Patent Description:
<CIT> relates to an electronic apparatus, a wireless communication method and a computer-readable medium. According to one embodiment, an electronic apparatus for wire-less communication comprises: a processing circuit configured to: deter-mine whether a first user equipment satisfies a condition for performing direct link communication with a second user equipment by using an unli-censed frequency band resource; and if the condition is satisfied, control the first user equipment to perform direct link communication with the second user equipment by using the unlicensed frequency band resource (see abstract).

<CIT> relates to transmitting a sidelink message by a terminal in a wireless communication system. The method comprises: selecting at least one sidelink message among a plurality of sidelink messages, on the basis of the importance of each of the sidelink messages; selecting at least one carrier among a plurality of predetermined carriers, on the basis of the priority of each of the carriers and the importance of the selected at least one sidelink message; and transmitting the selected at least one sidelink message through the selected at least one carrier, wherein a sidelink message having relatively high importance among the selected at least one sidelink message is preferentially transmitted through a carrier having relatively high priority among the selected at least one carrier.

<CIT> relates to a UE that may be configured for carrier aggregation using a primary component carrier (CC) and a secondary CC. The UE may attempt to detect a sidelink synchronization signal (SLSS) from another UE on the primary CC. The UE may, if the SLSS from the other UE is detected: determine, based on the detected SLSS, a common time synchronization for the primary CC and the secondary CC for vehicle-to-vehicle (V2V) sidelink transmissions in accordance with the carrier aggregation. The UE may, if the SLSS from the other UE is not detected: transmit an SLSS to enable determination of the common time synchronization for the primary CC and the secondary CC by the other UE. The SLSS may be transmitted on the primary CC.

Preferred embodiments of the invention are stipulated in the dependent claims.

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

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 licensed assisted sidelink access using an indication of multiple data channels, as described in more detail elsewhere herein. In some aspects, 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, in some aspects, 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. In some aspects, memory <NUM> and/or 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. In some aspects, 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, in some aspects, process <NUM> of <FIG>, process <NUM> of <FIG>, and/or other processes as described herein. In some aspects, executing instructions may include running the instructions, converting the instructions, compiling the instructions, and/or interpreting the instructions.

In some aspects, UE <NUM> may include means for transmitting, to a second UE via a sidelink sub-channel of a licensed carrier, an indication of multiple data channels of an unlicensed carrier to be used to attempt one or more sidelink communications between the first UE and the second UE; and/or means for attempting the one or more sidelink communications between the first UE and the second UE using the multiple data channels. Additionally, or alternatively, UE <NUM> may include means for receiving, from a first UE via a sidelink sub-channel of a licensed carrier, an indication of multiple data channels of an unlicensed carrier to be used to attempt one or more sidelink communications between the second UE and the first UE; and/or means for attempting the one or more sidelink communications between the second UE and the first UE using the multiple data channels. In some aspects, such means may include one or more components of UE <NUM> described in connection with <FIG>, such as controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, and/or receive processor <NUM>.

In some aspects, 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 controller/processor <NUM>.

As indicated above, <FIG> is provided as an aspect. Other aspects may differ from what is described with regard to <FIG>.

<FIG> is a diagram illustrating an aspect <NUM> of sidelink communications, in accordance with the present disclosure.

As shown in <FIG>, a first UE <NUM>-<NUM> may communicate with a second UE <NUM>-<NUM> (and one or more other UEs <NUM>) via one or more sidelink channels <NUM>. The UEs <NUM>-<NUM> and <NUM>-<NUM> may communicate using the one or more sidelink channels <NUM> for P2P communications, D2D communications, V2X communications (e.g., which may include V2V communications, V2I communications, and/or vehicle to pedestrian (V2P) communications), and/or mesh networking. In some aspects, the UEs <NUM> (e.g., UE <NUM>-<NUM> and/or UE <NUM>-<NUM>) may correspond to one or more other UEs described elsewhere herein, such as UE <NUM>. In some aspects, the one or more sidelink channels <NUM> may use a PC5 interface and/or may operate in a high frequency band (e.g., the <NUM> band). Additionally, or alternatively, the UEs <NUM> may synchronize timing of transmission time intervals (TTIs) (e.g., frames, subframes, slots, and/or symbols) using global navigation satellite system (GNSS) timing.

As further shown in <FIG>, the one or more sidelink channels <NUM> may include a physical sidelink control channel (PSCCH) <NUM>, a physical sidelink shared channel (PSSCH) <NUM>, and/or a physical sidelink feedback channel (PSFCH) <NUM>. The PSCCH <NUM> may be used to communicate control information, similar to a physical downlink control channel (PDCCH) and/or a physical uplink control channel (PUCCH) used for cellular communications with a base station <NUM> via an access link or an access channel. The PSSCH <NUM> may be used to communicate data, similar to a physical downlink shared channel (PDSCH) and/or a physical uplink shared channel (PUSCH) used for cellular communications with a base station <NUM> via an access link or an access channel. In some aspects, the PSCCH <NUM> may carry sidelink control information (SCI) <NUM>, which may indicate various control information used for sidelink communications, such as one or more resources (e.g., time resources, frequency resources, and/or spatial resources) where a transport block (TB) <NUM> may be carried on the PSSCH <NUM>. The TB <NUM> may include data. The PSFCH <NUM> may be used to communicate sidelink feedback <NUM>, such as hybrid automatic repeat request (HARQ) feedback (e.g., acknowledgement or negative acknowledgement (ACK/NACK) information), transmit power control (TPC), and/or a scheduling request (SR).

In some aspects, the one or more sidelink channels <NUM> may use resource pools. In some aspects, a scheduling assignment (e.g., included in SCI <NUM>) may be transmitted in sub-channels using specific resource blocks (RBs) across time. In some aspects, data transmissions (e.g., on the PSSCH <NUM>) associated with a scheduling assignment may occupy adjacent RBs in the same subframe as the scheduling assignment (e.g., using frequency division multiplexing). In some aspects, a scheduling assignment and associated data transmissions are not transmitted on adjacent RBs.

In some aspects, a UE <NUM> may operate using a transmission mode where resource selection and/or scheduling is performed by the UE <NUM> (e.g., rather than a base station <NUM>). In some aspects, the UE <NUM> may perform resource selection and/or scheduling by sensing channel availability for transmissions. In some aspects, the UE <NUM> may measure an RSSI parameter (e.g., a sidelink-RSSI (S-RSSI) parameter) associated with various sidelink channels, may measure an RSRP parameter (e.g., a PSSCH-RSRP parameter) associated with various sidelink channels, may measure an RSRQ parameter (e.g., a PSSCH-RSRQ parameter) associated with various sidelink channels, and may select a channel for transmission of a sidelink communication based at least in part on the measurement(s).

Additionally, or alternatively, the UE <NUM> may perform resource selection and/or scheduling using SCI <NUM> received in the PSCCH <NUM>, which may indicate occupied resources, and/or channel parameters. Additionally, or alternatively, the UE <NUM> may perform resource selection and/or scheduling by determining a channel busy rate (CBR) associated with various sidelink channels, which may be used for rate control (e.g., by indicating a maximum number of resource blocks that the UE <NUM> can use for a particular set of subframes).

In the transmission mode where resource selection and/or scheduling is performed by a UE <NUM>, the UE <NUM> may generate sidelink grants, and may transmit the grants in SCI <NUM>. A sidelink grant may indicate, in some aspects, one or more parameters (e.g., transmission parameters) to be used for an upcoming sidelink transmission, such as one or more resource blocks to be used for the upcoming sidelink transmission on the PSSCH <NUM> (e.g., for TBs <NUM>), one or more subframes to be used for the upcoming sidelink transmission, and/or an MCS to be used for the upcoming sidelink transmission. In some aspects, a UE <NUM> may generate a sidelink grant that indicates one or more parameters for semi-persistent scheduling (SPS), such as a periodicity of a sidelink transmission. Additionally, or alternatively, the UE <NUM> may generate a sidelink grant for event-driven scheduling, such as for an on-demand sidelink message.

As indicated above, <FIG> is provided as an aspect. Other aspects may differ from what is described with respect to <FIG>.

<FIG> is a diagram illustrating an aspect <NUM> of sidelink communications and access link communications, in accordance with the present disclosure.

As shown in <FIG>, a transmitter (Tx)/receiver (Rx) UE <NUM> and an Rx/Tx UE <NUM> may communicate with one another via a sidelink, as described above in connection with <FIG>. As further shown, in some sidelink modes, a base station <NUM> may communicate with the Tx/Rx UE <NUM> via a first access link. Additionally, or alternatively, in some sidelink modes, the base station <NUM> may communicate with the Rx/Tx UE <NUM> via a second access link. The Tx/Rx UE <NUM> and/or the Rx/Tx UE <NUM> may correspond to one or more UEs described elsewhere herein, such as the UE <NUM> of <FIG>. Thus, a direct link between UEs <NUM> (e.g., via a PC5 interface) may be referred to as a sidelink, and a direct link between a base station <NUM> and a UE <NUM> (e.g., via a Uu interface) may be referred to as an access link. Sidelink communications may be transmitted via the sidelink, and access link communications may be transmitted via the access link. An access link communication may be either a downlink communication (e.g., from a base station <NUM> to a UE <NUM>) or an uplink communication (e.g., from a UE <NUM> to a base station <NUM>).

<FIG> is a diagram illustrating aspects <NUM> of carrier aggregation, in accordance with the present disclosure.

Carrier aggregation is a technology that enables two or more component carriers (CCs, sometimes referred to as carriers) to be combined (e.g., into a single channel) for a single UE <NUM> to enhance data capacity. As shown, carriers can be combined in the same or different frequency bands. Additionally, or alternatively, contiguous or non-contiguous carriers can be combined. A base station <NUM> may configure carrier aggregation for a UE <NUM>, such as in a radio resource control (RRC) message, or in downlink control information (DCI.

As shown by reference number <NUM>, in some aspects, carrier aggregation may be configured in an intra-band contiguous mode where the aggregated carriers are contiguous to one another and are in the same band. As shown by reference number <NUM>, in some aspects, carrier aggregation may be configured in an intra-band non-contiguous mode where the aggregated carriers are non-contiguous to one another and are in the same band. As shown by reference number <NUM>, in some aspects, carrier aggregation may be configured in an inter-band non-contiguous mode where the aggregated carriers are non-contiguous to one another and are in different bands.

In carrier aggregation, a UE <NUM> may be configured with a primary carrier and one or more secondary carriers. In some aspects, the primary carrier may carry control information (e.g., downlink control information, and/or scheduling information) for scheduling data communications on one or more secondary carriers, which may be referred to as cross-carrier scheduling. In some aspects, a carrier (e.g., a primary carrier or a secondary carrier) may carry control information for scheduling data communications on the carrier, which may be referred to as self-carrier scheduling or carrier self-scheduling.

<FIG> is a diagram illustrating an aspect <NUM> of sidelink access with a licensed carrier <NUM> and an unlicensed carrier <NUM>, in accordance with the present disclosure. As shown in <FIG>, UEs <NUM> (e.g., UE <NUM>-<NUM>, UE <NUM>-<NUM>, UE <NUM>-<NUM>, and/or UE <NUM>-<NUM>) may communicate with one another at various times using a sidelink communication (also referred to as sidelink access or simply sidelink) via the licensed carrier <NUM>. Such sidelink communication may occur in the presence of the unlicensed carrier <NUM>, which may co-exist with other RATs. In some aspects, one RAT which may exist in the unlicensed carrier <NUM> is a WiFi network, and the WiFi network may have a device, e.g., WiFi device <NUM>, operating in the unlicensed carrier <NUM>.

At various times, certain UE devices may be communicating with one another via sidelink. In some aspects, during a given time as shown, UE <NUM>-<NUM> may be in sidelink communication with UE <NUM>-<NUM>, and UE <NUM>-<NUM> may be in sidelink communication with UE <NUM>-<NUM>. Such sidelink communications may occur without involvement of a base station. For example, such UEs may be in radio resource allocation (RRA) mode <NUM> sidelink communication allowing standalone deployment of UEs in which the UEs may sense to occupy and reserve channel access (as opposed to RRA mode <NUM> sidelink communication in which network control is used and UEs receive grants, e.g., from gNB, for channel access).

Scheduling access to licensed spectrum, e.g., the licensed carrier <NUM>, for such sidelink communication between devices is performed efficiently. Presently, sidelink is used predominantly in the V2X domain. As sidelink use cases evolve in vertical domains other than the V2X domain, ever growing amounts of data transfer will present an increasing burden to the licensed spectrum. Off-loading of data to unlicensed spectrum, e.g., the unlicensed carrier <NUM>, is seen as one way to address the data bandwidth limitations of the licensed spectrum. However, scheduling access to unlicensed spectrum for sidelink communications is not as efficient as scheduling access to licensed spectrum for sidelink communications. The terms licensed spectrum, licensed band, and licensed bands may be used interchangeably. Likewise, the terms unlicensed spectrum, unlicensed band, and unlicensed bands may be used interchangeably.

Some techniques and apparatuses described herein may improve access to unlicensed spectrum for sidelink communications by using an indication, via licensed spectrum, of multiple data channels for the sidelink via unlicensed spectrum. Some techniques and apparatuses described herein may use a load based equipment (LBE) technique for determining such access to unlicensed spectrum (as opposed to a frame based equipment (FBE) technique). LBE is a listen-before-talk (LBT) technique. LBT generally allows communications of devices to co-exist on a data channel without previous coordination. LBE is an LBT technique which allows devices to sense availability of a data channel at any time (as opposed to FBE, which is an LBT technique in which devices may sense availability of a data channel at predetermined times). As a result, by using an indication, via licensed spectrum, of multiple data channels for a sidelink communication via unlicensed spectrum, increased spectrum may be made efficiently available to UEs for sidelink access with greater robustness. By using the LBE technique for data channel access into the unlicensed spectrum, complexity and/or overhead associated with stricter synchronizations and/or timings may be avoided. Power savings benefits in channel access may be achieved over the unlicensed carrier, such as by limiting the need to conduct sensing.

<FIG> is a diagram illustrating an aspect <NUM> associated with licensed assisted sidelink access using an indication of multiple data channels, in accordance with the present disclosure. As shown in <FIG>, a first UE may transmit to a second UE via a sidelink sub-channel, e.g., sub-channel <NUM>-<NUM>, of a licensed carrier <NUM>. The first and/or second UEs may correspond to one or more other UEs described elsewhere herein, such as UE <NUM>. The sidelink sub-channel may provide sidelink communication between UEs as described elsewhere herein, such as the sidelink access as described with respect to the UEs <NUM>-<NUM> and <NUM>-<NUM>. The licensed carrier <NUM> may include licensed spectrum and/or licensed bands as described elsewhere herein, such as the licensed carrier <NUM>.

The first UE may transmit to the second UE an indication of multiple data channels <NUM> (e.g., channel <NUM>-<NUM>, channel <NUM>-<NUM>, channel <NUM>-<NUM>, and/or channel <NUM>-<NUM>) of an unlicensed carrier <NUM>. Such multiple data channels <NUM> may be used to attempt one or more sidelink communications between the first UE and the second UE. The multiple data channels <NUM> may include PSSCHs, such as the PSSCH <NUM> described elsewhere herein. In some aspects, the unlicensed carrier <NUM> may include unlicensed spectrum and/or unlicensed bands as described elsewhere herein, such as the unlicensed carrier <NUM>. The one or more sidelink communications between the first UE and the second UE may be attempted using one or more of the multiple data channels <NUM>. The multiple data channels <NUM> may be contiguous, or share a common border, back to back in time. By making the multiple data channels <NUM> contiguous, overall latency may be minimized.

When attempting a sidelink communication, a UE (e.g., the first UE or the second UE) may perform an LBT procedure to determine availability of a data channel and transmit via the data channel if available or perform another LBT procedure on another data channel if the data channel is unavailable. When attempting a sidelink communication, a UE (e.g., the first UE or the second UE) may monitor for a communication on a data channel and, if found, decode such communication. To monitor for a communication, the UE may perform blind decoding in situations where SCI may not be available.

The licensed carrier <NUM> may be used for Quality of Service (QoS) sensitive data and/or control, while the unlicensed carrier <NUM> may be used opportunistically to provide a larger data transfer pipeline which may include a relaxed QoS. In this way, licensed assisted QoS and/or congestion control for channel access may be provided over the unlicensed carrier.

The indication transmitted from the first UE to the second UE may identify one or more resources of the licensed carrier <NUM> to be used for HARQ feedback <NUM> corresponding to the multiple data channels <NUM> of the unlicensed carrier <NUM>. Providing the HARQ feedback <NUM> via the licensed carrier <NUM> (as opposed to the unlicensed carrier <NUM>) may provide improved reliability. With the HARQ feedback <NUM> provided through the licensed carrier <NUM> (as opposed to the unlicensed carrier <NUM>), highly reliable control signaling may be provided.

The indication transmitted from the first UE to the second UE may include one or more transmission parameters for respective ones of the multiple data channels <NUM>. The one or more transmission parameters may include one or more carrier frequency indications (CFIs) for the multiple data channels <NUM>, one or more bandwidth part (BWP) indicators for the multiple data channels <NUM>, one or more transmission configuration indicator (TCI) states for the multiple data channels <NUM>, one or more time domain resource allocations (TDRAs) for the multiple data channels <NUM>, one or more frequency domain resource allocations (FDRAs) for the multiple data channels <NUM>, one or more MCSs for the multiple data channels <NUM>, one or more HARQ parameters for the multiple data channels <NUM>, one or more sounding reference signal resource indicators (SRIs) for the multiple data channels <NUM>, or a combination thereof. The HARQ parameters may include one or more new data indicator (NDI) parameters and/or one or more redundancy version (RV) parameters. NDI parameters may be used for determination of sending new data. RV parameters may be used for determination of transmission characteristics.

As shown in <FIG>, in some aspects, the multiple data channels <NUM> may be grouped into one or more groups (e.g., Group <NUM> and/or Group <NUM>). One or more data channels included in a same group (e.g., PSSCH0 and PSSCH1 in Group <NUM>, and/or PSSCH2 and PSSCH3 in Group <NUM>) may be associated with one or more common transmission parameters for the group, such as one or more of the transmission parameters listed above. Configuring data channels included in a same group with common transmission parameters may save signaling overhead and/or bandwidth relating to indicating transmission parameters for the data channels.

Data channels of the multiple data channels <NUM> may occupy time slots. Such slots may be of greater duration, such as PSSCH2 being a slot of greater duration in Group <NUM>, or of lesser duration, such as PSSCH0 being a slot of lesser duration in Group <NUM>, as shown in <FIG>. A slot of lesser duration may be referred to as a mini-slot. The multiple data channels <NUM> may start with one or more mini-slots, such as PSSCH0 and PSSCH1, occupying mini-slots in Group <NUM>. Providing such mini-slots at the beginning of a train of multiple data channels <NUM> may reduce latency, such as in the event an initial LBT procedure is unable to access a data channel, perhaps due to congestion and/or interference, and another LBT procedure is to be attempted. In this way, mini-slots may provide multiple opportunities to obtain access to a data channel, which multiple opportunities may reduce latency in a sidelink communication.

In some aspects, the indication transmitted from the first UE to the second UE may be included in SCI, a medium access control (MAC) control element (CE) (MAC-CE), a radio resource control configuration message, or a combination thereof. For SCI, the indication may be included in a new SCI, e.g., a stage two sidelink control information (SCI-<NUM>).

Ensuring validity of a sidelink communication may be useful for avoiding undesirable communication. The indication transmitted from the first UE to the second UE may be determined to be valid once a handshaking procedure is completed. In some aspects, such as with a MAC-CE or another upper-layer communication, two-way handshaking may be used for added reliability in determining validity of the communication. For even greater reliability in determining validity of the communication, three-way handshaking may be used. The indication may be determined valid based at least in part on the handshaking procedure, in which case the indication may be used by the second UE (receiver). The indication may be used to arrange periodic communications, similar to a configured grant.

To allow the second UE (receiver) time to access the unlicensed carrier <NUM>, a delay or time gap may be added following transmission of the indication by the first UE (transmitter), but before the multiple data channels <NUM> are present on the unlicensed carrier <NUM>. The indication transmitted from the first UE to the second UE, and an initial data channel of the multiple data channels <NUM>, may be separated by a non-zero time gap, shown as "T" in <FIG>. The time gap T may be present to provide a predetermined delay between the end of a slot where the indication was transmitted and the beginning of a first data channel of the multiple data channels <NUM>.

The indication transmitted from the first UE to the second UE may indicate that SCI is to be transmitted using one or more data channels of the multiple data channels <NUM>. To permit other UEs to read and avoid collision with the sidelink communication, and better co-exist in the unlicensed carrier <NUM>, the first UE may transmit stage one sidelink control information (SCI-<NUM>) over the multiple data channels <NUM>. In some aspects, the SCI-<NUM> may appear in any slot of the multiple data channels <NUM>; the SCI-<NUM> may appear once in any given slot; and/or the SCI-<NUM> may appear at the beginning of the multiple data channels <NUM>, e.g., an initial slot. Transmitting SCI-<NUM> over the multiple data channels <NUM>, using the unlicensed carrier <NUM>, may provide an indication of occupancy of resources in the unlicensed carrier <NUM> such that another standalone sidelink system may read and avoid collision. A predetermined bit may be assigned to indicate the sidelink transmitter is to insert an SCI-<NUM> in one of the data channels in the train. The predetermined bit may be used by stand-alone sidelink UEs to determine occupancy of resources.

The second UE may receive, from the first UE via the sidelink sub-channel, e.g., sub-channel <NUM>-<NUM>, of licensed carrier <NUM>, the indication of multiple data channels <NUM> (e.g., channel <NUM>-<NUM>, channel <NUM>-<NUM>, channel <NUM>-<NUM>, and/or channel <NUM>-<NUM>) of unlicensed carrier <NUM>. Such indication may be used to attempt one or more sidelink communications between the second UE and the first UE. The one or more sidelink communications between the second UE and the first UE may be attempted using one or more of the multiple data channels <NUM>.

As described above, licensed assisted sidelink access may be performed using an indication of multiple data channels on an unlicensed carrier. In this way, robustness of sidelink communication may be improved by better allowing communications of other radio access technologies, such as WiFi communications, to co-exist with the sidelink communication on the unlicensed spectrum.

<FIG> is a diagram illustrating an aspect <NUM> associated with licensed assisted sidelink access using an indication of multiple data channels with LBT, in accordance with the present disclosure. As shown in <FIG>, a first UE may transmit to a second UE via a sidelink sub-channel, e.g., sub-channel <NUM>-<NUM>, of a licensed carrier <NUM>. The first and/or second UEs may correspond to one or more other UEs described elsewhere herein, such as UE <NUM>. The sidelink sub-channel may provide sidelink communication between UEs as described elsewhere herein, such as the sidelink access as described with respect to the UEs <NUM>-<NUM> and <NUM>-<NUM>. The licensed carrier <NUM> may include licensed spectrum and/or licensed bands as described elsewhere herein, such as the licensed carrier <NUM>.

The first UE may transmit to the second UE an indication of multiple data channels <NUM> of an unlicensed carrier <NUM>. Such multiple data channels <NUM> may be used to attempt one or more sidelink communications between the first UE and the second UE. The multiple data channels <NUM> may include PSSCHs, such as the PSSCH <NUM> described elsewhere herein. In some aspects, the unlicensed carrier <NUM> may include unlicensed spectrum and/or unlicensed bands as described elsewhere herein, such as the unlicensed carrier <NUM>. The one or more sidelink communications between the first UE and the second UE may be attempted using one or more of the multiple data channels <NUM>.

As described above with respect to <FIG>, LBT generally allows communications of devices to co-exist on a data channel, without previous coordination, by determining availability of a data channel and transmitting via such data channel if available (or performing another LBT procedure on another data channel if unavailable). The first UE (transmitter) may perform an LBT procedure to determine availability of a data channel, and selectively transmit a sidelink communication to the second UE (receiver) using the data channel based at least in part on the determined availability of the data channel. For improved sidelink communications between the first UE and the second UE, one or more LBT procedures may be performed in connection with data channels of the multiple data channels <NUM>.

As shown in <FIG>, the first UE (transmitter) may perform one or more LBT procedures <NUM> (e.g., LBT procedure <NUM>-<NUM>, LBT procedure <NUM>-<NUM>, LBT procedure <NUM>-<NUM>, and/or LBT procedure <NUM>-<NUM>) before transmitting on a data channel. In particular, the first UE may perform an LBT procedure <NUM> for a given data channel of the multiple data channels, such as the multiple data channels <NUM>, before the first UE attempts to transmit a sidelink communication on the given data channel. If the first UE determines that the data channel is available, e.g., based at least in part on sensing during the LBT procedure, the first UE may selectively transmit the sidelink communication via the data channel. If the first UE is unable to determine that the data channel is available, based at least in part on sensing during the LBT procedure, the first UE may perform a subsequent LBT procedure for a next data channel of the multiple data channels. The first UE may then perform an LBT procedure <NUM> on the next data channel, in similar fashion to the previous data channel, with the process repeating for determining availability of a data channel.

As shown in <FIG>, the first UE may perform a first LBT procedure <NUM>-<NUM> for a first data channel, e.g., PSSCH0, of the multiple data channels for attempting a sidelink communication. If the first UE is able to determine that the first data channel is available via the first LBT procedure <NUM>-<NUM>, the first UE may selectively transmit the sidelink communication via the first data channel, e.g., PSSCH0, to the second UE (receiver). If the first UE is unable to determine availability of the data channel via the first LBT procedure <NUM>-<NUM>, the first UE may perform a second LBT procedure <NUM>-<NUM> for a second data channel, e.g., PSSCH1, of the multiple data channels in similar fashion to the previous data channel, with the process repeating to determine availability of a data channel.

For improved error handling, when performing the first LBT procedure <NUM>-<NUM>, the first UE may use a cyclic prefix (CP) extension. By using a CP extension, the first UE may occupy the data channel earlier, such as up to one OFDM symbol before the specified starting point of the first data channel. The first UE may then communicate using the data channel, e.g., PSSCH, based at least in part on indicated TDRAs which may be specified for the data channel.

While a transmitting UE may perform an LBT procedure before attempting the sidelink communication, a receiving UE may perform blind decoding for a data channel for receiving the sidelink communication. As discussed above with respect to <FIG>, with blind decoding, SCI may not be available. The second UE (receiver) may attempt to receive the sidelink communication from the first UE (transmitter), without SCI, based at least in part on the indication from the first UE.

To further improve decoding, the second UE (receiver) may monitor for a reference signal, e.g., a DMRS sequence, according to a given threshold. The second UE may use the threshold to monitor for the reference signal, at a predetermined port, for the sidelink communication to initiate decoding of the data channel. The threshold may be relatively lower (stricter) for an earlier data channel, such as before a first cyclic redundancy check (CRC) process completes. The threshold may be relatively higher (relaxed) for a later data channel, such as after the first CRC process completes. For CRC processes, the second UE (receiver) may receive a HARQ response (acknowledgment (ACK) and/or negative acknowledgment (NACK)) reflecting an outcome of the CRC process.

<FIG> is a diagram illustrating an aspect <NUM> associated with licensed assisted sidelink access using an indication of multiple data channels with direction indication and direction switching, in accordance with the present disclosure. As shown in <FIG>, a first UE may transmit to a second UE via a sidelink sub-channel, e.g., sub-channel <NUM>-<NUM>, of a licensed carrier <NUM>. The first and/or second UEs may correspond to one or more other UEs described elsewhere herein, such as UE <NUM>. The sidelink sub-channel may provide sidelink communication between UEs as described elsewhere herein, such as the sidelink access as described with respect to the UEs <NUM>-<NUM> and <NUM>-<NUM>. The licensed carrier <NUM> may include licensed spectrum and/or licensed bands as described elsewhere herein, such as the licensed carrier <NUM>.

For improved data flow between the first UE and the second UE, the multiple data channels <NUM> may include one or more traffic direction indications for indicating a direction of data for a given data channel of the multiple data channels <NUM>, e.g., from the first UE to the second UE, or from the second UE to the first UE. Such direction indications may at times indicate a switch in direction.

As shown in <FIG>, the first UE may communicate a first traffic direction indication <NUM>-<NUM> indicating transmission of data from the first UE to the second UE using the first and second data channels of the multiple data channels <NUM>, e.g., PSSCH0 and PSSCH1 (Group <NUM>). The first UE may communicate the first traffic direction indication <NUM>-<NUM> on the sub-channel <NUM>-<NUM>. The second UE may communicate a second traffic direction indication <NUM>-<NUM> indicating a switch in traffic direction. The second UE may communicate the second traffic direction indication <NUM>-<NUM> indicating transmission of data from the second UE to the first UE using the third and fourth data channels of the multiple data channels <NUM>, e.g., PSSCH2 and PSSCH3 (Group <NUM>). The second UE may communicate the second traffic direction indication <NUM>-<NUM> on the sub-channel <NUM>-<NUM>.

Although direction switching is shown in <FIG> occurring between groups, such direction switching may occur following any individual data channel. In some aspects, one or more direction switches may occur within a group. By allowing one or more traffic direction indications at various points with respect to the data channels, the first UE and the second UE may flexibly communicate in either direction with one another. Allowing such flexibility in communication may improve efficiency of communication on the unlicensed carrier <NUM>.

While different data channels of the multiple data channels may be associated with different data directions as described above, all of the data channels of the multiple data channels could be associated with a same data direction, whether from the first UE to the second UE, or from the second UE to the first UE. The first UE could communicate an initial traffic direction indication indicating transmission of data from the first UE to the second UE for all of the data channels, e.g., multiple data channels <NUM>, without any subsequent traffic direction indications occurring. The second UE could communicate an initial traffic direction indication indicating transmission of data from the second UE to the first UE for all of the data channels, e.g., multiple data channels <NUM>, without any subsequent traffic direction indications occurring.

Different parameters may also be configured during changes in traffic direction. A first set of parameters, e.g., MCS, TCI, and/or SRI, could be configured for a first data channel, e.g., PSSCH0, and/or group, e.g., Group <NUM>, associated with the first traffic direction indication <NUM>-<NUM>. A second set of parameters, e.g., MCS, TCI, and/or SRI, could be configured for a second data channel, e.g., PSSCH2, and/or group, e.g., Group <NUM>, associated with the second traffic direction indication <NUM>-<NUM>. In some aspects, one or more parameters in the first set of parameters have values that match a corresponding one or more parameters in the second set of parameters.

To further support direction switching, an indication of a change in traffic direction between the first UE and the second UE may be associated with an LBT procedure, e.g., LBT procedure <NUM> of <FIG>, for determining availability of a channel. The LBT procedure may be a Type <NUM> LBT procedure for transmission of a sidelink communication in a later data channel, e.g., PSSCH1. To allow a UE (receiver) time to respond to a change in traffic direction, a time gap, e.g., "T," as described above with respect to <FIG>, may be associated with the LBT procedure and change in traffic direction. For improved error handling, a CP extension, as described above with respect to <FIG>, may be associated with the LBT procedure and change in traffic direction. A UE may use the CP extension to occupy a channel at an instant earlier than an OFDM symbol boundary might allow. By providing the time gap and/or CP extension with the LBT procedure, channel sharing between UEs, e.g., channel occupancy time (COT), may be improved.

<FIG> is a diagram illustrating an aspect <NUM> associated with licensed assisted sidelink access using an indication of multiple data channels with mapping, in accordance with the present disclosure. As shown in <FIG>, a first UE may transmit to a second UE via a sidelink sub-channel, e.g., sub-channel <NUM>-<NUM>, of a licensed carrier <NUM>. The first and/or second UEs may correspond to one or more other UEs described elsewhere herein, such as UE <NUM>. The sidelink sub-channel may provide sidelink communication between UEs as described elsewhere herein, such as the sidelink access as described with respect to the UEs <NUM>-<NUM> and <NUM>-<NUM>. The licensed carrier <NUM> may include licensed spectrum and/or licensed bands as described elsewhere herein, such as the licensed carrier <NUM>.

To manage channel access competition over the unlicensed carrier, e.g., unlicensed carrier <NUM>, and/or avoid collisions, the first UE and the second UE may map to radio access windows (RAWs) for accessing the unlicensed carrier. Such mapping may be associated with the indication described above in connection with <FIG>.

As shown in <FIG>, sub-channel, index dependent, RAWs <NUM> (first RAW <NUM>-<NUM> and/or second RAW <NUM>-<NUM>) may be defined by the indication for accessing the unlicensed carrier <NUM>. The sub-channel <NUM>-<NUM> of the licensed carrier <NUM> may be mapped to the first RAW <NUM>-<NUM> of the unlicensed carrier <NUM> (occurring later in time). A given UE, such as the first UE or the second UE, may be associated with the sub-channel <NUM>-<NUM>. The sub-channel <NUM>-<NUM> of the licensed carrier <NUM> may be mapped to the second RAW <NUM>-<NUM> of the unlicensed carrier <NUM> (occurring earlier in time). A given UE, such as the first UE or the second UE, may be associated with the sub-channel <NUM>-<NUM>. A starting data channel of the multiple data channels, e.g., PSSCH0, may start within the second RAW <NUM>-<NUM> occurring earlier in time. By mapping the data channels to radio access windows which occur at differing times, licensed assisted collision avoidance for channel access may be provided.

In some aspects, the indication from a UE may randomly select a candidate OFDM symbol within a RAW <NUM>. Such candidate OFDM may serve as a starting point of the train of data channels, e.g., PSSCH0, determined according to the particular sub-channel on which the indication was sent. Such mapping to RAWs, e.g., mapping pattern, may change at times, on a per slot basis.

As discussed above, RAWs may occur at different times, e.g., the first RAW <NUM>-<NUM> occurring later in time, and/or the second RAW <NUM>-<NUM> occurring earlier in time. Allowing RAWs to occur at different times may better avoid competition between sub-channels <NUM>.

To improve the distribution and/or timing between start times of RAWs, a penalty factor may be defined, such as during initial configuration, for use in a channel occupancy calculation between the sub-channels. The sidelink sub-channel with a RAW that is first in time, e.g., the second RAW <NUM>-<NUM>, associated with the sub-channel <NUM>-<NUM>, may be associated with a channel access penalty factor that is greater than a channel access penalty factor associated with a sidelink sub-channel with a RAW that is second in time, e.g., the first RAW <NUM>-<NUM>, associated with the sub-channel <NUM>-<NUM>. The channel occupancy calculation may be made, with associated penalty factors, for determining optimal start times of RAWs.

To improve congestion of data traffic through the unlicensed carrier <NUM>, the first UE may provide licensed assisted congestion control. In doing so, the first UE may define the unlicensed carrier, e.g., unlicensed carrier <NUM>, as "separate" and "affiliated" for congestion control determination. By "separate," the first UE may be configured to maintain, from the licensed carrier, e.g., licensed carrier <NUM>, separate channel occupancy ratio statuses, separate channel occupancy ratio limits for a same channel busy rate value, or a combination thereof. By "affiliated," the first UE may be configured to use a CBR measurement for the licensed carrier <NUM> to determine a channel occupancy limit for the unlicensed carrier <NUM>. Additionally, or alternatively, by "affiliated," the first UE may be configured to indicate that a channel occupancy ratio limit for the unlicensed carrier may be calculated based at least in part on the lesser of a first channel busy rate estimate for the licensed carrier <NUM> and a second channel busy rate estimate for the unlicensed carrier <NUM>. By configuring the first UE to so define the unlicensed carrier as "separate" and "affiliated" for congestion control determination, the first UE may improve congestion of data traffic through the unlicensed carrier.

<FIG> is a diagram illustrating an aspect <NUM> associated with licensed assisted sidelink access using an indication of multiple data channels with QoS, in accordance with the present disclosure. As shown in <FIG>, a first UE may transmit to a second UE via a sidelink sub-channel, e.g., sub-channel <NUM>-<NUM>, of a licensed carrier <NUM>. The first and/or second UEs may correspond to one or more other UEs described elsewhere herein, such as UE <NUM>. The sidelink sub-channel may provide sidelink communication between UEs as described elsewhere herein, such as the sidelink access as described with respect to the UEs <NUM>-<NUM> and <NUM>-<NUM>. The licensed carrier <NUM> may include licensed spectrum and/or licensed bands as described elsewhere herein, such as the licensed carrier <NUM>.

To improve performance through the unlicensed carrier <NUM>, the first UE and/or the second UE may support QoS associated with the one or more sidelink communications between the first UE and the second UE. As discussed above with respect to <FIG>, multiple RAWs may be used over the unlicensed carrier, e.g., unlicensed carrier <NUM>, to manage channel access competition and/or avoid collisions. Such RAWs may be configured to occur at different starting points which may reflect different prioritizations for QoS. In particular, a first UE (transmitter) may provide QoS by starting a first RAW before a second RAW, thereby prioritizing the first RAW over the second RAW.

As shown in <FIG>, to improve QoS, multiple RAWs <NUM> maybe provided with different starting points according to different QoS priorities. In particular, RAW <NUM>-<NUM> in the unlicensed carrier, associated with the sub-channel <NUM>-<NUM>, may have an earlier starting point than RAW <NUM>-<NUM> in the unlicensed carrier <NUM>, associated with the sub-channel <NUM>-<NUM>. By prioritizing the sub-channel <NUM>-<NUM> earlier in time, the sub-channel <NUM>-<NUM> may be associated with a higher QoS priority than the sub-channel <NUM>-<NUM>.

Configurations of the multiple RAWs <NUM> may be different from one another. The RAW <NUM>-<NUM> may be associated with a different range of CP extensions and/or a different number of mini-slots for the multiple data channels, e.g., multiple data channels <NUM>, than the RAW <NUM>-<NUM>. A higher priority communication may extend a CP extension, e.g., by an additional OFDM symbol, while a lower priority communication might not use a CP extension at all. Additionally, or alternatively, a higher priority communication may extend mini-slot channels, e.g., PSSCHs, such as up to seven mini-slot channels, while a lower priority communication may have zero mini-slot channels. By allowing configurations of the RAWs to be different from one another, performance through the unlicensed carrier <NUM> may be improved.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a first UE, in accordance with the present disclosure. Example process <NUM> is an example where the first UE (e.g., UE <NUM>) performs operations associated with licensed assisted sidelink access using an indication of multiple data channels.

As shown in <FIG>, in some aspects, process <NUM> may include transmitting, to a second UE via a sidelink sub-channel of a licensed carrier, an indication of multiple data channels of an unlicensed carrier to be used to attempt one or more sidelink communications between the first UE and the second UE (block <NUM>). For example, the first UE (e.g., using transmit processor <NUM>, controller/processor <NUM>, and/or memory <NUM>) may transmit, to a second UE via a sidelink sub-channel of a licensed carrier, an indication of multiple data channels of an unlicensed carrier to be used to attempt one or more sidelink communications between the first UE and the second UE, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include attempting the one or more sidelink communications between the first UE and the second UE using the multiple data channels (block <NUM>). For example, the first UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, and/or memory <NUM>) may attempt the one or more sidelink communications between the first UE and the second UE using the multiple data channels, as described above.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a second UE, in accordance with the present disclosure. Example process <NUM> is an example where the second UE (e.g., UE <NUM>) performs operations associated with licensed assisted sidelink access using an indication of multiple data channels.

As shown in <FIG>, in some aspects, process <NUM> may include receiving, from a first UE via a sidelink sub-channel of a licensed carrier, an indication of multiple data channels of an unlicensed carrier to be used to attempt one or more sidelink communications between the second UE and the first UE (block <NUM>). For example, the second UE (e.g., using receive processor <NUM>, controller/processor <NUM>, and/or memory <NUM>) may receive, from a first UE via a sidelink sub-channel of a licensed carrier, an indication of multiple data channels of an unlicensed carrier to be used to attempt one or more sidelink communications between the second UE and the first UE, as described above.

As further shown in <FIG>, in some aspects, process <NUM> may include attempting the one or more sidelink communications between the second UE and the first UE using the multiple data channels (block <NUM>). For example, the second UE (e.g., using receive processor <NUM>, transmit processor <NUM>, controller/processor <NUM>, and/or memory <NUM>) may attempt the one or more sidelink communications between the second UE and the first UE using the multiple data channels, as described above.

Claim 1:
A first user equipment, UE, for wireless communication, comprising:
means for transmitting, to a second UE via a sidelink sub-channel of a licensed carrier, an indication of multiple data channels of an unlicensed carrier to be used to attempt one or more sidelink communications between the first UE and the second UE; and
means for attempting the one or more sidelink communications between the first UE and the second UE using the multiple data channels,
wherein the indication identifies a switch in traffic direction between a first set of data channels, of the multiple data channels, and a second set of data channels of the multiple data channels, and wherein the indication identifies at least one of a time gap or a cyclic prefix extension for a listen-before-talk procedure associated with the switch in traffic direction.