WO2025236271A1

WO2025236271A1 - Uplink-only beam failure detection

Info

Publication number: WO2025236271A1
Application number: PCT/CN2024/093840
Authority: WO
Inventors: Qing Li; Junyi Li; Ruiming Zheng
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2024-05-17
Filing date: 2024-05-17
Publication date: 2025-11-20
Anticipated expiration: 2026-11-17

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit a beam sweep of uplink sounding reference signals (SRSs) on respective uplink beams to a first network entity. The UE may receive a beam indication of a selected uplink candidate beam from a second network entity. The UE may transmit a communication to the first network entity using the selected uplink candidate beam. Numerous other aspects are described.

Description

UPLINK-ONLY BEAM FAILURE DETECTION

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and specifically relate to techniques, apparatuses, and methods for uplink-only beam failure detection.

BACKGROUND

Wireless communication systems are widely deployed to provide various services that may include carrying voice, text, messaging, video, data, and/or other traffic. The services may include unicast, multicast, and/or broadcast services, among other examples. Typical wireless communication systems may employ multiple-access radio access technologies (RATs) capable of supporting communication with multiple users by sharing available system resources (for example, time domain resources, frequency domain resources, spatial domain resources, and/or device transmit power, among other examples) . Examples of such multiple-access RATs 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, and time division synchronous code division multiple access (TD-SCDMA) systems.

The above multiple-access RATs have been adopted in various telecommunication standards to provide common protocols that enable different wireless communication devices to communicate on a municipal, national, regional, or global level. An example telecommunication standard is New Radio (NR) . NR, which may also be referred to as 5G, is part of a continuous mobile broadband evolution promulgated by the Third Generation Partnership Project (3GPP) . NR (and other mobile broadband evolutions beyond NR) may be designed to better support Internet of things (IoT) and reduced capability device deployments, industrial connectivity, millimeter wave (mmWave) expansion, licensed and unlicensed spectrum access, non-terrestrial network (NTN) deployment, sidelink and other device-to-device direct communication technologies (for example, cellular vehicle-to-everything (CV2X) communication) , massive multiple-input multiple-output (MIMO) , disaggregated network architectures and network topology expansions, multiple-subscriber implementations, high-precision positioning, and/or radio frequency (RF) sensing, among other examples. As the demand for mobile broadband access continues to increase, further improvements in NR may be implemented, and other radio access technologies such as 6G may be introduced, to further advance mobile broadband evolution.

SUMMARY

Some aspects described herein relate to a method of wireless communication performed by a user equipment (UE) . The method may include transmitting a beam sweep of uplink sounding refernece signals (SRSs) on respective uplink beams to a first network entity. The method may include receiving a beam indication of a selected uplink candidate beam from a second network entity. The method may include transmitting a communication to the first network entity using the selected uplink candidate beam.

Some aspects described herein relate to a method of wireless communication performed by a first network entity. The method may include transmitting, to a UE, a request for a beam sweep of uplink SRSs to a second network entity. The method may include selecting an uplink candidate beam based at least in part on measurements of the uplink SRSs. The method may include transmitting a beam indication of the selected uplink candidate beam.

Some aspects described herein relate to a method of wireless communication performed by a first network entity. The method may include transmitting a configuration for a beam sweep of uplink SRSs to a second network entity. The method may include selecting an uplink candidate beam based at least in part on measurements of the uplink SRSs. The method may include transmitting a beam indication of the selected uplink candidate beam.

Some aspects described herein relate to an apparatus for wireless communication at a UE. The apparatus may include one or more memories and one or more processors coupled to the one or more memories. The one or more processors may be individually or collectively configured to transmit a beam sweep of uplink SRSs on respective uplink beams to a first network entity. The one or more processors may be individually or collectively configured to receive a beam indication of a selected uplink candidate beam from a second network entity. The one or more processors may be individually or collectively configured to transmit a communication to the first network entity using the selected uplink candidate beam.

Some aspects described herein relate to an apparatus for wireless communication at a first network entity. The apparatus may include one or more memories and one or more processors coupled to the one or more memories. The one or more processors may be individually or collectively configured to transmit, to a UE, a request for a beam sweep of uplink SRSs to a second network entity. The one or more processors may be individually or collectively configured to select an uplink candidate beam based at least in part on measurements of the uplink SRSs. The one or more processors may be individually or collectively configured to transmit a beam indication of the selected uplink candidate beam.

Some aspects described herein relate to an apparatus for wireless communication at a first network entity. The apparatus may include one or more memories and one or more processors coupled to the one or more memories. The one or more processors may be individually or collectively configured to transmit a configuration for a beam sweep of uplink SRSs to a second network entity. The one or more processors may be individually or collectively configured to select an uplink candidate beam based at least in part on measurements of the uplink SRSs. The one or more processors may be individually or collectively configured to transmit a beam indication of the selected uplink candidate beam.

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 beam sweep of uplink SRSs on respective uplink beams to a first network entity. The set of instructions, when executed by one or more processors of the UE, may cause the UE to receive a beam indication of a selected uplink candidate beam from a second network entity. The set of instructions, when executed by one or more processors of the UE, may cause the UE to transmit a communication to the first network entity using the selected uplink candidate beam.

Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a first network entity. The set of instructions, when executed by one or more processors of the first network entity, may cause the first network entity to transmit, to a UE, a request for a beam sweep of uplink SRSs to a second network entity. The set of instructions, when executed by one or more processors of the first network entity, may cause the first network entity to select an uplink candidate beam based at least in part on measurements of the uplink SRSs. The set of instructions, when executed by one or more processors of the first network entity, may cause the first network entity to transmit a beam indication of the selected uplink candidate beam.

Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a first network entity. The set of instructions, when executed by one or more processors of the first network entity, may cause the first network entity to transmit a configuration for a beam sweep of uplink SRSs to a second network entity. The set of instructions, when executed by one or more processors of the first network entity, may cause the first network entity to select an uplink candidate beam based at least in part on measurements of the uplink SRSs. The set of instructions, when executed by one or more processors of the first network entity, may cause the first network entity to transmit a beam indication of the selected uplink candidate beam.

Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for transmitting a beam sweep of uplink SRSs on respective uplink beams to a first network entity. The apparatus may include means for receiving a beam indication of a selected uplink candidate beam from a second network entity. The apparatus may include means for transmitting a communication to the first network entity using the selected uplink candidate beam.

Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for transmitting, to a UE, a request for a beam sweep of uplink SRSs to a second network entity. The apparatus may include means for selecting an uplink candidate beam based at least in part on measurements of the uplink SRSs. The apparatus may include means for transmitting a beam indication of the selected uplink candidate beam.

Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for transmitting a configuration for a beam sweep of uplink SRSs to a second network entity. The apparatus may include means for selecting an uplink candidate beam based at least in part on measurements of the uplink SRSs. The apparatus may include means for transmitting a beam indication of the selected uplink candidate beam.

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

The foregoing paragraphs of this section have broadly summarized some aspects of the present disclosure. These and additional aspects and associated advantages will be described hereinafter. The disclosed aspects may be used as a basis for modifying or designing other aspects for carrying out the same or similar purposes of the present disclosure. Such equivalent aspects do not depart from the scope of the appended claims. Characteristics of the aspects 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 drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The appended drawings illustrate some aspects of the present disclosure, but are not limiting of the scope of the present disclosure because the description may enable other aspects. Each of the drawings is provided for purposes of illustration and description, and not as a definition of the limits of the claims. The same or similar reference numbers in different drawings may identify the same or similar elements.

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

Fig. 2 is a diagram illustrating an example network node in communication with an example 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 an uplink dense deployment, in accordance with the present disclosure.

Fig. 5 is a diagram illustrating an example of sounding reference signal (SRS) resource sets, in accordance with the present disclosure.

Fig. 6 is a diagram illustrating an example of a possible beam failure, in accordance with the present disclosure.

Fig. 7 is a diagram illustrating an example of uplink (UL) -only beam failure recovery, in accordance with the present disclosure.

Fig. 8 is a diagram illustrating an example of UL-only beam failure recovery after beam failure detection by the network, in accordance with the present disclosure.

Fig. 9 is a diagram illustrating an example of UL-only beam failure recovery, in accordance with the present disclosure.

Fig. 10 is a diagram illustrating an example of UL-only beam failure recovery after beam failure detection by the UE, in accordance with the present disclosure.

Fig. 11 is a diagram illustrating an example process performed, for example, at a UE or an apparatus of a UE, in accordance with the present disclosure.

Fig. 12 is a diagram illustrating an example process performed, for example, at a first network entity or an apparatus of a first network entity, in accordance with the present disclosure.

Fig. 13 is a diagram illustrating an example process performed, for example, at a first network entity or an apparatus of a first network entity, in accordance with the present disclosure.

Fig. 14 is a diagram of an example apparatus for wireless communication, in accordance with the present disclosure.

Fig. 15 is a diagram of an example apparatus for wireless communication, in accordance with the present disclosure.

DETAILED DESCRIPTION

Various aspects of the present disclosure are described hereinafter with reference to the accompanying drawings. However, aspects of the present disclosure may be embodied in many different forms and is not to be construed as limited to any specific aspect illustrated by or described with reference to an accompanying drawing or otherwise presented in 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 may appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or in combination with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using various combinations or quantities of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover an apparatus having, or a method that is practiced using, other structures and/or functionalities in addition to or other than the structures and/or functionalities with which various aspects of the disclosure set forth herein may be practiced. 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 methods, operations, apparatuses, and techniques. These methods, operations, 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, or algorithms (collectively referred to as “elements” ) . These elements may be implemented using hardware, software, or a combination of hardware and software. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

In order to improve the coverage and capacity of uplink (UL) transmissions, an UL dense deployment may be used. The UL dense deployment may include a macro network entity providing macro coverage and multiple UL receive (Rx) points, such as multiple transmit receive points or multiple transmission and reception points (mTRPs) , providing UL micro coverage. Although the acronym “mTRP” refers to multiple TRPs, “mTRP” can be used in the singular, and when so used, can refer to a single TRP that is among multiple TRPs, within the context of an mTRP environment, providing micro coverage in coordination with a macro network entity. An mTRP that provides micro coverage may be considered a ” micro” mTRP. The mTRPs may be UL-only nodes where only UL signals and channels are received for reception by the network entity. A user equipment (UE) may transmit a signal or message to an UL-only node. Downlink (DL) signals and channels are transmitted from a different node (e.g., macro node, central node or central unit (CU) , serving cell, serving base station) , such as a network entity. The UL Rx points are connected to the network entity via a front haul or backhaul.

In some scenarios, an UL beam to an UL-only mTRP may fail. However, there is no DL reference signal from the UL-only mTRP for beam failure detection and no DL reference signal for selecting a best candidate beam that can be used for a beam failure recovery request. For UL-only mTRPs, if there is no detection of an UL-only beam failure and thus no UL-only beam failure recovery, UL communications may degrade or fail. As a result, UL throughput decreases and latency increases.

Various aspects relate generally to uplink communications. Some aspects more specifically relate to detection of an UL-only beam failure. In some aspects, the network may detect UL-only beam failure from missed or decoding failure of UL transmissions. In some aspects, the UE may detect UL-only beam failure when no expected response is received for an UL transmission. After a network entity (e.g., gNB) determines that there is an UL-only beam failure, the network entity may start beam failure recovery by transmitting a request for a beam sweep of UL sounding reference signals (SRSs) by the UE on uplink beams to the mTRPs (e.g., UL-only mTRPs) . The UE may perform the beam sweep of UL SRSs. The mTRPs and/or the network entity may measure the UL SRSs. The network entity or the mTRP may select a best (e.g., greatest strength, greatest quality, greatest reliability) UL candidate beam from among the UL beams of the beam sweep. The network entity may transmit an indication of the selected UL candidate beam to the UE 720. The UE may transmit a communication using the selected UL candidate beam.

Particular aspects of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. By detecting a beam failure and requesting a beam sweep of UL SRSs, the network entity may indicate a best UL candidate beam to the UE to improve the UL communications by the UE to UL-only mTRPs. As a result, the UL throughput will increase and latency will decrease.

Multiple-access radio access technologies (RATs) have been adopted in various telecommunication standards to provide common protocols that enable wireless communication devices to communicate on a municipal, enterprise, national, regional, or global level. For example, 5G New Radio (NR) is part of a continuous mobile broadband evolution promulgated by the Third Generation Partnership Project (3GPP) . 5G NR supports various technologies and use cases including enhanced mobile broadband (eMBB) , ultra-reliable low-latency communication (URLLC) , massive machine-type communication (mMTC) , millimeter wave (mmWave) technology, beamforming, network slicing, edge computing, Internet of Things (IoT) connectivity and management, and network function virtualization (NFV) .

As the demand for broadband access increases and as technologies supported by wireless communication networks evolve, further technological improvements may be adopted in or implemented for 5G NR or future RATs, such as 6G, to further advance the evolution of wireless communication for a wide variety of existing and new use cases and applications. Such technological improvements may be associated with new frequency band expansion, licensed and unlicensed spectrum access, overlapping spectrum use, small cell deployments, non-terrestrial network (NTN) deployments, disaggregated network architectures and network topology expansion, device aggregation, advanced duplex communication, sidelink and other device-to-device direct communication, IoT (including passive or ambient IoT) networks, reduced capability (RedCap) UE functionality, industrial connectivity, multiple-subscriber implementations, high-precision positioning, radio frequency (RF) sensing, and/or artificial intelligence or machine learning (AI/ML) , among other examples. These technological improvements may support use cases such as wireless backhauls, wireless data centers, extended reality (XR) and metaverse applications, meta services for supporting vehicle connectivity, holographic and mixed reality communication, autonomous and collaborative robots, vehicle platooning and cooperative maneuvering, sensing networks, gesture monitoring, human-brain interfacing, digital twin applications, asset management, and universal coverage applications using non-terrestrial and/or aerial platforms, among other examples. The methods, operations, apparatuses, and techniques described herein may enable one or more of the foregoing technologies and/or support one or more of the foregoing use cases.

Fig. 1 is a diagram illustrating an example of a wireless communication network 100 in accordance with the present disclosure. The wireless communication network 100 may be or may include elements of a 5G (or NR) network or a 6G network, among other examples. The wireless communication network 100 may include multiple network nodes 110, shown as a network node (NN) 110a, a network node 110b, a network node 110c, and a network node 110d. The network nodes 110 may support communications with multiple UEs 120, shown as a UE 120a, a UE 120b, a UE 120c, a UE 120d, and a UE 120e.

The network nodes 110 and the UEs 120 of the wireless communication network 100 may communicate using the electromagnetic spectrum, which may be subdivided by frequency or wavelength into various classes, bands, carriers, and/or channels. For example, devices of the wireless communication network 100 may communicate using one or more operating bands. In some aspects, multiple wireless networks 100 may be deployed in a given geographic area. Each wireless communication network 100 may support a particular RAT (which may also be referred to as an air interface) and may operate on one or more carrier frequencies in one or more frequency ranges. Examples of RATs include a 4G RAT, a 5G/NR RAT, and/or a 6G RAT, among other examples. In some examples, when multiple RATs are deployed in a given geographic area, each RAT in the geographic area may operate on different frequencies to avoid interference with one another.

Various operating bands have been defined as frequency range designations FR1 (410 MHz through 7.125 GHz) , FR2 (24.25 GHz through 52.6 GHz) , FR3 (7.125 GHz through 24.25 GHz) , FR4a or FR4-1 (52.6 GHz through 71 GHz) , FR4 (52.6 GHz through 114.25 GHz) , and FR5 (114.25 GHz through 300 GHz) . Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “Sub-6 GHz” band in some documents and articles. Similarly, FR2 is often referred to (interchangeably) as a “millimeter wave” band in some documents and articles, despite being different than the extremely high frequency (EHF) band (30 GHz through 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, which include FR3. Frequency bands falling within FR3 may inherit FR1 characteristics or FR2 characteristics, and thus may effectively extend features of FR1 or FR2 into mid-band frequencies. Thus, “sub-6 GHz, ” if used herein, may broadly refer to frequencies that are less than 6 GHz, that are within FR1, and/or that are included in mid-band frequencies. Similarly, the term “millimeter wave, ” if used herein, may broadly refer to frequencies that are included in mid-band frequencies, that are within FR2, FR4, FR4-a or FR4-1, or FR5, and/or that are within the EHF band. Higher frequency bands may extend 5G NR operation, 6G operation, and/or other RATs beyond 52.6 GHz. For example, each of FR4a, FR4-1, FR4, and FR5 falls within the EHF band. In some examples, the wireless communication network 100 may implement dynamic spectrum sharing (DSS) , in which multiple RATs (for example, 4G/LTE and 5G/NR) are implemented with dynamic bandwidth allocation (for example, based on user demand) in a single frequency band. It is contemplated that the frequencies included in these operating bands (for example, FR1, FR2, FR3, FR4, FR4-a, FR4-1, and/or FR5) may be modified, and techniques described herein may be applicable to those modified frequency ranges.

A network node 110 may include one or more devices, components, or systems that enable communication between a UE 120 and one or more devices, components, or systems of the wireless communication network 100. A network node 110 may be, may include, or may also be referred to as an NR network node, a 5G network node, a 6G network node, a Node B, an eNB, a gNB, an access point (AP) , a TRP, a mobility element, a core, a network entity, a network element, a network equipment, and/or another type of device, component, or system included in a radio access network (RAN) .

A network node 110 may be implemented as a single physical node (for example, a single physical structure) or may be implemented as two or more physical nodes (for example, two or more distinct physical structures) . For example, a network node 110 may be a device or system that implements part of a radio protocol stack, a device or system that implements a full radio protocol stack (such as a full gNB protocol stack) , or a collection of devices or systems that collectively implement the full radio protocol stack. For example, and as shown, a network node 110 may be an aggregated network node (having an aggregated architecture) , meaning that the network node 110 may implement a full radio protocol stack that is physically and logically integrated within a single node (for example, a single physical structure) in the wireless communication network 100. For example, an aggregated network node 110 may consist of a single standalone base station or a single TRP that uses a full radio protocol stack to enable or facilitate communication between a UE 120 and a core network of the wireless communication network 100.

Alternatively, and as also shown, a network node 110 may be a disaggregated network node (sometimes referred to as a disaggregated base station) , meaning that the network node 110 may implement a radio protocol stack that is physically distributed and/or logically distributed among two or more nodes in the same geographic location or in different geographic locations. For example, a disaggregated network node may have a disaggregated architecture. In some deployments, disaggregated network nodes 110 may be used in an integrated access and backhaul (IAB) network, in an open radio access network (O-RAN) (such as a network configuration in compliance with the O-RAN Alliance) , or in a virtualized radio access network (vRAN) , also known as a cloud radio access network (C-RAN) , to facilitate scaling by separating base station functionality into multiple units that can be individually deployed.

The network nodes 110 of the wireless communication network 100 may include one or more central units (CUs) , one or more distributed units (DUs) , and/or one or more radio units (RUs) . A CU may host one or more higher layer control functions, such as radio resource control (RRC) functions, packet data convergence protocol (PDCP) functions, and/or service data adaptation protocol (SDAP) functions, among other examples. A DU may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and/or one or more higher physical (PHY) layers depending, at least in part, on a functional split, such as a functional split defined by the 3GPP. In some examples, a DU also may host one or more lower PHY layer functions, such as a fast Fourier transform (FFT) , an inverse FFT (iFFT) , beamforming, physical random access channel (PRACH) extraction and filtering, and/or scheduling of resources for one or more UEs 120, among other examples. An RU may host RF processing functions or lower PHY layer functions, such as an FFT, an iFFT, beamforming, or PRACH extraction and filtering, among other examples, according to a functional split, such as a lower layer functional split. In such an architecture, each RU can be operated to handle over the air (OTA) communication with one or more UEs 120.

In some aspects, a single network node 110 may include a combination of one or more CUs, one or more DUs, and/or one or more RUs. Additionally or alternatively, a network node 110 may include one or more Near-Real Time (Near-RT) RAN Intelligent Controllers (RICs) and/or one or more Non-Real Time (Non-RT) RICs. In some examples, a CU, a DU, and/or an RU may be implemented as a virtual unit, such as a virtual central unit (VCU) , a virtual distributed unit (VDU) , or a virtual radio unit (VRU) , among other examples. A virtual unit may be implemented as a virtual network function, such as associated with a cloud deployment.

Some network nodes 110 (for example, a base station, an RU, or a TRP) may provide communication coverage for a particular geographic area. In the 3GPP, the term “cell” can refer to a coverage area of a network node 110 or to a network node 110 itself, depending on the context in which the term is used. A network node 110 may support one or multiple (for example, three) cells. In some examples, a network node 110 may provide communication coverage for a macro cell, a micro cell, a pico cell, a femto cell, or another type of cell. A macro cell may cover a relatively large geographic area (for example, several kilometers in radius) and may allow unrestricted access by UEs 120 with service subscriptions. A micro or pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs 120 with service subscriptions. A femto cell may cover a relatively small geographic area (for example, a home) and may allow restricted access by UEs 120 having association with the femto cell (for example, UEs 120 in a closed subscriber group (CSG) ) . A network node 110 for a macro cell may be referred to as a macro network node. A network node 110 for a pico cell may be referred to as a pico network node. A network node 110 for a femto cell may be referred to as a femto network node or an in-home network node. In some examples, a cell may not necessarily be stationary. For example, the geographic area of the cell may move according to the location of an associated mobile network node 110 (for example, a train, a satellite base station, an unmanned aerial vehicle, or an NTN network node) .

The wireless communication network 100 may be a heterogeneous network that includes network nodes 110 of different types, such as macro network nodes, pico network nodes, femto network nodes, relay network nodes, aggregated network nodes, and/or disaggregated network nodes, among other examples. In the example shown in Fig. 1, the network node 110a may be a macro network node for a macro cell 130a, the network node 110b may be a pico network node for a pico cell 130b, and the network node 110c may be a femto network node for a femto cell 130c. Various different types of network nodes 110 may generally transmit at different power levels, serve different coverage areas, and/or have different impacts on interference in the wireless communication network 100 than other types of network nodes 110. For example, macro network nodes may have a high transmit power level (for example, 5 to 40 watts) , whereas pico network nodes, femto network nodes, and relay network nodes may have lower transmit power levels (for example, 0.1 to 2 watts) .

In some examples, a network node 110 may be, may include, or may operate as an RU, a TRP, or a base station that communicates with one or more UEs 120 via a radio access link (which may be referred to as a “Uu” link) . The radio access link may include a downlink and an uplink. “Downlink” (or “DL” ) refers to a communication direction from a network node 110 to a UE 120, and “uplink” (or “UL” ) refers to a communication direction from a UE 120 to a network node 110. Downlink channels may include one or more control channels and one or more data channels. A downlink control channel may be used to transmit downlink control information (DCI) (for example, scheduling information, reference signals, and/or configuration information) from a network node 110 to a UE 120. A downlink data channel may be used to transmit downlink data (for example, user data associated with a UE 120) from a network node 110 to a UE 120. Downlink control channels may include one or more physical downlink control channels (PDCCHs) , and downlink data channels may include one or more physical downlink shared channels (PDSCHs) . Uplink channels may similarly include one or more control channels and one or more data channels. An uplink control channel may be used to transmit uplink control information (UCI) (for example, reference signals and/or feedback corresponding to one or more downlink transmissions) from a UE 120 to a network node 110. An uplink data channel may be used to transmit uplink data (for example, user data associated with a UE 120) from a UE 120 to a network node 110. Uplink control channels may include one or more physical uplink control channels (PUCCHs) , and uplink data channels may include one or more physical uplink shared channels (PUSCHs) . The downlink and the uplink may each include a set of resources on which the network node 110 and the UE 120 may communicate.

Downlink and uplink resources may include time domain resources (frames, subframes, slots, and/or symbols) , frequency domain resources (frequency bands, component carriers, subcarriers, resource blocks, and/or resource elements) , and/or spatial domain resources (particular transmit directions and/or beam parameters) . Frequency domain resources of some bands may be subdivided into bandwidth parts (BWPs) . A BWP may be a continuous block of frequency domain resources (for example, a continuous block of resource blocks) that are allocated for one or more UEs 120. A UE 120 may be configured with both an uplink BWP and a downlink BWP (where the uplink BWP and the downlink BWP may be the same BWP or different BWPs) . A BWP may be dynamically configured (for example, by a network node 110 transmitting a DCI configuration to the one or more UEs 120) and/or reconfigured, which means that a BWP can be adjusted in real-time (or near-real-time) based on changing network conditions in the wireless communication network 100 and/or based on the specific requirements of the one or more UEs 120. This enables more efficient use of the available frequency domain resources in the wireless communication network 100 because fewer frequency domain resources may be allocated to a BWP for a UE 120 (which may reduce the quantity of frequency domain resources that a UE 120 is required to monitor) , leaving more frequency domain resources to be spread across multiple UEs 120. Thus, BWPs may also assist in the implementation of lower-capability UEs 120 by facilitating the configuration of smaller bandwidths for communication by such UEs 120.

As described above, in some aspects, the wireless communication network 100 may be, may include, or may be included in, an IAB network. In an IAB network, at least one network node 110 is an anchor network node that communicates with a core network. An anchor network node 110 may also be referred to as an IAB donor (or “IAB-donor” ) . The anchor network node 110 may connect to the core network via a wired backhaul link. For example, an Ng interface of the anchor network node 110 may terminate at the core network. Additionally or alternatively, an anchor network node 110 may connect to one or more devices of the core network that provide a core access and mobility management function (AMF) . An IAB network also generally includes multiple non-anchor network nodes 110, which may also be referred to as relay network nodes or simply as IAB nodes (or “IAB-nodes” ) . Each non-anchor network node 110 may communicate directly with the anchor network node 110 via a wireless backhaul link to access the core network, or may communicate indirectly with the anchor network node 110 via one or more other non-anchor network nodes 110 and associated wireless backhaul links that form a backhaul path to the core network. Some anchor network node 110 or other non-anchor network node 110 may also communicate directly with one or more UEs 120 via wireless access links that carry access traffic. In some examples, network resources for wireless communication (such as time resources, frequency resources, and/or spatial resources) may be shared between access links and backhaul links.

In some examples, any network node 110 that relays communications may be referred to as a relay network node, a relay station, or simply as a relay. A relay may receive a transmission of a communication from an upstream station (for example, another network node 110 or a UE 120) and transmit the communication to a downstream station (for example, a UE 120 or another network node 110) . In this case, the wireless communication network 100 may include or be referred to as a “multi-hop network. ” In the example shown in Fig. 1, the network node 110d (for example, a relay network node) may communicate with the network node 110a (for example, a macro network node) and the UE 120d in order to facilitate communication between the network node 110a and the UE 120d. Additionally or alternatively, a UE 120 may be or may operate as a relay station that can relay transmissions to or from other UEs 120. A UE 120 that relays communications may be referred to as a UE relay or a relay UE, among other examples.

The UEs 120 may be physically dispersed throughout the wireless communication network 100, and each UE 120 may be stationary or mobile. A UE 120 may be, may include, or may be included in an access terminal, another terminal, a mobile station, or a subscriber unit. A UE 120 may be, include, or be coupled with a cellular phone (for example, 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 (for example, a smart watch, smart clothing, smart glasses, a smart wristband, and/or smart jewelry, such as a smart ring or a smart bracelet) , an entertainment device (for example, a music device, a video device, and/or a satellite radio) , an XR device, a vehicular component or sensor, a smart meter or sensor, industrial manufacturing equipment, a Global Navigation Satellite System (GNSS) device (such as a Global Positioning System device or another type of positioning device) , a UE function of a network node, and/or any other suitable device or function that may communicate via a wireless medium.

A UE 120 and/or a network node 110 may include one or more chips, system-on-chips (SoCs) , chipsets, packages, or devices that individually or collectively constitute or comprise a processing system. The processing system includes processor (or “processing” ) circuitry in the form of one or multiple processors, microprocessors, processing units (such as central processing units (CPUs) , graphics processing units (GPUs) , neural processing units (NPUs) and/or digital signal processors (DSPs) ) , processing blocks, application-specific integrated circuits (ASIC) , programmable logic devices (PLDs) (such as field programmable gate arrays (FPGAs) ) , or other discrete gate or transistor logic or circuitry (all of which may be generally referred to herein individually as “processors” or collectively as “the processor” or “the processor circuitry” ) . One or more of the processors may be individually or collectively configurable or configured to perform various functions or operations described herein. A group of processors collectively configurable or configured to perform a set of functions may include a first processor configurable or configured to perform a first function of the set and a second processor configurable or configured to perform a second function of the set, or may include the group of processors all being configured or configurable to perform the set of functions.

The processing system may further include memory circuitry in the form of one or more memory devices, memory blocks, memory elements or other discrete gate or transistor logic or circuitry, each of which may include tangible storage media such as random-access memory (RAM) or read-only memory (ROM) , or combinations thereof (all of which may be generally referred to herein individually as “memories” or collectively as “the memory” or “the memory circuitry” ) . One or more of the memories may be coupled (for example, operatively coupled, communicatively coupled, electronically coupled, or electrically coupled) with one or more of the processors and may individually or collectively store processor-executable code (such as software) that, when executed by one or more of the processors, may configure one or more of the processors to perform various functions or operations described herein. Additionally or alternatively, in some examples, one or more of the processors may be preconfigured to perform various functions or operations described herein without requiring configuration by software. The processing system may further include or be coupled with one or more modems (such as a Wi-Fi (for example, Institute of Electrical and Electronics Engineers (IEEE) compliant) modem or a cellular (for example, 3GPP 4G LTE, 5G, or 6G compliant) modem) . In some implementations, one or more processors of the processing system include or implement one or more of the modems. The processing system may further include or be coupled with multiple radios (collectively “the radio” ) , multiple RF chains, or multiple transceivers, each of which may in turn be coupled with one or more of multiple antennas. In some implementations, one or more processors of the processing system include or implement one or more of the radios, RF chains or transceivers. The UE 120 may include or may be included in a housing that houses components associated with the UE 120 including the processing system.

Some UEs 120 may be considered machine-type communication (MTC) UEs, evolved or enhanced machine-type communication (eMTC) , UEs, further enhanced eMTC (feMTC) UEs, or enhanced feMTC (efeMTC) UEs, or further evolutions thereof, all of which may be simply referred to as “MTC UEs” ) . An MTC UE may be, may include, or may be included in or coupled with a robot, an uncrewed aerial vehicle, a remote device, a sensor, a meter, a monitor, and/or a location tag. Some UEs 120 may be considered IoT devices and/or may be implemented as NB-IoT (narrowband IoT) devices. An IoT UE or NB-IoT device may be, may include, or may be included in or coupled with an industrial machine, an appliance, a refrigerator, a doorbell camera device, a home automation device, and/or a light fixture, among other examples. Some UEs 120 may be considered Customer Premises Equipment, which may include telecommunications devices that are installed at a customer location (such as a home or office) to enable access to a service provider's network (such as included in or in communication with the wireless communication network 100) .

Some UEs 120 may be classified according to different categories in association with different complexities and/or different capabilities. UEs 120 in a first category may facilitate massive IoT in the wireless communication network 100, and may offer low complexity and/or cost relative to UEs 120 in a second category. UEs 120 in a second category may include mission-critical IoT devices, legacy UEs, baseline UEs, high-tier UEs, advanced UEs, full-capability UEs, and/or premium UEs that are capable of URLLC, enhanced mobile broadband (eMBB) , and/or precise positioning in the wireless communication network 100, among other examples. A third category of UEs 120 may have mid-tier complexity and/or capability (for example, a capability between UEs 120 of the first category and UEs 120 of the second capability) . A UE 120 of the third category may be referred to as a reduced capacity UE ( “RedCap UE” ) , a mid-tier UE, an NR-Light UE, and/or an NR-Lite UE, among other examples. RedCap UEs may bridge a gap between the capability and complexity of NB-IoT devices and/or eMTC UEs, and mission-critical IoT devices and/or premium UEs. RedCap UEs may include, for example, wearable devices, IoT devices, industrial sensors, and/or cameras that are associated with a limited bandwidth, power capacity, and/or transmission range, among other examples. RedCap UEs may support healthcare environments, building automation, electrical distribution, process automation, transport and logistics, and/or smart city deployments, among other examples.

In some examples, two or more UEs 120 (for example, shown as UE 120a and UE 120e) may communicate directly with one another using sidelink communications (for example, without communicating by way of a network node 110 as an intermediary) . As an example, the UE 120a may directly transmit data, control information, or other signaling as a sidelink communication to the UE 120e. This is in contrast to, for example, the UE 120a first transmitting data in an UL communication to a network node 110, which then transmits the data to the UE 120e in a DL communication. In various examples, the UEs 120 may transmit and receive sidelink communications using peer-to-peer (P2P) communication protocols, device-to-device (D2D) communication protocols, vehicle-to-everything (V2X) communication protocols (which may include vehicle-to-vehicle (V2V) protocols, vehicle-to-infrastructure (V2I) protocols, and/or vehicle-to-pedestrian (V2P) protocols) , and/or mesh network communication protocols. In some deployments and configurations, a network node 110 may schedule and/or allocate resources for sidelink communications between UEs 120 in the wireless communication network 100. In some other deployments and configurations, a UE 120 (instead of a network node 110) may perform, or collaborate or negotiate with one or more other UEs to perform, scheduling operations, resource selection operations, and/or other operations for sidelink communications.

In various examples, some of the network nodes 110 and the UEs 120 of the wireless communication network 100 may be configured for full-duplex operation in addition to half-duplex operation. A network node 110 or a UE 120 operating in a half-duplex mode may perform only one of transmission or reception during particular time resources, such as during particular slots, symbols, or other time periods. Half-duplex operation may involve time-division duplexing (TDD) , in which DL transmissions of the network node 110 and UL transmissions of the UE 120 do not occur in the same time resources (that is, the transmissions do not overlap in time) . In contrast, a network node 110 or a UE 120 operating in a full-duplex mode can transmit and receive communications concurrently (for example, in the same time resources) . By operating in a full-duplex mode, network nodes 110 and/or UEs 120 may generally increase the capacity of the network and the radio access link. In some examples, full-duplex operation may involve frequency-division duplexing (FDD) , in which DL transmissions of the network node 110 are performed in a first frequency band or on a first component carrier and transmissions of the UE 120 are performed in a second frequency band or on a second component carrier different than the first frequency band or the first component carrier, respectively. In some examples, full-duplex operation may be enabled for a UE 120 but not for a network node 110. For example, a UE 120 may simultaneously transmit an UL transmission to a first network node 110 and receive a DL transmission from a second network node 110 in the same time resources. In some other examples, full-duplex operation may be enabled for a network node 110 but not for a UE 120. For example, a network node 110 may simultaneously transmit a DL transmission to a first UE 120 and receive an UL transmission from a second UE 120 in the same time resources. In some other examples, full-duplex operation may be enabled for both a network node 110 and a UE 120.

In some examples, the UEs 120 and the network nodes 110 may perform MIMO communication. “MIMO” generally refers to transmitting or receiving multiple signals (such as multiple layers or multiple data streams) simultaneously over the same time and frequency resources. MIMO techniques generally exploit multipath propagation. MIMO may be implemented using various spatial processing or spatial multiplexing operations. In some examples, MIMO may support simultaneous transmission to multiple receivers, referred to as multi-user MIMO (MU-MIMO) . Some RATs may employ advanced MIMO techniques, such as mTRP operation (including redundant transmission or reception on multiple TRPs) , reciprocity in the time domain or the frequency domain, single-frequency-network (SFN) transmission, or non-coherent joint transmission (NCJT) .

In some aspects, a UE (e.g., a UE 120) may include a communication manager 140. As described in more detail elsewhere herein, the communication manager 140 may transmit a beam sweep of uplink sounding reference signals (SRSs) on respective uplink beams to a first network entity. The communication manager 140 may receive a beam indication of a selected uplink candidate beam from a second network entity. The communication manager 140 may transmit a communication to the first network entity using the selected uplink candidate beam. Additionally, or alternatively, the communication manager 140 may perform one or more other operations described herein.

In some aspects, a first network entity (e.g., a network node 110) may include a communication manager 150. As described in more detail elsewhere herein, the communication manager 150 may transmit, to a user equipment (UE) , a request for a beam sweep of uplink sounding reference signals (SRSs) to a second network entity. The communication manager 150 may select an uplink candidate beam based at least in part on measurements of the uplink SRSs. The communication manager 150 may transmit a beam indication of the selected uplink candidate beam.

In some aspects, a first network entity (e.g., a network node 110) may include a communication manager 150. As described in more detail elsewhere herein, the communication manager 150 may transmit a configuration for a beam sweep of uplink sounding reference signals (SRSs) to a second network entity. The communication manager 150 may select an uplink candidate beam based at least in part on measurements of the uplink SRSs. The communication manager 150 may transmit a beam indication of the selected uplink candidate beam. 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 network node 110 in communication with an example UE 120 in a wireless network in accordance with the present disclosure.

As shown in Fig. 2, the network node 110 may include a data source 212, a transmit processor 214, a transmit (TX) MIMO processor 216, a set of modems 232 (shown as 232a through 232t, where t ≥ 1) , a set of antennas 234 (shown as 234a through 234v, where v ≥ 1) , a MIMO detector 236, a receive processor 238, a data sink 239, a controller/processor 240, a memory 242, a communication unit 244, a scheduler 246, and/or a communication manager 150 or 160, among other examples. In some configurations, one or a combination of the antenna (s) 234, the modem (s) 232, the MIMO detector 236, the receive processor 238, the transmit processor 214, and/or the TX MIMO processor 216 may be included in a transceiver of the network node 110. The transceiver may be under control of and used by one or more processors, such as the controller/processor 240, and in some aspects in conjunction with processor-readable code stored in the memory 242, to perform aspects of the methods, processes, and/or operations described herein. In some aspects, the network node 110 may include one or more interfaces, communication components, and/or other components that facilitate communication with the UE 120 or another network node.

The terms “processor, ” “controller, ” or “controller/processor” may refer to one or more controllers and/or one or more processors. For example, reference to “a/the processor, ” “a/the controller/processor, ” or the like (in the singular) should be understood to refer to any one or more of the processors described in connection with Fig. 2, such as a single processor or a combination of multiple different processors. Reference to “one or more processors” should be understood to refer to any one or more of the processors described in connection with Fig. 2. For example, one or more processors of the network node 110 may include transmit processor 214, TX MIMO processor 216, MIMO detector 236, receive processor 238, and/or controller/processor 240. Similarly, one or more processors of the UE 120 may include MIMO detector 256, receive processor 258, transmit processor 264, TX MIMO processor 266, and/or controller/processor 280.

In some aspects, a single processor may perform all of the operations described as being performed by the one or more processors. In some aspects, a first set of (one or more) processors of the one or more processors may perform a first operation described as being performed by the one or more processors, and a second set of (one or more) processors of the one or more processors may perform a second operation described as being performed by the one or more processors. The first set of processors and the second set of processors may be the same set of processors or may be different sets of processors. Reference to “one or more memories” should be understood to refer to any one or more memories of a corresponding device, such as the memory described in connection with Fig. 2. For example, operation described as being performed by one or more memories can be performed by the same subset of the one or more memories or different subsets of the one or more memories.

For downlink communication from the network node 110 to the UE 120, the transmit processor 214 may receive data ( “downlink data” ) intended for the UE 120 (or a set of UEs that includes the UE 120) from the data source 212 (such as a data pipeline or a data queue) . In some examples, the transmit processor 214 may select one or more MCSs for the UE 120 in accordance with one or more channel quality indicators (CQIs) received from the UE 120. The network node 110 may process the data (for example, including encoding the data) for transmission to the UE 120 on a downlink in accordance with the MCS (s) selected for the UE 120 to generate data symbols. The transmit processor 214 may process system information (for example, semi-static resource partitioning information (SRPI) ) and/or control information (for example, CQI requests, grants, and/or upper layer signaling) and provide overhead symbols and/or control symbols. The transmit processor 214 may generate reference symbols for reference signals (for example, a cell-specific reference signal (CRS) , a demodulation reference signal (DMRS) , or a channel state information (CSI) reference signal (CSI-RS) ) and/or synchronization signals (for example, a primary synchronization signal (PSS) or a secondary synchronization signals (SSS) ) .

The TX MIMO processor 216 may perform spatial processing (for example, 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 (for example, T output symbol streams) to the set of modems 232. For example, each output symbol stream may be provided to a respective modulator component (shown as MOD) of a modem 232. Each modem 232 may use the respective modulator component to process (for example, to modulate) a respective output symbol stream (for example, for orthogonal frequency division multiplexing (OFDM) ) to obtain an output sample stream. Each modem 232 may further use the respective modulator component to process (for example, convert to analog, amplify, filter, and/or upconvert) the output sample stream to obtain a time domain downlink signal. The modems 232a through 232t may together transmit a set of downlink signals (for example, T downlink signals) via the corresponding set of antennas 234.

A downlink signal may include a DCI communication, a MAC control element (MAC-CE) communication, an RRC communication, a downlink reference signal, or another type of downlink communication. Downlink signals may be transmitted on a PDCCH, a PDSCH, and/or on another downlink channel. A downlink signal may carry one or more transport blocks (TBs) of data. A TB may be a unit of data that is transmitted over an air interface in the wireless communication network 100. A data stream (for example, from the data source 212) may be encoded into multiple TBs for transmission over the air interface. The quantity of TBs used to carry the data associated with a particular data stream may be associated with a TB size common to the multiple TBs. The TB size may be based on or otherwise associated with radio channel conditions of the air interface, the MCS used for encoding the data, the downlink resources allocated for transmitting the data, and/or another parameter. In general, the larger the TB size, the greater the amount of data that can be transmitted in a single transmission, which reduces signaling overhead. However, larger TB sizes may be more prone to transmission and/or reception errors than smaller TB sizes, but such errors may be mitigated by more robust error correction techniques.

For uplink communication from the UE 120 to the network node 110, uplink signals from the UE 120 may be received by an antenna 234, may be processed by a modem 232 (for example, a demodulator component, shown as DEMOD, of a modem 232) , may be detected by the MIMO detector 236 (for example, a receive (Rx) MIMO processor) if applicable, and/or may be further processed by the receive processor 238 to obtain decoded data and/or control information. The receive processor 238 may provide the decoded data to a data sink 239 (which may be a data pipeline, a data queue, and/or another type of data sink) and provide the decoded control information to a processor, such as the controller/processor 240.

The network node 110 may use the scheduler 246 to schedule one or more UEs 120 for downlink or uplink communications. In some aspects, the scheduler 246 may use DCI to dynamically schedule DL transmissions to the UE 120 and/or UL transmissions from the UE 120. In some examples, the scheduler 246 may allocate recurring time domain resources and/or frequency domain resources that the UE 120 may use to transmit and/or receive communications using an RRC configuration (for example, a semi-static configuration) , for example, to perform semi-persistent scheduling (SPS) or to configure a configured grant (CG) for the UE 120.

One or more of the transmit processor 214, the TX MIMO processor 216, the modem 232, the antenna 234, the MIMO detector 236, the receive processor 238, and/or the controller/processor 240 may be included in an RF chain of the network node 110. An RF chain may include one or more filters, mixers, oscillators, amplifiers, analog-to-digital converters (ADCs) , and/or other devices that convert between an analog signal (such as for transmission or reception via an air interface) and a digital signal (such as for processing by one or more processors of the network node 110) . In some aspects, the RF chain may be or may be included in a transceiver of the network node 110.

In some examples, the network node 110 may use the communication unit 244 to communicate with a core network and/or with other network nodes. The communication unit 244 may support wired and/or wireless communication protocols and/or connections, such as Ethernet, optical fiber, common public radio interface (CPRI) , and/or a wired or wireless backhaul, among other examples. The network node 110 may use the communication unit 244 to transmit and/or receive data associated with the UE 120 or to perform network control signaling, among other examples. The communication unit 244 may include a transceiver and/or an interface, such as a network interface.

The UE 120 may include a set of antennas 252 (shown as antennas 252a through 252r, where r ≥ 1) , a set of modems 254 (shown as modems 254a through 254u, where u ≥ 1) , a MIMO detector 256, a receive processor 258, a data sink 260, a data source 262, a transmit processor 264, a TX MIMO processor 266, a controller/processor 280, a memory 282, and/or a communication manager 140, among other examples. One or more of the components of the UE 120 may be included in a housing 284. In some aspects, one or a combination of the antenna (s) 252, the modem (s) 254, the MIMO detector 256, the receive processor 258, the transmit processor 264, or the TX MIMO processor 266 may be included in a transceiver that is included in the UE 120. The transceiver may be under control of and used by one or more processors, such as the controller/processor 280, and in some aspects in conjunction with processor-readable code stored in the memory 282, to perform aspects of the methods, processes, or operations described herein. In some aspects, the UE 120 may include another interface, another communication component, and/or another component that facilitates communication with the network node 110 and/or another UE 120.

For downlink communication from the network node 110 to the UE 120, the set of antennas 252 may receive the downlink communications or signals from the network node 110 and may provide a set of received downlink signals (for example, R received signals) to the set of modems 254. For example, each received signal may be provided to a respective demodulator component (shown as DEMOD) of a modem 254. Each modem 254 may use the respective demodulator component to condition (for example, filter, amplify, downconvert, and/or digitize) a received signal to obtain input samples. Each modem 254 may use the respective demodulator component to further demodulate or process the input samples (for example, for OFDM) to obtain received symbols. The MIMO detector 256 may obtain received symbols from the set of modems 254, may perform MIMO detection on the received symbols if applicable, and may provide detected symbols. The receive processor 258 may process (for example, decode) the detected symbols, may provide decoded data for the UE 120 to the data sink 260 (which may include a data pipeline, a data queue, and/or an application executed on the UE 120) , and may provide decoded control information and system information to the controller/processor 280.

For uplink communication from the UE 120 to the network node 110, the transmit processor 264 may receive and process data ( “uplink data” ) from a data source 262 (such as a data pipeline, a data queue, and/or an application executed on the UE 120) and control information from the controller/processor 280. The control information may include one or more parameters, feedback, one or more signal measurements, and/or other types of control information. In some aspects, the receive processor 258 and/or the controller/processor 280 may determine, for a received signal (such as received from the network node 110 or another UE) , one or more parameters relating to transmission of the uplink communication. The one or more parameters may include a reference signal received power (RSRP) parameter, a received signal strength indicator (RSSI) parameter, a reference signal received quality (RSRQ) parameter, a CQI parameter, or a transmit power control (TPC) parameter, among other examples. The control information may include an indication of the RSRP parameter, the RSSI parameter, the RSRQ parameter, the CQI parameter, the TPC parameter, and/or another parameter. The control information may facilitate parameter selection and/or scheduling for the UE 120 by the network node 110.

The transmit processor 264 may generate reference symbols for one or more reference signals, such as an uplink DMRS, an uplink sounding reference signal (SRS) , and/or another type of reference signal. The symbols from the transmit processor 264 may be precoded by the TX MIMO processor 266, if applicable, and further processed by the set of modems 254 (for example, for DFT-s-OFDM or CP-OFDM) . The TX MIMO processor 266 may perform spatial processing (for example, 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 (for example, U output symbol streams) to the set of modems 254. For example, each output symbol stream may be provided to a respective modulator component (shown as MOD) of a modem 254. Each modem 254 may use the respective modulator component to process (for example, to modulate) a respective output symbol stream (for example, for OFDM) to obtain an output sample stream. Each modem 254 may further use the respective modulator component to process (for example, convert to analog, amplify, filter, and/or upconvert) the output sample stream to obtain an uplink signal.

The modems 254a through 254u may transmit a set of uplink signals (for example, R uplink signals or U uplink symbols) via the corresponding set of antennas 252. An uplink signal may include a UCI communication, a MAC-CE communication, an RRC communication, or another type of uplink communication. Uplink signals may be transmitted on a PUSCH, a PUCCH, and/or another type of uplink channel. An uplink signal may carry one or more TBs of data. Sidelink data and control transmissions (that is, transmissions directly between two or more UEs 120) may generally use similar techniques as were described for uplink data and control transmission, and may use sidelink-specific channels such as a physical sidelink shared channel (PSSCH) , a physical sidelink control channel (PSCCH) , and/or a physical sidelink feedback channel (PSFCH) .

One or more antennas of the set of antennas 252 or the set of antennas 234 may include, or may be included within, one or more antenna panels, one or more antenna groups, one or more sets of antenna elements, or one or more antenna arrays, among other examples. An antenna panel, an antenna group, a set of antenna elements, 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, or one or more antenna elements coupled with one or more transmission or reception components, such as one or more components of Fig. 2. As used herein, “antenna” can refer to one or more antennas, one or more antenna panels, one or more antenna groups, one or more sets of antenna elements, or one or more antenna arrays. “Antenna panel” can refer to a group of antennas (such as antenna elements) arranged in an array or panel, which may facilitate beamforming by manipulating parameters of the group of antennas. “Antenna module” may refer to circuitry including one or more antennas, which may also include one or more other components (such as filters, amplifiers, or processors) associated with integrating the antenna module into a wireless communication device.

In some examples, each of the antenna elements of an antenna 234 or an antenna 252 may include one or more sub-elements for radiating or receiving radio frequency signals. For example, a single antenna element may include a first sub-element cross-polarized with a second sub-element that can be used to independently transmit cross-polarized signals. The antenna elements may include patch antennas, dipole antennas, and/or other types of antennas arranged in a linear pattern, a two-dimensional pattern, or another pattern. A spacing between antenna elements may be such that signals with a desired wavelength transmitted separately by the antenna elements may interact or interfere constructively and destructively along various directions (such as to form a desired beam) . For example, given an expected range of wavelengths or frequencies, the spacing may provide a quarter wavelength, a half wavelength, or another fraction of a wavelength of spacing between neighboring antenna elements to allow for the desired constructive and destructive interference patterns of signals transmitted by the separate antenna elements within that expected range.

The amplitudes and/or phases of signals transmitted via antenna elements and/or sub-elements may be modulated and shifted relative to each other (such as by manipulating phase shift, phase offset, and/or amplitude) to generate one or more beams, which is referred to as beamforming. The term “beam” may refer to a directional transmission of a wireless signal toward a receiving device or otherwise in a desired direction. “Beam” may also generally refer to a direction associated with such a directional signal transmission, a set of directional resources associated with the signal transmission (for example, an angle of arrival, a horizontal direction, and/or a vertical direction) , and/or a set of parameters that indicate one or more aspects of a directional signal, a direction associated with the signal, and/or a set of directional resources associated with the signal. In some implementations, antenna elements may be individually selected or deselected for directional transmission of a signal (or signals) by controlling amplitudes of one or more corresponding amplifiers and/or phases of the signal (s) to form one or more beams. The shape of a beam (such as the amplitude, width, and/or presence of side lobes) and/or the direction of a beam (such as an angle of the beam relative to a surface of an antenna array) can be dynamically controlled by modifying the phase shifts, phase offsets, and/or amplitudes of the multiple signals relative to each other.

Different UEs 120 or network nodes 110 may include different numbers of antenna elements. For example, a UE 120 may include a single antenna element, two antenna elements, four antenna elements, eight antenna elements, or a different number of antenna elements. As another example, a network node 110 may include eight antenna elements, 24 antenna elements, 64 antenna elements, 128 antenna elements, or a different number of antenna elements. Generally, a larger number of antenna elements may provide increased control over parameters for beam generation relative to a smaller number of antenna elements, whereas a smaller number of antenna elements may be less complex to implement and may use less power than a larger number of antenna elements. Multiple antenna elements may support multiple-layer transmission, in which a first layer of a communication (which may include a first data stream) and a second layer of a communication (which may include a second data stream) are transmitted using the same time and frequency resources with spatial multiplexing.

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.

Fig. 3 is a diagram illustrating an example disaggregated base station architecture 300 in accordance with the present disclosure. One or more components of the example disaggregated base station architecture 300 may be, may include, or may be included in one or more network nodes (such one or more network nodes 110) . The disaggregated base station architecture 300 may include a CU 310 that can communicate directly with a core network 320 via a backhaul link, or that can communicate indirectly with the core network 320 via one or more disaggregated control units, such as a Non-RT RIC 350 associated with a Service Management and Orchestration (SMO) Framework 360 and/or a Near-RT RIC 370 (for example, via an E2 link) . The CU 310 may communicate with one or more DUs 330 via respective midhaul links, such as via F1 interfaces. Each of the DUs 330 may communicate with one or more RUs 340 via respective fronthaul links. Each of the RUs 340 may communicate with one or more UEs 120 via respective RF access links. In some deployments, a UE 120 may be simultaneously served by multiple RUs 340.

Each of the components of the disaggregated base station architecture 300, including the CUs 310, the DUs 330, the RUs 340, the Near-RT RICs 370, the Non-RT RICs 350, and the SMO Framework 360, may include one or more interfaces or may be coupled with one or more interfaces for receiving or transmitting signals, such as data or information, via a wired or wireless transmission medium.

In some aspects, the CU 310 may be logically split into one or more CU user plane (CU-UP) units and one or more CU control plane (CU-CP) units. A CU-UP unit may communicate bidirectionally with a CU-CP unit via an interface, such as the E1 interface when implemented in an O-RAN configuration. The CU 310 may be deployed to communicate with one or more DUs 330, as necessary, for network control and signaling. Each 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. For example, a DU 330 may host various layers, such as an RLC layer, a MAC layer, or one or more PHY layers, such as one or more high PHY layers or one or more low PHY layers. Each layer (which also may be referred to as a module) may be implemented with an interface for communicating signals with other layers (and modules) hosted by the DU 330, or for communicating signals with the control functions hosted by the CU 310. Each RU 340 may implement lower layer functionality. In some aspects, real-time and non-real-time aspects of control and user plane communication with the RU (s) 340 may be controlled by the corresponding DU 330.

The SMO Framework 360 may support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non-virtualized network elements, the SMO Framework 360 may 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 360 may interact with a cloud computing platform (such as an open cloud (O-Cloud) platform 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. A virtualized network element may include, but is not limited to, a CU 310, a DU 330, an RU 340, a non-RT RIC 350, and/or a Near-RT RIC 370. In some aspects, the SMO Framework 360 may communicate with a hardware aspect of a 4G RAN, a 5G NR RAN, and/or a 6G RAN, such as an open eNB (O-eNB) 380, via an O1 interface. Additionally or alternatively, the SMO Framework 360 may communicate directly with each of one or more RUs 340 via a respective O1 interface. In some deployments, this configuration can enable each DU 330 and the CU 310 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.

The Non-RT RIC 350 may include or may implement a logical function that enables non-real-time control and optimization of RAN elements and resources, AI/ML workflows including model training and updates, and/or policy-based guidance of applications and/or features in the Near-RT RIC 370. The Non-RT RIC 350 may be coupled to or may communicate with (such as via an A1 interface) the Near-RT RIC 370. The Near-RT RIC 370 may include or may implement a logical function that enables near-real-time control and optimization of RAN elements and resources via data collection and actions via an interface (such as via an E2 interface) connecting one or more CUs 310, one or more DUs 330, and/or an O-eNB with the Near-RT RIC 370.

In some aspects, to generate AI/ML models to be deployed in the Near-RT RIC 370, the Non-RT RIC 350 may receive parameters or external enrichment information from external servers. Such information may be utilized by the Near-RT RIC 370 and may be received at the SMO Framework 360 or the Non-RT RIC 350 from non-network data sources or from network functions. In some examples, the Non-RT RIC 350 or the Near-RT RIC 370 may tune RAN behavior or performance. For example, the Non-RT RIC 350 may monitor long-term trends and patterns for performance and may employ AI/ML models to perform corrective actions via the SMO Framework 360 (such as reconfiguration via an O1 interface) or via creation of RAN management policies (such as A1 interface policies) .

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

The network node 110, the controller/processor 240 of the network node 110, the UE 120, the controller/processor 280 of the UE 120, the CU 310, the DU 330, the RU 340, or any other component (s) of Figs. 1, 2, or 3 may implement one or more techniques or perform one or more operations associated with detecting an uplink beam failure, as described in more detail elsewhere herein. For example, the controller/processor 240 of the network node 110, the controller/processor 280 of the UE 120, any other component (s) of Fig. 2, the CU 310, the DU 330, or the RU 340 may perform or direct operations of, for example, process 1100 of Fig. 11, process 1200 of Fig. 12, process 1300 of Fig. 13, or other processes as described herein (alone or in conjunction with one or more other processors) . The memory 242 may store data and program codes for the network node 110, the network node 110, the CU 310, the DU 330, or the RU 340. The memory 282 may store data and program codes for the UE 120. In some examples, the memory 242 or the memory 282 may include a non-transitory computer-readable medium storing a set of instructions (for example, code or program code) for wireless communication. The memory 242 may include one or more memories, such as a single memory or multiple different memories (of the same type or of different types) . The memory 282 may include one or more memories, such as a single memory or multiple different memories (of the same type or of different types) . For example, the set of instructions, when executed (for example, directly, or after compiling, converting, or interpreting) by one or more processors of the network node 110, the UE 120, the CU 310, the DU 330, or the RU 340, may cause the one or more processors to perform process 1100 of Fig. 11, process 1200 of Fig. 12, process 1300 of Fig. 13, 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, a UE (e.g., a UE 120) includes means for transmitting a beam sweep of uplink SRSs on respective uplink beams to a first network entity; means for receiving a beam indication of a selected uplink candidate beam from a second network entity; and/or means for transmitting a communication to the first network entity using the selected uplink candidate beam. The means for the user equipment (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 first network entity (e.g., a network node 110) includes means for transmitting, to a UE, a request for a beam sweep of uplink SRSs to a second network entity; means for selecting an uplink candidate beam based at least in part on measurements of the uplink SRSs; and/or means for transmitting a beam indication of the selected uplink candidate beam.

In some aspects, a first network entity (e.g., a network node 110) includes means for transmitting a configuration for a beam sweep of uplink SRSs to a second network entity; means for selecting an uplink candidate beam based at least in part on measurements of the uplink SRSs; and/or means for transmitting a beam indication of the selected uplink candidate beam. In some aspects, the means for the first network entity to perform operations described herein may include, for example, one or more of communication manager 150, transmit processor 214, TX MIMO processor 216, modem 232, antenna 234, MIMO detector 236, receive processor 238, controller/processor 240, memory 242, or scheduler 246.

Fig. 4 is a diagram illustrating an example 400 of an UL dense deployment, in accordance with the present disclosure.

In order to improve the coverage and capacity of UL transmissions, an UL dense deployment may be used. As shown by example 400, the UL dense deployment may include a network entity 405 providing macro coverage and multiple UL receive (Rx) points, shown by mTRP k 410 and mTRP l 415, providing UL micro coverage. The mTRPs may be UL-only nodes where only UL signals and channels are received for reception by the network entity 405. A UE 420 (or UE 425) may transmit a message to an UL-only node. DL signals and channels are transmitted from a different node (e.g., macro node, central node, serving cell, serving base station, or CU) , such as the network entity 405. The UL Rx points are connected to the network entity 405 via a backhaul.

The UL dense deployment reduces the UL path loss, which is helpful when UL coverage is the bottleneck. The UL dense deployment can also help with deployment costs and complexity because the UL Rx points do not transmit any DL signals. The UL Rx points are expected to just receive an UL signal or message and transmit the UL signal or message to the macro node, with or without some processing. Example 400 shows that an synchronization signal block (SSB) or a CSI-RS may be received from the network entity 405 for UL beam association.

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 SRS resource sets, in accordance with the present disclosure.

UL dense deployments may include network entities that receive SRSs from a UE (e.g., UE 425) . The UE 425 may be configured with one or more SRS resource sets to allocate resources for SRS transmissions by the UE 425. For example, a configuration for SRS resource sets may be indicated in a radio resource control (RRC) message (e.g., an RRC configuration message or an RRC reconfiguration message) . As shown by reference number 505, an SRS resource set may include one or more resources (e.g., shown as SRS resources) , which may include time resources and/or frequency resources (e.g., a slot, a symbol, a resource block, and/or a periodicity for the time resources) .

As shown by reference number 510, an SRS resource may include one or more antenna ports on which an SRS is to be transmitted (e.g., in a time-frequency resource) . Thus, a configuration for an SRS resource set may indicate one or more time-frequency resources in which an SRS is to be transmitted, and may indicate one or more antenna ports on which the SRS is to be transmitted in those time-frequency resources. In some aspects, the configuration for an SRS resource set may indicate a use case (e.g., in an SRS-SetUse information element) for the SRS resource set. For example, an SRS resource set may have a use case of antenna switching, codebook, non-codebook, or beam management.

An antenna switching SRS resource set may be used to indicate downlink CSI with reciprocity between an uplink and downlink channel. For example, when there is reciprocity between an uplink channel and a downlink channel, the network entity 405 may use an antenna switching SRS (e.g., an SRS transmitted using a resource of an antenna switching SRS resource set) to acquire downlink CSI (e.g., to determine a downlink precoder to be used to communicate with the UE 425) .

A codebook SRS resource set may be used to indicate uplink CSI when the network entity 405 indicates an uplink precoder to the UE 425. For example, when the network entity 405 is configured to indicate an uplink precoder to the UE 425 (e.g., using a precoder codebook) , the network entity 405 may use a codebook SRS (e.g., an SRS transmitted using a resource of a codebook SRS resource set) to acquire uplink CSI (e.g., to determine an uplink precoder to be indicated to the UE 425 and used by the UE 425 to communicate with the network entity 405) . In some aspects, virtual ports (e.g., a combination of two or more antenna ports) with a maximum transmit power may be supported at least for a codebook SRS.

A non-codebook SRS resource set may be used to indicate uplink CSI when the UE 425 selects an uplink precoder (e.g., instead of the network entity 405 indicating an uplink precoder to be used by the UE 425) . For example, when the UE 425 is configured to select an uplink precoder, the network entity 405 may use a non-codebook SRS (e.g., an SRS transmitted using a resource of a non-codebook SRS resource set) to acquire uplink CSI. In this case, the non-codebook SRS may be precoded using a precoder selected by the UE 425 (e.g., which may be indicated to the network entity 405) . A beam management SRS resource set may be used for indicating CSI for millimeter wave communications.

An SRS resource can be configured as periodic, semi-persistent (sometimes referred to as semi-persistent scheduling (SPS) ) , or aperiodic. A periodic SRS resource may be configured via a configuration message that indicates a periodicity of the SRS resource (e.g., a slot-level periodicity, where the SRS resources occurs every Y slots) and a slot offset. In some cases, a periodic SRS resource may always be activated, and may not be dynamically activated or deactivated. A semi-persistent SRS resource may also be configured via a configuration message that indicates a periodicity and a slot offset for the semi-persistent SRS resource, and may be dynamically activated and deactivated (e.g., using DCI or a MAC-CE) . An aperiodic SRS resource may be triggered dynamically, such as via DCI (e.g., UE-specific DCI or group common DCI) or a MAC-CE.

In some aspects, the UE 425 may be configured with a mapping between SRS ports (e.g., antenna ports) and corresponding SRS resources. The UE 425 may transmit an SRS on a particular SRS resource using an SRS port indicated in the configuration. In some aspects, an SRS resource may span N adjacent symbols within a slot (e.g., where N equals 1, 2, or 4) . The UE 425 may be configured with X SRS ports (e.g., where X ≤ 4) . In some aspects, each of the X SRS ports may be mapped to a corresponding symbol of the SRS resource and used for transmission of an SRS in that symbol.

As shown in Fig. 5, in some aspects, different SRS resource sets indicated to the UE 425 (e.g., having different use cases) may overlap (e.g., in time and/or in frequency, such as in the same slot) . For example, as shown by reference number 515, a first SRS resource set (e.g., shown as SRS Resource Set 1) is shown as having an antenna switching use case. As shown, this example antenna switching SRS resource set includes a first SRS resource (shown as SRS Resource A) and a second SRS resource (shown as SRS Resource B) . Thus, an antenna switching SRS may be transmitted in SRS Resource A (e.g., a first time-frequency resource) using antenna port 0 and antenna port 1 and may be transmitted in SRS Resource B (e.g., a second time-frequency resource) using antenna port 2 and antenna port 3.

As shown by reference number 520, a second SRS resource set (e.g., shown as SRS Resource Set 2) may be a codebook use case. As shown, this example codebook SRS resource set includes only the first SRS resource (shown as SRS Resource A) . Thus, codebook SRSs may be transmitted in SRS Resource A (e.g., the first time-frequency resource) using antenna port 0 and antenna port 1. In this case, the UE 120 may not transmit codebook SRSs in SRS Resource B (e.g., the second time-frequency resource) using antenna port 2 and antenna port 3.

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

Fig. 6 is a diagram illustrating an example 600 of a possible beam failure, in accordance with the present disclosure.

As illustrated in example 600, for UL-only mTRPs, there is no DL reference signal (e.g., SSB or CSI-RS transmissions) from mTRP 410 for beam failure detection and no DL reference signal for selecting a best candidate beam that can be used for a beam failure recovery request. For UL-only mTRPs, if there is no detection of an UL-only beam failure and thus no UL-only beam failure recovery, UL-only communications may degrade or fail. As a result, UL throughput decreases and latency increases.

As indicated above, Fig. 6 is provided as an example. Other examples may differ from what is described with regard to Fig. 6.

Fig. 7 is a diagram illustrating an example 700 of UL-only beam failure recovery, in accordance with the present disclosure. Example 700 shows a macro network entity 705 for both DL and UL transmissions (e.g., network node 110a, gNB, single TRP (sTRP) ) that may communicate with UE 720 (e.g., UE 120) and multiple TRPs for UL only transmissions mTRP k 710 (e.g., network node 110b) and mTRP l 715 (e.g., network node 110c) via a wireless network (e.g., wireless communication network 100) .

According to various aspects described herein, a network entity (e.g., mTRP, gNB) may detect an UL-only beam failure from missed or decoding failures of UL transmissions. For example, as shown by reference number 725, the network entity 705 may schedule an UL transmission for UE 720, via an UL grant in DCI. As shown by reference number 730, mTRP 710 may not receive the scheduled UL transmission or failed decoding the received UL transmission. After mTRP 710 informs the network entity 705 that the UL transmission was not received or failed. Based at least in part on the number of beam failures, based at least in part on the measurements (e.g., below a threshold) or failed UL transmissions, within a UL beam failure monitoring window (e.g., a timer is configured with a time interval for monitoring the UL beam failure) , UL beam failure may be claimed by a network entity accordingly (e.g., network entity 705 or network entity 710) . In example 700, the network entity 710 may indicate UL beam failure to the network entity 705, if the network entity claims or triggers the UL beam failure detection. Based at least in part on the claimed UL beam failure (either by network entity 710 or network entity 705) , The network entity 705 may transmit a request for a beam sweep of UL SRSs by UE 720 on uplink beams to the mTRPs 710 (e.g., UL-only mTRPs) for UL beam selection (e.g., if no UL candidate beam available) . The UE 720 may perform the beam sweep of UL SRSs. The mTRPs may measure the UL SRSs and report the measurement to the network entity 705. The network entity 705 may select a best (e.g., greatest strength, greatest quality, greatest reliability) uplink candidate beam from among the uplink beams of the beam sweep based on the received measurements of the uplink beams of the beam sweep. Alternatively, mTRP 710 may measure the UL SRSs and/or selects the UL candidate beam, mTRP 710 may indicate the selected uplink candidate beam to the network entity 705. The network entity 705 may transmit an indication of the selected uplink candidate beam to the UE 720. In some aspects, the network entity 705 may configure or activate periodic or semi-persistent UL SRS sweeping bursts to network entity 710 with or without UL data transmissions or schedule one or more SRS sweeping burst with or without UL data transmissions from time to time for UL beam monitoring and/or UL candidate beam selection. In this case, the network entity 705 may transmit an indication of the selected uplink candidate beam to the UE 720 after UL beam failure is claimed or triggered (e.g., by either network entity 710 or network entity 705 as described previously) . The UE 720 may transmit a communication using the selected uplink candidate beam. By detecting a beam failure and optionally requesting a beam sweep of UL SRSs, the network entity 705 may indicate a best UL candidate beam to the UE 720 to improve the UL communications by the UE 720 to UL-only mTRPs. As a result, the UL throughput will increase and latency will decrease.

As indicated above, Fig. 7 is provided as an example. Other examples may differ from what is described with regard to Fig. 7.

Fig. 8 is a diagram illustrating an example 800 of UL-only beam failure recovery after beam failure detection by the network, in accordance with the present disclosure.

In some aspects, the network entity 705 may detect UL-only beam failure. As shown by reference number 805, the network entity 705 may schedule one or more UL transmissions. As shown by reference number 810, mTRP 710 may detect an UL beam failure instance due to the UL transmission missed or failed decoding. The quantity of missed UL transmissions or the quantity of times that decoding failed for UL transmissions within a time window (e.g., configured time duration for monitoring UL beam failure detection monitoring) may satisfy a threshold amount (e.g., meet or exceed a minimum quantity of missed or failed UL transmissions) . The threshold amount may be configured by the network entity 705. As shown by reference number 815, mTRP 710 may report the measurement or the UL beam failure instance (e.g., missed or failed decoding the UL transmission as shown with the reference number 807, or the measurement is below a threshold for UL beam failure instance detection) to the network entity 705. Further, as shown by the reference number 817, the mTRP 710 may claim UL beam failure (e.g., the number of UL beam failure instances is above the threshold for UL beam failure detection within the monitoring window) .

In some aspects, a failure may be counted if an RSRP measurement is below an RSRP threshold configured for UL beam failure detection.. For example, a DMRS of a transmitted PUSCH message may have an RSRP below the RSRP threshold, or a transmitted SRS may have an RSRP below the RSRP threshold.

Additionally, or alternatively, as shown by the reference number 819, the network entity 705 may claim UL beam failure (e.g., the received number of UL beam failure instances is above the threshold for UL beam failure detection or based on the received measurements respectively associated with UL beam failure instances within the monitoring window) . In some aspects, the received measurements (e.g., as shown with the reference number 815) may also include UL candidate beam measurements. In this case, the network entity 705 may determine the selected UL candidate beam based on the measurements and indicate the selected UL candidate beams directly to the UE (e.g., as shown with the reference number 845 via skipping the steps as shown with the reference numbers 820, 825, 830, 825) .

The network entity 705 may determine that another UL beam is to be used by the UE 720, as part of an UL beam failure recovery for an UL-only TRP such as mTRP 710. As shown by reference number 820, for example, if there is no best UL candidate beam (s) available, the network entity 705 may transmit a request for the UE 720 to beam sweep UL SRSs in UL beams as UL beam candidate beams. In some aspects, a MAC CE may activate or a DCI may indicate UL SRSs and/or the beams to sweep for UL candidate beam selection. Accordingly, as shown by reference number 825, the UE 720 may transmit a beam sweep of UL SRSs, where one or more UL SRSs are in each UL beam among a set of UL beams. The set of UL beams may be in a sweep of different directions for selection of the best UL candidate beam.

The network entity 705 and/or mTRP 710 may select the best UL candidate beam. The best beam may be the beam with the greatest strength, quality, and/or reliability among the beams used for the UL SRSs based at least in part on measurements of the UL SRSs. As shown by reference number 830, mTRP 710 may select the best UL candidate beam. As shown by reference number 835, mTRP 710 may report the measurements of the UL SRSs and/or the best candidate beam selection. In some aspects, as shown by reference number 840, the network entity 705 may select the best UL candidate beam (e.g. based on the measurements received from mTRPs) .

As shown by reference number 845, the network entity 705 may transmit an indication of the selected UL candidate beam. The network entity 705 may transmit the indication in a new UL grant or activate the selected UL candidate beam via a MAC-CE. In some aspects, the network entity 705 may transmit DCI that indicates an UL transmission with a selected SRS index corresponding to an UL SRS of the selected UL candidate beam. Additionally or alternatively, the network entity 705 may transmit a transmission configuration indicator (TCI) state associated with a selected SRS index in the UL grant DCI. In some aspects, the network entity 705 may transmit a MAC CE that activates an UL SRS index associated with the selected UL candidate beam or a UL TCI state associated with the selected SRS index for the selected UL candidate beam. In some aspects, the network entity 705 may transmit an UL beam failure recovery response (e.g., containing selected UL candidate beam) to the UE.

As shown by reference number 850, the UE 720 may transmit a communication to mTRP 710 using the selected UL candidate beam. The UE 720 may avoid degraded or missed communications to mTRP 710, which improves UL throughput and reduces latency. The UE 720 may consider the UL beam failure recovery to be successful if the UE 720 does not receive any UL grant or request for a beam sweep of UL SRSs after a time duration configured for UL beam failure recovery.

As indicated above, Fig. 8 is provided as an example. Other examples may differ from what is described with regard to Fig. 8.

Fig. 9 is a diagram illustrating an example 900 of UL-only beam failure recovery, in accordance with the present disclosure.

In some aspects, the UE 720 may detect an UL-only beam failure from missed or decoding failure of expected responses to UL transmissions. For example, as shown by reference number 905, the UE 720 may initiate or originate an UL transmission and expect a response. If the UL transmission is associated with a random access channel (RACH) procedure (e.g., physical RACH (PRACH) message 1) , the response may be a message 2 for responding a PRACH message 1 from the UE (e.g., Random Access Response (RAR) ) . If the UL transmission is a scheduling request (SR) , the response may be a grant in DCI for a UL transmission. If the UL transmission is based on configured UL grant, an HARQ feedback is expected. For example, an explicit acknowledgement (ACK) or negative ACK (NACK) ) in DCI or MAC-CE, or an implicit ACK via a DCI with a new grant for a new data transmission (e.g., the New Data Indicator (NDI) toggled or changed its value with the same HARQ ID) or an implicit NACK with a grant for the data retransmission (e.g., NDI not toggled or changed with the same HARQ ID) . The feedback may be monitored within a configured window or time duration for an explicit or implicit feedback to a UL transmission (e.g., UE initiated or originated UL transmission) . As shown by reference number 910, the UE 720 may not receive the expected response to the UL transmission to the network entity 710. The UE 720 may determine that an UL beam failure to mTRP 710 has been claimed or triggered (e.g., the number of failed responses is above a threshold configured during an UL beam failure monitoring window or duration configured) and that a beam failure recovery is expected to be performed. The UE 720 may report the UL beam failure to the network entity 705 asking for UL beam failure recovery (e.g., UL beam failure recovery request) , either directly or via mTRP 710 if any UL candidate beam to mTRP 710 is available.

After receiving the beam failure report, the network entity 705 may transmit a request (e.g., indication or configuration) for a beam sweep of UL SRSs by UE 720 on uplink beams to the mTRPs (e.g., UL-only mTRPs) . The UE 720 may perform the beam sweep of UL SRSs, and an UL candidate beam may be selected, as described in connection with examples 700 of Fig. 7 and example 800 of Fig. 8. In some aspects, the network entity 705 may send a UL beam failure recovery response with a selected UL candidate beam upon receiving the UL beam failure recovery request. As a result, the UL throughput will increase and latency will decrease.

As indicated above, Fig. 9 is provided as an example. Other examples may differ from what is described with regard to Fig. 9.

Fig. 10 is a diagram illustrating an example 1000 of UL-only beam failure recovery after beam failure detection by the UE, in accordance with the present disclosure.

In some aspects, the UE 720 may detect UL-only beam failure. As shown by reference number 1005, the UE 720 may transmit an UL transmission (e.g., UE initiated or originated UL transmission based on the UL configuration received from the network entity 705) . As shown by reference number 1010, the UE 720 may claim or trigger an UL beam failure if the number of missed expected responses (e.g., the number of detected beam failure instances as shown with the reference number 1007) is above a threshold (e.g., configured for UL beam failure detection) within a configured time duration for receiving responses to UE initiated or originated UL transmissions. As shown by reference number 1015, UE 720 may transmit an indication of the UL beam failure to the network entity 705 (e.g., UL beam failure recovery request) . Additionally or alternatively, the UE 720 may transmit the indication to mTRP 710 if any UL candidate beam is available, which forwards the report to the network entity 705.

The network entity 705 may determine that another UL beam is to be used by the UE 720, as part of an UL beam failure recovery for an UL-only TRP such as mTRP 710. As shown by reference number 1020, if no selected UL candidate beam is available, the network entity 705 may transmit a request for the UE 720 to beam sweep UL SRSs in UL beams as UL beam candidate beams. In some aspects, DCI or MAC-CE may indicate UL SRSs and/or the beams to sweep. Accordingly, as shown by reference number 1025, the UE 720 may transmit a beam sweep of UL SRSs, where one or more UL SRSs are in each UL beam among a set of UL beams. The set of UL beams may be in a sweep of different directions for selection of the best UL candidate beam.

The network entity 705 and/or mTRP 710 may select the best UL candidate beam. The best beam may be the beam with the greatest strength, quality, and/or reliability among the beams used for the UL SRSs based at least in part on measurements of the UL SRSs. As shown by reference number 1030, mTRP 710 may select the best UL candidate beam. As shown by reference number 1035, mTRP 710 may report the measurements of the UL SRSs and/or the beam selection. In some aspects, as shown by reference number 1040, the network entity 705 may select the best UL candidate beam (e.g., based on the received measurements) .

As shown by reference number 1045, the network entity 705 may transmit an indication of the selected UL candidate beam. The network entity 705 may transmit the indication in a new UL grant. In some aspects, the network entity 705 may transmit DCI that indicates an UL transmission with a selected SRS index corresponding to an UL SRS of the selected UL candidate beam. The network entity 705 may transmit a TCI state associated with a selected SRS index. The indication may include an UL reconfiguration with the selected UL candidate beam. The indication may include a DCI or MAC-CE that indicates or activates the selected UL candidate beam or a UL beam failure recovery response (e.g., as described with the reference number 845 in Fig. 8) .

As shown by reference number 1050, the UE 720 may transmit a communication to mTRP 710 using the selected UL candidate beam. The UE 720 may avoid degraded or missed communications to mTRP 710, which improves UL throughput and reduces latency. The UE 720 may consider the UL beam failure recovery to be successful if the UE 720 does not receive any UL grant or request for a beam sweep of UL SRSs after a time duration configured for UL beam failure recovery. The UE 720 may also consider the UL beam failure recovery to be successful if the UE 720 receives an expected response to an UL transmission within a time duration configured for UL beam failure detection.

As indicated above, Fig. 10 is provided as an example. Other examples may differ from what is described with regard to Fig. 10.

Fig. 11 is a diagram illustrating an example process 1100 performed, for example, at a UE or an apparatus of a UE, in accordance with the present disclosure. Example process 1100 is an example where the apparatus or the UE (e.g., UE 120, UE 720) performs operations associated with uplink beam failure detection.

As shown in Fig. 11, in some aspects, process 1100 may include transmitting a beam sweep of uplink sounding reference signals (SRSs) on respective uplink beams to a first network entity (block 1110) . For example, the UE (e.g., using transmission component 1404 and/or communication manager 1406, depicted in Fig. 14) may transmit a beam sweep of uplink sounding reference signals (SRSs) on respective uplink beams to a first network entity, as described above.

As further shown in Fig. 11, in some aspects, process 1100 may include receiving a beam indication of a selected uplink candidate beam from a second network entity (block 1120) . For example, the UE (e.g., using reception component 1402 and/or communication manager 1406, depicted in Fig. 14) may receive a beam indication of a selected uplink candidate beam from a second network entity, as described above.

As further shown in Fig. 11, in some aspects, process 1100 may include transmitting a communication to the first network entity using the selected uplink candidate beam (block 1130) . For example, the UE (e.g., using transmission component 1404 and/or communication manager 1406, depicted in Fig. 14) may transmit a communication to the first network entity using the selected uplink candidate beam, as described above.

Process 1100 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, process 1100 includes detecting a beam failure.

In a second aspect, alone or in combination with the first aspect, detecting the beam failure includes detecting a missed or decoding failure of a response to an uplink transmission from the second network entity.

In a third aspect, alone or in combination with one or more of the first and second aspects, the beam indication includes an SRS index in DCI.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the beam indication includes a TCI state in DCI, and the TCI state is associated with an SRS index.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, process 1100 includes receiving a sweep indication of the beam sweep for candidate beam selection.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the beam indication includes an uplink reconfiguration with a selected uplink candidate beam.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the beam indication includes a MAC-CE activation message for the selected uplink candidate beam.

Although Fig. 11 shows example blocks of process 1100, in some aspects, process 1100 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 11. Additionally, or alternatively, two or more of the blocks of process 1100 may be performed in parallel.

Fig. 12 is a diagram illustrating an example process 1200 performed, for example, at a first network entity or an apparatus of a first network entity, in accordance with the present disclosure. Example process 1200 is an example where the apparatus or the first network entity (e.g., network node 110, network entity 705, mTRP 710) performs operations associated with uplink beam failure detection.

As shown in Fig. 12, in some aspects, process 1200 may include transmitting, to a UE, a request for a beam sweep of uplink sounding reference signals (SRSs) to a second network entity (block 1210) . For example, the first network entity (e.g., using transmission component 1504 and/or communication manager 1506, depicted in Fig. 15) may transmit, to a UE, a request for a beam sweep of uplink SRSs to a second network entity, as described above.

As further shown in Fig. 12, in some aspects, process 1200 may include selecting an uplink candidate beam based at least in part on measurements of the uplink SRSs (block 1220) . For example, the first network entity (e.g., using communication manager 1506, depicted in Fig. 15) may select an uplink candidate beam based at least in part on measurements of the uplink SRSs, as described above.

As further shown in Fig. 12, in some aspects, process 1200 may include transmitting a beam indication of the selected uplink candidate beam (block 1230) . For example, the first network entity (e.g., using transmission component 1504 and/or communication manager 1506, depicted in Fig. 15) may transmit a beam indication of the selected uplink candidate beam, as described above.

Process 1200 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, process 1200 includes transmitting a schedule for the beam sweep.

In a second aspect, alone or in combination with the first aspect, process 1200 includes detecting beam failure based at least in part on a quantity of missing or failed scheduled uplink transmissions that satisfy a beam failure threshold within a time window.

In a third aspect, alone or in combination with one or more of the first and second aspects, a failed scheduled uplink transmission includes an RSRP measurement of a PUSCH DMRS that does not satisfy an RSRP threshold.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, a failed scheduled uplink transmission includes an RSRP measurement of an SRS that does not satisfy an RSRP threshold.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the second network entity is an uplink-only mTRP.

Although Fig. 12 shows example blocks of process 1200, in some aspects, process 1200 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 12. Additionally, or alternatively, two or more of the blocks of process 1200 may be performed in parallel.

Fig. 13 is a diagram illustrating an example process 1300 performed, for example, at a first network entity or an apparatus of a first network entity, in accordance with the present disclosure. Example process 1300 is an example where the apparatus or the first network entity (e.g., netowrk node 110, network entity 705, mTRP 710) performs operations associated with uplink beam failure detection.

As shown in Fig. 13, in some aspects, process 1300 may include transmitting a configuration for a beam sweep of uplink sounding reference signals (SRSs) to a second network entity (block 1310) . For example, the first network entity (e.g., using transmission component 1504 and/or communication manager 1506, depicted in Fig. 15) may transmit a configuration for a beam sweep of uplink sounding reference signals (SRSs) to a second network entity, as described above.

As further shown in Fig. 13, in some aspects, process 1300 may include selecting an uplink candidate beam based at least in part on measurements of the uplink SRSs (block 1320) . For example, the first network entity (e.g., using communication manager 1506, depicted in Fig. 15) may select an uplink candidate beam based at least in part on measurements of the uplink SRSs, as described above.

As further shown in Fig. 13, in some aspects, process 1300 may include transmitting a beam indication of the selected uplink candidate beam (block 1330) . For example, the first network entity (e.g., using transmission component 1504 and/or communication manager 1506, depicted in Fig. 15) may transmit a beam indication of the selected uplink candidate beam, as described above.

Process 1300 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 beam indication includes an SRS index in DCI.

In a second aspect, alone or in combination with the first aspect, the beam indication includes a TCI state in DCI, and the TCI state is associated with an SRS index.

In a third aspect, alone or in combination with one or more of the first and second aspects, the beam indication includes an uplink reconfiguration with the selected uplink candidate beam.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the beam indication includes a MAC-CE activation message for the selected uplink candidate beam.

Although Fig. 13 shows example blocks of process 1300, in some aspects, process 1300 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 13. Additionally, or alternatively, two or more of the blocks of process 1300 may be performed in parallel.

Fig. 14 is a diagram of an example apparatus 1400 for wireless communication, in accordance with the present disclosure. The apparatus 1400 may be a UE, or a UE may include the apparatus 1400. In some aspects, the apparatus 1400 includes a reception component 1402, a transmission component 1404, and/or a communication manager 1406, which may be in communication with one another (for example, via one or more buses and/or one or more other components) . In some aspects, the communication manager 1406 is the communication manager 140 described in connection with Fig. 1. As shown, the apparatus 1400 may communicate with another apparatus 1408, such as a UE or a network node (such as a CU, a DU, an RU, or a base station) , using the reception component 1402 and the transmission component 1404.

In some aspects, the apparatus 1400 may be configured to perform one or more operations described herein in connection with Figs. 1-10. Additionally, or alternatively, the apparatus 1400 may be configured to perform one or more processes described herein, such as process 1100 of Fig. 11. In some aspects, the apparatus 1400 and/or one or more components shown in Fig. 14 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. 14 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 one or more memories. 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 one or more controllers or one or more processors to perform the functions or operations of the component.

The reception component 1402 may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus 1408. The reception component 1402 may provide received communications to one or more other components of the apparatus 1400. In some aspects, the reception component 1402 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 1400. In some aspects, the reception component 1402 may include one or more antennas, one or more modems, one or more demodulators, one or more MIMO detectors, one or more receive processors, one or more controllers/processors, one or more memories, or a combination thereof, of the UE described in connection with Fig. 2.

The transmission component 1404 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus 1408. In some aspects, one or more other components of the apparatus 1400 may generate communications and may provide the generated communications to the transmission component 1404 for transmission to the apparatus 1408. In some aspects, the transmission component 1404 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 1408. In some aspects, the transmission component 1404 may include one or more antennas, one or more modems, one or more modulators, one or more transmit MIMO processors, one or more transmit processors, one or more controllers/processors, one or more memories, or a combination thereof, of the UE described in connection with Fig. 2. In some aspects, the transmission component 1404 may be co-located with the reception component 1402 in one or more transceivers.

The communication manager 1406 may support operations of the reception component 1402 and/or the transmission component 1404. For example, the communication manager 1406 may receive information associated with configuring reception of communications by the reception component 1402 and/or transmission of communications by the transmission component 1404. Additionally, or alternatively, the communication manager 1406 may generate and/or provide control information to the reception component 1402 and/or the transmission component 1404 to control reception and/or transmission of communications.

The transmission component 1404 may transmit a beam sweep of uplink SRSs on respective uplink beams to a first network entity. The reception component 1402 may receive a beam indication of a selected uplink candidate beam from a second network entity. The transmission component 1404 may transmit a communication to the first network entity using the selected uplink candidate beam.

The communication manager 1406 may detect a beam failure. The reception component 1402 may receive a sweep indication of the beam sweep for candidate beam selection.

The number and arrangement of components shown in Fig. 14 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. 14. Furthermore, two or more components shown in Fig. 14 may be implemented within a single component, or a single component shown in Fig. 14 may be implemented as multiple, distributed components. Additionally, or alternatively, a set of (one or more) components shown in Fig. 14 may perform one or more functions described as being performed by another set of components shown in Fig. 14.

Fig. 15 is a diagram of an example apparatus 1500 for wireless communication, in accordance with the present disclosure. The apparatus 1500 may be a first network entity, or a first network entity may include the apparatus 1500. In some aspects, the apparatus 1500 includes a reception component 1502, a transmission component 1504, and/or a communication manager 1506, which may be in communication with one another (for example, via one or more buses and/or one or more other components) . In some aspects, the communication manager 1506 is the communication manager 150 described in connection with Fig. 1. As shown, the apparatus 1500 may communicate with another apparatus 1508, such as a UE or a network node (such as a CU, a DU, an RU, or a base station) , using the reception component 1502 and the transmission component 1504.

In some aspects, the apparatus 1500 may be configured to perform one or more operations described herein in connection with Figs. 1-10. Additionally, or alternatively, the apparatus 1500 may be configured to perform one or more processes described herein, such as process 1200 of Fig. 12, process 1300 of Fig. 13, or a combination thereof. In some aspects, the apparatus 1500 and/or one or more components shown in Fig. 15 may include one or more components of the first network entity described in connection with Fig. 2. Additionally, or alternatively, one or more components shown in Fig. 15 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 one or more memories. 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 one or more controllers or one or more processors to perform the functions or operations of the component.

The reception component 1502 may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus 1508. The reception component 1502 may provide received communications to one or more other components of the apparatus 1500. In some aspects, the reception component 1502 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 1500. In some aspects, the reception component 1502 may include one or more antennas, one or more modems, one or more demodulators, one or more MIMO detectors, one or more receive processors, one or more controllers/processors, one or more memories, or a combination thereof, of the first network entity described in connection with Fig. 2.

The transmission component 1504 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus 1508. In some aspects, one or more other components of the apparatus 1500 may generate communications and may provide the generated communications to the transmission component 1504 for transmission to the apparatus 1508. In some aspects, the transmission component 1504 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 1508. In some aspects, the transmission component 1504 may include one or more antennas, one or more modems, one or more modulators, one or more transmit MIMO processors, one or more transmit processors, one or more controllers/processors, one or more memories, or a combination thereof, of the first network entity described in connection with Fig. 2. In some aspects, the transmission component 1504 may be co-located with the reception component 1502 in one or more transceivers.

The communication manager 1506 may support operations of the reception component 1502 and/or the transmission component 1504. For example, the communication manager 1506 may receive information associated with configuring reception of communications by the reception component 1502 and/or transmission of communications by the transmission component 1504. Additionally, or alternatively, the communication manager 1506 may generate and/or provide control information to the reception component 1502 and/or the transmission component 1504 to control reception and/or transmission of communications.

In some aspects associated with beam failure detection by the network (e.g., first network entity or mTRP) , the transmission component 1504 may transmit, to a UE, a request for a beam sweep of uplink SRSs to a second network entity (e.g., gNB) . The communication manager 1506 may select an uplink candidate beam based at least in part on measurements of the uplink SRSs. The transmission component 1504 may transmit a beam indication of the selected uplink candidate beam.

The transmission component 1504 may transmit a schedule for the beam sweep. The communication manager 1506 may detect beam failure based at least in part on a quantity of missing or failed scheduled uplink transmissions that satisfy a beam failure threshold within a time window.

In some aspects associated with beam failure detection by a UE. The transmission component 1504 may transmit a configuration for a beam sweep of uplink SRSs to a second network entity. The communication manager 1506 may select an uplink candidate beam based at least in part on measurements of the uplink SRSs. The transmission component 1504 may transmit a beam indication of the selected uplink candidate beam.

The number and arrangement of components shown in Fig. 15 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. 15. Furthermore, two or more components shown in Fig. 15 may be implemented within a single component, or a single component shown in Fig. 15 may be implemented as multiple, distributed components. Additionally, or alternatively, a set of (one or more) components shown in Fig. 15 may perform one or more functions described as being performed by another set of components shown in Fig. 15.

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

Aspect 1: A method of wireless communication performed by a user equipment (UE) , comprising: transmitting a beam sweep of uplink sounding reference signals (SRSs) on respective uplink beams to a first network entity; receiving a beam indication of a selected uplink candidate beam from a second network entity; and transmitting a communication to the first network entity using the selected uplink candidate beam.

Aspect 2: The method of Aspect 1, further comprising detecting a beam failure.

Aspect 3: The method of Aspect 2, wherein detecting the beam failure includes detecting a missed or decoding failure of a response to an uplink transmission from the second network entity.

Aspect 4: The method of any of Aspects 1-3, wherein the beam indication includes an SRS index in downlink control information.

Aspect 5: The method of any of Aspects 1-4, wherein the beam indication includes a transmission configuration indicator (TCI) state in downlink control information, and wherein the TCI state is associated with an SRS index.

Aspect 6: The method of any of Aspects 1-5, further comprising receiving a sweep indication of the beam sweep for candidate beam selection.

Aspect 7: The method of any of Aspects 1-6, wherein the beam indication includes an uplink reconfiguration with a selected uplink candidate beam.

Aspect 8: The method of any of Aspects 1-7, wherein the beam indication includes a medium access control control element (MAC-CE) activation message for the selected uplink candidate beam.

Aspect 9: A method of wireless communication performed by a first network entity, comprising: transmitting, to a user equipment (UE) , a request for a beam sweep of uplink sounding reference signals (SRSs) to a second network entity; selecting an uplink candidate beam based at least in part on measurements of the uplink SRSs; and transmitting a beam indication of the selected uplink candidate beam.

Aspect 10: The method of Aspect 9, further comprising transmitting a schedule for the beam sweep.

Aspect 11: The method of any of Aspects 9-10, further comprising detecting beam failure based at least in part on a quantity of missing or failed scheduled uplink transmissions that satisfy a beam failure threshold within a time window.

Aspect 12: The method of Aspect 11, wherein a failed scheduled uplink transmission includes a reference signal received power (RSRP) measurement of a physical uplink shared channel demodulation reference signal that does not satisfy an RSRP threshold.

Aspect 13: The method of Aspect 11, wherein a failed scheduled uplink transmission includes a reference signal received power (RSRP) measurement of an SRS that does not satisfy an RSRP threshold.

Aspect 14: The method of any of Aspects 9-13, wherein the second network entity is an uplink-only multiple transmit receive point.

Aspect 15: A method of wireless communication performed by a first network entity, comprising: transmitting a configuration for a beam sweep of uplink sounding reference signals (SRSs) to a second network entity; selecting an uplink candidate beam based at least in part on measurements of the uplink SRSs; and transmitting a beam indication of the selected uplink candidate beam.

Aspect 16: The method of Aspect 15, wherein the beam indication includes an SRS index in downlink control information.

Aspect 17: The method of any of Aspects 15-16, wherein the beam indication includes a transmission configuration indicator (TCI) state in downlink control information, and wherein the TCI state is associated with an SRS index.

Aspect 18: The method of any of Aspects 15-17, wherein the beam indication includes an uplink reconfiguration with the selected uplink candidate beam.

Aspect 19: The method of any of Aspects 15-18, wherein the beam indication includes a medium access control control element (MAC-CE) activation message for the selected uplink candidate beam.

Aspect 20: An apparatus for wireless communication at a device, the apparatus comprising one or more processors; one or more memories coupled with the one or more processors; and instructions stored in the one or more memories and executable by the one or more processors to cause the apparatus to perform the method of one or more of Aspects 1-19.

Aspect 21: An apparatus for wireless communication at a device, the apparatus comprising one or more memories and one or more processors coupled to the one or more memories, the one or more processors configured to cause the device to perform the method of one or more of Aspects 1-19.

Aspect 22: An apparatus for wireless communication, the apparatus comprising at least one means for performing the method of one or more of Aspects 1-19.

Aspect 23: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by one or more processors to perform the method of one or more of Aspects 1-19.

Aspect 24: 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 1-19.

Aspect 25: A device for wireless communication, the device comprising a processing system that includes one or more processors and one or more memories coupled with the one or more processors, the processing system configured to cause the device to perform the method of one or more of Aspects 1-19.

Aspect 26: An apparatus for wireless communication at a device, the apparatus comprising one or more memories and one or more processors coupled to the one or more memories, the one or more processors individually or collectively configured to cause the device to perform the method of one or more of Aspects 1-19.

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 or a combination of hardware and at least one of software or firmware. “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, 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 or a combination of hardware and software. It will be apparent that systems or methods described herein may be implemented in different forms of hardware or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems or methods is not limiting of the aspects. Thus, the operation and behavior of the systems or methods are described herein without reference to specific software code, because those skilled in the art will understand that software and hardware can be designed to implement the systems or methods based, at least in part, on the description herein. A component being configured to perform a function means that the component has a capability to perform the function, and does not require the function to be actually performed by the component, unless noted otherwise.

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, or not equal to the threshold, among other examples.

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 (for example, 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, ” and similar terms are intended to be open-ended terms that do not limit an element that they modify (for example, an element “having” A may also have B) . Further, the phrase “based on” is intended to mean “based on or otherwise in association with” 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 (for example, if used in combination with “either” or “only one of” ) . It should be understood that “one or more” is equivalent to “at least one. ”

Even though particular combinations of features are recited in the claims 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 or disclosed in the specification. The disclosure of various aspects includes each dependent claim in combination with every other claim in the claim set.

Claims

An apparatus for wireless communication at a user equipment (UE) , comprising:

one or more memories; and

one or more processors, coupled to the one or more memories, individually or collectively configured to cause the UE to:

transmit a beam sweep of uplink sounding reference signals (SRSs) on respective uplink beams to a first network entity;

receive a beam indication of a selected uplink candidate beam from a second network entity; and

transmit a communication to the first network entity using the selected uplink candidate beam.
The apparatus of claim 1, wherein the one or more processors are individually or collectively configured to cause the UE to detect a beam failure.
The apparatus of claim 2, wherein to detect the beam failure, the one or more processors are configured to cause the UE to detect a missed or decoding failure of a response to an uplink transmission from the second network entity.
The apparatus of claim 1, wherein the beam indication includes an SRS index in downlink control information.
The apparatus of claim 1, wherein the beam indication includes a transmission configuration indicator (TCI) state in downlink control information, and wherein the TCI state is associated with an SRS index.
The apparatus of claim 1, wherein the one or more processors are individually or collectively configured to cause the UE to receive a sweep indication of the beam sweep for candidate beam selection.
The apparatus of claim 1, wherein the beam indication includes an uplink reconfiguration with a selected uplink candidate beam.
The apparatus of claim 1, wherein the beam indication includes a medium access control control element (MAC-CE) activation message for the selected uplink candidate beam.
An apparatus for wireless communication at a first network entity, comprising:

one or more memories; and

one or more processors, coupled to the one or more memories, individually or collectively configured to cause the first network entity to:

transmit, to a user equipment (UE) , a request for a beam sweep of uplink sounding reference signals (SRSs) to a second network entity;

select an uplink candidate beam based at least in part on measurements of the uplink SRSs; and

transmit a beam indication of the selected uplink candidate beam.
The apparatus of claim 9, wherein the one or more processors are individually or collectively configured to cause the first network entity to transmit a schedule for the beam sweep.
The apparatus of claim 9, wherein the one or more processors are individually or collectively configured to cause the first network entity to detect beam failure based at least in part on a quantity of missing or failed scheduled uplink transmissions that satisfy a beam failure threshold within a time window.
The apparatus of claim 11, wherein a failed scheduled uplink transmission includes a reference signal received power (RSRP) measurement of a physical uplink shared channel demodulation reference signal that does not satisfy an RSRP threshold.
The apparatus of claim 11, wherein a failed scheduled uplink transmission includes a reference signal received power (RSRP) measurement of an SRS that does not satisfy an RSRP threshold.
The apparatus of claim 9, wherein the second network entity is an uplink-only multiple transmit receive point.
An apparatus for wireless communication at a first network entity, comprising:

one or more memories; and

one or more processors, coupled to the one or more memories, individually or collectively configured to cause the first network entity to:

transmit a configuration for a beam sweep of uplink sounding reference signals (SRSs) to a second network entity;

select an uplink candidate beam based at least in part on measurements of the uplink SRSs; and

transmit a beam indication of the selected uplink candidate beam.
The apparatus of claim 15, wherein the beam indication includes an SRS index in downlink control information.
The apparatus of claim 15, wherein the beam indication includes a transmission configuration indicator (TCI) state in downlink control information, and wherein the TCI state is associated with an SRS index.
The apparatus of claim 15, wherein the beam indication includes an uplink reconfiguration with the selected uplink candidate beam.
The apparatus of claim 15, wherein the beam indication includes a medium access control control element (MAC-CE) activation message for the selected uplink candidate beam.