WO2022036502A1

WO2022036502A1 - Methods and apparatus for uplink timing and beam adjustment with preconfigured uplink resources

Info

Publication number: WO2022036502A1
Application number: PCT/CN2020/109519
Authority: WO
Inventors: Linhai He; Ruiming Zheng; Jing LEI
Original assignee: Qualcomm Incorporated
Priority date: 2020-08-17
Filing date: 2020-08-17
Publication date: 2022-02-24

Abstract

The present disclosure relates to methods and devices for wireless communication including an apparatus, e.g., a UE and/or a base station. In one aspect, the apparatus may receive at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time or frequency locations for uplink resources. The apparatus may also measure a RSRP of the set of candidate SSBs in the at least one uplink transmission request. Additionally, the apparatus may determine at least one uplink beam for uplink transmissions based on the set of downlink reference signals. The apparatus may also receive uplink timing synchronization information based on the at least one uplink transmission request.

Description

METHODS AND APPARATUS FOR UPLINK TIMING AND BEAM ADJUSTMENT WITH PRECONFIGURED UPLINK RESOURCES

BACKGROUND Technical Field

The present disclosure relates generally to communication systems, and more particularly, to beam transmissions in wireless communication systems.

Introduction

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G New Radio (NR) . 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT) ) , and other requirements. 5G NR includes services associated with enhanced (pc) mobile broadband (eMBB) , massive machine type communications (mMTC) , and ultra-reliable low latency communications (URLLC) . Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.

SUMMARY

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a user equipment (UE) . The apparatus may determine to enter into a radio resource control (RRC) idle state or a RRC inactive state with a base station. The apparatus may also monitor a paging channel after entering into the RRC idle state or the RRC inactive state. The apparatus may also receive at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources. Further, the apparatus may measure a reference signal received power (RSRP) of the set of downlink reference signals in the at least one uplink transmission request, where the set of downlink reference signals correspond to a set of candidate synchronization signal blocks (SSBs) . The apparatus may also determine at least one uplink beam for uplink transmissions based on the set of downlink reference signals. The apparatus may also receive uplink timing synchronization information based on the at least one uplink transmission request. The apparatus may also adjust at least one of an uplink timing or the at least one uplink beam based on the measured RSRP of the set of candidate SSBs. Additionally, the apparatus may perform a random access channel (RACH) procedure over a common physical RACH (PRACH) using a PRACH preamble when the measured RSRP of the set of candidate SSBs is below an RSRP threshold. The apparatus may also transmit the at least one preconfigured sequence on the determined at least one uplink beam when the measured RSRP of the set of candidate SSBs is above an RSRP threshold. The apparatus may also receive a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) within a response timing window. The apparatus may also update an uplink timing based on the received TAC MAC-CE. The apparatus may also receive a release of preconfigured uplink resources (PUR) .

In another aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a base station. The apparatus may configure preconfigured uplink resources (PUR) for a user equipment (UE) . The apparatus may also determine whether the UE enters into a radio resource control (RRC) idle state or a RRC inactive state. The apparatus may also transmit at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources. Additionally, the apparatus may monitor for the at least one preconfigured sequence via the set of time or frequency locations for the uplink resources. The apparatus may also transmit uplink timing synchronization information based on the at least one uplink transmission request. The apparatus may also perform a random access channel (RACH) procedure with the UE over a common physical RACH (PRACH) using a PRACH preamble. The apparatus may also receive, from the UE, the at least one preconfigured sequence via the set of time and frequency locations for the uplink resources. Moreover, the apparatus may determine at least one of an uplink timing or a beam configuration for the UE. The apparatus may also transmit a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) . The apparatus may also release the PUR for the UE when the at least one preconfigured sequence is not received via the set of time and frequency locations for the uplink resources. The apparatus may also reconfigure the PUR for the UE.

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network.

FIG. 2A is a diagram illustrating an example of a first frame, in accordance with various aspects of the present disclosure.

FIG. 2B is a diagram illustrating an example of DL channels within a subframe, in accordance with various aspects of the present disclosure.

FIG. 2C is a diagram illustrating an example of a second frame, in accordance with various aspects of the present disclosure.

FIG. 2D is a diagram illustrating an example of UL channels within a subframe, in accordance with various aspects of the present disclosure.

FIG. 3 is a diagram illustrating an example of a base station and user equipment (UE) in an access network.

FIG. 4 is a diagram illustrating example communication between a UE and a base station in accordance with one or more techniques of the present disclosure.

FIG. 5 is a diagram illustrating example time and frequency resources in accordance with one or more techniques of the present disclosure.

FIG. 6 is a diagram illustrating example communication between a UE and a base station in accordance with one or more techniques of the present disclosure.

FIG. 7 is a flowchart of a method of wireless communication.

FIG. 8 is a flowchart of a method of wireless communication.

FIG. 9 is a diagram illustrating an example of a hardware implementation for an example apparatus.

FIG. 10 is a diagram illustrating an example of a hardware implementation for an example apparatus.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

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

By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs) , central processing units (CPUs) , application processors, digital signal processors (DSPs) , reduced instruction set computing (RISC) processors, systems on a chip (SoC) , baseband processors, field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM) , a read-only memory (ROM) , an electrically erasable programmable ROM (EEPROM) , optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.

FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network 100. The wireless communications system (also referred to as a wireless wide area network (WWAN) ) includes base stations 102, UEs 104, an Evolved Packet Core (EPC) 160, and another core network 190 (e.g., a 5G Core (5GC) ) . The base stations 102 may include macrocells (high power cellular base station) and/or small cells (low power cellular base station) . The macrocells include base stations. The small cells include femtocells, picocells, and microcells.

The base stations 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) ) may interface with the EPC 160 through first backhaul links 132 (e.g., S1 interface) . The base stations 102 configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN) ) may interface with core network 190 through second backhaul links 184. In addition to other functions, the base stations 102 may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity) , inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS) , subscriber and equipment trace, RAN information management (RIM) , paging, positioning, and delivery of warning messages. The base stations 102 may communicate directly or indirectly (e.g., through the EPC 160 or core network 190) with each other over third backhaul links 134 (e.g., X2 interface) . The first backhaul links 132, the second backhaul links 184, and the third backhaul links 134 may be wired or wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, the small cell 102' may have a coverage area 110' that overlaps the coverage area 110 of one or more macro base stations 102. A network that includes both small cell and macrocells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs) , which may provide service to a restricted group known as a closed subscriber group (CSG) . The communication links 120 between the base stations 102 and the UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and/or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations 102/UEs 104 may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL) . The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell) .

Certain UEs 104 may communicate with each other using device-to-device (D2D) communication link 158. The D2D communication link 158 may use the DL/UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , and a physical sidelink control channel (PSCCH) . D2D communication may be through a variety of wireless D2D communications systems, such as for example, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

The wireless communications system may further include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154, e.g., in a 5 GHz unlicensed frequency spectrum or the like. When communicating in an unlicensed frequency spectrum, the STAs 152/AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.

The small cell 102' may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102' may employ NR and use the same unlicensed frequency spectrum (e.g., 5 GHz, or the like) as used by the Wi-Fi AP 150. The small cell 102', employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network.

The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz –7.125 GHz) and FR2 (24.25 GHz –52.6 GHz) . The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz –300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band.

With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like if used herein may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, or may be within the EHF band.

A base station 102, whether a small cell 102' or a large cell (e.g., macro base station) , may include and/or be referred to as an eNB, gNodeB (gNB) , or another type of base station. Some base stations, such as gNB 180 may operate in a traditional sub 6 GHz spectrum, in millimeter wave frequencies, and/or near millimeter wave frequencies in communication with the UE 104. When the gNB 180 operates in millimeter wave or near millimeter wave frequencies, the gNB 180 may be referred to as a millimeter wave base station. The millimeter wave base station 180 may utilize beamforming 182 with the UE 104 to compensate for the path loss and short range. The base station 180 and the UE 104 may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming.

The base station 180 may transmit a beamformed signal to the UE 104 in one or more transmit directions 182'. The UE 104 may receive the beamformed signal from the base station 180 in one or more receive directions 182”. The UE 104 may also transmit a beamformed signal to the base station 180 in one or more transmit directions. The base station 180 may receive the beamformed signal from the UE 104 in one or more receive directions. The base station 180/UE 104 may perform beam training to determine the best receive and transmit directions for each of the base station 180/UE 104. The transmit and receive directions for the base station 180 may or may not be the same. The transmit and receive directions for the UE 104 may or may not be the same.

The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation as well as other functions. The PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176. The IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and/or other IP services. The BM-SC 170 may provide functions for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN) , and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS traffic to the base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information.

The core network 190 may include an Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. The AMF 192 may be in communication with a Unified Data Management (UDM) 196. The AMF 192 is the control node that processes the signaling between the UEs 104 and the core network 190. Generally, the AMF 192 provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF 195. The UPF 195 provides UE IP address allocation as well as other functions. The UPF 195 is connected to the IP Services 197. The IP Services 197 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a Packet Switch (PS) Streaming (PSS) Service, and/or other IP services.

The base station may include and/or be referred to as a gNB, Node B, eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , a transmit reception point (TRP) , or some other suitable terminology. The base station 102 provides an access point to the EPC 160 or core network 190 for a UE 104. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA) , a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player) , a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc. ) . The UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

Referring again to FIG. 1, in certain aspects, the UE 104 may include a reception component 198 configured to determine to enter into a radio resource control (RRC) idle state or a RRC inactive state with a base station. Reception component 198 may also be configured to monitor a paging channel after entering into the RRC idle state or the RRC inactive state. Reception component 198 may also be configured to receive at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources. Reception component 198 may also be configured to measure a reference signal received power (RSRP) of the set of downlink reference signals in the at least one uplink transmission request, where the set of downlink reference signals correspond to a set of candidate synchronization signal blocks (SSBs) . Reception component 198 may also be configured to determine at least one uplink beam for uplink transmissions based on the set of downlink reference signals. Reception component 198 may also be configured to receive uplink timing synchronization information based on the at least one uplink transmission request. Reception component 198 may also be configured to adjust at least one of an uplink timing or the at least one uplink beam based on the measured RSRP of the set of candidate SSBs. Reception component 198 may also be configured to perform a random access channel (RACH) procedure over a common physical RACH (PRACH) using a PRACH preamble when the measured RSRP of the set of candidate SSBs is below an RSRP threshold. Reception component 198 may also be configured to transmit the at least one preconfigured sequence on the determined at least one uplink beam when the measured RSRP of the set of candidate SSBs is above an RSRP threshold. Reception component 198 may also be configured to receive a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) within a response timing window. Reception component 198 may also be configured to update an uplink timing based on the received TAC MAC-CE. Reception component 198 may also be configured to receive a release of preconfigured uplink resources (PUR) .

Referring again to FIG. 1, in certain aspects, the base station 180 may include a transmission component 199 configured to configure preconfigured uplink resources (PUR) for a user equipment (UE) . Transmission component 199 may also be configured to determine whether the UE enters into a radio resource control (RRC) idle state or a RRC inactive state. Transmission component 199 may also be configured to transmit at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources. Transmission component 199 may also be configured to monitor for the at least one preconfigured sequence via the set of time or frequency locations for the uplink resources. Transmission component 199 may also be configured to transmit uplink timing synchronization information based on the at least one uplink transmission request. Transmission component 199 may also be configured to perform a random access channel (RACH) procedure with the UE over a common physical RACH (PRACH) using a PRACH preamble. Transmission component 199 may also be configured to receive, from the UE, the at least one preconfigured sequence via the set of time and frequency locations for the uplink resources. Transmission component 199 may also be configured to determine at least one of an uplink timing or a beam configuration for the UE. Transmission component 199 may also be configured to transmit a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) . Transmission component 199 may also be configured to release the PUR for the UE when the at least one preconfigured sequence is not received via the set of time and frequency locations for the uplink resources. Transmission component 199 may also be configured to reconfigure the PUR for the UE.

Although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

FIG. 2A is a diagram 200 illustrating an example of a first subframe within a 5G NR frame structure. FIG. 2B is a diagram 230 illustrating an example of DL channels within a 5G NR subframe. FIG. 2C is a diagram 250 illustrating an example of a second subframe within a 5G NR frame structure. FIG. 2D is a diagram 280 illustrating an example of UL channels within a 5G NR subframe. The 5G NR frame structure may be frequency division duplexed (FDD) in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for either DL or UL, or may be time division duplexed (TDD) in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for both DL and UL. In the examples provided by FIGs. 2A, 2C, the 5G NR frame structure is assumed to be TDD, with subframe 4 being configured with slot format 28 (with mostly DL) , where D is DL, U is UL, and F is flexible for use between DL/UL, and subframe 3 being configured with slot format 1 (with all UL) . While

subframes

3, 4 are shown with slot formats 1, 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. UEs are configured with the slot format (dynamically through DL control information (DCI) , or semi-statically/statically through radio resource control (RRC) signaling) through a received slot format indicator (SFI) . Note that the description infra applies also to a 5G NR frame structure that is TDD.

Other wireless communication technologies may have a different frame structure and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms) . Each subframe may include one or more time slots. Subframes may also include mini-slots, which may include 7, 4, or 2 symbols. Each slot may include 7 or 14 symbols, depending on the slot configuration. For slot configuration 0, each slot may include 14 symbols, and for slot configuration 1, each slot may include 7 symbols. The symbols on DL may be cyclic prefix (CP) OFDM (CP-OFDM) symbols. The symbols on UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also referred to as single carrier frequency-division multiple access (SC-FDMA) symbols) (for power limited scenarios; limited to a single stream transmission) . The number of slots within a subframe is based on the slot configuration and the numerology. For slot configuration 0, different numerologies μ0 to 4 allow for 1, 2, 4, 8, and 16 slots, respectively, per subframe. For slot configuration 1, different numerologies 0 to 2 allow for 2, 4, and 8 slots, respectively, per subframe. Accordingly, for slot configuration 0 and numerology μ, there are 14 symbols/slot and 2 ^μ slots/subframe. The subcarrier spacing and symbol length/duration are a function of the numerology. The subcarrier spacing may be equal to 2 ^μ*15 kHz, where μ is the numerology 0 to 4. As such, the numerology μ=0 has a subcarrier spacing of 15 kHz and the numerology μ=4 has a subcarrier spacing of 240 kHz. The symbol length/duration is inversely related to the subcarrier spacing. FIGs. 2A-2D provide an example of slot configuration 0 with 14 symbols per slot and numerology μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a set of frames, there may be one or more different bandwidth parts (BWPs) (see FIG. 2B) that are frequency division multiplexed. Each BWP may have a particular numerology.

A resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs) ) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs) . The number of bits carried by each RE depends on the modulation scheme.

As illustrated in FIG. 2A, some of the REs carry reference (pilot) signals (RS) for the UE.The RS may include demodulation RS (DM-RS) (indicated as R for one particular configuration, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS) , beam refinement RS (BRRS) , and phase tracking RS (PT-RS) .

FIG. 2B illustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs) , each CCE including six RE groups (REGs) , each REG including 12 consecutive REs in an OFDM symbol of an RB. A PDCCH within one BWP may be referred to as a control resource set (CORESET) . A UE is configured to monitor PDCCH candidates in a PDCCH search space (e.g., common search space, UE-specific search space) during PDCCH monitoring occasions on the CORESET, where the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs may be located at greater and/or lower frequencies across the channel bandwidth. A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE 104 to determine subframe/symbol timing and a physical layer identity. A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI) . Based on the PCI, the UE can determine the locations of the aforementioned DM-RS. The physical broadcast channel (PBCH) , which carries a master information block (MIB) , may be logically grouped with the PSS and SSS to form a synchronization signal (SS) /PBCH block (also referred to as SS block (SSB) ) . The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN) . The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs) , and paging messages.

As illustrated in FIG. 2C, some of the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH) . The PUSCH DM-RS may be transmitted in the first one or two symbols of the PUSCH. The PUCCH DM-RS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. The UE may transmit sounding reference signals (SRS) . The SRS may be transmitted in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

FIG. 2D illustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI) , such as scheduling requests, a channel quality indicator (CQI) , a precoding matrix indicator (PMI) , a rank indicator (RI) , and hybrid automatic repeat request (HARQ) ACK/NACK feedback. The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR) , a power headroom report (PHR) , and/or UCI.

FIG. 3 is a block diagram of a base station 310 in communication with a UE 350 in an access network. In the DL, IP packets from the EPC 160 may be provided to a controller/processor 375. The controller/processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor 375 provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs) , RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release) , inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification) , and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs) , error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs) , re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs) , demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor 316 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK) , quadrature phase-shift keying (QPSK) , M-phase-shift keying (M-PSK) , M-quadrature amplitude modulation (M-QAM) ) . The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318 TX. Each transmitter 318 TX may modulate an RF carrier with a respective spatial stream for transmission.

At the UE 350, each receiver 354 RX receives a signal through its respective antenna 352. Each receiver 354 RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 may perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they may be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT) . The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 310. These soft decisions may be based on channel estimates computed by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station 310 on the physical channel. The data and control signals are then provided to the controller/processor 359, which implements layer 3 and layer 2 functionality.

The controller/processor 359 can be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller/processor 359 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller/processor 359 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

Similar to the functionality described in connection with the DL transmission by the base station 310, the controller/processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification) ; RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

Channel estimates derived by a channel estimator 358 from a reference signal or feedback transmitted by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antenna 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a respective spatial stream for transmission.

The UL transmission is processed at the base station 310 in a manner similar to that described in connection with the receiver function at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.

The controller/processor 375 can be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller/processor 375 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 350. IP packets from the controller/processor 375 may be provided to the EPC 160. The controller/processor 375 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

At least one of the TX processor 368, the RX processor 356, and the controller/processor 359 may be configured to perform aspects in connection with 198 of FIG. 1.

At least one of the TX processor 316, the RX processor 370, and the controller/processor 375 may be configured to perform aspects in connection with 199 of FIG. 1.

Some aspects of wireless communications, e.g., enhanced machine type communication (eMTC) or narrowband (NB) internet of things (NB-IoT) communication, may utilize a small data transfer (SDT) in radio resource control (RRC) idle or RRC inactive mode. RRC idle mode can correspond to a complete release from a connection between a UE and a base station or network, and the network may utilize a complete reconfiguration with the UE to reestablish the connection. RRC inactive mode may be similar to a sleep mode, where there is no data exchanged between the UE and the base station or network, but the network maintains the connection and configuration with the UE. So the UE can be reconnected with the base station or network quickly in RRC inactive mode.

In some aspects, the base station or network can preconfigure the UE with uplink resources, e.g., preconfigured uplink resources (PUR) , while the UE is in an RRC connected mode. If a UE has a small amount of data to send (e.g., subject to a threshold configured by the network) , the UE may transmit the data over preconfigured uplink resources (PUR) , without going through normal data transfer procedures. The normal data transfer procedures can include performing a random access channel (RACH) procedure, then establishing an RRC connection setup, then transferring the data, and then releasing an RRC connection.

In some instances, the establishment of the PUR may reduce the latency of the data transfer. For instance, by utilizing the PUR, the UE can skip the aforementioned normal RACH data transfer procedures and transfer the data with a reduced latency in RRC idle state or RRC inactive state. These data transmissions using PUR can be utilized in some types of wireless communications, e.g., new radio (NR) communications.

FIG. 4 is a diagram 400 illustrating example communication between a UE 402, a base station 404, and a network 406. As shown in FIG. 4, at 410, in an RRC release message (msg) , base station 404 may signal a radio resource configuration of PUR for UE 402 to use. At 420, the UE 402 can be in an RRC inactive state. If UE 402 has a small amount of data to send and it has valid uplink (UL) timing, UE 402 can request, e.g., via an RRC resume request, a small data transfer without transitioning to RRC connected mode. As shown at 430, the RRC resume request, together with uplink data, can be sent over PUR to the base station 404. At 432, the base station 404 can then send the uplink data to the core network 406. In some instances, the network 406 can determine to keep the UE 402 in RRC idle or RRC inactive mode, or whether to transition the UE 402 to RRC connected mode.

As further shown in FIG. 4, at 440, after the UE 402 transmits the uplink data over PUR, the UE 402 can monitor a dedicated PUR (D-PUR) search space, e.g., a UE specific search space (USS) , or PUR search space for the network’s response. The USS includes the resources on a PDCCH where the UE can monitor for incoming control messages. In some aspects, this monitoring can be controlled by a timer, and when the timer expires, the UE can return to RRC inactive mode.

As displayed in FIG. 4, at 450, the base station 404 can send an RRC release message to the UE 402. At 460, the network 406 can send downlink data to the base station 404, and at 462, the base station 404 can send the downlink data to the UE 402. At 470, the UE can maintain the RRC inactive mode. So the UE 402 can stay in RRC inactive mode and also send data, e.g., a SDT, to the base station 404 or network 406 via PUR.

There may be a number of shortcomings or limitations of small data transfers over PUR. For instance, the use of PUR may correspond to a UE having the same UL timing as when the UE was configured the PUR. However, the target use case of PUR may be IoT devices, which typically include traffic with a low duty cycle. Hence, by the time of a subsequent PUR occasion, a UE’s uplink timing may have drifted enough that it is no longer usable. This may occur when the UE moves enough that the PUR may no longer be valid.

Some aspects of wireless communications can also include UL timing maintenance, as a UE may need to maintain a valid UL timing in order to transmit uplink data, e.g., via PUR. In RRC connected mode, a network and a UE can stay synchronized to a UE’s UL timing. For instance, in RRC connected mode, whenever the UE transmits uplink data, the network can estimate the UE’s UL timing. If a UE’s latest UL timing has changed more than a preconfigured threshold, the network may send the UE a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) to change its timing offset for UL transmissions.

In addition, a UE and a network can jointly maintain a timing alignment timer. This timer can be started or restarted whenever the network sends a TAC to the UE, i.e., when the UE’s UL timing is updated. Once a UE’s timing alignment timer expires, the UE’s UL timing may be considered invalid. If a UE has new UL data to send but its uplink timing has expired, the UE may trigger a RACH procedure, in which the network may provide the UE with new UL timing information. If the network has new downlink (DL) data for the UE, but the UE’s timing alignment timer has expired, the network can request the UE to perform a RACH procedure to reestablish its UL timing. This procedure can also be referred to as a PDCCH order.

There can be a number of challenges for maintaining UL timing in RRC idle mode or RRC inactive mode. For instance, a UE may not perform regular UL transmissions in RRC idle mode or RRC inactive mode. So if a UE moves and its UL timing changes, then the UE may not be able to use the PUR. As such, there may not be an easy way for a UE and a network to maintain UL synchronization.

Based on the above, there is a present need to maintain UL timing in RRC idle mode or RRC inactive mode. There is also a present need for a UE to monitor communication with a network or base station in RRC idle mode or RRC inactive mode. Further, there is a present need for beam adjustment in RRC idle mode or RRC inactive mode.

Aspects of the present disclosure can maintain UL timing in RRC idle mode or RRC inactive mode. For instance, aspects of the present disclosure can allow a UE to monitor communication with a network or base station in RRC idle mode or RRC inactive mode. Additionally, aspects of the present disclosure can include beam adjustments in RRC idle mode or RRC inactive mode.

In some aspects of the present disclosure, in RRC idle mode or RRC inactive mode, a UE may monitor a paging channel in each idle discontinuous reception (I-DRX) cycle. The network can request that a UE, in a paging message, transmit a preconfigured sequence. The network can obtain a UE’s latest UL timing and transmit (Tx) or receive (Rx) beam from this requested UL transmission. This new UL timing and transmit (Tx) or receive (Rx) beam information may then be used for a UE’s subsequent transmissions over PUR. The preconfigured sequence can be a PRACH preamble. The request may be referred to as an uplink transmission request (UTR) . In this procedure, the UE can establish the UL timing in a short amount of time.

The aforementioned procedure of the present disclosure may be useful for UEs with a number of properties. For example, this procedure may be useful for UEs with UL timing that may not drift too much over several PUR occasions. Also, this procedure may be useful when a UE has relatively low mobility, e.g., a UE does not change its serving cell over several PUR occasions.

Aspects of the present disclosure can include a number of different network or base station procedures. The network may send an UTR in a paging message to a UE in a cell where a UE’s PUR are configured. The UTR can be sent in either a medium access control (MAC) control element (MAC-CE) or an RRC message. The UTR can include a number of traits, such as a preconfigured sequence for the UE to transmit. This preconfigured sequence can be a PRACH preamble. The UTR can also include a set of candidate SSBs for the UE and a reference signal received power (RSRP) threshold for the candidate SSBs. Further, the UTR can include a set of time or frequency locations of UL resources over which the UE may transmit the provided PRACH preamble. The UTR can also include a Tx power ramping step. The UTR can also include a mapping between each candidate SSB and the time or frequency location of the provided UL resources.

FIG. 5 is a diagram 500 illustrating example time and frequency resources in accordance with one or more techniques of the present disclosure. As shown in FIG. 5, diagram 500 includes a mapping between a number of candidate SSBs and the time or frequency location of UL resources. FIG. 5 displays that an UTR can include a mapping between each candidate SSB and the time or frequency location of provided UL resources. As shown in FIG. 5, the network or base station can assign a synchronization signal block (SSB) , e.g., SSB1, to a certain slot, e.g., slot one (1) , and assign another SSB, e.g., SSB2, to another slot, e.g., slot two (2) .

The network or base station may choose to send the uplink transmission request to the UE at different time periods. For instances, a network or base station may transmit the uplink transmission request periodically based on the network’s estimate of how fast a UE’s UL timing may drift. After the UE receives the SSBs, the UE can measure the strength of the beams. The UE can then select the beam that includes an RSRP above an RSRP threshold.

After a network receives a UE’s preamble transmission, the network can estimate a UE’s UL timing and then send the UE its new UL timing in a TAC MAC-CE. This TAC MAC-CE can be a number of sizes, such as a 12-bit absolute TAC MAC-CE or a 6-bit TAC MAC-CE. The size of the TAC MAC-CE may depend on the size of the adjustment to the UE’s UL timing. The response may also serve as an acknowledgement (ACK) to a UE’s UL transmission. Further, the network or base station can update its Tx or Rx beam for communicating with the UE over the next PUR occasion.

If a network does not receive a UE’s preamble transmission in any of the time or frequency locations it provided to the UE, the network may release a UE’s PUR in the cell and stop the procedure. Alternatively, a network may choose to continue and find the UE in its new serving cell through the steps above, and then reconfigure the PUR for the UE in its new cell. Once a network receives a UE’s UL transmission in its new cell, the network can send the UE the new PUR configuration together with the TAC MAC-CE.

Aspects of the present disclosure can also include a variety of UE procedures. After a UE receives an UTR in its paging message, the UE may perform a number of steps. For instance, the UE can measure the RSRP of the candidate SSBs provided in the UTR. If none of the candidate SSBs have an RSRP above the provided RSRP threshold, a UE can perform a RACH procedure over a common PRACH. If the preconfigured sequence in the UTR is a PRACH preamble, the UE can use the preamble in its RACH procedure. Otherwise, the UE can select a SSB from the set of candidate SSBs which have an RSRP above the provided RSRP threshold. The UE can also transmit the preconfigure sequence in the first available time or frequency location associated with the selected SSB. The Tx power for the transmission can be determined by the measured RSRP of the selected SSB.

After a UE transmits the preconfigured sequence, the UE can start a time window, e.g., ra-ResponseWindow, to monitor the response from the network or base station. So the UE can monitor the USS for a response from the network or base station. If the UE receives a new TAC MAC-CE by the end of the time window, e.g., ra- ResponseWindow, the UE can update its UL timing. The UL timing may be the UL timing that the UE will use for its next PUR transmission. In addition, the UE can update its uplink Tx beam for subsequent transmissions over the PUR to the beam that the UE used to transmit the PRACH preamble. Otherwise, if the UE does not receive a new TAC MAC-CE, the UE can repeat the first step over the next available time or frequency resources until they are no longer available. At this point, the UE can stop the procedure. When performing the retransmission, the UE may increase its Tx power by a Tx power ramping step provided in the UTR until the UE’s maximum permitted Tx power is reached.

FIG. 6 is a diagram 600 illustrating example communication between a UE 602 and a base station 604.

At 610, base station 604 may configure preconfigured uplink resources (PUR) for a UE, e.g., UE 602. At 612, base station 604 may determine whether the UE, e.g., UE 602, enters into a radio resource control (RRC) idle state or a RRC inactive state. At 614, UE 602 may determine to enter into a RRC idle state or a RRC inactive state with a base station. At 616, UE 602 may monitor a paging channel after entering into the RRC idle state or the RRC inactive state.

At 620, base station 604 may transmit at least one uplink transmission request, e.g., request 624, in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources. At 622, UE 602 may receive at least one uplink transmission request, e.g., request 624, in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources.

In some aspects, the at least one uplink transmission request may include at least one of an uplink timing request or a beam configuration. Also, the at least one preconfigured sequence may be a physical random access channel (PRACH) preamble. The paging message may be associated with a cell for preconfigured uplink resources (PUR) . Additionally, each of the set of candidate SSBs may be mapped to one of the set of time or frequency locations of the uplink resources. The at least one uplink transmission request may also include an RSRP threshold for the set of candidate SSBs. Moreover, the at least one uplink transmission request may be transmitted and/or received via a medium access control (MAC) control element (MAC-CE) or a radio resource control (RRC) message.

At 630, UE 602 may measure a reference signal received power (RSRP) of the set of downlink reference signals in the at least one uplink transmission request, where the set of downlink reference signals correspond to a set of candidate synchronization signal blocks (SSBs) . At 632, UE 602 may determine at least one uplink beam for uplink transmissions based on the set of downlink reference signals. At 634, UE 602 may adjust at least one of an uplink timing or the at least one uplink beam based on the measured RSRP of the set of candidate SSBs. At 636, base station 604 may monitor for the at least one preconfigured sequence via the set of time or frequency locations for the uplink resources. In some aspects, the UE may not be able to adjust the uplink timing when it transmits the preconfigured sequence. For instance, the network or base station may inform the UE of this adjustment after it receives the UE’s UL transmission.

At 640, UE 602 may perform a random access channel (RACH) procedure, e.g., RACH procedure 644, over a common physical RACH (PRACH) using a PRACH preamble when the measured RSRP of the set of candidate SSBs is below an RSRP threshold. At 642, base station 604 may perform a random access channel (RACH) procedure, e.g., RACH procedure 644, with the UE over a common physical RACH (PRACH) using a PRACH preamble.

At 650, UE 602 may transmit the at least one preconfigured sequence, e.g., sequence 654, on the determined at least one uplink beam when the measured RSRP of the set of candidate SSBs is above an RSRP threshold. At 652, base station 604 may receive, from the UE, the at least one preconfigured sequence, e.g., sequence 654, via the set of time or frequency locations for the uplink resources. The at least one preconfigured sequence may be transmitted and/or received via the set of time or frequency locations for the uplink resources. In some aspects, the UE may measure the RSRP of the candidate SSBs and select one SSB, where the selected SSB may have an RSRP above a configured threshold. This configured threshold may either be broadcast by the network or provided in the uplink Tx request. In some instances, if none of the candidate SSBs has an RSRP above the configured threshold, the UE may perform a RACH procedure over common PRACH. Based on the selected SSB, the UE may determine its uplink Tx beam and the uplink resource associated with the selected SSB. The UE may also transmit the preconfigured sequence in the time and frequency location of the selected uplink resource.

At 656, base station 604 may determine at least one of an uplink timing or a beam configuration for the UE.

At 660, base station 604 may transmit uplink timing synchronization information, e.g., information 664, based on the at least one uplink transmission request. At 662, UE 602 may receive uplink timing synchronization information, e.g., information 664, based on the at least one uplink transmission request.

At 670, base station 604 may transmit a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) , e.g., TAC MAC-CE 674. At 672, UE 602 may receive a TAC MAC-CE, e.g., TAC MAC-CE 674 within a response timing window. At 674, UE 602 may update an uplink timing based on the received TAC MAC-CE.

At 680, base station 604 may release the preconfigured uplink resources (PUR) , e.g., release 684, for the UE when the at least one preconfigured sequence is not received via the set of time and frequency locations for the uplink resources. At 682, UE 602 may receive a release of preconfigured uplink resources (PUR) , e.g., release 684.

At 690, base station 604 may reconfigure the preconfigured uplink resources (PUR) for the UE. In some aspects, the UE 602 may determine a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) is not received within a response timing window. The UE 602 may also determine whether an amount of uplink resource locations of the set of time and frequency locations for uplink resources is less than an uplink resource location threshold. Also, the UE 602 may transmit the least one preconfigured sequence in a subsequent available time and frequency location of the set of time and frequency locations of the uplink resources when the amount of uplink resource locations is less than the uplink resource location threshold. Also, a transmit (Tx) power of the at least one uplink beam may be determined based on the measured RSRP of one of the set of candidate SSBs.

FIG. 7 is a flowchart 700 of a method of wireless communication. The method may be performed by a UE or a component of a UE (e.g., the

UE

104, 350, 602; the apparatus 902; a processing system, which may include the memory 360 and which may be the entire UE or a component of the UE, such as the TX processor 368, the controller/processor 359, transmitter 354TX, antenna (s) 352, and/or the like) . Optional aspects are illustrated with a dashed line. The methods described herein can provide a number of benefits, such as improving communication signaling, resource utilization, and/or power savings.

At 702, the apparatus may determine to enter into a RRC idle state or a RRC inactive state with a base station, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 702 may be performed by determination component 940.

At 704, the apparatus may monitor a paging channel after entering into the RRC idle state or the RRC inactive state, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 704 may be performed by determination component 940.

At 706, the apparatus may receive at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 706 may be performed by determination component 940.

In some aspects, the at least one uplink transmission request may include at least one of an uplink timing request or a beam configuration, as described in connection with the examples in FIGs. 4, 5, and 6. Also, the at least one preconfigured sequence may be a physical random access channel (PRACH) preamble, as described in connection with the examples in FIGs. 4, 5, and 6. The paging message may be associated with a cell for preconfigured uplink resources (PUR) , as described in connection with the examples in FIGs. 4, 5, and 6. Additionally, each of the set of candidate SSBs may be mapped to one of the set of time or frequency locations of the uplink resources, as described in connection with the examples in FIGs. 4, 5, and 6. The at least one uplink transmission request may also include an RSRP threshold for the set of candidate SSBs, as described in connection with the examples in FIGs. 4, 5, and 6. Moreover, the at least one uplink transmission request may be received via a medium access control (MAC) control element (MAC-CE) or a radio resource control (RRC) message, as described in connection with the examples in FIGs. 4, 5, and 6.

At 708, the apparatus may measure a reference signal received power (RSRP) of the set of downlink reference signals in the at least one uplink transmission request, where the set of downlink reference signals correspond to a set of candidate synchronization signal blocks (SSBs) , as described in connection with the examples in FIGs. 4, 5, and 6. For example, 708 may be performed by determination component 940.

At 710, the apparatus may determine at least one uplink beam for uplink transmissions based on the set of downlink reference signals, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 710 may be performed by determination component 940.

At 712, the apparatus may adjust at least one of an uplink timing or the at least one uplink beam based on the measured RSRP of the set of candidate SSBs, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 712 may be performed by determination component 940.

At 714, the apparatus may perform a random access channel (RACH) procedure over a common physical RACH (PRACH) using a PRACH preamble when the measured RSRP of the set of candidate SSBs is below an RSRP threshold, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 714 may be performed by determination component 940.

At 716, the apparatus may transmit the at least one preconfigured sequence on the determined at least one uplink beam when the measured RSRP of the set of candidate SSBs is above an RSRP threshold, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 716 may be performed by determination component 940. The at least one preconfigured sequence may be transmitted via the set of time or frequency locations for the uplink resources, as described in connection with the examples in FIGs. 4, 5, and 6.

At 717, the apparatus may receive uplink timing synchronization information based on the at least one uplink transmission request, as described in connection with the examples in FIGs. 4, 5, and 6.

At 718, the apparatus may receive a TAC MAC-CE within a response timing window, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 718 may be performed by determination component 940.

At 720, the apparatus may update an uplink timing based on the received TAC MAC-CE, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 720 may be performed by determination component 940.

At 722, the apparatus may receive a release of preconfigured uplink resources (PUR) , as described in connection with the examples in FIGs. 4, 5, and 6. For example, 722 may be performed by determination component 940.

FIG. 8 is a flowchart 800 of a method of wireless communication. The method may be performed by a base station or a component of a base station (e.g., the

base station

102, 180, 310, 604; the apparatus 1002; a processing system, which may include the memory 376 and which may be the entire base station or a component of the base station, such as the antenna (s) 320, receiver 318RX, the RX processor 370, the controller/processor 375, and/or the like) . Optional aspects are illustrated with a dashed line. The methods described herein can provide a number of benefits, such as improving communication signaling, resource utilization, and/or power savings.

At 802, the apparatus may configure preconfigured uplink resources (PUR) for a user equipment (UE) , as described in connection with the examples in FIGs. 4, 5, and 6. For example, 802 may be performed by determination component 1040.

At 804, the apparatus may determine whether the UE enters into a radio resource control (RRC) idle state or a RRC inactive state, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 804 may be performed by determination component 1040.

At 806, the apparatus may transmit at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 806 may be performed by determination component 1040.

In some aspects, the at least one uplink transmission request may include at least one of an uplink timing request or a beam configuration, as described in connection with the examples in FIGs. 4, 5, and 6. Also, the at least one preconfigured sequence may be a physical random access channel (PRACH) preamble, as described in connection with the examples in FIGs. 4, 5, and 6. The paging message may be associated with a cell for the PUR, as described in connection with the examples in FIGs. 4, 5, and 6. Further, each of the set of candidate SSBs may be mapped to one of the set of time or frequency locations of the uplink resources, as described in connection with the examples in FIGs. 4, 5, and 6. The at least one uplink transmission request may include a reference signal received power (RSRP) threshold for the set of candidate SSBs, as described in connection with the examples in FIGs. 4, 5, and 6. Also, the at least one uplink transmission request may be transmitted via a medium access control (MAC) control element (MAC-CE) or a radio resource control (RRC) message, as described in connection with the examples in FIGs. 4, 5, and 6.

At 808, the apparatus may monitor for the at least one preconfigured sequence via the set of time or frequency locations for the uplink resources, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 808 may be performed by determination component 1040.

At 810, the apparatus may perform a random access channel (RACH) procedure with the UE over a common physical RACH (PRACH) using a PRACH preamble, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 810 may be performed by determination component 1040.

At 812, the apparatus may receive, from the UE, the at least one preconfigured sequence via the set of time and frequency locations for the uplink resources, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 812 may be performed by determination component 1040.

At 814, the apparatus may determine at least one of an uplink timing or a beam configuration for the UE, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 814 may be performed by determination component 1040.

At 815, the apparatus may transmit uplink timing synchronization information based on the at least one uplink transmission request, as described in connection with the examples in FIGs. 4, 5, and 6.

At 816, the apparatus may transmit a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) , as described in connection with the examples in FIGs. 4, 5, and 6. For example, 816 may be performed by determination component 1040. The updated uplink transmission request may include at least one of an updated uplink timing request or an updated beam configuration, as described in connection with the examples in FIGs. 4, 5, and 6.

At 818, the apparatus may release the PUR for the UE when the at least one preconfigured sequence is not received via the set of time and frequency locations for the uplink resources, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 818 may be performed by determination component 1040.

At 820, the apparatus may reconfigure the PUR for the UE, as described in connection with the examples in FIGs. 4, 5, and 6. For example, 820 may be performed by determination component 1040.

FIG. 9 is a diagram 900 illustrating an example of a hardware implementation for an apparatus 902. The apparatus 902 is a UE and includes a cellular baseband processor 904 (also referred to as a modem) coupled to a cellular RF transceiver 922 and one or more subscriber identity modules (SIM) cards 920, an application processor 906 coupled to a secure digital (SD) card 908 and a screen 910, a Bluetooth module 912, a wireless local area network (WLAN) module 914, a Global Positioning System (GPS) module 916, and a power supply 918. The cellular baseband processor 904 communicates through the cellular RF transceiver 922 with the UE 104 and/or BS 102/180. The cellular baseband processor 904 may include a computer-readable medium/memory. The computer-readable medium/memory may be non-transitory. The cellular baseband processor 904 is responsible for general processing, including the execution of software stored on the computer-readable medium/memory. The software, when executed by the cellular baseband processor 904, causes the cellular baseband processor 904 to perform the various functions described supra. The computer-readable medium/memory may also be used for storing data that is manipulated by the cellular baseband processor 904 when executing software. The cellular baseband processor 904 further includes a reception component 930, a communication manager 932, and a transmission component 934. The communication manager 932 includes the one or more illustrated components. The components within the communication manager 932 may be stored in the computer-readable medium/memory and/or configured as hardware within the cellular baseband processor 904. The cellular baseband processor 904 may be a component of the UE 350 and may include the memory 360 and/or at least one of the TX processor 368, the RX processor 356, and the controller/processor 359. In one configuration, the apparatus 902 may be a modem chip and include just the baseband processor 904, and in another configuration, the apparatus 902 may be the entire UE (e.g., see 350 of FIG. 3) and include the aforediscussed additional modules of the apparatus 902.

The communication manager 932 includes a determination component 940 that is configured to receive at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of candidate synchronization signal blocks (SSBs) , or a set of time or frequency locations for uplink resources, e.g., as described in connection with step 706 above. Determination component 940 can also be configured to measure a reference signal received power (RSRP) of the set of candidate SSBs in the at least one uplink transmission request, e.g., as described in connection with step 708 above. Determination component 940 can also be configured to determine at least one uplink beam for uplink transmissions based on the set of downlink reference signals, e.g., as described in connection with step 710 above.

The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowcharts of FIGs. 6 and 7. As such, each block in the aforementioned flowcharts of FIGs. 6 and 7 may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

In one configuration, the apparatus 902, and in particular the cellular baseband processor 904, includes means for receiving at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of candidate synchronization signal blocks (SSBs) , or a set of time or frequency locations for uplink resources. The apparatus 902 can also include means for measuring a reference signal received power (RSRP) of the set of candidate SSBs in the at least one uplink transmission request. The apparatus 902 can also include means for determining at least one uplink beam for uplink transmissions based on the measured RSRP of the set of candidate SSBs. The aforementioned means may be one or more of the aforementioned components of the apparatus 902 configured to perform the functions recited by the aforementioned means. As described supra, the apparatus 902 may include the TX Processor 368, the RX Processor 356, and the controller/processor 359. As such, in one configuration, the aforementioned means may be the TX Processor 368, the RX Processor 356, and the controller/processor 359 configured to perform the functions recited by the aforementioned means.

FIG. 10 is a diagram 1000 illustrating an example of a hardware implementation for an apparatus 1002. The apparatus 1002 is a base station and includes a baseband unit 1004. The baseband unit 1004 may communicate through a cellular RF transceiver with the UE 104. The baseband unit 1004 may include a computer-readable medium/memory. The baseband unit 1004 is responsible for general processing, including the execution of software stored on the computer-readable medium/memory. The software, when executed by the baseband unit 1004, causes the baseband unit 1004 to perform the various functions described supra. The computer-readable medium/ memory may also be used for storing data that is manipulated by the baseband unit 1004 when executing software. The baseband unit 1004 further includes a reception component 1030, a communication manager 1032, and a transmission component 1034. The communication manager 1032 includes the one or more illustrated components. The components within the communication manager 1032 may be stored in the computer-readable medium/memory and/or configured as hardware within the baseband unit 1004. The baseband unit 1004 may be a component of the BS 310 and may include the memory 376 and/or at least one of the TX processor 316, the RX processor 370, and the controller/processor 375.

The communication manager 1032 includes a determination component 1040 that is configured to configure preconfigured uplink resources (PUR) for a user equipment (UE) , e.g., as described in connection with step 802 above. Determination component 1040 can also be configured to transmit at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of candidate synchronization signal blocks (SSBs) , or a set of time or frequency locations for uplink resources, e.g., as described in connection with step 806 above. Determination component 1040 can also be configured to monitor for the at least one preconfigured sequence via the set of time or frequency locations for the uplink resources, e.g., as described in connection with step 808 above.

The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowcharts of FIGs. 6 and 8. As such, each block in the aforementioned flowcharts of FIGs. 6 and 8 may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

In one configuration, the apparatus 1002, and in particular the baseband unit 1004, includes means for configuring preconfigured uplink resources (PUR) for a user equipment (UE) . The apparatus 1002 can also include means for transmitting at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of candidate synchronization signal blocks (SSBs) , or a set of time or frequency locations for uplink resources. The apparatus 1002 can also include means for monitoring for the at least one preconfigured sequence via the set of time or frequency locations for the uplink resources. The aforementioned means may be one or more of the aforementioned components of the apparatus 1002 configured to perform the functions recited by the aforementioned means. As described supra, the apparatus 1002 may include the TX Processor 316, the RX Processor 370, and the controller/processor 375. As such, in one configuration, the aforementioned means may be the TX Processor 316, the RX Processor 370, and the controller/processor 375 configured to perform the functions recited by the aforementioned means.

Further disclosure is included in the Appendix.

It is understood that the specific order or hierarchy of blocks in the processes/flowcharts disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes/flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more. ” The word “exemplary” is used herein to mean “serving as an example, instance, or illustration. ” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module, ” “mechanism, ” “element, ” “device, ” and the like may not be a substitute for the word “means. ” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for. ”

Claims

A method of wireless communication of a user equipment (UE) , comprising:

receiving at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources;

determining at least one uplink beam for uplink transmissions based on the set of downlink reference signals; and

receiving uplink timing synchronization information based on the at least one uplink transmission request.
The method of claim 1, further comprising:

measuring a reference signal received power (RSRP) of the set of downlink reference signals in the at least one uplink transmission request, wherein the set of downlink reference signals correspond to a set of candidate synchronization signal blocks (SSBs) .
The method of claim 2, further comprising:

adjusting at least one of an uplink timing or the at least one uplink beam based on the measured RSRP of the set of candidate SSBs.
The method of claim 2, further comprising:

transmitting the at least one preconfigured sequence on the determined at least one uplink beam when the measured RSRP of the set of candidate SSBs is above an RSRP threshold.
The method of claim 4, wherein the at least one preconfigured sequence is transmitted via the set of time and frequency locations for the uplink resources.
The method of claim 2, further comprising:

performing a random access channel (RACH) procedure over a common physical RACH (PRACH) using a PRACH preamble when the measured RSRP of the set of candidate SSBs is below an RSRP threshold.
The method of claim 1, wherein the at least one preconfigured sequence is a physical random access channel (PRACH) preamble.
The method of claim 1, further comprising:

receiving a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) within a response timing window.
The method of claim 8, further comprising:

updating an uplink timing based on the received TAC MAC-CE.
The method of claim 1, wherein each of the set of downlink reference signals is mapped to one of the set of time and frequency locations of the uplink resources.
The method of claim 1, wherein the at least one uplink transmission request includes an RSRP threshold for the set of downlink reference signals.
The method of claim 1, further comprising:

receiving a release of preconfigured uplink resources (PUR) .
The method of claim 1, wherein the paging message is associated with a cell with preconfigured uplink resources (PUR) .
The method of claim 1, further comprising:

determining to enter into a radio resource control (RRC) idle state or a RRC inactive state with a base station.
The method of claim 14, further comprising:

monitoring a paging channel after entering into the RRC idle state or the RRC inactive state.
The method of claim 1, wherein the at least one uplink transmission request is received via a medium access control (MAC) control element (MAC-CE) or a radio resource control (RRC) message.
An apparatus for wireless communication of a user equipment (UE) , comprising:

a memory; and

at least one processor coupled to the memory and configured to:

receive at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources;

determine at least one uplink beam for uplink transmissions based on the set of downlink reference signals; and

receive uplink timing synchronization information based on the at least one uplink transmission request.
The apparatus of claim 17, wherein the at least one processor is further configured to:

measure a reference signal received power (RSRP) of the set of downlink reference signals in the at least one uplink transmission request, wherein the set of downlink reference signals correspond to a set of candidate synchronization signal blocks (SSBs) .
The apparatus of claim 18, wherein the at least one processor is further configured to:

adjust at least one of an uplink timing or the at least one uplink beam based on the measured RSRP of the set of candidate SSBs.
The apparatus of claim 18, wherein the at least one processor is further configured to:

transmit the at least one preconfigured sequence on the determined at least one uplink beam when the measured RSRP of the set of candidate SSBs is above an RSRP threshold.
The apparatus of claim 20, wherein the at least one preconfigured sequence is transmitted via the set of time and frequency locations for the uplink resources.
The apparatus of claim 18, wherein the at least one processor is further configured to:

perform a random access channel (RACH) procedure over a common physical RACH (PRACH) using a PRACH preamble when the measured RSRP of the set of candidate SSBs is below an RSRP threshold.
The apparatus of claim 17, wherein the at least one preconfigured sequence is a physical random access channel (PRACH) preamble.
The apparatus of claim 17, wherein the at least one processor is further configured to:

receive a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) within a response timing window.
The apparatus of claim 24, wherein the at least one processor is further configured to:

update an uplink timing based on the received TAC MAC-CE.
The apparatus of claim 17, wherein each of the set of downlink reference signals is mapped to one of the set of time and frequency locations of the uplink resources.
The apparatus of claim 17, wherein the at least one uplink transmission request includes an RSRP threshold for the set of downlink reference signals.
The apparatus of claim 17, wherein the at least one processor is further configured to:

receive a release of preconfigured uplink resources (PUR) .
The apparatus of claim 17, wherein the paging message is associated with a cell with preconfigured uplink resources (PUR) .
The apparatus of claim 17, wherein the at least one processor is further configured to:

determine to enter into a radio resource control (RRC) idle state or a RRC inactive state with a base station.
The apparatus of claim 30, wherein the at least one processor is further configured to:

monitor a paging channel after entering into the RRC idle state or the RRC inactive state.
The apparatus of claim 17, wherein the at least one uplink transmission request is received via a medium access control (MAC) control element (MAC-CE) or a radio resource control (RRC) message.
An apparatus for wireless communication of a user equipment (UE) , comprising:

means for receiving at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources;

means for determining at least one uplink beam for uplink transmissions based on the set of downlink reference signals; and

means for receiving uplink timing synchronization information based on the at least one uplink transmission request.
The apparatus of claim 33, further comprising:

means for measuring a reference signal received power (RSRP) of the set of downlink reference signals in the at least one uplink transmission request, wherein the set of downlink reference signals correspond to a set of candidate synchronization signal blocks (SSBs) .
The apparatus of claim 34, further comprising:

means for adjusting at least one of an uplink timing or the at least one uplink beam based on the measured RSRP of the set of candidate SSBs.
The apparatus of claim 34, further comprising:

means for transmitting the at least one preconfigured sequence on the determined at least one uplink beam when the measured RSRP of the set of candidate SSBs is above an RSRP threshold.
The apparatus of claim 36, wherein the at least one preconfigured sequence is transmitted via the set of time and frequency locations for the uplink resources.
The apparatus of claim 34, further comprising:

means for performing a random access channel (RACH) procedure over a common physical RACH (PRACH) using a PRACH preamble when the measured RSRP of the set of candidate SSBs is below an RSRP threshold.
The apparatus of claim 33, wherein the at least one preconfigured sequence is a physical random access channel (PRACH) preamble.
The apparatus of claim 33, further comprising:

means for receiving a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) within a response timing window.
The apparatus of claim 40, further comprising:

means for updating an uplink timing based on the received TAC MAC-CE.
The apparatus of claim 33, wherein each of the set of downlink reference signals is mapped to one of the set of time and frequency locations of the uplink resources.
The apparatus of claim 33, wherein the at least one uplink transmission request includes an RSRP threshold for the set of downlink reference signals.
The apparatus of claim 33, further comprising:

means for receiving a release of preconfigured uplink resources (PUR) .
The apparatus of claim 33, wherein the paging message is associated with a cell with preconfigured uplink resources (PUR) .
The apparatus of claim 33, further comprising:

means for determining to enter into a radio resource control (RRC) idle state or a RRC inactive state with a base station.
The apparatus of claim 46, further comprising:

means for monitoring a paging channel after entering into the RRC idle state or the RRC inactive state.
The apparatus of claim 33, wherein the at least one uplink transmission request is received via a medium access control (MAC) control element (MAC-CE) or a radio resource control (RRC) message.
A computer-readable medium storing computer executable code for wireless communication of a user equipment (UE) , the code when executed by a processor causes the processor to:

receive at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources;

determine at least one uplink beam for uplink transmissions based on the set of downlink reference signals; and

receive uplink timing synchronization information based on the at least one uplink transmission request.
A method of wireless communication of a base station, comprising:

configuring preconfigured uplink resources (PUR) for a user equipment (UE) ;

transmitting at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources;

monitoring for the at least one preconfigured sequence via the set of time and frequency locations for the uplink resources; and

transmitting uplink timing synchronization information based on the at least one uplink transmission request.
The method of claim 50, wherein the set of downlink reference signals correspond to a set of candidate synchronization signal blocks (SSBs) .
The method of claim 50, wherein the at least one preconfigured sequence is a physical random access channel (PRACH) preamble.
The method of claim 50, further comprising:

receiving, from the UE, the at least one preconfigured sequence via the set of time and frequency locations for the uplink resources.
The method of claim 53, further comprising:

determining at least one of an uplink timing or a beam configuration for the UE.
The method of claim 53, further comprising:

transmitting a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) .
The method of claim 50, further comprising:

releasing the PUR for the UE when the at least one preconfigured sequence is not received via the set of time and frequency locations for the uplink resources.
The method of claim 50, further comprising:

reconfiguring the PUR for the UE.
The method of claim 50, further comprising:

performing a random access channel (RACH) procedure with the UE over a common physical RACH (PRACH) using a PRACH preamble.
The method of claim 50, wherein the paging message is associated with a cell for the PUR.
The method of claim 50, wherein each of the set of downlink reference signals is mapped to one of the set of time and frequency locations of the uplink resources.
The method of claim 50, wherein the at least one uplink transmission request includes a reference signal received power (RSRP) threshold for the set of downlink reference signals.
The method of claim 50, further comprising:

determining whether the UE enters into a radio resource control (RRC) idle state or a RRC inactive state.
The method of claim 50, wherein the at least one uplink transmission request is transmitted via a medium access control (MAC) control element (MAC-CE) or a radio resource control (RRC) message.
An apparatus for wireless communication of a base station, comprising:

a memory; and

at least one processor coupled to the memory and configured to:

configure preconfigured uplink resources (PUR) for a user equipment (UE) ;

transmit at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources;

monitor for the at least one preconfigured sequence via the set of time and frequency locations for the uplink resources; and

transmit uplink timing synchronization information based on the at least one uplink transmission request.
The apparatus of claim 64, wherein the set of downlink reference signals correspond to a set of candidate synchronization signal blocks (SSBs) .
The apparatus of claim 64, wherein the at least one preconfigured sequence is a physical random access channel (PRACH) preamble.
The apparatus of claim 64, wherein the at least one processor is further configured to:

receive, from the UE, the at least one preconfigured sequence via the set of time and frequency locations for the uplink resources.
The apparatus of claim 67, wherein the at least one processor is further configured to:

determine at least one of an uplink timing or a beam configuration for the UE.
The apparatus of claim 67, wherein the at least one processor is further configured to:

transmit a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) .
The apparatus of claim 64, wherein the at least one processor is further configured to:

releasing the PUR for the UE when the at least one preconfigured sequence is not received via the set of time and frequency locations for the uplink resources.
The apparatus of claim 64, wherein the at least one processor is further configured to:

reconfigure the PUR for the UE.
The apparatus of claim 64, wherein the at least one processor is further configured to:

perform a random access channel (RACH) procedure with the UE over a common physical RACH (PRACH) using a PRACH preamble.
The apparatus of claim 64, wherein the paging message is associated with a cell for the PUR.
The apparatus of claim 64, wherein each of the set of downlink reference signals is mapped to one of the set of time and frequency locations of the uplink resources.
The apparatus of claim 64, wherein the at least one uplink transmission request includes a reference signal received power (RSRP) threshold for the set of downlink reference signals.
The apparatus of claim 64, wherein the at least one processor is further configured to:

determine whether the UE enters into a radio resource control (RRC) idle state or a RRC inactive state.
The apparatus of claim 64, wherein the at least one uplink transmission request is transmitted via a medium access control (MAC) control element (MAC-CE) or a radio resource control (RRC) message.
An apparatus for wireless communication of a base station, comprising:

means for configuring preconfigured uplink resources (PUR) for a user equipment (UE) ;

means for transmitting at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources;

means for monitoring for the at least one preconfigured sequence via the set of time or frequency locations for the uplink resources; and

means for transmitting uplink timing synchronization information based on the at least one uplink transmission request.
The apparatus of claim 78, wherein the set of downlink reference signals correspond to a set of candidate synchronization signal blocks (SSBs) .
The apparatus of claim 78, wherein the at least one preconfigured sequence is a physical random access channel (PRACH) preamble.
The apparatus of claim 78, further comprising:

means for receiving, from the UE, the at least one preconfigured sequence via the set of time and frequency locations for the uplink resources.
The apparatus of claim 81, further comprising:

means for determining at least one of an uplink timing or a beam configuration for the UE.
The apparatus of claim 81, further comprising:

means for transmitting a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) .
The apparatus of claim 78, further comprising:

means for releasing the PUR for the UE when the at least one preconfigured sequence is not received via the set of time and frequency locations for the uplink resources.
The apparatus of claim 78, further comprising:

means for reconfiguring the PUR for the UE.
The apparatus of claim 78, further comprising:

means for performing a random access channel (RACH) procedure with the UE over a common physical RACH (PRACH) using a PRACH preamble.
The apparatus of claim 78, wherein the paging message is associated with a cell for the PUR.
The apparatus of claim 78, wherein each of the set of downlink reference signals is mapped to one of the set of time and frequency locations of the uplink resources.
The apparatus of claim 78, wherein the at least one uplink transmission request includes a reference signal received power (RSRP) threshold for the set of downlink reference signals.
The apparatus of claim 78, further comprising:

means for determining whether the UE enters into a radio resource control (RRC) idle state or a RRC inactive state.
The apparatus of claim 78, wherein the at least one uplink transmission request is transmitted via a medium access control (MAC) control element (MAC-CE) or a radio resource control (RRC) message.
A computer-readable medium storing computer executable code for wireless communication of a base station, the code when executed by a processor causes the processor to:

configure preconfigured uplink resources (PUR) for a user equipment (UE) ;

transmit at least one uplink transmission request in a paging message, the at least one uplink transmission request including at least one of at least one preconfigured sequence, a set of downlink reference signals, or a set of time and frequency locations for uplink resources;

monitor for the at least one preconfigured sequence via the set of time or frequency locations for the uplink resources; and

transmit uplink timing synchronization information based on the at least one uplink transmission request.
The method of claim 1, further comprising:

determining a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) is not received within a response timing window;

determining whether an amount of uplink resource locations of the set of time and frequency locations for uplink resources is less than an uplink resource location threshold; and

transmitting the least one preconfigured sequence in a subsequent available time and frequency location of the set of time and frequency locations of the uplink resources when the amount of uplink resource locations is less than the uplink resource location threshold.
The method of claim 2, wherein a transmit (Tx) power of the at least one uplink beam is determined based on the measured RSRP of one of the set of candidate SSBs.
The apparatus of claim 17, wherein the at least one processor is further configured to:

determine a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) is not received within a response timing window;

determine whether an amount of uplink resource locations of the set of time and frequency locations for uplink resources is less than an uplink resource location threshold; and

transmit the least one preconfigured sequence in a next available time and frequency location of the set of time and frequency locations of the uplink resources when the amount of uplink resource locations is less than the uplink resource location threshold.
The apparatus of claim 18, wherein a transmit (Tx) power of the at least one uplink beam is determined based on the measured RSRP of one of the set of candidate SSBs.
The apparatus of claim 33, further comprising:

means for determining a timing advance command (TAC) medium access control (MAC) control element (MAC-CE) is not received within a response timing window;

means for determining whether an amount of uplink resource locations of the set of time and frequency locations for uplink resources is less than an uplink resource location threshold; and

means for transmitting the least one preconfigured sequence in a next available time and frequency location of the set of time and frequency locations of the uplink resources when the amount of uplink resource locations is less than the uplink resource location threshold.
The apparatus of claim 34, wherein a transmit (Tx) power of the at least one uplink beam is determined based on the measured RSRP of one of the set of candidate SSBs.