1 to 2 watts) .

A network controller 130 may couple to or communicate with a set of base stations 110 and may provide coordination and control for these base stations 110. The network controller 130 may communicate with the base stations 110 via a backhaul communication link. The base stations 110 may communicate with one another directly or indirectly via a wireless or wireline backhaul communication link.

The UEs 120 may be dispersed throughout the wireless network 100, and each UE 120 may be stationary or mobile. A UE 120 may include, for example, an access terminal, a terminal, a mobile station, and/or a subscriber unit. A UE 120 may be a cellular phone (e.g., a smart phone) , a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device, a biometric device, a wearable device (e.g., a smart watch, smart clothing, smart glasses, a smart wristband, smart jewelry (e.g., a smart ring or a smart bracelet) ) , an entertainment device (e.g., a music device, a video device, and/or a satellite radio) , a vehicular component or sensor, a smart meter/sensor, industrial manufacturing equipment, a global positioning system device, and/or any other suitable device that is configured to communicate via a wireless medium.

Some UEs 120 may be considered machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. An MTC UE and/or an eMTC UE may include, for example, a robot, a drone, a remote device, a sensor, a meter, a monitor, and/or a location tag, that may communicate with a base station, another device (e.g., a remote device) , or some other entity. Some UEs 120 may be considered Internet-of-Things (IoT) devices, and/or may be implemented as NB-IoT (narrowband IoT) devices. Some UEs 120 may be considered a Customer Premises Equipment. A UE 120 may be included inside a housing that houses components of the UE 120, such as processor components and/or memory components. In some examples, the processor components and the memory components may be coupled together. For example, the processor components (e.g., one or more processors) and the memory components (e.g., a memory) may be operatively coupled, communicatively coupled, electronically coupled, and/or electrically coupled.

In general, any number of wireless networks 100 may be deployed in a given geographic area. Each wireless network 100 may support a particular RAT and may operate on one or more frequencies. A RAT may be referred to as a radio technology, an air interface, or the like. A frequency may be referred to as a carrier, a frequency channel, or the like. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

In some examples, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using a base station 110 as an intermediary to communicate with one another) . For example, the UEs 120 may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (e.g., which may include a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, or a vehicle-to-pedestrian (V2P) protocol) , and/or a mesh network. In such examples, a UE 120 may perform scheduling operations, resource selection operations, and/or other operations described elsewhere herein as being performed by the base station 110.

Devices of the wireless network 100 may communicate using the electromagnetic spectrum, which may be subdivided by frequency or wavelength into various classes, bands, channels, or the like. For example, devices of the wireless network 100 may communicate using one or more operating bands. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz –7.125 GHz) and FR2 (24.25 GHz –52.6 GHz) . It should be understood that although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “Sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz –300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band.

The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Recent 5G NR studies have identified an operating band for these mid-band frequencies as frequency range designation FR3 (7.125 GHz –24.25 GHz) . Frequency bands falling within FR3 may inherit FR1 characteristics and/or FR2 characteristics, and thus may effectively extend features of FR1 and/or FR2 into mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operation beyond 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR4a or FR4-1 (52.6 GHz –71 GHz) , FR4 (52.6 GHz –114.25 GHz) , and FR5 (114.25 GHz –300 GHz) . Each of these higher frequency bands falls within the EHF band.

With the above examples in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like, if used herein, may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like, if used herein, may broadly represent frequencies that may include mid-band frequencies, may be within FR2, FR4, FR4-a or FR4-1, and/or FR5, or may be within the EHF band. It is contemplated that the frequencies included in these operating bands (e.g., FR1, FR2, FR3, FR4, FR4-a, FR4-1, and/or FR5) may be modified, and techniques described herein are applicable to those modified frequency ranges.

Deployment of communication systems, such as 5G NR systems, may be arranged in multiple manners with various components or constituent parts. In a 5G NR system, or network, a network node, a network entity, a mobility element of a network, a RAN node, a core network node, a network element, or a network equipment, such as a base station (BS, e.g., base station 110) , or one or more units (or one or more components) performing base station functionality, may be implemented in an aggregated or disaggregated architecture. For example, a BS (such as a Node B (NB) , eNB, NR BS, 5G NB, access point (AP) , a TRP, a cell, or the like) may be implemented as an aggregated base station (also known as a standalone BS or a monolithic BS) or a disaggregated base station.

An aggregated base station may be configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node. A disaggregated base station may be configured to utilize a protocol stack that is physically or logically distributed among two or more units (such as one or more central or centralized units (CUs) , one or more distributed units (DUs) , or one or more radio units (RUs) ) . In some aspects, a CU may be implemented within a RAN node, and one or more DUs may be co-located with the CU, or alternatively, may be geographically or virtually distributed throughout one or multiple other RAN nodes. The DUs may be implemented to communicate with one or more RUs. Each of the CU, DU and RU also can be implemented as virtual units, i.e., a virtual centralized unit (VCU) , a virtual distributed unit (VDU) , or a virtual radio unit (VRU) .

Base station-type operation or network design may consider aggregation characteristics of base station functionality. For example, disaggregated base stations may be utilized in an integrated access backhaul (IAB) network, an O-RAN (such as the network configuration sponsored by the O-RAN Alliance) , or a virtualized radio access network (vRAN) , also known as a cloud radio access network (C-RAN) ) . Disaggregation may include distributing functionality across two or more units at various physical locations, as well as distributing functionality for at least one unit virtually, which can enable flexibility in network design. The various units of the disaggregated base station, or disaggregated RAN architecture, can be configured for wired or wireless communication with at least one other unit.

Accordingly, as described herein, the term “base station” (e.g., the base station 110) or “network node” may refer to an aggregated base station, a disaggregated base station, an IAB node, a relay node, and/or one or more components thereof. For example, in some aspects, the term “base station” or “network node” may refer to a CU, a DU, an RU, a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) , or a Non-Real Time (Non-RT) RIC, or a combination thereof. In some aspects, the term “base station” or “network node” may refer to one device configured to perform one or more functions, such as those described herein in connection with the base station 110. In some aspects, the term “base station” or “network node” may refer to multiple devices configured to perform the one or more functions. For example, in some distributed systems, each of a number of different devices (which may be located in the same geographic location or in different geographic locations) may be configured to perform at least a portion of a function, or to duplicate performance of at least a portion of the function, and the term “base station” or “network node” may refer to any one or more of those different devices. In some aspects, the term “base station” or “network node” may refer to one or more virtual base stations and/or one or more virtual base station functions. For example, in some aspects, two or more base station functions may be instantiated on a single device. In some aspects, the term “base station” or “network node” may refer to one of the base station functions and not another. In this way, a single device may include more than one base station.

In some aspects, the UE 120 may include a communication manager 140. As described in more detail elsewhere herein, the communication manager 140 may transmit a msgA of a two-step random access channel (RACH) procedure to a network node on a serving cell, wherein the serving cell is associated with a first timing advance group (TAG) and a second TAG; and receive, from the network node on the serving cell, an absolute timing advance (TA) command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to the first TAG or the second TAG. Additionally, or alternatively, the communication manager 140 may perform one or more other operations described herein.

In some aspects, the base station 110 may include a communication manager 150. As described in more detail elsewhere herein, the communication manager 150 may receive, from a UE 120, a msgA of a two-step RACH procedure on a serving cell; and transmit, to the UE 120 on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to a first TAG associated with the serving cell or a second TAG associated with the serving cell. Additionally, or alternatively, the communication manager 150 may perform one or more other operations described herein.

As indicated above, Fig. 1 is provided as an example. Other examples may differ from what is described with regard to Fig. 1.

Fig. 2 is a diagram illustrating an example 200 of a base station 110 in communication with a UE 120 in a wireless network 100, in accordance with the present disclosure. The base station 110 may be equipped with a set of antennas 234a through 234t, such as T antennas (T ≥ 1) . The UE 120 may be equipped with a set of antennas 252a through 252r, such as R antennas (R ≥ 1) .

At the base station 110, a transmit processor 220 may receive data, from a data source 212, intended for the UE 120 (or a set of UEs 120) . The transmit processor 220 may select one or more modulation and coding schemes (MCSs) for the UE 120 based at least in part on one or more channel quality indicators (CQIs) received from that UE 120. The base station 110 may process (e.g., encode and modulate) the data for the UE 120 based at least in part on the MCS (s) selected for the UE 120 and may provide data symbols for the UE 120. The transmit processor 220 may process system information (e.g., for semi-static resource partitioning information (SRPI) ) and control information (e.g., CQI requests, grants, and/or upper layer signaling) and provide overhead symbols and control symbols. The transmit processor 220 may generate reference symbols for reference signals (e.g., a cell-specific reference signal (CRS) or a demodulation reference signal (DMRS) ) and synchronization signals (e.g., a primary synchronization signal (PSS) or a secondary synchronization signal (SSS) ) . A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, the overhead symbols, and/or the reference symbols, if applicable, and may provide a set of output symbol streams (e.g., T output symbol streams) to a corresponding set of modems 232 (e.g., T modems) , shown as modems 232a through 232t. For example, each output symbol stream may be provided to a modulator component (shown as MOD) of a modem 232. Each modem 232 may use a respective modulator component to process a respective output symbol stream (e.g., for OFDM) to obtain an output sample stream. Each modem 232 may further use a respective modulator component to process (e.g., convert to analog, amplify, filter, and/or upconvert) the output sample stream to obtain a downlink signal. The modems 232a through 232t may transmit a set of downlink signals (e.g., T downlink signals) via a corresponding set of antennas 234 (e.g., T antennas) , shown as antennas 234a through 234t.

At the UE 120, a set of antennas 252 (shown as antennas 252a through 252r) may receive the downlink signals from the base station 110 and/or other base stations 110 and may provide a set of received signals (e.g., R received signals) to a set of modems 254 (e.g., R modems) , shown as modems 254a through 254r. For example, each received signal may be provided to a demodulator component (shown as DEMOD) of a modem 254. Each modem 254 may use a respective demodulator component to condition (e.g., filter, amplify, downconvert, and/or digitize) a received signal to obtain input samples. Each modem 254 may use a demodulator component to further process the input samples (e.g., for OFDM) to obtain received symbols. A MIMO detector 256 may obtain received symbols from the modems 254, may perform MIMO detection on the received symbols if applicable, and may provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols, may provide decoded data for the UE 120 to a data sink 260, and may provide decoded control information and system information to a controller/processor 280. The term “controller/processor” may refer to one or more controllers, one or more processors, or a combination thereof. A channel processor may determine a reference signal received power (RSRP) parameter, a received signal strength indicator (RSSI) parameter, a reference signal received quality (RSRQ) parameter, and/or a CQI parameter, among other examples. In some examples, one or more components of the UE 120 may be included in a housing 284.

The network controller 130 may include a communication unit 294, a controller/processor 290, and a memory 292. The network controller 130 may include, for example, one or more devices in a core network. The network controller 130 may communicate with the base station 110 via the communication unit 294.

One or more antennas (e.g., antennas 234a through 234t and/or antennas 252a through 252r) may include, or may be included within, one or more antenna panels, one or more antenna groups, one or more sets of antenna elements, and/or one or more antenna arrays, among other examples. An antenna panel, an antenna group, a set of antenna elements, and/or an antenna array may include one or more antenna elements (within a single housing or multiple housings) , a set of coplanar antenna elements, a set of non-coplanar antenna elements, and/or one or more antenna elements coupled to one or more transmission and/or reception components, such as one or more components of Fig. 2.

On the uplink, at the UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., for reports that include RSRP, RSSI, RSRQ, and/or CQI) from the controller/processor 280. The transmit processor 264 may generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by the modems 254 (e.g., for DFT-s-OFDM or CP-OFDM) , and transmitted to the base station 110. In some examples, the modem 254 of the UE 120 may include a modulator and a demodulator. In some examples, the UE 120 includes a transceiver. The transceiver may include any combination of the antenna (s) 252, the modem (s) 254, the MIMO detector 256, the receive processor 258, the transmit processor 264, and/or the TX MIMO processor 266. The transceiver may be used by a processor (e.g., the controller/processor 280) and the memory 282 to perform aspects of any of the methods described herein (e.g., with reference to Figs. 6A-6B and Figs. 7-10) .

At the base station 110, the uplink signals from UE 120 and/or other UEs may be received by the antennas 234, processed by the modem 232 (e.g., a demodulator component, shown as DEMOD, of the modem 232) , detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by the UE 120. The receive processor 238 may provide the decoded data to a data sink 239 and provide the decoded control information to the controller/processor 240. The base station 110 may include a communication unit 244 and may communicate with the network controller 130 via the communication unit 244. The base station 110 may include a scheduler 246 to schedule one or more UEs 120 for downlink and/or uplink communications. In some examples, the modem 232 of the base station 110 may include a modulator and a demodulator. In some examples, the base station 110 includes a transceiver. The transceiver may include any combination of the antenna (s) 234, the modem (s) 232, the MIMO detector 236, the receive processor 238, the transmit processor 220, and/or the TX MIMO processor 230. The transceiver may be used by a processor (e.g., the controller/processor 240) and the memory 242 to perform aspects of any of the methods described herein (e.g., with reference to Figs. 6A-6B and Figs. 7-10) .

The controller/processor 240 of the base station 110, the controller/processor 280 of the UE 120, and/or any other component (s) of Fig. 2 may perform one or more techniques associated with an enhanced absolute timing advance (TA) command for uplink multiple transmission reception point (mTRP) operation, as described in more detail elsewhere herein. In some aspects, the network node described herein is the base station 110, is included in the base station 110, or includes one or more components of the base station 110 shown in Fig. 2. For example, the controller/processor 240 of the base station 110, the controller/processor 280 of the UE 120, and/or any other component (s) of Fig. 2 may perform or direct operations of, for example, process 700 of Fig. 7, process 800 of Fig. 8, and/or other processes as described herein. The memory 242 and the memory 282 may store data and program codes for the base station 110 and the UE 120, respectively. In some examples, the memory 242 and/or the memory 282 may include a non-transitory computer-readable medium storing one or more instructions (e.g., code and/or program code) for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, and/or interpreting) by one or more processors of the base station 110 and/or the UE 120, may cause the one or more processors, the UE 120, and/or the base station 110 to perform or direct operations of, for example, process 700 of Fig. 7, process 800 of Fig. 8, and/or other processes as described herein. In some examples, executing instructions may include running the instructions, converting the instructions, compiling the instructions, and/or interpreting the instructions, among other examples.

In some aspects, the UE 120 includes means for transmitting a msgA of a two-step random access channel (RACH) procedure to a network node on a serving cell, wherein the serving cell is associated with a first timing advance group (TAG) and a second TAG; and/or means for receiving, from the network node on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to the first TAG or the second TAG. The means for the UE to perform operations described herein may include, for example, one or more of communication manager 140, antenna 252, modem 254, MIMO detector 256, receive processor 258, transmit processor 264, TX MIMO processor 266, controller/processor 280, or memory 282.

In some aspects, a network node (e.g., base station 110) includes means for receiving, from a UE 120, a msgA of a two-step RACH procedure on a serving cell; and/or means for transmitting, to the UE 120 on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to a first TAG associated with the serving cell or a second TAG associated with the serving cell. In some aspects, the means for the network node to perform operations described herein may include, for example, one or more of communication manager 150, transmit processor 220, TX MIMO processor 230, modem 232, antenna 234, MIMO detector 236, receive processor 238, controller/processor 240, memory 242, or scheduler 246.

While blocks in Fig. 2 are illustrated as distinct components, the functions described above with respect to the blocks may be implemented in a single hardware, software, or combination component or in various combinations of components. For example, the functions described with respect to the transmit processor 264, the receive processor 258, and/or the TX MIMO processor 266 may be performed by or under the control of the controller/processor 280.

As indicated above, Fig. 2 is provided as an example. Other examples may differ from what is described with regard to Fig. 2.

Fig. 3 is a diagram illustrating an example 300 disaggregated base station architecture, in accordance with the present disclosure.

The disaggregated base station architecture shown in Fig. 3 may include one or more CUs 310 that can communicate directly with a core network 320 via a backhaul link, or indirectly with the core network 320 through one or more disaggregated base station units (such as a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) 325 via an E2 link, or a Non-Real Time (Non-RT) RIC 315 associated with a Service Management and Orchestration (SMO) Framework 305, or both) . A CU 310 may communicate with one or more DUs 330 via respective midhaul links, such as an F1 interface. The DUs 330 may communicate with one or more RUs 340 via respective fronthaul links. The RUs 340 may communicate with respective UEs 120 via one or more radio frequency (RF) access links. In some implementations, the UE 120 may be simultaneously served by multiple RUs 340.

Each of the units (e.g., the CUs 310, the DUs 330, the RUs 340) , as well as the Near-RT RICs 325, the Non-RT RICs 315, and the SMO Framework 305, may include one or more interfaces or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units, or an associated processor or controller providing instructions to the communication interfaces of the units, can be configured to communicate with one or more of the other units via the transmission medium. For example, the units can include a wired interface configured to receive or transmit signals over a wired transmission medium to one or more of the other units. Additionally, the units can include a wireless interface, which may include a receiver, a transmitter or transceiver (such as an RF transceiver) , configured to receive or transmit signals, or both, over a wireless transmission medium to one or more of the other units.

In some aspects, the CU 310 may host one or more higher layer control functions. Such control functions can include radio resource control (RRC) , packet data convergence protocol (PDCP) , service data adaptation protocol (SDAP) , or the like. Each control function can be implemented with an interface configured to communicate signals with other control functions hosted by the CU 310. The CU 310 may be configured to handle user plane functionality (e.g., Central Unit –User Plane (CU-UP) ) , control plane functionality (e.g., Central Unit –Control Plane (CU-CP) ) , or a combination thereof. In some implementations, the CU 310 can be logically split into one or more CU-UP units and one or more CU-CP units. The CU-UP unit can communicate bidirectionally with the CU-CP unit via an interface, such as the E1 interface when implemented in an O-RAN configuration. The CU 310 can be implemented to communicate with the DU 330, as necessary, for network control and signaling.

The DU 330 may correspond to a logical unit that includes one or more base station functions to control the operation of one or more RUs 340. In some aspects, the DU 330 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, or the like) depending, at least in part, on a functional split, such as those defined by the 3rd Generation Partnership Project (3GPP) . In some aspects, the DU 330 may further host one or more low-PHY layers. Each layer (or module) can be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU 330, or with the control functions hosted by the CU 310.

Lower-layer functionality can be implemented by one or more RUs 340. In some deployments, an RU 340, controlled by a DU 330, may correspond to a logical node that hosts RF processing functions, or low-PHY layer functions (such as performing fast Fourier transform (FFT) , inverse FFT (iFFT) , digital beamforming, physical random access channel (PRACH) extraction and filtering, or the like) , or both, based at least in part on the functional split, such as a lower layer functional split. In such an architecture, the RU (s) 340 can be implemented to handle over the air (OTA) communication with one or more UEs 120. In some implementations, real-time and non-real-time aspects of control and user plane communication with the RU (s) 340 can be controlled by the corresponding DU 330. In some scenarios, this configuration can enable the DU (s) 330 and the CU 310 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.

The SMO Framework 305 may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non-virtualized network elements, the SMO Framework 305 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements which may be managed via an operations and maintenance interface (such as an O1 interface) . For virtualized network elements, the SMO Framework 305 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 390) to perform network element life cycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an O2 interface) . Such virtualized network elements can include, but are not limited to, CUs 310, DUs 330, RUs 340 and Near-RT RICs 325. In some implementations, the SMO Framework 305 can communicate with a hardware aspect of a 4G RAN, such as an open eNB (O-eNB) 311, via an O1 interface. Additionally, in some implementations, the SMO Framework 305 can communicate directly with one or more RUs 340 via an O1 interface. The SMO Framework 305 also may include a Non-RT RIC 315 configured to support functionality of the SMO Framework 305.

The Non-RT RIC 315 may be configured to include a logical function that enables non-real-time control and optimization of RAN elements and resources, Artificial Intelligence/Machine Learning (AI/ML) workflows including model training and updates, or policy-based guidance of applications/features in the Near-RT RIC 325. The Non-RT RIC 315 may be coupled to or communicate with (such as via an A1 interface) the Near-RT RIC 325. The Near-RT RIC 325 may be configured to include a logical function that enables near-real-time control and optimization of RAN elements and resources via data collection and actions over an interface (such as via an E2 interface) connecting one or more CUs 310, one or more DUs 330, or both, as well as an O-eNB, with the Near-RT RIC 325.

In some implementations, to generate AI/ML models to be deployed in the Near-RT RIC 325, the Non-RT RIC 315 may receive parameters or external enrichment information from external servers. Such information may be utilized by the Near-RT RIC 325 and may be received at the SMO Framework 305 or the Non-RT RIC 315 from non-network data sources or from network functions. In some examples, the Non-RT RIC 315 or the Near-RT RIC 325 may be configured to tune RAN behavior or performance. For example, the Non-RT RIC 315 may monitor long-term trends and patterns for performance and employ AI/ML models to perform corrective actions through the SMO Framework 305 (such as reconfiguration via O1) or via creation of RAN management policies (such as A1 policies) .

As indicated above, Fig. 3 is provided as an example. Other examples may differ from what is described with regard to Fig. 3.

Fig. 4 is a diagram illustrating an example 400 of TRP differentiation at a UE 120 based at least in part on a control resource set (CORESET) pool index, in accordance with the present disclosure. In some aspects, a CORESET pool index (or CORESETPoolIndex) value may be used by the UE 120 to identify a TRP 405 associated with an uplink grant received on a physical downlink control channel (PDCCH) . For example, as shown by reference number 410, the UE 120 may be configured to differentiate among multiple TRPs 405 based at least in part on a CORESET pool index in uplink multiple downlink control information (mDCI) multi-TRP (mTRP) operation, where multiple TRPs 405 may be configured to transmit, to the UE 120, uplink DCI that carries an uplink grant (e.g., for a physical uplink shared channel (PUSCH) ) .

A CORESET may refer to a control region that is structured to support an efficient use of resources, such as by flexible configuration or reconfiguration of resources for one or more PDCCHs associated with a UE 120. In some aspects, a CORESET may occupy the first symbol of an orthogonal frequency division multiplexing (OFDM) slot, the first two symbols of an OFDM slot, or the first three symbols of an OFDM slot. Thus, a CORESET may include multiple resource blocks (RBs) in the frequency domain, and either one, two, or three symbols in the time domain. In 5G, a quantity of resources included in a CORESET may be flexibly configured, such as by using radio resource control (RRC) signaling to indicate a frequency domain region (for example, a quantity of resource blocks) or a time domain region (for example, a quantity of symbols) for the CORESET.

As illustrated in Fig. 4, a UE 120 may be configured with multiple CORESETs in a given bandwidth part (BWP) of a serving cell. Each CORESET configured for the UE 120 may be associated with a CORESET identifier (CORESET ID) . For example, a first CORESET configured for the UE 120 may be associated with CORESET ID 1, a second CORESET configured for the UE 120 may be associated with CORESET ID 2, a third CORESET configured for the UE 120 may be associated with CORESET ID 3, and a fourth CORESET configured for the UE 120 may be associated with CORESET ID 4.

As further illustrated in Fig. 4, two or more (for example, up to five) CORESETs may be grouped into a CORESET pool. Each CORESET pool may be associated with a CORESET pool index. As an example, CORESET ID 1 and CORESET ID 2 may be grouped into CORESET pool index 0, and CORESET ID 3 and CORESET ID 4 may be grouped into CORESET pool index 1. In an mTRP configuration, each CORESET pool index value may be associated with a particular TRP 405. As an example, and as illustrated in Fig. 4, a first TRP 405 (TRP ₁) may be associated with CORESET pool index 0 and a second TRP 405 (TRP ₂) may be associated with CORESET pool index 1. The UE 120 may be configured by a higher layer parameter, such as PDCCH-Config, with information identifying an association between a TRP 405 and a CORESET pool index value assigned to the TRP 405.

Accordingly, the UE 120 may identify the TRP 405 that transmitted a downlink control information (DCI) message carrying an uplink grant by determining the CORESET ID of the CORESET in which the PDCCH carrying the DCI uplink grant was transmitted, determining the CORESET pool index value associated with the CORESET pool in which the CORESET ID is included, and identifying the TRP 405 associated with the CORESET pool index value. The UE 120 may then transmit a PUSCH to the identified TRP 405 associated with the CORESET pool index value using scheduling parameters (e.g., time and frequency resources, an MCS, and/or other parameters) indicated in the uplink grant. Furthermore, the different TRPs 405 that communicate with the UE 120 in mDCI mTRP operation may be associated with different time delays (e.g., based on the TRPs 405 having different geographical locations) . Accordingly, as shown by reference number 420, different TRPs 405 may be associated with different TA values in mDCI mTRP operation. For example, in Fig. 4, the first TRP is associated with a first TA (TA ₁) and the second TRP is associated with a second TA (TA ₂) . Accordingly, when transmitting the PUSCH to the identified TRP 405 associated with the CORESET pool index value (e.g., to the TRP 405 that transmitted the DCI carrying the uplink grant) , the UE 120 may apply the TA associated with the identified TRP 405.

As indicated above, Fig. 4 is provided as an example. Other examples may differ from what is described with regard to Fig. 4.

Fig. 5 is a diagram illustrating an example 500 of a two-step random access procedure, in accordance with the present disclosure. As shown in Fig. 5, a base station 110 and a UE 120 may communicate with one another to perform the two-step random access procedure, which may also referred to as a two-step random access channel (RACH) procedure.

As shown by reference number 505, the base station 110 may transmit, and the UE 120 may receive, one or more synchronization signal blocks (SSBs) and random access configuration information. In some aspects, the random access configuration information may be transmitted in and/or indicated by system information (e.g., in one or more system information blocks (SIBs) ) and/or an SSB, such as for contention-based random access. Additionally, or alternatively, the random access configuration information may be transmitted in an RRC message and/or a PDCCH order message that triggers a RACH procedure, such as for contention-free random access. The random access configuration information may include one or more parameters to be used in the two-step random access procedure, such as one or more parameters for transmitting a random access message (RAM) and/or receiving a random access response (RAR) to the RAM.

As shown by reference number 510, the UE 120 may transmit, and the base station 110 may receive, a RAM preamble on a physical random access channel (PRACH) . As shown by reference number 515, the UE 120 may transmit, and the base station 110 may receive, a RAM payload on a PUSCH. As shown, the UE 120 may transmit the RAM preamble and the RAM payload to the base station 110 as part of an initial (or first) step of the two-step random access procedure. In some aspects, the RAM may be referred to as message A, msgA, a first message, or an initial message in a two-step random access procedure. Furthermore, in some aspects, the RAM preamble may be referred to as a message A preamble, a msgA preamble, a preamble, or a PRACH preamble, and the RAM payload may be referred to as a message A payload, a msgA payload, or a payload. In some aspects, the RAM may include some or all of the contents of message 1 (msg1) and message 3 (msg3) of a four-step random access procedure. For example, the RAM preamble may include some or all contents of message 1 (e.g., a PRACH preamble) , and the RAM payload may include some or all contents of message 3 (e.g., a UE identifier, such as a cell radio network temporary identifier (C-RNTI) , uplink control information (UCI) , and/or a PUSCH transmission) .

As shown by reference number 520, the base station 110 may receive the RAM preamble transmitted by the UE 120. If the base station 110 successfully receives and decodes the RAM preamble, the base station 110 may then receive and decode the RAM payload.

As shown by reference number 525, the base station 110 may transmit an RAR (sometimes referred to as an RAR message) . As shown, the base station 110 may transmit the RAR message as part of a second step of the two-step random access procedure. In some aspects, the RAR message may be referred to as message B, msgB, or a second message in a two-step random access procedure. The RAR message may include some or all of the contents of message 2 (msg2) and message 4 (msg4) of a four-step random access procedure. For example, the RAR message may include the detected PRACH preamble identifier, the detected UE identifier, a TA value, and/or contention resolution information.

As shown by reference number 530, as part of the second step of the two-step random access procedure, the base station 110 may transmit a PDCCH communication for the RAR. The PDCCH communication may schedule a PDSCH communication that includes the RAR. For example, the PDCCH communication may indicate a resource allocation (e.g., in DCI) for the PDSCH communication.

As shown by reference number 535, as part of the second step of the two-step random access procedure, the base station 110 may transmit the PDSCH communication for the RAR, as scheduled by the PDCCH communication. The RAR may be included in a medium access control (MAC) protocol data unit (PDU) of the PDSCH communication. As shown by reference number 540, if the UE 120 successfully receives the RAR, the UE 120 may transmit a hybrid automatic repeat request (HARQ) acknowledgement (ACK) .

In a wireless network, various events may trigger the two-step random access procedure (e.g., causing the UE 120 to transmit the msgA preamble on the PRACH and the msgA payload on the PUSCH) . For example, the two-step random access procedure may be triggered to enable initial access to the wireless network when the UE 120 is in an RRC idle state, to reestablish an RRC connection, to transmit uplink data in an RRC connected state when there are no available physical uplink control channel (PUCCH) resources for transmitting a scheduling request, and/or to perform beam failure recovery, among other examples. Furthermore, in some cases, the two-step random access procedure may be triggered when the UE 120 is in an RRC connected mode and an uplink synchronization status of the UE 120 is non-synchronized and/or to establish a time alignment for a secondary timing advance group (TAG) . For example, a TAG may generally include one or more serving cells that have the same uplink TA value, where a TAG that contains a primary cell (Pcell) or a primary secondary cell (PScell) may be referred to as a primary TAG and a TAG that contains only secondary cells (Scells) may be referred to as a secondary TAG.

Accordingly, in cases where the two-step random access procedure is triggered while the UE 120 is in an RRC connected mode based on the UE 120 having a non-synchronized uplink synchronization status and/or a need to establish a time alignment for a secondary TAG, the UE 120 may transmit the msgA preamble on the PRACH and the msgA payload on the PUSCH within a Pcell or a PScell. After transmitting the msgA preamble and the msgA payload, the UE 120 then monitors a PDCCH for a response (e.g., an RAR message) from the base station 110 within a configured window, sometimes referred to as an RAR window. For example, when initiating contention-free random access, the UE 120 may transmit the msgA preamble and the msgA payload using a dedicated preamble and a dedicated PUSCH resource configured for the UE 120, and the two-step random access procedure may end when the UE 120 receives the RAR message within the RAR window. However, when the UE 120 is initiating the two-step RACH procedure to align uplink timing, the UE 120 may need to initiate contention-based random access, because an absolute TA command to synchronize uplink timing is carried in a contention resolution message (e.g., the msgB PDSCH) . For example, in the RRC connected mode, the UE 120 may be assigned a C-RNTI that is dedicated to the UE 120, which may be indicated to the base station 110 in a C-RNTI MAC control element (MAC-CE) included in the msgA transmission. The UE 120 may then monitor the PDCCH for an RAR message that is identified by the C-RNTI dedicated to the UE 120.

Accordingly, in cases where the UE 120 receives a downlink assignment on the PDCCH for the C-RNTI dedicated to the UE 120, the MAC PDU of the msgB PDSCH communication may contain an absolute TA command within a MAC-CE. The UE 120 may then process the absolute TA command carried in the MAC-CE to synchronize uplink timing. For example, in Fig. 5, reference number 545 depicts an example structure for the MAC-CE that carries the absolute TA command. In particular, the MAC-CE that carries the absolute TA command (sometimes referred to as an absolute timing advance command MAC-CE) generally has a fixed size of two (2) octets. As shown, the MAC-CE includes a TA command field that indicates an index associated with a TA value used to control the amount of timing adjustment that the UE 120 applies on the uplink. As shown, the MAC-CE carrying the absolute TA command has a size of twelve (12) bits, which includes the last four (4) bits in the first octet and all eight (8) bits in the second octet. As further shown, the first octet in the MAC-CE includes four (4) reserved bits (shown as “R” ) that are set to zero (0) . Accordingly, when the UE 120 receives the absolute TA command in a contention resolution message in reply to a msgA transmission including the C-RNTI MAC-CE, the UE 120 may apply the TA command for a primary TAG that contains a Pcell and/or a PScell. However, in some cases, in cases where a serving cell is configured to support mDCI mTRP operation (e.g., as shown in Fig. 4) , one serving cell may be configured with two TAGs that correspond to different TRPs that may be associated with different TAs based on the different TRPs being associated with different time delays. In such cases, if a Pcell or PScell is configured with two TAGs to enable uplink mDCI mTRP operation, there may be ambiguity as to whether the TA command carried in the contention resolution message is applicable to the first TAG or the second TAG. Accordingly, some aspects described herein relate to techniques to indicate a TAG associated with a TA command in cases where a Pcell or PScell is associated with two TAGs. Further details are provided below with reference to Figs. 5A-5B.

As indicated above, Fig. 5 is provided as an example. Other examples may differ from what is described with regard to Fig. 5.

Figs. 6A-6B are diagrams illustrating examples 600 associated with an enhanced absolute TA command for uplink mTRP operation, in accordance with the present disclosure. As shown in Figs. 6A-6B, examples 600 include communication between a base station and a UE in a wireless network (e.g., wireless network 100) . In some aspects, the base station and the UE may communicate via a wireless access link, which may include an uplink and a downlink.

As shown in Figs. 6A-6B, and by reference number 610, the base station and the UE may communicate on the uplink according to an mDCI mTRP configuration, where a Pcell or PScell includes a first TRP (shown as TRP ₁) and a second TRP (shown as TRP ₂) such that the UE may transmit on the uplink to either the first TRP or the second TRP included in the Pcell or PScell. In some aspects, mDCI mTRP operation may be configured per component carrier or per bandwidth part. Accordingly, as shown by reference number 620, there may be multiple TA values within one serving cell (e.g., where the first TRP and the second TRP have different geographical locations, such that the uplink propagation delay between the UE and the first TRP is different from the uplink propagation delay between the UE and the second TRP) . For example, as shown, the first TRP may be associated with a first TA and the second TRP may be associated with a second TA. Accordingly, in cases where the base station configures mDCI mTRP operation in a special cell (Spcell) , which generally refers to a Pcell or a PScell, the Spcell may be associated with a first TAG based on the first TA associated with the first TRP and a second TAG based on the second TA associated with the second TRP.

As shown in Figs. 6A-6B, and by reference number 630, the UE may transmit a msgA communication to the base station to initiate a two-step RACH procedure. For example, in cases where the UE is in an RRC connected mode with a non-synchronized uplink synchronization status, the UE may transmit the msgA communication in the Pcell or PScell in which mDCI mTRP operation is configured to initiate a two-step contention-based RACH procedure in which a contention resolution message includes an absolute TA command. For example, in some aspects, the base station may assign a C-RNTI to the UE, which may be used to provide the UE with uplink grants, downlink assignments, and/or other scheduling in an RRC connected mode. Accordingly, in some aspects, the UE may transmit a msgA preamble on a PRACH and a msgA payload on a PUSCH, where the msgA payload may include the C-RNTI assigned to the UE.

As further shown in Figs. 6A-6B, and by reference number 640, the UE may receive a msgB communication from the base station in reply to the msgA communication. For example, after the UE transmits the msgA preamble and the msgA payload that includes the C-RNTI assigned to the UE (e.g., within a C-RNTI MAC-CE) , the UE may monitor the PDCCH of the Pcell or PScell for an RAR message (or contention resolution message) that is identified by (e.g., scrambled by) the C-RNTI assigned to the UE. For example, as shown, the msgB communication may include a PDCCH that is scrambled by the C-RNTI assigned to the UE, and the PDCCH may schedule a PDSCH that includes the contention resolution message. In some aspects, the contention resolution message may include a MAC PDU that contains an absolute TA command MAC-CE. Furthermore, because the absolute TA command MAC-CE contains only one (1) TA command, but the Pcell or PScell includes two (2) TAGs that respectively correspond to the first TRP and the second TRP, the absolute TA command MAC-CE may be associated with information to indicate whether the TA command carried in the absolute TA command MAC-CE is applicable to the first TAG that includes the first TRP or the second TAG that includes the second TRP.

For example, as shown in Fig. 6A, and by reference number 650, the absolute TA command MAC-CE may include a one-bit indicator to indicate whether the TA command applies to the first TAG or the second TAG. For example, as shown, the absolute TA command MAC-CE includes a TA command field with twelve (12) bits to indicate an index to a TA value used to control a timing adjustment that the UE 120 is to apply on the uplink. Furthermore, as shown, one reserved bit in the absolute TA command MAC-CE is used to indicate whether the UE is to apply the TA value indicated in the TA command field for the first TAG or the second TAG. For example, the one-bit indicator may indicate a TRP identifier associated with the TA command or the one-bit indicator may indicate a CORESET pool index identifier associated with the TA command (e.g., where the CORESET pool index identifier corresponds to a TRP, as described above with reference to Fig. 4) . For example, a first TRP identifier and/or CORESET pool index identifier may be associated with the first TAG associated with the first TRP, and a second TRP identifier and/or CORESET pool index identifier may be associated with the second TAG associated with the second TRP. Accordingly, the TA command carried in the absolute TA command MAC-CE may apply to the first TAG associated with the first TRP identifier and/or first CORESET pool index identifier if the one-bit indicator is set to a first value (e.g., zero (0) ) . Otherwise, the TA command carried in the absolute TA command MAC-CE may apply to the second TAG associated with the second TRP identifier and/or the second CORESET pool index identifier in cases where the one-bit indicator is set to a second value (e.g., one (1) ) .

Additionally, or alternatively, rather than using an explicit indication in the absolute TA command MAC-CE, the TA command carried in the absolute TA command MAC-CE may have an implicit association with either the first TAG that is associated with the first TRP or the second TAG that is associated with the second TRP. For example, in some aspects, the UE may transmit the msgA preamble using a beam that corresponds to a selected SSB index (e.g., an index for an SSB that has a highest RSRP or otherwise satisfies one or more beam selection criteria) . Furthermore, in some aspects, the UE may transmit the msgA preamble in a PRACH occasion that includes configured time and frequency resources in which the UE is permitted to transmit the msgA preamble. In mDCI mTRP operation, a set of SSB indexes and/or PRACH occasions may be allocated among the first TRP and the second TRP. Accordingly, as shown in Fig. 6B, and by reference number 660, whether the absolute TA command carried in the absolute TA command MAC-CE is applicable to the first TAG or the second TAG may be based at least in part on the SSB index and/or PRACH occasion used by the UE for the msgA transmission. For example, in intra-cell mTRP operation, the first half of the SSB indexes and/or PRACH occasions that are available for the msgA preamble transmission may correspond to the first TAG of the Pcell or PScell, and the second half of the SSB indexes and/or PRACH occasions that are available for the msgA preamble transmission may correspond to the second TAG of the Pcell or PScell. Accordingly, if the UE uses an SSB index or PRACH occasion in the first half of the available SSB indexes or PRACH occasions, the absolute TA command may be applicable to the first TAG associated with the first TRP. Otherwise, if the UE uses an SSB index or PRACH occasion in the second half of the available SSB indexes or PRACH occasions, the absolute TA command may be applicable to the second TAG associated with the second TRP. Alternatively, in inter-cell mTRP operation, a first set of SSB indexes and/or PRACH occasions may be associated with a serving cell physical cell identity (PCI) corresponding to the first TAG, and a second set of SSB indexes and/or PRACH occasions may be associated with a non-serving cell PCI corresponding to the second TAG. In this case, if the UE uses an SSB index or PRACH occasion in the first set of SSB indexes or PRACH occasions associated with the serving cell PCI, the absolute TA command may be applicable to the first TAG associated with the first TRP. Otherwise, if the UE uses an SSB index or PRACH occasion in the second set of SSB indexes or PRACH occasions associated with the non-serving cell PCI, the absolute TA command may be applicable to the second TAG associated with the second TRP.

As indicated above, Figs. 6A-6B are provided as examples. Other examples may differ from what is described with regard to Figs. 6A-6B.

Fig. 7 is a diagram illustrating an example process 700 performed, for example, by a UE, in accordance with the present disclosure. Example process 700 is an example where the UE (e.g., UE 120) performs operations associated with enhanced absolute TA command for uplink mDCI mTRP operation.

As shown in Fig. 7, in some aspects, process 700 may include transmitting a msgA of a two-step RACH procedure to a network node on a serving cell, wherein the serving cell is associated with a first TAG and a second TAG (block 710) . For example, the UE (e.g., using communication manager 140 and/or transmission component 904, depicted in Fig. 9) may transmit a msgA of a two-step RACH procedure to a network node on a serving cell, wherein the serving cell is associated with a first TAG and a second TAG, as described above.

As further shown in Fig. 7, in some aspects, process 700 may include receiving, from the network node on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to the first TAG or the second TAG (block 720) . For example, the UE (e.g., using communication manager 140 and/or reception component 902, depicted in Fig. 9) may receive, from the network node on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to the first TAG or the second TAG, as described above.

Process 700 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, the absolute TA command is received in a MAC-CE that has a one-bit field to indicate whether the absolute TA command applies to the first TAG or the second TAG.

In a second aspect, alone or in combination with the first aspect, a value of the one-bit field indicates a CORESET pool index identifier associated with the first TAG or the second TAG.

In a third aspect, alone or in combination with one or more of the first and second aspects, a value of the one-bit field indicates a TRP identifier associated with the first TAG or the second TAG.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes an SSB index associated with a RACH occasion used to transmit a random access preamble in the msgA.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the SSB index associated with the RACH occasion used to transmit the random access preamble in the msgA is included in a first set of SSB indexes associated with the first TAG or a second set of SSB indexes associated with the second TAG.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the SSB index associated with the RACH occasion used to transmit the random access preamble in the msgA is associated with a serving cell PCI or a non-serving cell PCI.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes a PRACH occasion used to transmit a random access preamble in the msgA.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the PRACH occasion used to transmit the random access preamble in the msgA is included in a first set of PRACH occasions associated with the first TAG or a second set of PRACH occasions associated with the second TAG.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the PRACH occasion used to transmit the random access preamble in the msgA is associated with a serving cell PCI or a non-serving cell PCI.

Although Fig. 7 shows example blocks of process 700, in some aspects, process 700 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 7. Additionally, or alternatively, two or more of the blocks of process 700 may be performed in parallel.

Fig. 8 is a diagram illustrating an example process 800 performed, for example, by a network node, in accordance with the present disclosure. Example process 800 is an example where the network node (e.g., base station 110 or a component that performs functionality of base station 110, such as a CU, DU, or RU) performs operations associated with enhanced absolute TA command for uplink mTRP operation.

As shown in Fig. 8, in some aspects, process 800 may include receiving, from a UE, a msgA of a two-step RACH procedure on a serving cell (block 810) . For example, the network node (e.g., using communication manager 150 and/or reception component 1002, depicted in Fig. 10) may receive, from a UE, a msgA of a two-step RACH procedure on a serving cell, as described above.

As further shown in Fig. 8, in some aspects, process 800 may include transmitting, to the UE on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to a first TAG associated with the serving cell or a second TAG associated with the serving cell (block 820) . For example, the network node (e.g., using communication manager 150 and/or transmission component 1004, depicted in Fig. 10) may transmit, to the UE on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to a first TAG associated with the serving cell or a second TAG associated with the serving cell, as described above.

Process 800 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, the absolute TA command is transmitted in a MAC-CE that has a one-bit field to indicate whether the absolute TA command applies to the first TAG or the second TAG.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes an SSB index associated with a RACH occasion used by the UE to transmit a random access preamble in the msgA.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes a PRACH occasion used by the UE to transmit a random access preamble in the msgA.

Although Fig. 8 shows example blocks of process 800, in some aspects, process 800 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 8. Additionally, or alternatively, two or more of the blocks of process 800 may be performed in parallel.

Fig. 9 is a diagram of an example apparatus 900 for wireless communication. The apparatus 900 may be a UE, or a UE may include the apparatus 900. In some aspects, the apparatus 900 includes a reception component 902 and a transmission component 904, which may be in communication with one another (for example, via one or more buses and/or one or more other components) . As shown, the apparatus 900 may communicate with another apparatus 906 (such as a UE, a base station, or another wireless communication device) using the reception component 902 and the transmission component 904. As further shown, the apparatus 900 may include the communication manager 140.

In some aspects, the apparatus 900 may be configured to perform one or more operations described herein in connection with Figs. 6A-6B. Additionally, or alternatively, the apparatus 900 may be configured to perform one or more processes described herein, such as process 700 of Fig. 7. In some aspects, the apparatus 900 and/or one or more components shown in Fig. 9 may include one or more components of the UE described in connection with Fig. 2. Additionally, or alternatively, one or more components shown in Fig. 9 may be implemented within one or more components described in connection with Fig. 2. Additionally, or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

The reception component 902 may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus 906. The reception component 902 may provide received communications to one or more other components of the apparatus 900. In some aspects, the reception component 902 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples) , and may provide the processed signals to the one or more other components of the apparatus 900. In some aspects, the reception component 902 may include one or more antennas, a modem, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the UE described in connection with Fig. 2.

The transmission component 904 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus 906. In some aspects, one or more other components of the apparatus 900 may generate communications and may provide the generated communications to the transmission component 904 for transmission to the apparatus 906. In some aspects, the transmission component 904 may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples) , and may transmit the processed signals to the apparatus 906. In some aspects, the transmission component 904 may include one or more antennas, a modem, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described in connection with Fig. 2. In some aspects, the transmission component 904 may be co-located with the reception component 902 in a transceiver.

The transmission component 904 may transmit a msgA of a two-step RACH procedure to a network node on a serving cell, wherein the serving cell is associated with a first TAG and a second TAG. The reception component 902 may receive, from the network node on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to the first TAG or the second TAG.

The number and arrangement of components shown in Fig. 9 are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown in Fig. 9. Furthermore, two or more components shown in Fig. 9 may be implemented within a single component, or a single component shown in Fig. 9 may be implemented as multiple, distributed components. Additionally, or alternatively, a set of (one or more) components shown in Fig. 9 may perform one or more functions described as being performed by another set of components shown in Fig. 9.

Fig. 10 is a diagram of an example apparatus 1000 for wireless communication. The apparatus 1000 may be a base station, or a base station may include the apparatus 1000. In some aspects, the apparatus 1000 includes a reception component 1002 and a transmission component 1004, which may be in communication with one another (for example, via one or more buses and/or one or more other components) . As shown, the apparatus 1000 may communicate with another apparatus 1006 (such as a UE, a base station, or another wireless communication device) using the reception component 1002 and the transmission component 1004. As further shown, the apparatus 1000 may include the communication manager 150.

In some aspects, the apparatus 1000 may be configured to perform one or more operations described herein in connection with Figs. 6A-6B. Additionally, or alternatively, the apparatus 1000 may be configured to perform one or more processes described herein, such as process 800 of Fig. 8. In some aspects, the apparatus 1000 and/or one or more components shown in Fig. 10 may include one or more components of the base station described in connection with Fig. 2. Additionally, or alternatively, one or more components shown in Fig. 10 may be implemented within one or more components described in connection with Fig. 2. Additionally, or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

The reception component 1002 may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus 1006. The reception component 1002 may provide received communications to one or more other components of the apparatus 1000. In some aspects, the reception component 1002 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples) , and may provide the processed signals to the one or more other components of the apparatus 1000. In some aspects, the reception component 1002 may include one or more antennas, a modem, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the base station described in connection with Fig. 2.

The transmission component 1004 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus 1006. In some aspects, one or more other components of the apparatus 1000 may generate communications and may provide the generated communications to the transmission component 1004 for transmission to the apparatus 1006. In some aspects, the transmission component 1004 may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples) , and may transmit the processed signals to the apparatus 1006. In some aspects, the transmission component 1004 may include one or more antennas, a modem, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the base station described in connection with Fig. 2. In some aspects, the transmission component 1004 may be co-located with the reception component 1002 in a transceiver.

The reception component 1002 may receive, from a UE, a msgA of a two-step RACH procedure on a serving cell. The transmission component 1004 may transmit, to the UE on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to a first TAG associated with the serving cell or a second TAG associated with the serving cell.

The number and arrangement of components shown in Fig. 10 are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown in Fig. 10. Furthermore, two or more components shown in Fig. 10 may be implemented within a single component, or a single component shown in Fig. 10 may be implemented as multiple, distributed components. Additionally, or alternatively, a set of (one or more) components shown in Fig. 10 may perform one or more functions described as being performed by another set of components shown in Fig. 10.

The following provides an overview of some Aspects of the present disclosure:

Aspect 1: A method of wireless communication performed by a UE, comprising: transmitting a msgA of a two-step RACH procedure to a network node on a serving cell, wherein the serving cell is associated with a first TAG and a second TAG; and receiving, from the network node on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to the first TAG or the second TAG.

Aspect 2: The method of Aspect 1, wherein the absolute TA command is received in a MAC-CE that has a one-bit field to indicate whether the absolute TA command applies to the first TAG or the second TAG.

Aspect 3: The method of Aspect 2, wherein a value of the one-bit field indicates a CORESET pool index identifier associated with the first TAG or the second TAG.

Aspect 4: The method of Aspect 2, wherein a value of the one-bit field indicates a TRP identifier associated with the first TAG or the second TAG.

Aspect 5: The method of Aspect 1, wherein the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes an SSB index associated with a RACH occasion used to transmit a random access preamble in the msgA.

Aspect 6: The method of Aspect 5, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the SSB index associated with the RACH occasion used to transmit the random access preamble in the msgA is included in a first set of SSB indexes associated with the first TAG or a second set of SSB indexes associated with the second TAG.

Aspect 7: The method of Aspect 5, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the SSB index associated with the RACH occasion used to transmit the random access preamble in the msgA is associated with a serving cell PCI or a non-serving cell PCI.

Aspect 8: The method of Aspect 1, wherein the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes a PRACH occasion used to transmit a random access preamble in the msgA.

Aspect 9: The method of Aspect 8, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the PRACH occasion used to transmit the random access preamble in the msgA is included in a first set of PRACH occasions associated with the first TAG or a second set of PRACH occasions associated with the second TAG.

Aspect 10: The method of Aspect 8, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the PRACH occasion used to transmit the random access preamble in the msgA is associated with a serving cell PCI or a non-serving cell PCI.

Aspect 11: A method of wireless communication performed by a network node, comprising: receiving, from a UE, a msgA of a two-step RACH procedure on a serving cell; and transmitting, to the UE on the serving cell, an absolute TA command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to a first TAG associated with the serving cell or a second TAG associated with the serving cell.

Aspect 12: The method of Aspect 11, wherein the absolute TA command is transmitted in a MAC-CE that has a one-bit field to indicate whether the absolute TA command applies to the first TAG or the second TAG.

Aspect 13: The method of Aspect 12, wherein a value of the one-bit field indicates a CORESET pool index identifier associated with the first TAG or the second TAG.

Aspect 14: The method of Aspect 12, wherein a value of the one-bit field indicates a TRP identifier associated with the first TAG or the second TAG.

Aspect 15: The method of Aspect 11, wherein the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes an SSB index associated with a RACH occasion used by the UE to transmit a random access preamble in the msgA.

Aspect 16: The method of Aspect 15, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the SSB index associated with the RACH occasion used to transmit the random access preamble in the msgA is included in a first set of SSB indexes associated with the first TAG or a second set of SSB indexes associated with the second TAG.

Aspect 17: The method of Aspect 15, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the SSB index associated with the RACH occasion used to transmit the random access preamble in the msgA is associated with a serving cell PCI or a non-serving cell PCI.

Aspect 18: The method of Aspect 11, wherein the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes a PRACH occasion used by the UE to transmit a random access preamble in the msgA.

Aspect 19: The method of Aspect 18, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the PRACH occasion used to transmit the random access preamble in the msgA is included in a first set of PRACH occasions associated with the first TAG or a second set of PRACH occasions associated with the second TAG.

Aspect 20: The method of Aspect 18, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the PRACH occasion used to transmit the random access preamble in the msgA is associated with a serving cell PCI or a non-serving cell PCI.

Aspect 21: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 1-10.

Aspect 22: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of Aspects 1-10.

Aspect 23: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 1-10.

Aspect 24: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 1-10.

Aspect 25: A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform the method of one or more of Aspects 1-10.

Aspect 26: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 11-20.

Aspect 27: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of Aspects 11-20.

Aspect 28: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 11-20.

Aspect 29: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 11-20.

Aspect 30: A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform the method of one or more of Aspects 11-20.

The foregoing disclosure provides illustration and description but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construed as hardware and/or a combination of hardware and software. “Software” shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, and/or functions, among other examples, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. As used herein, a “processor” is implemented in hardware and/or a combination of hardware and software. It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware and/or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the aspects. Thus, the operation and behavior of the systems and/or methods are described herein without reference to specific software code, since those skilled in the art will understand that software and hardware can be designed to implement the systems and/or methods based, at least in part, on the description herein.

As used herein, “satisfying a threshold” may, depending on the context, refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, or the like.

Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. Many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. The disclosure of various aspects includes each dependent claim in combination with every other claim in the claim set. As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a + b, a + c, b + c, and a + b + c, as well as any combination with multiples of the same element (e.g., a + a, a + a + a, a + a + b, a +a + c, a + b + b, a + c + c, b + b, b + b + b, b + b + c, c + c, and c + c + c, or any other ordering of a, b, and c) .

No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more. ” Further, as used herein, the article “the” is intended to include one or more items referenced in connection with the article “the” and may be used interchangeably with “the one or more. ” Furthermore, as used herein, the terms “set” and “group” are intended to include one or more items and may be used interchangeably with “one or more. ” Where only one item is intended, the phrase “only one” or similar language is used. Also, as used herein, the terms “has, ” “have, ” “having, ” or the like are intended to be open-ended terms that do not limit an element that they modify (e.g., an element “having” A may also have B) . Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Also, as used herein, the term “or” is intended to be inclusive when used in a series and may be used interchangeably with “and/or, ” unless explicitly stated otherwise (e.g., if used in combination with “either” or “only one of” ) .

Claims

A user equipment (UE) for wireless communication, comprising:

a memory; and

one or more processors, coupled to the memory, configured to:

transmit a msgA of a two-step random access channel (RACH) procedure to a network node on a serving cell, wherein the serving cell is associated with a first timing advance group (TAG) and a second TAG; and

receive, from the network node on the serving cell, an absolute timing advance (TA) command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to the first TAG or the second TAG.
The UE of claim 1, wherein the absolute TA command is received in a medium access control (MAC) control element (MAC-CE) that has a one-bit field to indicate whether the absolute TA command applies to the first TAG or the second TAG.
The UE of claim 2, wherein a value of the one-bit field indicates a control resource set pool index identifier associated with the first TAG or the second TAG.
The UE of claim 2, wherein a value of the one-bit field indicates a transmission reception point identifier associated with the first TAG or the second TAG.
The UE of claim 1, wherein the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes a synchronization signal block (SSB) index associated with a RACH occasion used to transmit a random access preamble in the msgA.
The UE of claim 5, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the SSB index associated with the RACH occasion used to transmit the random access preamble in the msgA is included in a first set of SSB indexes associated with the first TAG or a second set of SSB indexes associated with the second TAG.
The UE of claim 5, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the SSB index associated with the RACH occasion used to transmit the random access preamble in the msgA is associated with a serving cell physical cell identity (PCI) or a non-serving cell PCI.
The UE of claim 1, wherein the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes a physical RACH (PRACH) occasion used to transmit a random access preamble in the msgA.
The UE of claim 8, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the PRACH occasion used to transmit the random access preamble in the msgA is included in a first set of PRACH occasions associated with the first TAG or a second set of PRACH occasions associated with the second TAG.
The UE of claim 8, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the PRACH occasion used to transmit the random access preamble in the msgA is associated with a serving cell physical cell identity (PCI) or a non-serving cell PCI.
A network node for wireless communication, comprising:

a memory; and

one or more processors, coupled to the memory, configured to:

receive, from a user equipment (UE) , a msgA of a two-step random access channel (RACH) procedure on a serving cell; and

transmit, to the UE on the serving cell, an absolute timing advance (TA) command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to a first timing advance group (TAG) associated with the serving cell or a second TAG associated with the serving cell.
The network node of claim 11, wherein the absolute TA command is transmitted in a medium access control (MAC) control element (MAC-CE) that has a one-bit field to indicate whether the absolute TA command applies to the first TAG or the second TAG.
The network node of claim 12, wherein a value of the one-bit field indicates a control resource set pool index identifier associated with the first TAG or the second TAG.
The network node of claim 12, wherein a value of the one-bit field indicates a transmission reception point identifier associated with the first TAG or the second TAG.
The network node of claim 11, wherein the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes a synchronization signal block (SSB) index associated with a RACH occasion used by the UE to transmit a random access preamble in the msgA.
The network node of claim 15, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the SSB index associated with the RACH occasion used to transmit the random access preamble in the msgA is included in a first set of SSB indexes associated with the first TAG or a second set of SSB indexes associated with the second TAG.
The network node of claim 15, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the SSB index associated with the RACH occasion used to transmit the random access preamble in the msgA is associated with a serving cell physical cell identity (PCI) or a non-serving cell PCI.
The network node of claim 11, wherein the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes a physical RACH (PRACH) occasion used by the UE to transmit a random access preamble in the msgA.
The network node of claim 18, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the PRACH occasion used to transmit the random access preamble in the msgA is included in a first set of PRACH occasions associated with the first TAG or a second set of PRACH occasions associated with the second TAG.
The network node of claim 18, wherein the absolute TA command applies to the first TAG or the second TAG based at least in part on whether the PRACH occasion used to transmit the random access preamble in the msgA is associated with a serving cell physical cell identity (PCI) or a non-serving cell PCI.
A method of wireless communication performed by a user equipment (UE) , comprising:

transmitting a msgA of a two-step random access channel (RACH) procedure to a network node on a serving cell, wherein the serving cell is associated with a first timing advance group (TAG) and a second TAG; and

receiving, from the network node on the serving cell, an absolute timing advance (TA) command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to the first TAG or the second TAG.
The method of claim 21, wherein the absolute TA command is received in a medium access control (MAC) control element (MAC-CE) that has a one-bit field to indicate whether the absolute TA command applies to the first TAG or the second TAG.
The method of claim 22, wherein a value of the one-bit field indicates a control resource set pool index identifier or a transmission reception point identifier associated with the first TAG or the second TAG.
The method of claim 21, wherein the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes a synchronization signal block (SSB) index associated with a RACH occasion used to transmit a random access preamble in the msgA.
The method of claim 21, wherein the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes a physical RACH (PRACH) occasion used to transmit a random access preamble in the msgA.
A method of wireless communication performed by a network node, comprising:

receiving, from a user equipment (UE) , a msgA of a two-step random access channel (RACH) procedure on a serving cell; and

transmitting, to the UE on the serving cell, an absolute timing advance (TA) command in a msgB of the two-step RACH procedure, wherein the absolute TA command is associated with information that indicates whether the absolute TA command applies to a first timing advance group (TAG) associated with the serving cell or a second TAG associated with the serving cell.
The method of claim 26, wherein the absolute TA command is transmitted in a medium access control (MAC) control element (MAC-CE) that has a one-bit field to indicate whether the absolute TA command applies to the first TAG or the second TAG.
The method of claim 27, wherein a value of the one-bit field indicates a control resource set pool index or a transmission reception point identifier associated with the first TAG or the second TAG.
The method of claim 26, wherein the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes a synchronization signal block (SSB) index associated with a RACH occasion used by the UE to transmit a random access preamble in the msgA.
The method of claim 26, wherein the information that indicates whether the absolute TA command applies to the first TAG or the second TAG includes a physical RACH (PRACH) occasion used by the UE to transmit a random access preamble in the msgA.