Patent Description:
<CIT> relates to mobile communications where a radio telephone handset communicates with a telephone network by two-way exchange of radio signals between the handset and a transceiver. <CIT> relates to a satellite trunked radio service system for satellite communication. <CIT> relates to a mobile satellite communication system configured to operate with standard mobile user equipment. <CIT> relates to system architectures and associated processes for providing high speed and high quality packet data services via a LEO/MEO satellite system.

In accordance with the invention and the independent claims, a method of wireless communication performed by a user equipment, a method of wireless communication performed by a base station, and an apparatus for each is provided. Further preferable aspects are provided in the dependent claims.

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

A non-terrestrial base station (referred to hereafter as a BS or a base station) may provide access to a non-terrestrial network for UEs or ground stations. As used herein, a ground station may refer to a radio station designed for communication with a non-terrestrial BS via a non-terrestrial network. A reference to a UE herein can also refer to a ground station. Furthermore, a reference to a BS can also refer to a relay station.

The BS may transmit beams using multiple antennas that each cover a surface area. The footprint of a beam transmitted by an antenna can be defined as a cell. A UE may acquire the BS based at least in part on searching for a synchronization signal using a spatial technique (e.g., by pointing a receive antenna beam towards the satellite), a frequency technique (e.g., by scanning different frequencies until the BS's signal is acquired), a timing technique (e.g., by searching for a starting time of a signal), a sequence-based technique (e.g., by identifying a code sequence of a synchronization signal), and/or the like. Examples of a synchronization signal include a synchronization signal block (SSB), a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), and/or the like.

Once the UE detects a beam, the UE and the BS may perform a random access channel (RACH) procedure, such as a physical RACH (PRACH) procedure, to access the network. In the RACH procedure, the UE may transmit a RACH preamble on a particular set of resources. A set of RACH resources may be associated with a RACH occasion. For example, a RACH occasion may correspond to one or more RACH resources for one or more beams. However, RACH resource and RACH occasion may be used interchangeably herein.

In a non-terrestrial network, PRACH preamble resources may be larger than in a terrestrial network, such as an LTE network or a <NUM>/NR terrestrial network. This may be due to non-terrestrial networks being associated with larger Doppler shifts (and thus a wider subcarrier spacing) and longer delays than a terrestrial network, which may necessitate a larger frequency allocation and a longer time allocation for the RACH preamble. Also, a larger number of UEs may be expected to perform handovers concurrently in a non-terrestrial network, particularly a non-terrestrial network in which the cells are in constant motion (e.g., when the cells are provided by a satellite in low earth orbit or mid earth orbit). Furthermore, the cell may be larger than a terrestrial network cell, which may mean that a larger number of UEs may be expected to perform RACH procedures on the cell. In such cases, it may be difficult for a BS to multiplex PRACH resources within the frequency region used for other channels (e.g., data channels, control channels, and/or the like), which may lead to fragmented data transmissions. Furthermore, to reduce the overhead associated with large numbers of UEs performing RACH procedures, it may be beneficial to multiplex RACH resources for some beams on the same time and/or frequency resources.

Some techniques and apparatuses described herein provide techniques for configuring RACH occasions of multiple beams in a non-terrestrial network. For example, some techniques and apparatuses described herein provide for the configuration of multiple RACH resources to be provided in respective frequency regions of corresponding beams, thereby reducing frequency retune disruptions and reducing impact on overall operating bandwidth. As another example, some techniques and apparatuses described herein provide the configuration of RACH resources on a bandwidth part or subband that does not overlap frequency regions of the respective beams, or on a frequency region of a beam of the respective beams, or on a combination thereof. These options are described in more detail elsewhere herein. Furthermore, some techniques and apparatuses described herein provide guard periods for a RACH procedure when the RACH resource is in a different subband or frequency region than a beam's frequency region. Even further, some techniques and apparatuses described herein provide multiplexing of RACH resources, thereby conserving air interface resources. Thus, efficiency of resource utilization is improved and data transmission continuity is improved.

In some aspects, as shown, a cell may be provided by a base station <NUM> of a non-terrestrial network. As used herein, a non-terrestrial network may refer to a network for which access is provided by a non-terrestrial base station, such as a base station carried by a satellite, a balloon, a dirigible, an airplane, an unmanned aerial vehicle, a high altitude platform station, and/or the like.

A relay station may also be referred to as a relay BS, a relay base station, a relay, and/or the like In some aspects, a relay station may be implemented using a non-terrestrial platform, similarly to the base station described above.

Wireless network <NUM> may be a heterogeneous network that includes BSs of different types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/or the like These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in wireless network <NUM>.

A UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, and/or the like A UE 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 or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.

A RAT may also be referred to as a radio technology, an air interface, and/or the like A frequency may also be referred to as a carrier, a frequency channel, and/or the like Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs.

Transmit processor <NUM> may also process system information (e.g., for semi-static resource partitioning information (SRPI), and/or the like) and control information (e.g., CQI requests, grants, upper layer signaling, and/or the like) and provide overhead symbols and control symbols. Each modulator <NUM> may process a respective output symbol stream (e.g., for OFDM, and/or the like) to obtain an output sample stream.

Each demodulator <NUM> may further process the input samples (e.g., for OFDM, and/or the like) to obtain received symbols. A channel processor may determine reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), channel quality indicator (CQI), and/or the like In some aspects, one or more components of UE <NUM> may be included in a housing.

Controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform one or more techniques associated with random access channel frequency multiplexing for a non-terrestrial network, as described in more detail elsewhere herein. For example, controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of 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. Memories <NUM> and <NUM> may store data and program codes for base station <NUM> and UE <NUM>, respectively.

The stored program codes, when executed by processor <NUM> and/or other processors and modules at UE <NUM>, may cause the UE <NUM> to perform operations described with respect to process <NUM> of <FIG> and/or other processes as described herein. The stored program codes, when executed by processor <NUM> and/or other processors and modules at base station <NUM>, may cause the base station <NUM> to perform operations described with respect to process <NUM> of <FIG> and/or other processes as described herein.

In some aspects, UE <NUM> may include means for receiving configuration information identifying locations of respective random access channel (RACH) resources for a plurality of beams associated with a non-terrestrial network, wherein the plurality of beams are associated with respective frequency regions; means for performing a RACH procedure with regard to the selected beam using a RACH resource associated with the selected beam; means for performing an operation to resolve a conflict between the RACH resource and another uplink transmission in the expanded time window; means for receiving information indicating an association between a synchronization signal block (SSB) time index of one or more beams and one or more corresponding RACH resources associated with the one or more beams; means for identifying the RACH resource associated with a beam of the one or more beams based at least in part on the information indicating the association; means for identifying a RACH resource, of the respective RACH resources, based at least in part on an association between a synchronization signal block (SSB) time index of the selected beam and the RACH resource associated with the selected beam; and/or the like. In some aspects, such means may include one or more components of UE <NUM> described in connection with <FIG>.

In some aspects, base station <NUM> may include means for transmitting configuration information for a plurality of beams for a non-terrestrial network, wherein the configuration information identifies respective random access channel (RACH) resources for the plurality of beams, and wherein the plurality of beams are associated with respective frequency regions; means for performing a RACH procedure with regard to a selected beam, of the plurality of beams, using a RACH resource associated with the selected beam; means for transmitting information indicating an association between a synchronization signal block (SSB) time index of the selected beam and the RACH resource associated with the selected beam; means for identifying the RACH resource based at least in part on an association between a synchronization signal block (SSB) time index of the selected beam and the RACH resource associated with the selected beam; and/or the like. In some aspects, such means may include one or more components of base station <NUM> described in connection with <FIG>.

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 processor <NUM>.

<FIG> is a diagram illustrating an example <NUM> of cells <NUM>, <NUM>, <NUM>, and <NUM> provided by a base station of a non-terrestrial network, in accordance with various aspects of the present disclosure. The center frequencies associated with the cells are indicated by the fill of the corresponding cell. Each cell may be provided by a respective beam of a BS (e.g., BS <NUM>). For example, the BS may generate multiple beams associated with respective frequency regions. These cells may not necessarily be circular. In some aspects, a beam may be an analog beam (e.g., generated by a cone antenna or a different type of antenna). In some aspects, the beam may be a digital beam, which may be formed by signal manipulation across an antenna array.

If N is the number of beams provided by a BS, and M is the number of bandwidth parts or subbands provided by the beams, where N is greater than or equal to M, the BS may use N/M beams per subband or bandwidth part. In some aspects, the BS may use one beam per frequency region (e.g., subband or bandwidth part), and frequency regions of the beams may be configured not to overlap in the spatial domain (e.g., cells <NUM> and <NUM> may be associated with different frequency regions since cells <NUM> and <NUM> spatially overlap each other, whereas cells <NUM> and <NUM> may use the same frequency region since cells <NUM> and <NUM> do not spatially overlap each other).

A RACH procedure for a UE covered by a cell may be performed via the beam that provides (e.g., covers) the cell. According to the techniques and apparatuses described herein, a RACH resource for the RACH procedure (e.g., a resource for a RACH preamble of the RACH procedure and/or for other communications of the RACH procedure) may be provided in a frequency region of the corresponding beam or outside of the frequency region of the corresponding beam. For example, the RACH resources of the beams of BS <NUM> may be configured independently (e.g., on different frequency regions) or jointly (e.g., on a same frequency region). Furthermore, in some aspects, the RACH resources of the beams of BS <NUM> may be multiplexed (e.g., time division multiplexed, frequency division multiplexed, code division multiplexed, and/or the like), which may conserve air interface resources and reduce interruption of the frequency regions of the beams.

As used herein, a frequency region may refer to a configured bandwidth of a beam or a cell bandwidth of the beam with which data is transmitted. For example, a frequency region may correspond to a bandwidth part or subband of a beam.

<FIG> is a diagram illustrating an example <NUM> of configuring random access channel (RACH) resources for beams of a non-terrestrial network, in accordance with various aspects of the present disclosure. As shown, <FIG> includes a BS <NUM> and a UE <NUM>. In some aspects, BS <NUM> may include a relay station. In some aspects, UE <NUM> may include a ground station.

As shown in <FIG>, and by reference number <NUM>, the BS <NUM> may transmit configuration information that identifies RACH resources for beams to be transmitted by the BS <NUM>. For example, the configuration information may be transmitted using radio resource configuration (RRC) information, downlink control information (DCI), a system information block (SIB), broadcast information, and/or the like. In some aspects, the configuration information may indicate a mapping between an SSB and a corresponding RACH resource, as described in more detail elsewhere herein. The configuration information is described in more detail in connection with reference number <NUM>.

As shown by reference number <NUM>, the configuration information may identify RACH resources for corresponding beams that may be transmitted by the BS <NUM>. In other words, the configuration information may be beam-specific. For example, the configuration information may identify a first RACH resource (e.g., RACH Resource A) for a first beam (e.g., Beam <NUM>), a second RACH resource (e.g., RACH Resource B) for a second beam (e.g., Beam <NUM>), and so on. Thus, the RACH resources of the beams may be configured independently of each other. By configuring the RACH resources independently, improved flexibility in RACH configuration may be achieved. This may be particularly helpful in the case of NTN communications, wherein different BSs may be associated with significantly different capabilities, so a uniform RACH configuration may not be ideal or feasible. In some aspects, the RACH resources for the beams may be configured jointly (e.g., on a same frequency region or using a single configuration that is common to two or more beams), which may conserve resources associated with independently configuring the RACH resources. Particular configurations of the RACH resources are described in connection with <FIG>.

As shown by reference number <NUM>, the UE <NUM> may detect a selected beam of the plurality of beams provided by the BS <NUM>. For example, the UE <NUM> may detect an SSB of the selected beam, which may be transmitted by a corresponding antenna. Thus, the UE <NUM> may determine to access the NTN using the selected beam. In some aspects, the UE <NUM> may identify a RACH resource (and/or a RACH occasion associated with the RACH resource) based at least in part on an SSB index of the selected beam, as described in more detail in connection with <FIG>.

As shown by reference number <NUM>, the UE <NUM> and the BS <NUM> may perform the RACH procedure with the BS <NUM> using the RACH resource of the selected beam. For example, the UE <NUM> may transmit a RACH preamble using the RACH resource, may receive a RACH response using the RACH resource, and/or the like. The BS <NUM> may monitor the RACH resource for the RACH preamble, and may transmit a RACH response based at least in part on the RACH preamble. In some aspects, the UE <NUM> may use a guard period for the transmission of the RACH resource, such as when the BS <NUM> is to retune to the frequency region associated with the RACH resource, as described in more detail in connection with <FIG>.

<FIG> is a diagram illustrating an example <NUM> of a RACH resource configuration wherein RACH resources are provided in frequency regions of respective beams, in accordance with various aspects of the present disclosure. As shown in <FIG>, in some aspects, a RACH resource of each beam (shown as Beam <NUM>/<NUM>/<NUM> RACH) may be located in a frequency region (e.g., bandwidth part, subband, and/or the like). The configuration shown in <FIG> is referred to herein as Option <NUM> for clarity of description.

<FIG> is a diagram illustrating examples <NUM> of RACH resource configurations wherein at least some RACH resources are provided outside frequency regions of respective beams, in accordance with various aspects of the present disclosure. <FIG> illustrates a first example <NUM> (referred to as Option 2A), a second example <NUM> (referred to as Option 2B), and a third example <NUM> (referred to as Option 2C).

In Option 2A, the RACH resources for the bands are provided outside of any frequency region of all of the bands. For example, the RACH resources are provided in a RACH frequency region (e.g., bandwidth part (BWP), subband (SB), and/or the like). This may be a frequency region used only to carry RACH messaging, a frequency region used for RACH and synchronization messaging, a frequency region of a cell other than the cells provided by Beams <NUM>, <NUM>, and <NUM>, and/or the like. In Option 2B, the RACH resource for the beams are provided in one of the frequency regions of the beams. Here, the RACH resources for each of the beams are provided in the frequency region of Beam <NUM>. Option 2C may be considered a combination of Option 2A and Option 2B, wherein some RACH resources are provided in the RACH frequency region and other RACH resources are provided in the frequency region of one or more of the beams.

Options <NUM> and 2B may use less bandwidth than Options 2A and 2C since no PRACH frequency region is provided. Furthermore, Option <NUM> may not require a frequency retuning operation on the part of the antennas that transmit Beams <NUM> through <NUM>, thereby reducing delay and enabling random access without a guard period. Option 2A may provide increased flexibility and simplicity in a scheduler design and may increase the available resources on Beams <NUM> through <NUM>. Options 2A, 2B, and 2C may provide the ability to multiplex more than one RACH resource on the same frequency/time resource, which may improve efficiency of resource allocation. Furthermore, Options 2B and 2C may provide increased resource availability for beams whose frequency regions are not used for the RACH resources.

In some aspects, such as for Options 2A, 2B, and/or 2C, and when a common SSB frequency region is used for the plurality of beams, an association between SSB indices and RACH resources (e.g., RACH occasions) can be defined. Thus, a UE that receives an SSB on a particular time index may identify the corresponding RACH resource based at least in part on the association, even when the RACH occasions are not contiguous to the SSB. In some aspects, the association may be identified explicitly (e.g., in the configuration information provided by the BS) or based at least in part on a mapping (e.g., a mapping defined in a specification and/or the like).

In each of Options 2A, 2B, and 2C, the RACH resources can be multiplexed with each other. For example, the RACH resources may be multiplexed in any one or more of the time domain, the frequency domain, the code domain, or another domain. This may improve resource utilization of the RACH procedure.

Other examples may differ from what is described with respect to <FIG> and <FIG>.

<FIG> is a diagram illustrating an example <NUM> of a guard period to be used in connection with a RACH procedure, in accordance with various aspects of the present disclosure. For example, for the purpose of example <NUM>, base stations may be of a first type or a second type. The first type is a BS with a bandwidth capability that supports a bandwidth wider than the BS's frequency region (including the PRACH frequency region, if applicable). The second type is a BS with a bandwidth capability that does not support a bandwidth wider than the BS's frequency region.

In order to receive a RACH preamble from a UE that is outside of the BS's frequency region, a BS of the first type may not need to retune to a frequency region of the RACH preamble. However, a BS of the second type may retune to the frequency region of the RACH preamble. There may be some delay inherent to the frequency retuning operation. Some techniques and apparatuses described herein provide a guard period for a BS to retune from the BS's frequency region to the RACH preamble's frequency region when the BS is of the second type. For example, some techniques and apparatuses described herein may selectively use the guard period or omit the guard period based at least in part on whether the BS supports the bandwidth wider than the BS's frequency region.

The guard period is shown by reference number <NUM>, and the RACH resource for the beam is shown by reference number <NUM>. As shown, the RACH resource is provided outside of the beam's frequency region <NUM> and in a RACH frequency region <NUM>. According to the present invention, when the BS is of the first type, the BS may not require the guard period, so no guard period may be provided. According to the present invention, when the BS is of the second type, the BS may need to retune to and from the RACH frequency region <NUM>, and the guard period <NUM> may provide time for the retuning operation. Thus, compatibility for BSs with different capabilities is improved.

In some aspects, the guard period may be implemented by the UE. For example, the UE may be configured to use the resources shown by the guard period (e.g., the resource allocation that is wider than the RACH resource <NUM>) as the RACH resource. In the case that other uplink data collides with the RACH resource (e.g., the guard period), the UE may perform an operation to handle or mitigate the conflict (e.g., puncturing, rate matching, dropping, and/or the like). Thus, the UE may provide a guard period for BSs that do not support a bandwidth wider than the BS's frequency region.

<FIG> is a diagram illustrating an example <NUM> of a RACH resource configuration wherein RACH resources are provided adjacent to frequency regions of respective beams, in accordance with various aspects of the present disclosure. In example <NUM>, RACH resources are provided adjacent to or in an overlapped region of the frequency region of the corresponding beam. For example, as shown by reference number <NUM>, a RACH resource for Beam <NUM> is provided in a RACH frequency region adjacent to Beam <NUM>'s frequency region. Furthermore, as shown by reference number <NUM>, RACH resources for Beam <NUM> and Beam <NUM> are provided in Beam <NUM>'s frequency region and adjacent to Beam <NUM>'s frequency region. In some aspects, the RACH resources for two beams may be provided in an overlapped area of the frequency regions of the two beams. Thus, the BS's support for additional bandwidth beyond the beam's frequency region can be reduced (e.g., minimized), thereby reducing complexity at the BS.

In some aspects, the RACH resources may be multiplexed with each other, which may reduce resource utilization of the RACH resources. For example, the RACH resources may be provided in overlapping frequency, and may be multiplexed in time, in code, and/or the like.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a user equipment, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where a UE (e.g., user equipment <NUM>, a ground station, and/or the like) performs operations associated with random access channel frequency multiplexing for a non-terrestrial network.

As shown in <FIG>, in some aspects, process <NUM> may include receiving configuration information identifying locations of respective random access channel (RACH) resources for a plurality of beams associated with a non-terrestrial network, wherein the plurality of beams are associated with respective frequency regions (block <NUM>). For example, the UE (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) may receive configuration information identifying locations of respective random access channel (RACH) resources for a plurality of beams associated with a non-terrestrial network, as described above. In some aspects, the plurality of beams are associated with respective frequency regions.

As further shown in <FIG>, in some aspects, process <NUM> may include performing a RACH procedure with regard to the selected beam using a RACH resource associated with the selected beam (block <NUM>). For example, the UE (e.g., using controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like) may perform a RACH procedure with regard to the selected beam using a RACH resource associated with the selected beam, as described above. In some aspects, the UE may transmit a RACH preamble using the RACH resource associated with the selected beam.

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

In a first aspect, at least one RACH resource, of the respective RACH resources, is outside of a frequency region associated with a corresponding beam of the plurality of beams.

In a second aspect, alone or in combination with the first aspect, each RACH resource, of the respective RACH resources, is within a corresponding frequency region associated with a respective beam of the plurality of beams.

In a third aspect, alone or in combination with the first aspect and/or the second aspect, the respective RACH resources are configured jointly.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the respective RACH resources are configured independently from each other.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the configuration information is beam-specific.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the respective RACH resources are on a bandwidth part or subband that does not overlap a respective frequency region of any of the plurality of beams.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the respective RACH resources are within a particular frequency region corresponding to a particular beam of the plurality of beams.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, one or more first RACH resources, of the respective RACH resources, are on a bandwidth part or subband that does not overlap any frequency region of the plurality of beams.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, one or more second RACH resources, of the respective RACH resources, are in a frequency region of a particular beam of the plurality of beams.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the respective RACH resources are multiplexed with each other.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, a RACH resource associated with a selected beam, of the plurality of beams, uses an expanded time window based at least in part on a bandwidth capability of a transmitter of the selected beam (e.g., the BS <NUM>).

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, the UE may perform an operation to resolve a conflict between the RACH resource and another uplink transmission in the expanded time window.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, at least one RACH resource is provided adjacent to an edge or in an overlapped area of a frequency region associated with a corresponding beam.

In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, one or more first RACH resources corresponding to one or more first beams, of the plurality of beams, are multiplexed with one or more second RACH resources corresponding to one or more second beams, of the plurality of beams, in a frequency region in which the one or more first RACH resources are located.

In a fifteenth aspect, alone or in combination with one or more of the first through fourteenth aspects, the UE may receive information indicating an association between a synchronization signal block (SSB) time index of one or more beams and one or more corresponding RACH resources associated with the one or more beams; and identify the RACH resource associated with a beam of the one or more beams based at least in part on the information indicating the association.

In a sixteenth aspect, alone or in combination with one or more of the first through fifteenth aspects, the UE may identify a RACH resource, of the respective RACH resources, based at least in part on an association between a synchronization signal block (SSB) time index of the selected beam and the RACH resource associated with the selected beam.

In a seventeenth aspect, alone or in combination with one or more of the first through sixteenth aspects, the respective RACH resources are not contiguous in a frequency domain.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a base station, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where a base station (e.g., base station <NUM>, a relay station, and/or the like) performs operations associated with random access channel frequency multiplexing for a non-terrestrial network.

As shown in <FIG>, in some aspects, process <NUM> may include transmitting configuration information for a plurality of beams for a non-terrestrial network, wherein the configuration information identifies respective random access channel (RACH) resources for the plurality of beams, and wherein the plurality of beams are associated with respective frequency regions (block <NUM>). For example, the base station (e.g., using controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like) may transmit configuration information for a plurality of beams for a non-terrestrial network, as described above. In some aspects, the configuration information identifies respective random access channel (RACH) resources for the plurality of beams. In some aspects, the plurality of beams are associated with respective frequency regions. In some aspects, a base station that provides the configuration information to a UE may not be the same base station as performs the RACH procedure with the UE.

As further shown in <FIG>, in some aspects, process <NUM> may include performing a RACH procedure with regard to a selected beam, of the plurality of beams, using a RACH resource associated with the selected beam (block <NUM>). For example, the base station (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) may perform a RACH procedure with regard to a selected beam, of the plurality of beams, using a RACH resource associated with the selected beam, as described above.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the respective RACH resources are on a bandwidth part or subband that does not overlap respective frequency regions of any of the plurality of beams.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the respective RACH resources are within a particular frequency region corresponding to a particular beam of the plurality of beams.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, one or more first RACH resources, of the respective RACH resources, are on a bandwidth part or subband that does not overlap respective frequency regions of any beam of the plurality of beams.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, one or more second RACH resources, of the respective RACH resources, are in a frequency region of a particular beam of the plurality of beams.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the respective RACH resources are multiplexed with each other.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the RACH resource associated with the selected beam selectively uses an expanded time window based at least in part on a bandwidth capability of the base station.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, when the bandwidth capability indicates that the base station supports a bandwidth wider than a frequency region of a beam of the plurality of beams, the expanded time window is not used.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, when the bandwidth capability indicates that the base station does not support a bandwidth wider than the frequency region of the beam, the expanded time window is used.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, the expanded time window is used when the RACH resource associated with the selected beam is on a bandwidth part or subband that does not overlap a frequency region of the selected beam for which the RACH procedure is to be performed.

In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, the at least one RACH resource is provided adjacent to an edge or in an overlapped area of the frequency region associated with the corresponding beam.

In a fifteenth aspect, alone or in combination with one or more of the first through fourteenth aspects, the at least one RACH resource is multiplexed with another RACH resource corresponding to a beam with a frequency region in which the at least one RACH resource is located.

In a sixteenth aspect, alone or in combination with one or more of the first through fifteenth aspects, the base station may transmit information indicating an association between a synchronization signal block (SSB) time index of the selected beam and the RACH resource associated with the selected beam.

In a seventeenth aspect, alone or in combination with one or more of the first through sixteenth aspects, the base station may identify the RACH resource based at least in part on an association between a synchronization signal block (SSB) time index of the selected beam and the RACH resource associated with the selected beam.

In an eighteenth aspect, alone or in combination with one or more of the first through seventeenth aspects, the respective RACH resources are not contiguous in a frequency domain.

Claim 1:
A method of wireless communication performed by a user equipment, UE (<NUM>), the method comprising:
receiving (<NUM>), from a base station, configuration information identifying locations of respective random access channel, RACH, resources for a plurality of beams associated with a non-terrestrial network, wherein the plurality of beams are associated with respective frequency regions;
performing (<NUM>) a RACH procedure with regard to a selected beam using a RACH resource associated with the selected beam, wherein the RACH resource is outside of a beam frequency region associated with the base station; and wherein:
the RACH resource comprises a guard region when a bandwidth capability of the base station does not support a bandwidth wider than the frequency region associated with the base station, the guard region providing an amount of time for a performance of a retuning operation; or
the RACH resource does not comprise the guard region when the bandwidth capability of the base station supports a bandwidth wider than the frequency region associated with the base station.