Patent Description:
Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE).

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

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

3GPP DRAFT R1-<NUM> relates to random access procedures for NR and discloses that for multi-beam operation, a limited number of RACH occasions before RAR reception (window) should be configured by the network and the UE should use different Tx beams for different RACH transmission occasions. Furthermore, at gNB, the DL Tx beam for Msg2 is obtained from the detected RACH occasion or the group of preambles. Further prior art is known from 3GPP DRAFT; R1-<NUM>.

Some aspects described herein relate to a method for wireless communication at a user equipment, UE. The method comprises: receiving, from a base station, a message that indicates a plurality of subsets within a set of random access occasions, wherein each subset of the plurality of subsets is associated with a corresponding beam of a plurality of beams, wherein each corresponding beam is different from remaining beams of the plurality of beams, wherein each subset of the plurality of subsets is associated with a corresponding synchronization signal of a plurality of synchronization signals, wherein each corresponding synchronization signal is different from remaining synchronization signals of the plurality of synchronization signals; transmitting, to the base station and based at least in part on the message, at least one random access preamble, wherein the at least one random access preamble is transmitted within one or more subsets, of the plurality of subsets, using one or more corresponding beams of the plurality of beams; and transmitting a plurality of random access preambles across random access occasions that are included within one subset of the plurality of subsets.

Some aspects described herein relate to an apparatus for wireless communication at a user equipment, UE, the apparatus comprising means for carrying out the method disclose above.

Some aspects described herein relate to a method of wireless communication performed by a base station. The method comprises: transmitting, to a user equipment, UE, a message that indicates a plurality of subsets within a set of random access occasions, wherein each subset of the plurality of subsets is associated with a corresponding beam of a plurality of beams, wherein each corresponding beam is different from remaining beams of the plurality of beams, wherein each subset of the plurality of subsets is associated with a corresponding synchronization signal of a plurality of synchronization signals, wherein each corresponding synchronization signal is different from remaining synchronization signals of the plurality of synchronization signals receiving, from the UE and based at least in part on the message, at least one random access preamble, wherein the at least one random access preamble is received within one or more subsets, of the plurality of subsets, using one or more corresponding beams of the plurality of beams; and receiving a plurality of random access preambles across random access occasions that are included within one subset of the plurality of subsets.

Some aspects described herein relate to an apparatus of wireless communication at a base station, BS, the apparatus comprising means for carrying out the method disclosed above.

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

Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages, will be better understood from the following description when considered in connection with the accompanying figures.

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

One skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure.

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

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

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

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

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

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

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

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

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

In general, any number of wireless networks <NUM> may be deployed in a given geographic area. Each wireless network <NUM> may support a particular RAT and may operate on one or more frequencies. A RAT may be referred to as a radio technology, an air interface, or the like. A frequency may be referred to as a carrier, a frequency channel, or the like.

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

Devices of the wireless network <NUM> may communicate using the electromagnetic spectrum, which may be subdivided by frequency or wavelength into various classes, bands, channels, or the like. For example, devices of the wireless network <NUM> may communicate using one or more operating bands. In <NUM> NR, two initial operating bands have been identified as frequency range designations FR1 (<NUM> - <NUM>) and FR2 (<NUM> - <NUM>). It should be understood that although a portion of FR1 is greater than <NUM>, FR1 is often referred to (interchangeably) as a "Sub-<NUM>" 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" or "mmW" band in documents and articles, despite being different from the extremely high frequency (EHF) band (<NUM> - <NUM>) which is identified by the International Telecommunications Union (ITU) as a "millimeter wave" band.

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

In some aspects, the wireless network <NUM> may further include one or more wired components. For example, one or more UEs <NUM> may receive data over-the-air as well as via wired connection and combine the packets received to increase throughput.

The base station <NUM> may be equipped with a set of antennas 234a through 234t, such as T antennas (T ≥ <NUM>). The UE <NUM> may be equipped with a set of antennas 252a through 252r, such as R antennas (R ≥ <NUM>).

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

At the UE <NUM>, a set of antennas <NUM> (shown as antennas 252a through 252r) may receive the downlink signals from the base station <NUM> and/or other base stations <NUM> and may provide a set of received signals (e.g., R received signals) to a set of modems <NUM> (e.g., R modems), shown as modems 254a through 254r. For example, each received signal may be provided to a demodulator component (shown as DEMOD) of a modem <NUM>. Each modem <NUM> may use a respective demodulator component to condition (e.g., filter, amplify, downconvert, and/or digitize) a received signal to obtain input samples. Each modem <NUM> may use a demodulator component to further process the input samples (e.g., for OFDM) to obtain received symbols. A MIMO detector <NUM> may obtain received symbols from the modems <NUM>, may perform MIMO detection on the received symbols if applicable, and may provide detected symbols. A receive processor <NUM> may process (e.g., demodulate and decode) the detected symbols, may provide decoded data for the UE <NUM> to a data sink <NUM>, and may provide decoded control information and system information to a controller/processor <NUM>. In some examples, one or more components of the UE <NUM> may be included in a housing <NUM>.

The network controller <NUM> may include a communication unit <NUM>, a controller/processor <NUM>, and a memory <NUM>. The network controller <NUM> may include, for example, one or more devices in a core network. The network controller <NUM> may communicate with the base station <NUM> via the communication unit <NUM>.

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

On the uplink, at the UE <NUM>, a transmit processor <NUM> may receive and process data from a data source <NUM> and control information (e.g., for reports that include RSRP, RSSI, RSRQ, and/or CQI) from the controller/processor <NUM>. The transmit processor <NUM> may generate reference symbols for one or more reference signals. The symbols from the transmit processor <NUM> may be precoded by a TX MIMO processor <NUM> if applicable, further processed by the modems <NUM> (e.g., for DFT-s-OFDM or CP-OFDM), and transmitted to the base station <NUM>. In some examples, the modem <NUM> of the UE <NUM> may include a modulator and a demodulator. In some examples, the UE <NUM> includes a transceiver. The transceiver may include any combination of the antenna(s) <NUM>, the modem(s) <NUM>, the MIMO detector <NUM>, the receive processor <NUM>, the transmit processor <NUM>, and/or the TX MIMO processor <NUM>. The transceiver may be used by a processor (e.g., the controller/processor <NUM>) and the memory <NUM> to perform aspects of any of the methods described herein (e.g., with reference to <FIG>).

At the base station <NUM>, the uplink signals from UE <NUM> and/or other UEs may be received by the antennas <NUM>, processed by the modem <NUM> (e.g., a demodulator component, shown as DEMOD, of the modem <NUM>), detected by a MIMO detector <NUM> if applicable, and further processed by a receive processor <NUM> to obtain decoded data and control information sent by the UE <NUM>. The receive processor <NUM> may provide the decoded data to a data sink <NUM> and provide the decoded control information to the controller/processor <NUM>. The base station <NUM> may include a communication unit <NUM> and may communicate with the network controller <NUM> via the communication unit <NUM>. The base station <NUM> may include a scheduler <NUM> to schedule one or more UEs <NUM> for downlink and/or uplink communications. In some examples, the modem <NUM> of the base station <NUM> may include a modulator and a demodulator. In some examples, the base station <NUM> includes a transceiver. The transceiver may include any combination of the antenna(s) <NUM>, the modem(s) <NUM>, the MIMO detector <NUM>, the receive processor <NUM>, the transmit processor <NUM>, and/or the TX MIMO processor <NUM>. The transceiver may be used by a processor (e.g., the controller/processor <NUM>) and the memory <NUM> to perform aspects of any of the methods described herein (e.g., with reference to <FIG>).

The controller/processor <NUM> of the base station <NUM>, the controller/processor <NUM> of the UE <NUM>, and/or any other component(s) of <FIG> may perform one or more techniques associated with random access occasion bundling, as described in more detail elsewhere herein. For example, the controller/processor <NUM> of the base station <NUM>, the controller/processor <NUM> of the UE <NUM>, and/or any other component(s) of <FIG> may perform or direct operations of, for example, process <NUM> of <FIG>, process <NUM> of <FIG>, and/or other processes as described herein. The memory <NUM> and the memory <NUM> may store data and program codes for the base station <NUM> and the UE <NUM>, respectively. In some examples, the memory <NUM> and/or the memory <NUM> may include a non-transitory computer-readable medium storing one or more instructions (e.g., code and/or program code) for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, and/or interpreting) by one or more processors of the base station <NUM> and/or the UE <NUM>, may cause the one or more processors, the UE <NUM>, and/or the base station <NUM> to perform or direct operations of, for example, process <NUM> of <FIG>, process <NUM> of <FIG>, and/or other processes as described herein. In some examples, executing instructions may include running the instructions, converting the instructions, compiling the instructions, and/or interpreting the instructions, among other examples.

In some aspects, a UE (e.g., UE <NUM> and/or apparatus <NUM> of <FIG>) may include means for receiving, from a base station (e.g., base station <NUM> and/or apparatus <NUM> of <FIG>), a message that indicates a plurality of subsets within a set of random access occasions, wherein each subset of the plurality of subsets is associated with a corresponding beam of a plurality of beams, wherein each corresponding beam is different from remaining beams of the plurality of beams; and/or means for transmitting, to the base station and based at least in part on the message, at least one random access preamble, wherein the at least one random access preamble is transmitted within one or more subsets, of the plurality of subsets, using one or more corresponding beams of the plurality of beams. The means for the UE to perform operations described herein may include, for example, one or more of antenna <NUM>, modem <NUM>, MIMO detector <NUM>, receive processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, controller/processor <NUM>, or memory <NUM>.

In some aspects, a base station (e.g., base station <NUM> and/or apparatus <NUM> of <FIG>) may include means for transmitting, to a UE (e.g., UE <NUM> and/or apparatus <NUM> of <FIG>), a message that indicates a plurality of subsets within a set of random access occasions, wherein each subset of the plurality of subsets is associated with a corresponding beam of a plurality of beams, wherein each corresponding beam is different from remaining beams of the plurality of beams; and/or means for receiving, from the UE and based at least in part on the message, at least one random access preamble, wherein the at least one random access preamble is received within one or more subsets, of the plurality of subsets, using one or more corresponding beams of the plurality of beams. The means for the base station to perform operations described herein may include, for example, one or more of transmit processor <NUM>, TX MIMO processor <NUM>, modem <NUM>, antenna <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, memory <NUM>, or scheduler <NUM>.

For example, the functions described with respect to the transmit processor <NUM>, the receive processor <NUM>, and/or the TX MIMO processor <NUM> may be performed by or under the control of the controller/processor <NUM>.

In some aspects, the hardware depicted in <FIG> may be integrated (e.g., the controller/processor <NUM> integrated at least in part with memory <NUM>, the controller/processor <NUM> integrated at least in part with memory <NUM>, and so on). In some aspects, the hardware depicted in <FIG> may be separated (e.g., functions of transmit processor <NUM>, TX MIMO processor <NUM>, modulator <NUM>, antenna <NUM>, demodulator <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, memory <NUM>, and/or scheduler <NUM> may be conceptually, virtually, and/or physically divided between a central unit (CU) and a distributed unit (DU)).

<FIG> is a diagram illustrating an example beamforming architecture <NUM> that supports beamforming for mmW communications, in accordance with the present disclosure. In some aspects, architecture <NUM> may implement aspects of wireless network <NUM>. In some aspects, architecture <NUM> may be implemented in a transmitting device (e.g., a first wireless communication device, UE, or base station) and/or a receiving device (e.g., a second wireless communication device, UE, or base station), as described herein.

Broadly, <FIG> is a diagram illustrating example hardware components of a wireless communication device in accordance with certain aspects of the disclosure. The illustrated components may include those that may be used for antenna element selection and/or for beamforming for transmission of wireless signals. There are numerous architectures for antenna element selection and implementing phase shifting, only one example of which is illustrated here. The architecture <NUM> includes a modem (modulator/demodulator) <NUM>, a digital to analog converter (DAC) <NUM>, a first mixer <NUM>, a second mixer <NUM>, and a splitter <NUM>. The architecture <NUM> also includes multiple first amplifiers <NUM>, multiple phase shifters <NUM>, multiple second amplifiers <NUM>, and an antenna array <NUM> that includes multiple antenna elements <NUM>. In some examples, the modem <NUM> may be one or more of the modems <NUM> or modems <NUM> described in connection with <FIG>.

Transmission lines or other waveguides, wires, and/or traces are shown connecting the various components to illustrate how signals to be transmitted may travel between components. Reference numbers <NUM>, <NUM>, <NUM>, and <NUM> indicate regions in the architecture <NUM> in which different types of signals travel or are processed. Specifically, reference number <NUM> indicates a region in which digital baseband signals travel or are processed, reference number <NUM> indicates a region in which analog baseband signals travel or are processed, reference number <NUM> indicates a region in which analog intermediate frequency (IF) signals travel or are processed, and reference number <NUM> indicates a region in which analog radio frequency (RF) signals travel or are processed. The architecture also includes a local oscillator A <NUM>, a local oscillator B <NUM>, and a controller/processor <NUM>. In some aspects, controller/processor <NUM> corresponds to controller/processor <NUM> of the base station described above in connection with <FIG> and/or controller/processor <NUM> of the UE described above in connection with <FIG>.

Each of the antenna elements <NUM> may include one or more sub-elements for radiating or receiving RF signals. For example, a single antenna element <NUM> may include a first sub-element cross-polarized with a second sub-element that can be used to independently transmit cross-polarized signals. The antenna elements <NUM> may include patch antennas, dipole antennas, or other types of antennas arranged in a linear pattern, a two dimensional pattern, or another pattern. A spacing between antenna elements <NUM> may be such that signals with a desired wavelength transmitted separately by the antenna elements <NUM> may interact or interfere (e.g., to form a desired beam). For example, given an expected range of wavelengths or frequencies, the spacing may provide a quarter wavelength, half wavelength, or other fraction of a wavelength of spacing between neighboring antenna elements <NUM> to allow for interaction or interference of signals transmitted by the separate antenna elements <NUM> within that expected range.

The modem <NUM> processes and generates digital baseband signals and may also control operation of the DAC <NUM>, first and second mixers <NUM> and <NUM>, splitter <NUM>, first amplifiers <NUM>, phase shifters <NUM>, and/or the second amplifiers <NUM> to transmit signals via one or more or all of the antenna elements <NUM>. The modem <NUM> may process signals and control operation in accordance with a communication standard such as a wireless standard discussed herein. The DAC <NUM> may convert digital baseband signals received from the modem <NUM> (and that are to be transmitted) into analog baseband signals. The first mixer <NUM> upconverts analog baseband signals to analog IF signals within an IF using a local oscillator A <NUM>. For example, the first mixer <NUM> may mix the signals with an oscillating signal generated by the local oscillator A <NUM> to "move" the baseband analog signals to the IF. In some cases, some processing or filtering (not shown) may take place at the IF. The second mixer <NUM> upconverts the analog IF signals to analog RF signals using the local oscillator B <NUM>. Similar to the first mixer, the second mixer <NUM> may mix the signals with an oscillating signal generated by the local oscillator B <NUM> to "move" the IF analog signals to the RF or the frequency at which signals will be transmitted or received. The modem <NUM> and/or the controller/processor <NUM> may adjust the frequency of local oscillator A <NUM> and/or the local oscillator B <NUM> so that a desired IF and/or RF frequency is produced and used to facilitate processing and transmission of a signal within a desired bandwidth.

In the illustrated architecture <NUM>, signals upconverted by the second mixer <NUM> are split or duplicated into multiple signals by the splitter <NUM>. The splitter <NUM> in architecture <NUM> splits the RF signal into multiple identical or nearly identical RF signals. In other examples, the split may take place with any type of signal, including with baseband digital, baseband analog, or IF analog signals. Each of these signals may correspond to an antenna element <NUM>, and the signal travels through and is processed by amplifiers <NUM> and <NUM>, phase shifters <NUM>, and/or other elements corresponding to the respective antenna element <NUM> to be provided to and transmitted by the corresponding antenna element <NUM> of the antenna array <NUM>. In one example, the splitter <NUM> may be an active splitter that is connected to a power supply and provides some gain so that RF signals exiting the splitter <NUM> are at a power level equal to or greater than the signal entering the splitter <NUM>. In another example, the splitter <NUM> is a passive splitter that is not connected to power supply and the RF signals exiting the splitter <NUM> may be at a power level lower than the RF signal entering the splitter <NUM>.

After being split by the splitter <NUM>, the resulting RF signals may enter an amplifier, such as a first amplifier <NUM>, or a phase shifter <NUM> corresponding to an antenna element <NUM>. The first and second amplifiers <NUM> and <NUM> are illustrated with dashed lines because one or both of them might not be necessary in some aspects. In some aspects, both the first amplifier <NUM> and second amplifier <NUM> are present. In some aspects, neither the first amplifier <NUM> nor the second amplifier <NUM> is present. In some aspects, one of the two amplifiers <NUM> and <NUM> is present but not the other. By way of example, if the splitter <NUM> is an active splitter, the first amplifier <NUM> may not be used. By way of further example, if the phase shifter <NUM> is an active phase shifter that can provide a gain, the second amplifier <NUM> might not be used.

The amplifiers <NUM> and <NUM> may provide a desired level of positive or negative gain. A positive gain (positive dB) may be used to increase an amplitude of a signal for radiation by a specific antenna element <NUM>. A negative gain (negative dB) may be used to decrease an amplitude and/or suppress radiation of the signal by a specific antenna element. Each of the amplifiers <NUM> and <NUM> may be controlled independently (e.g., by the modem <NUM> or the controller/processor <NUM>) to provide independent control of the gain for each antenna element <NUM>. For example, the modem <NUM> and/or the controller/processor <NUM> may have at least one control line connected to each of the splitter <NUM>, first amplifiers <NUM>, phase shifters <NUM>, and/or second amplifiers <NUM> that may be used to configure a gain to provide a desired amount of gain for each component and thus each antenna element <NUM>.

The phase shifter <NUM> may provide a configurable phase shift or phase offset to a corresponding RF signal to be transmitted. The phase shifter <NUM> may be a passive phase shifter not directly connected to a power supply. Passive phase shifters might introduce some insertion loss. The second amplifier <NUM> may boost the signal to compensate for the insertion loss. The phase shifter <NUM> may be an active phase shifter connected to a power supply such that the active phase shifter provides some amount of gain or prevents insertion loss. The settings of each of the phase shifters <NUM> are independent, meaning that each can be independently set to provide a desired amount of phase shift or the same amount of phase shift or some other configuration. The modem <NUM> and/or the controller/processor <NUM> may have at least one control line connected to each of the phase shifters <NUM> and which may be used to configure the phase shifters <NUM> to provide a desired amount of phase shift or phase offset between antenna elements <NUM>.

In the illustrated architecture <NUM>, RF signals received by the antenna elements <NUM> are provided to one or more first amplifiers <NUM> to boost the signal strength. The first amplifiers <NUM> may be connected to the same antenna arrays <NUM> (e.g., for time division duplex (TDD) operations). The first amplifiers <NUM> may be connected to different antenna arrays <NUM>. The boosted RF signal is input into one or more phase shifters <NUM> to provide a configurable phase shift or phase offset for the corresponding received RF signal to enable reception via one or more Rx beams. The phase shifter <NUM> may be an active phase shifter or a passive phase shifter. The settings of the phase shifters <NUM> are independent, meaning that each can be independently set to provide a desired amount of phase shift or the same amount of phase shift or some other configuration. The modem <NUM> and/or the controller/processor <NUM> may have at least one control line connected to each of the phase shifters <NUM> and which may be used to configure the phase shifters <NUM> to provide a desired amount of phase shift or phase offset between antenna elements <NUM> to enable reception via one or more Rx beams.

The outputs of the phase shifters <NUM> may be input to one or more second amplifiers <NUM> for signal amplification of the phase shifted received RF signals. The second amplifiers <NUM> may be individually configured to provide a configured amount of gain. The second amplifiers <NUM> may be individually configured to provide an amount of gain to ensure that the signals input to combiner <NUM> have the same magnitude. The amplifiers <NUM> and/or <NUM> are illustrated in dashed lines because they might not be necessary in some aspects. In some aspects, both the amplifier <NUM> and the amplifier <NUM> are present. In another aspect, neither the amplifier <NUM> nor the amplifier <NUM> are present. In other aspects, one of the amplifiers <NUM> and <NUM> is present but not the other.

In the illustrated architecture <NUM>, signals output by the phase shifters <NUM> (via the amplifiers <NUM> when present) are combined in combiner <NUM>. The combiner <NUM> in architecture <NUM> combines the RF signal into a signal. The combiner <NUM> may be a passive combiner (e.g., not connected to a power source), which may result in some insertion loss. The combiner <NUM> may be an active combiner (e.g., connected to a power source), which may result in some signal gain. When combiner <NUM> is an active combiner, it may provide a different (e.g., configurable) amount of gain for each input signal so that the input signals have the same magnitude when they are combined. When combiner <NUM> is an active combiner, the combiner <NUM> may not need the second amplifier <NUM> because the active combiner may provide the signal amplification.

The output of the combiner <NUM> is input into mixers <NUM> and <NUM>. Mixers <NUM> and <NUM> generally down convert the received RF signal using inputs from local oscillators <NUM> and <NUM>, respectively, to create intermediate or baseband signals that carry the encoded and modulated information. The output of the mixers <NUM> and <NUM> are input into an analog-to-digital converter (ADC) <NUM> for conversion to analog signals. The analog signals output from ADC <NUM> is input to modem <NUM> for baseband processing, such as decoding, de-interleaving, or similar operations.

The architecture <NUM> is given by way of example only to illustrate an architecture for transmitting and/or receiving signals. In some cases, the architecture <NUM> and/or each portion of the architecture <NUM> may be repeated multiple times within an architecture to accommodate or provide an arbitrary number of RF chains, antenna elements, and/or antenna panels. Furthermore, numerous alternate architectures are possible and contemplated. For example, although only a single antenna array <NUM> is shown, two, three, or more antenna arrays may be included, each with one or more of their own corresponding amplifiers, phase shifters, splitters, mixers, DACs, ADCs, and/or modems. For example, a single UE may include two, four, or more antenna arrays for transmitting or receiving signals at different physical locations on the UE or in different directions.

Furthermore, mixers, splitters, amplifiers, phase shifters and other components may be located in different signal type areas (e.g., represented by different ones of the reference numbers <NUM>, <NUM>, <NUM>, and <NUM>) in different implemented architectures. For example, a split of the signal to be transmitted into multiple signals may take place at the analog RF, analog IF, analog baseband, or digital baseband frequencies in different examples. Similarly, amplification and/or phase shifts may also take place at different frequencies. For example, in some aspects, one or more of the splitter <NUM>, amplifiers <NUM> and <NUM>, or phase shifters <NUM> may be located between the DAC <NUM> and the first mixer <NUM> or between the first mixer <NUM> and the second mixer <NUM>. In one example, the functions of one or more of the components may be combined into one component. For example, the phase shifters <NUM> may perform amplification to include or replace the first amplifiers <NUM> and/or the second amplifiers <NUM>. By way of another example, a phase shift may be implemented by the second mixer <NUM> to obviate the need for a separate phase shifter <NUM>. This technique is sometimes called local oscillator (LO) phase shifting. In some aspects of this configuration, there may be multiple IF to RF mixers (e.g., for each antenna element chain) within the second mixer <NUM>, and the local oscillator B <NUM> may supply different local oscillator signals (with different phase offsets) to each IF to RF mixer.

The modem <NUM> and/or the controller/processor <NUM> may control one or more of the other components <NUM> through <NUM> to select one or more antenna elements <NUM> and/or to form beams for transmission of one or more signals. For example, the antenna elements <NUM> may be individually selected or deselected for transmission of a signal (or signals) by controlling an amplitude of one or more corresponding amplifiers, such as the first amplifiers <NUM> and/or the second amplifiers <NUM>. Beamforming includes generation of a beam using multiple signals on different antenna elements, where one or more or all of the multiple signals are shifted in phase relative to each other. The formed beam may carry physical or higher layer reference signals or information. As each signal of the multiple signals is radiated from a respective antenna element <NUM>, the radiated signals interact, interfere (constructive and destructive interference), and amplify each other to form a resulting beam. The shape (such as the amplitude, width, and/or presence of side lobes) and the direction (such as an angle of the beam relative to a surface of the antenna array <NUM>) can be dynamically controlled by modifying the phase shifts or phase offsets imparted by the phase shifters <NUM> and amplitudes imparted by the amplifiers <NUM> and <NUM> of the multiple signals relative to each other. The controller/processor <NUM> may be located partially or fully within one or more other components of the architecture <NUM>. For example, the controller/processor <NUM> may be located within the modem <NUM> in some aspects.

In some aspects, the beamforming architecture <NUM> may include additional components, such as dielectric walls and/or other components that assist in constructive and destructive interferences that contribute to formation of beams.

<FIG> is a diagram illustrating an example <NUM> of a synchronization signal (SS) hierarchy, in accordance with the present disclosure. As shown in <FIG>, the SS hierarchy may include an SS burst set <NUM>, which may include multiple SS bursts <NUM>, shown as SS burst <NUM> through SS burst N-<NUM>, where N is a maximum number of repetitions of the SS burst <NUM> that may be transmitted by the base station. As further shown, each SS burst <NUM> may include one or more SS blocks (SSBs) <NUM>, shown as SSB <NUM> through SSB M-<NUM>, where M is a maximum number of SSBs <NUM> that can be carried by an SS burst <NUM>. In some aspects, different SSBs <NUM> may be beam-formed differently (e.g., transmitted using different beams), and may be used for cell search, cell acquisition, beam management, and/or beam selection (e.g., as part of an initial network access procedure). An SS burst set <NUM> may be periodically transmitted by a wireless node (e.g., base station <NUM>), such as every X milliseconds, as shown in <FIG>. In some aspects, an SS burst set <NUM> may have a fixed or dynamic length, shown as Y milliseconds in <FIG>. In some cases, an SS burst set <NUM> or an SS burst <NUM> may be referred to as a discovery reference signal (DRS) transmission window or an SSB measurement time configuration (SMTC) window.

In some aspects, an SSB <NUM> may include resources that carry a PSS <NUM>, an SSS <NUM>, and/or a physical broadcast channel (PBCH) <NUM>. In some aspects, multiple SSBs <NUM> are included in an SS burst <NUM> (e.g., with transmission on different beams), and the PSS <NUM>, the SSS <NUM>, and/or the PBCH <NUM> may be the same across each SSB <NUM> of the SS burst <NUM>. In some aspects, a single SSB <NUM> may be included in an SS burst <NUM>. In some aspects, the SSB <NUM> may be at least four symbols (e.g., OFDM symbols) in length, where each symbol carries one or more of the PSS <NUM> (e.g., occupying one symbol), the SSS <NUM> (e.g., occupying one symbol), and/or the PBCH <NUM> (e.g., occupying two symbols). In some aspects, an SSB <NUM> may be referred to as an SS/PBCH block.

In some aspects, the symbols of an SSB <NUM> are consecutive, as shown in <FIG>. In some aspects, the symbols of an SSB <NUM> are non-consecutive. Similarly, in some aspects, one or more SSBs <NUM> of the SS burst <NUM> may be transmitted in consecutive radio resources (e.g., consecutive symbols) during one or more slots. Additionally, or alternatively, one or more SSBs <NUM> of the SS burst <NUM> may be transmitted in non-consecutive radio resources.

In some aspects, the SS bursts <NUM> may have a burst period, and the SSBs <NUM> of the SS burst <NUM> may be transmitted by a wireless node (e.g., base station <NUM>) according to the burst period. In this case, the SSBs <NUM> may be repeated during each SS burst <NUM>. In some aspects, the SS burst set <NUM> may have a burst set periodicity, whereby the SS bursts <NUM> of the SS burst set <NUM> are transmitted by the wireless node according to the fixed burst set periodicity. In other words, the SS bursts <NUM> may be repeated during each SS burst set <NUM>.

In some aspects, an SSB <NUM> may include an SSB index, which may correspond to a beam used to carry the SSB <NUM>. A UE <NUM> may monitor for and/or measure SSBs <NUM> using different receive (Rx) beams during an initial network access procedure and/or a cell search procedure, among other examples. Based at least in part on the monitoring and/or measuring, the UE <NUM> may indicate one or more SSBs <NUM> with a best signal parameter (e.g., an RSRP parameter) to a base station <NUM>. The base station <NUM> and the UE <NUM> may use the one or more indicated SSBs <NUM> to select one or more beams to be used for communication between the base station <NUM> and the UE <NUM> (e.g., for a random access channel (RACH) procedure). Additionally, or alternatively, the UE <NUM> may use the SSB <NUM> and/or the SSB index to determine a cell timing for a cell via which the SSB <NUM> is received (e.g., a serving cell).

In some aspects, the PBCH may include a DMRS and/or a payload including a master information block (MIB).

<FIG> is a diagram illustrating an example of a four-step random access procedure, in accordance with the present disclosure. As shown in <FIG>, a base station <NUM> and a UE <NUM> may communicate with one another to perform the four-step random access procedure.

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

As shown by reference number <NUM>, the UE <NUM> may transmit a RAM, which may include a preamble (sometimes referred to as a random access preamble, a physical RACH (PRACH) preamble, or a RAM preamble). The message that includes the preamble may be referred to as a message <NUM>, msg1, MSG1, a first message, or an initial message in a four-step random access procedure. The random access message may include a random access preamble identifier.

As shown by reference number <NUM>, the base station <NUM> may transmit an RAR as a reply to the preamble. The message that includes the RAR may be referred to as message <NUM>, msg2, MSG2, or a second message in a four-step random access procedure. In some aspects, the RAR may indicate the detected random access preamble identifier (e.g., received from the UE <NUM> in msg1). Additionally, or alternatively, the RAR may indicate a resource allocation to be used by the UE <NUM> to transmit message <NUM> (msg3).

In some aspects, as part of the second step of the four-step random access procedure, the base station <NUM> may transmit a PDCCH communication for the RAR. The PDCCH communication may schedule a physical downlink shared channel (PDSCH) communication that includes the RAR. For example, the PDCCH communication may indicate a resource allocation for the PDSCH communication. Also, as part of the second step of the four-step random access procedure, the base station <NUM> may transmit the PDSCH communication for the RAR, as scheduled by the PDCCH communication. The RAR may be included in a medium access control (MAC) protocol data unit (PDU) of the PDSCH communication.

As shown by reference number <NUM>, the UE <NUM> may transmit an RRC connection request message. The RRC connection request message may be referred to as message <NUM>, msg3, MSG3, or a third message of a four-step random access procedure. In some aspects, the RRC connection request may include a UE identifier, uplink control information (UCI), and/or a physical uplink shared channel (PUSCH) communication (e.g., an RRC connection request).

As shown by reference number <NUM>, the base station <NUM> may transmit an RRC connection setup message. The RRC connection setup message may be referred to as message <NUM>, msg4, MSG4, or a fourth message of a four-step random access procedure. In some aspects, the RRC connection setup message may include the detected UE identifier, a timing advance value, and/or contention resolution information. As shown by reference number <NUM>, if the UE <NUM> successfully receives the RRC connection setup message, the UE <NUM> may transmit a hybrid automatic repeat request (HARQ) acknowledgement (ACK).

In some aspects, other examples may use a two-step random access procedure.

A UE and/or a base station may perform beamforming (e.g., using hardware as described in connection with <FIG>) when wirelessly communicating. In some situations, the UE and/or the base station may experience reduced signal power when using mmW and/or other radio frequencies (e.g., FR2 and/or other frequencies). Accordingly, the UE and/or the base station may perform beam refinement, in which the UE and/or the base station selects a subbeam within a selected beam (e.g., a narrower subbeam within the selected beam), in order to increase signal power. The UE and/or the base station may perform beam refinement for transmissions (e.g., by selecting a subbeam that can be transmitted at higher power) and/or for receptions (e.g., by selecting a reception filter that is narrower than a reception filter used to receive transmissions on the selected beam).

Some techniques and apparatuses described herein allow a base station (e.g., base station <NUM>) to configure a set of random access occasions for a UE (e.g., UE <NUM>) into a plurality of subsets such that each subset of random access occasions is associated with a corresponding beam. Each corresponding beam is also different from remaining beams of the plurality of beams. Accordingly, the UE <NUM> may perform beam refinement (e.g., by selecting a subbeam that can be transmitted at higher power) across subsets. The UE <NUM> may therefore increase reliability and quality of transmissions to the base station <NUM>. Additionally, or alternatively, the base station <NUM> may perform beam refinement (e.g., by selecting a reception filter that is narrower) within subsets. The base station <NUM> may perform accurate beam refinement because the UE <NUM> transmits within each subset using the same corresponding beam. The base station <NUM> may therefore increase reliability and quality of receptions at the base station <NUM>.

<FIG> is a diagram illustrating an example <NUM> associated with random access occasion bundling, in accordance with the present disclosure. As shown in <FIG>, example <NUM> includes a set of random access occasions 605a, 605b, 605c, and 605d (also referred to as "ROs"). A random access occasion may comprise one or more resources in time (e.g., one or more symbols across one or more slots of one or more radio frames) during which a UE (e.g., UE <NUM>) may transmit a random access preamble (e.g., as described in connection with <FIG>) to a base station (e.g., base station <NUM>). In some aspects, the set may include at least two random access occasions.

In some aspects, the set may be periodic. For example, the set may include one or more random access occasions that repeat in time according to one or more periodicities. In some aspects, the set may be periodic without end (e.g., until the base station <NUM> reconfigures the set, such as with an RRC message). As an alternative, the set may end after one of the random access occasions or after a quantity of periods have occurred. In some aspects, the set may include a finite number of random access occasions that are not periodic.

As further shown in <FIG>, the set of random access occasions is divided into a plurality of subsets (also referred to as "RO bundles"). For example, the base station <NUM> may transmit, and the UE <NUM> may receive, a message indicating the plurality of subsets. In some aspects, the message may include an RRC message, a remaining minimum system information (RMSI) message, and/or another message. Each subset of the plurality of subsets may be associated with a corresponding beam (e.g., formed using hardware as described in connection with <FIG>) of a plurality of beams, and each corresponding beam is different from remaining beams of the plurality of beams. In example <NUM>, a first subset ("RO bundle <NUM>") is associated with beam 610a, and a second subset ("RO bundle <NUM>") is associated with beam 610b. Each subset of the plurality of subsets is associated with a corresponding synchronization signal (e.g., an SSB as described in connection with <FIG>) of a plurality of synchronization signals, and each corresponding synchronization signal is different from remaining synchronization signals of the plurality of synchronization signals. In some aspects, each synchronization signal of the plurality of synchronization signals may be associated with a corresponding beam of the plurality of beams, and each corresponding beam may be different from remaining beams of the plurality of beams. Accordingly, the UE <NUM> may select one of the plurality of beams by, for example, selecting a corresponding one of the plurality of synchronization signals.

In some aspects, the plurality of subsets may be distinct from one or more subsets associated with legacy UEs. For example, the legacy UEs may include one or more UEs that are not configured for bundling random access occasions (e.g., as described above), that do not include hardware for beamforming (e.g., as described in connection with <FIG>), and/or are otherwise not configured to perform (e.g., not programmed to perform and/or do not include hardware capable of performing) beam refinement.

In some aspects, each subset of the plurality of subsets may be associated with a corresponding beam of the plurality of beams according to a rule stored in a memory of the UE <NUM> and/or the base station <NUM>. For example, the rule may be set forth in 3GPP specifications and/or another standard. Additionally, or alternatively, each subset of the plurality of subsets may be associated with a corresponding beam of the plurality of beams according to a rule indicated by the message from the base station <NUM>. For example, a set of random access occasions may be divided into subsets, where each subset includes a quantity of consecutive random access occasions that can be represented by a variable k, where the variable is indicated by the message. In one example, when the set of random access occasions includes six random access occasions, the base station <NUM> may indicate that k = <NUM> such that the set is divided into three subsets, where each subset includes two random access occasions that are consecutive in time. In another example, when the set of random access occasions includes six random access occasions that repeated in time according to a periodicity, the base station <NUM> may indicate that k = <NUM> such that the set is divided into two subsets, where each subset includes three random access occasions that are consecutive in time, and the subsets repeat in time according to the periodicity.

Based at least in part on the message from the base station <NUM>, the UE <NUM> may transmit at least one random access preamble within one or more subsets, of the plurality of subsets, using one or more corresponding beams of the plurality of beams. Accordingly, the UE <NUM> may select a beam to form (e.g., using hardware as described in connection with <FIG>), for transmitting a random access preamble, based at least in part on which subset, of the plurality of subsets, within which the UE <NUM> transmits the random access preamble.

The UE transmits a plurality of random access preambles across random access occasions that are included within one subset, of the plurality of subsets. The plurality of random access preambles may be duplicates of a same random access preamble or otherwise associated with each other (e.g., each random access preamble including one or more portions of data that link the preamble to remaining preambles of the plurality of random access preambles). Accordingly, the base station <NUM> may perform beam refinement (e.g., by narrowing a reception filter) based at least in part on the plurality of random access preambles transmitted within one subset. The base station <NUM> may perform the refinement because the UE <NUM> will transmit the plurality of random access preambles using a same beam that corresponds to the one subset. For example, as shown in <FIG>, the UE <NUM> transmits random access preambles in random access occasions 605a and 605b with the same beam 610a. In some aspects, the UE <NUM> may transmit the plurality of random access preambles, across random access occasions that are included within the one subset, based at least in part on an indication, from the base station <NUM>, to repeat transmissions. The indication may be included in the message from the base station <NUM> or included in a separate message. Additionally, or alternatively, the indication may be included in an RRC message, RMSI, and/or another message.

Additionally, the UE <NUM> may transmit a plurality of random access preambles across random access occasions that are included in different subsets of the plurality of subsets. The plurality of random access preambles may be duplicates of a same random access preamble or otherwise associated with each other (e.g., each random access preamble including one or more portions of data that links the preamble to remaining preambles of the plurality of random access preamble). Accordingly, the UE <NUM> may perform beam refinement (e.g., by sweeping subbeams) based at least in part on the plurality of random access preambles transmitted across different subsets. The UE <NUM> may perform the refinement because the base station <NUM> is not expecting the UE <NUM> to transmit the plurality of random access preambles across different subsets using a same beam. For example, as shown in <FIG>, the UE <NUM> transmits random access preambles in random access occasions 605a and 605c (or in random access occasions 605b and 605d and/or another combination of random access occasions across subsets) using different beams (e.g., beams 610a and 610b, respectively).

In some aspects, a legacy UE may transmit, and the base station <NUM> may receive, an additional random access preamble. Accordingly, the base station <NUM> may receive from the UE <NUM> and the legacy UE using a combination of a subbeam, based at least in part on one or more corresponding beams used by the UE <NUM>, with a beam associated with the additional random access preamble. For example, the base station <NUM> may perform beam refinement (e.g., as described above), based at least in part on random access preambles transmitted by the UE <NUM>, to determine the subbeam to use for the UE <NUM>. The base station <NUM> may combine the determined subbeam with the beam used by the legacy UE to determine a reception filter to use such that the base station <NUM> can receive from both the UE <NUM> and the legacy UE.

By using techniques as described in connection with <FIG>, the UE <NUM> can perform beam refinement (e.g., by selecting a subbeam that can be transmitted at higher power) across subsets. The UE <NUM> therefore increases reliability and quality of transmissions to the base station <NUM>. Additionally, or alternatively, the base station <NUM> can perform beam refinement (e.g., by selecting a reception filter that is narrower) within subsets. The base station <NUM> therefore increases reliability and quality of receptions at the base station <NUM>.

In some aspects, other examples may include additional random access occasions (e.g., more than four) or fewer random access occasions (e.g., two or three). Additionally, or alternatively, other examples may also include additional subsets and thus additional corresponding beams (e.g., more than two).

<FIG> is a diagram illustrating an example <NUM> associated with random access occasion bundling, in accordance with the present disclosure. As shown in <FIG>, example <NUM> includes communication between a base station <NUM> and a UE <NUM>. In some aspects, the base station <NUM> and the UE <NUM> may be included in a wireless network, such as wireless network <NUM>.

In some aspects, as described in connection with <FIG>, the base station <NUM> may configure a set of random access occasions that are divided into a plurality of subsets (also referred to as "RO bundles"). For example, the base station <NUM> may transmit, and the UE <NUM> may receive, one or more messages (e.g., RRC messages, RMSI, and/or other messages) that indicate the set of random access occasions and the plurality of subsets. As further described in connection with <FIG>, each subset of the plurality of subsets may be associated with a corresponding beam (e.g., formed using hardware as described in connection with <FIG>) of a plurality of beams, and each corresponding beam may be different from remaining beams of the plurality of beams. Additionally, or alternatively, each subset of the plurality of subsets may be associated with a corresponding synchronization signal (e.g., an SSB as described in connection with <FIG>) of a plurality of synchronization signals, and each corresponding synchronization signal may be different from remaining synchronization signals of the plurality of synchronization signals. In some aspects, each synchronization signal of the plurality of synchronization signals may be associated with a corresponding beam of the plurality of beams, and each corresponding beam may be different from remaining beams of the plurality of beams. Accordingly, the UE <NUM> may select one of the plurality of beams by, for example, selecting a corresponding one of the plurality of synchronization signals.

As shown in connection with reference number <NUM>, the UE <NUM> may transmit, and the base station <NUM> may receive, a random access preamble in a random access occasion that is included within one subset (e.g., one "RO bundle"), of the plurality of subsets. The UE <NUM> may transmit the random access preamble using the corresponding beam for that subset.

As shown in connection with reference number <NUM>, the base station <NUM> may perform beam refinement. For example, the base station <NUM> may narrow or otherwise adjust a reception filter. The base station <NUM> may perform the refinement because the UE <NUM> may transmit additional random access preambles in the one subset (e.g., as described in connection with reference number <NUM>) using a same beam that corresponds to the one subset.

As shown in connection with reference number <NUM>, the UE <NUM> may transmit, and the base station <NUM> may receive, another random access preamble in another random access occasion that is included within the one subset (e.g., one "RO bundle"), of the plurality of subsets. The UE <NUM> may transmit the additional random access preamble using the corresponding beam for that subset. In some aspects, the random access preamble and the additional random access preamble may be duplicates of a same random access preamble or otherwise associated with each other (e.g., the random access preamble including one or more portions of data that links the preamble to the additional random access preamble and/or the additional random access preamble including one or more portions of data that links the additional preamble to the random access preamble).

In some aspects, the UE <NUM> may transmit the additional random access preamble based at least in part on an indication, from the base station <NUM>, to repeat transmissions. The indication may be included in the one or more messages used to configure the set of random access occasions and the plurality of subsets or may be included in a separate message. Additionally, or alternatively, the indication may be included in an RRC message, RMSI, and/or another message.

As shown in connection with reference number <NUM>, the UE <NUM> may perform beam refinement. For example, the UE <NUM> may narrow or otherwise adjust a beam used for transmitting to the base station <NUM>. The UE <NUM> may perform the refinement because the base station <NUM> is not expecting the UE <NUM> to transmit random access preambles across different subsets using a same beam.

As shown in connection with reference number <NUM>, the UE <NUM> may transmit, and the base station <NUM> may receive, a random access preamble in a random access occasion that is included within another subset (e.g., another "RO bundle"), of the plurality of subsets. The UE <NUM> may transmit the random access preamble using the corresponding beam for that subset.

As shown in connection with reference number <NUM>, the base station <NUM> may perform beam refinement. For example, the base station <NUM> may narrow or otherwise adjust a reception filter. The base station <NUM> may perform the refinement because the UE <NUM> may transmit additional random access preambles in the same subset (e.g., as described below in connection with reference number <NUM>) using a same beam that corresponds to that subset.

As shown in connection with reference number <NUM>, the UE <NUM> may transmit, and the base station <NUM> may receive, another random access preamble in another random access occasion that is included within the same subset (e.g., the same "RO bundle"), of the plurality of subsets. The UE <NUM> may transmit the additional random access preamble using the corresponding beam for that subset. In some aspects, the random access preamble and the additional random access preamble may be duplicates of a same random access preamble or otherwise associated with each other (e.g., the random access preamble including one or more portions of data that links the preamble to the additional random access preamble and/or the additional random access preamble including one or more portions of data that links the additional preamble to the random access preamble).

The UE <NUM> may perform additional beam refinement across additional subsets when the plurality of subsets include more than two subsets. Additionally, or alternatively, the base station <NUM> may perform additional beam refinement within subsets when the subsets include more than two random access occasions.

In some aspects, the base station <NUM> may further transmit, and the UE <NUM> may receive, a random access response (e.g., as described in connection with <FIG>). In some aspects, the random access response may indicate a beam, of the one or more corresponding beams, to use.

Additionally, in some aspects, the UE <NUM> may further transmit, and the base station <NUM> may receive, an additional random access message (e.g., a msg3 as described in connection with <FIG>). In some aspects, the UE <NUM> may transmit the additional random access message using a same beam as a beam used for one or more random access preambles. For example, the UE <NUM> may have transmitted random access preambles within one subset such that the UE <NUM> selects the corresponding beam for that subset. As an alternative, the UE <NUM> may transmit the additional random access message using a beam indicated by the random access response (e.g., as described above). For example, the UE <NUM> may have transmitted random access preambles across subsets such that the base station <NUM> indicates which beam, of the corresponding beams for those subsets, to use.

By using techniques as described in connection with <FIG>, the UE <NUM> can increase reliability and quality of transmissions to the base station <NUM>. Additionally, or alternatively, the base station <NUM> can increase reliability and quality of receptions at the base station <NUM>.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a UE, in accordance with the present disclosure. Example process <NUM> is an example where the UE (e.g., UE <NUM> and/or apparatus <NUM> of <FIG>) performs operations associated with random access occasion bundling.

As shown in <FIG>, in some aspects, process <NUM> may include receiving, from a base station (e.g., base station <NUM> and/or apparatus <NUM> of <FIG>), a message that indicates a plurality of subsets within a set of random access occasions (block <NUM>). For example, the UE (e.g., using reception component <NUM>, depicted in <FIG>) may receive, from a base station, a message that indicates a plurality of subsets within a set of random access occasions, as described herein. In some aspects, each subset of the plurality of subsets is associated with a corresponding beam of a plurality of beams, and each corresponding beam is different from remaining beams of the plurality of beams.

As further shown in <FIG>, in some aspects, process <NUM> may include transmitting, to the base station and based at least in part on the message, at least one random access preamble (block <NUM>). For example, the UE (e.g., using transmission component <NUM>, depicted in <FIG>) may transmit, to the base station and based at least in part on the message, at least one random access preamble, as described herein. In some aspects, the at least one random access preamble is transmitted within one or more subsets, of the plurality of subsets, using one or more corresponding beams of the plurality of beams.

In a first aspect, each subset of the plurality of subsets is associated with a corresponding beam of the plurality of beams according to a rule stored in the UE.

In a second aspect, alone or in combination with the first aspect, each subset of the plurality of subsets is associated with a corresponding beam of the plurality of beams according to a rule indicated by the message.

In a third aspect, alone or in combination with one or more of the first and second aspects, transmitting the at least one random access preamble includes transmitting a plurality of random access preambles across random access occasions that are included within one subset, of the plurality of subsets.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the plurality of random access preambles are duplicates of a same random access preamble.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the plurality of random access preambles are associated with each other.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, process <NUM> further includes receiving (e.g., using reception component <NUM>), from the base station, an indication to repeat transmissions across random access occasions included within one of the plurality of subsets, such that the plurality of random access preambles are transmitted based at least in part on receiving the indication.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the indication is included within RMSI received from the base station.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, transmitting the at least one random access preamble includes transmitting a plurality of random access preambles across random access occasions that are included in different subsets of the plurality of subsets.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, process <NUM> further includes transmitting (e.g., using transmission component <NUM>), to the base station, an additional random access message, where transmitting the at least one random access preamble includes transmitting one or more random access preambles across random access occasions that are included within one subset, of the plurality of subsets, and the additional random access message is transmitted using a same beam as a beam used for the one or more random access preambles.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, process <NUM> further includes receiving (e.g., using reception component <NUM>), from the base station, a response to the at least one random access preamble, and transmitting (e.g., using transmission component <NUM>), to the base station, an additional random access message, the additional random access message being transmitted using a beam, of the one or more corresponding beams, indicated by the response to the at least one random access preamble.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the plurality of subsets are distinct from one or more subsets associated with legacy UEs.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a base station, in accordance with the present disclosure. Example process <NUM> is an example where the base station (e.g., base station <NUM> and/or apparatus <NUM> of <FIG>) performs operations associated with random access occasion bundling.

As shown in <FIG>, in some aspects, process <NUM> may include transmitting, to a UE (e.g., UE <NUM> and/or apparatus <NUM> of <FIG>), a message that indicates a plurality of subsets within a set of random access occasions (block <NUM>). For example, the base station (e.g., using transmission component <NUM>, depicted in <FIG>) may transmit, to a UE, a message that indicates a plurality of subsets within a set of random access occasions, as described herein. In some aspects, each subset of the plurality of subsets is associated with a corresponding beam of a plurality of beams, and each corresponding beam is different from remaining beams of the plurality of beams.

As further shown in <FIG>, in some aspects, process <NUM> may include receiving, from the UE and based at least in part on the message, at least one random access preamble (block <NUM>). For example, the base station (e.g., using reception component <NUM>, depicted in <FIG>) may receive, from the UE and based at least in part on the message, at least one random access preamble, as described herein. In some aspects, the at least one random access preamble is received within one or more subsets, of the plurality of subsets, using one or more corresponding beams of the plurality of beams.

In a first aspect, each subset of the plurality of subsets is associated with a corresponding beam of the plurality of beams according to a rule stored in the base station.

In a third aspect, alone or in combination with one or more of the first and second aspects, receiving the at least one random access preamble includes receiving a plurality of random access preambles across random access occasions that are included within one subset, of the plurality of subsets.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, process <NUM> further includes transmitting (e.g., using transmission component <NUM>), to the UE, an indication to repeat transmissions across random access occasions included within one of the plurality of subsets, such that the plurality of random access preambles are received based at least in part on transmitting the indication.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the indication is included within RMSI transmitted to the UE.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, receiving the at least one random access preamble includes receiving a plurality of random access preambles across random access occasions that are included in different subsets of the plurality of subsets.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, process <NUM> further includes receiving (e.g., using reception component <NUM>), from the UE, an additional random access message, where receiving the at least one random access preamble includes receiving one or more random access preambles across random access occasions that are included within one subset, of the plurality of subsets, and the additional random access message is received using a same beam as a beam used for the one or more random access preambles.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, process <NUM> further includes transmitting (e.g., using transmission component <NUM>), to the UE, a response to the at least one random access preamble, and receiving (e.g., using reception component <NUM>), from the UE, an additional random access message, the additional random access message being received using a beam, of the one or more corresponding beams, indicated by the response to the at least one random access preamble.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, process <NUM> further includes receiving (e.g., using reception component <NUM>), from a legacy UE, an additional random access preamble, the additional random access preamble being associated with a beam, and the at least one random access preamble and the additional random access preamble being received using a combination of a subbeam, based at least in part on the one or more corresponding beams, with the beam associated with the additional random access preamble.

<FIG> is a block diagram of an example apparatus <NUM> for wireless communication. The apparatus <NUM> may be a UE, or a UE may include the apparatus <NUM>. In some aspects, the apparatus <NUM> includes a reception component <NUM> and a transmission component <NUM>, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus <NUM> may communicate with another apparatus <NUM> (such as a UE, a base station, or another wireless communication device) using the reception component <NUM> and the transmission component <NUM>. As further shown, the apparatus <NUM> may include a random access message component <NUM>, among other examples.

In some aspects, the apparatus <NUM> may be configured to perform one or more operations described herein in connection with <FIG>. Additionally, or alternatively, the apparatus <NUM> may be configured to perform one or more processes described herein, such as process <NUM> of <FIG>, or a combination thereof. In some aspects, the apparatus <NUM> and/or one or more components shown in <FIG> may include one or more components of the UE described above in connection with <FIG>. Additionally, or alternatively, one or more components shown in <FIG> may be implemented within one or more components described above in connection with <FIG>. Additionally, or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

In some aspects, the reception component <NUM> may receive, from the apparatus <NUM>, a message that indicates a plurality of subsets within a set of random access occasions. Each subset of the plurality of subsets may be associated with a corresponding beam of a plurality of beams, and each corresponding beam may be different from remaining beams of the plurality of beams. Accordingly, the transmission component <NUM> may transmit, to the apparatus <NUM> and based at least in part on the message, at least one random access preamble. For example, the random access message component <NUM> may encode the at least one random access preamble for the transmission component <NUM> to transmit. In some aspects, the random access message component <NUM> may include a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection with <FIG>. The transmission component <NUM> may transmit the at least one random access preamble within one or more subsets, of the plurality of subsets, using one or more corresponding beams of the plurality of beams.

In some aspects, the reception component <NUM> may further receive, from the apparatus <NUM>, an indication to repeat transmissions across random access occasions included within one of the plurality of subsets. Accordingly, the transmission component <NUM> may transmit a plurality of random access preambles, across the random access occasions included within the one subset, based at least in part on the reception component <NUM> receiving the indication. Additionally, or alternatively, the transmission component <NUM> may transmit a plurality of random access preambles across random access occasions included within different subsets.

In some aspects, the reception component <NUM> may receive, from the apparatus <NUM>, a response to the at least one random access preamble. In some aspects, the transmission component <NUM> may transmit, to the apparatus <NUM>, an additional random access message. The transmission component <NUM> may transmit the additional random access message using a same beam as a beam used for one or more random access preambles transmitted across random access occasions that are included within one subset, of the plurality of subsets. As an alternative, the transmission component <NUM> may transmit the additional random access message using a beam, of the one or more corresponding beams, indicated by the response to the at least one random access preamble.

<FIG> is a block diagram of an example apparatus <NUM> for wireless communication. The apparatus <NUM> may be a base station, or a base station may include the apparatus <NUM>. In some aspects, the apparatus <NUM> includes a reception component <NUM> and a transmission component <NUM>, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus <NUM> may communicate with another apparatus <NUM> (such as a UE, a base station, or another wireless communication device) using the reception component <NUM> and the transmission component <NUM>. As further shown, the apparatus <NUM> may include a random access response component <NUM>, among other examples.

In some aspects, the apparatus <NUM> may be configured to perform one or more operations described herein in connection with <FIG>. Additionally, or alternatively, the apparatus <NUM> may be configured to perform one or more processes described herein, such as process <NUM> of <FIG>, or a combination thereof. In some aspects, the apparatus <NUM> and/or one or more components shown in <FIG> may include one or more components of the base station described above in connection with <FIG>. Additionally, or alternatively, one or more components shown in <FIG> may be implemented within one or more components described above in connection with <FIG>. Additionally, or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

In some aspects, the reception component <NUM> may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with <FIG>.

In some aspects, the transmission component <NUM> may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with <FIG>.

In some aspects, the transmission component <NUM> may transmit, to the apparatus <NUM>, a message that indicates a plurality of subsets within a set of random access occasions. Each subset of the plurality of subsets may be associated with a corresponding beam of a plurality of beams, and each corresponding beam may be different from remaining beams of the plurality of beams. Accordingly, the reception component <NUM> may receive, from the apparatus <NUM> and based at least in part on the message, at least one random access preamble. The reception component <NUM> may receive the at least one random access preamble within one or more subsets, of the plurality of subsets, using one or more corresponding beams of the plurality of beams.

In some aspects, the transmission component <NUM> may transmit, to the apparatus <NUM>, an indication to repeat transmissions across random access occasions included within one of the plurality of subsets. Accordingly, the reception component <NUM> may receive the plurality of random access preambles, across the random access occasions included within the one subset, based at least in part on the transmission component <NUM> transmitting the indication. Additionally, or alternatively, the reception component <NUM> may receive a plurality of random access preambles across random access occasions included within different subsets.

In some aspects, the transmission component <NUM> may transmit, to the apparatus <NUM>, a response to the at least one random access preamble. For example, the random access response component <NUM> may encode the response for the transmission component <NUM> to transmit. In some aspects, the random access response component <NUM> may include a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with <FIG>.

In some aspects, the reception component <NUM> may receive, from the apparatus <NUM>, an additional random access message. The reception component <NUM> may receive the additional random access message using a same beam as a beam used for one or more random access preambles received across random access occasions that are included within one subset, of the plurality of subsets. As an alternative, the reception component <NUM> may receive the additional random access message using a beam, of the one or more corresponding beams, indicated by the response to the at least one random access preamble.

In some aspects, the reception component <NUM> may receive, from a legacy apparatus (e.g., a legacy UE), an additional random access preamble. Accordingly, the reception component <NUM> may receive the additional random access preamble and the at least one random access preamble using a combination of a subbeam, based at least in part on the one or more corresponding beams, with a beam associated with the additional random access preamble.

provides illustration and description but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed.

As used herein, a "processor" is implemented in hardware and/or a combination of hardware and software. Thus, the operation and behavior of the systems and/or methods are described herein without reference to specific software code, since those skilled in the art will understand that software and hardware can be designed to implement the systems and/or methods based, at least in part, on the description herein.

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

Many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. The disclosure of various aspects includes each dependent claim in combination with every other claim in the claim set. As an example, "at least one of: a, b, or c" is intended to cover a, b, c, a + b, a + c, b + c, and a + b + c, as well as any combination with multiples of the same element (e.g., a + a, a + a + a, a + a + b, a + a + c, a + b + b, a + c + c, b + b, b + b + b, b + b + c, c + c, and c + c + c, or any other ordering of a, b, and c).

Claim 1:
A method for wireless communication at a user equipment, UE, (<NUM>) comprising:
receiving, from a base station (<NUM>), a message that indicates a plurality of subsets within a set of random access occasions (605a, 605b, 605c, 605e), wherein each subset (605a, 605b; 605c, 605d) of the plurality of subsets is associated with a corresponding beam of a plurality of beams (<NUM>), wherein each corresponding beam is different from remaining beams of the plurality of beams (<NUM>), wherein each subset of the plurality of subsets is associated with a corresponding synchronization signal of a plurality of synchronization signals, wherein each corresponding synchronization signal is different from remaining synchronization signals of the plurality of synchronization signals;
transmitting, to the base station (<NUM>) and based at least in part on the message, at least one random access preamble, wherein the at least one random access preamble is transmitted within one or more subsets, of the plurality of subsets, using one or more corresponding beams of the plurality of beams (<NUM>); and
transmitting a plurality of random access preambles across random access occasions that are included within one subset of the plurality of subsets.