METHOD AND APPARATUS FOR CONTINUOUS CHANNEL RESERVATION FOR SIDELINK COMMUNICATION

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may obtain a channel occupancy time (COT) in an unlicensed frequency spectrum band. The COT may include an initial time interval for an initial transmission and a subsequent time interval for a subsequent transmission. In the initial time interval, the UE may transmit control information and data to another UE, where the control information indicates the subsequent time interval. The other UE may selectively perform communications during the subsequent time interval. The UE may perform the subsequent transmission during the subsequent time interval.

FIELD OF DISCLOSURE

The following relates to wireless communications, including a method and apparatus for continuous channel reservation for sidelink communication.

BACKGROUND

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support method and apparatus for continuous channel reservation for sidelink communication. The described techniques provide for a user equipment (UE) capable of sidelink communications (e.g., UE-to-UE communication) to configure another UE with a time interval indication for one or more sidelink transmissions in control information for an initial transmission. For example, a UE may obtain a channel occupancy time (COT) in an unlicensed frequency spectrum band. The COT may include an initial time interval for an initial transmission and a subsequent time interval for a subsequent transmission. In the initial time interval, the UE may transmit control information and data to another UE, where the control information indicates the subsequent time interval. The other UE may selectively perform communications during the subsequent time interval (e.g., may refrain from transmitting or receiving if resources over the subsequent time interval are occupied). The UE may perform the subsequent transmission during the subsequent time interval.

A method for wireless communication at a first UE is described. The method may include obtaining a COT in an unlicensed frequency spectrum band for transmitting first control information and first data and second control information and second data, the first control information and the first data to be transmitted during at least a portion of a first time interval of the COT and the second control information and the second data to be transmitted during at least a portion of a second time interval of the COT subsequent to the first time interval, transmitting, during at least the portion of the first time interval and to a second UE, the first control information and the first data over a sidelink shared channel, the first control information indicating the second time interval, and transmitting, during at least the portion of the second time interval, the second control information and the second data over the sidelink shared channel.

An apparatus for wireless communication at a first UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to obtain a COT in an unlicensed frequency spectrum band for transmitting first control information and first data and second control information and second data, the first control information and the first data to be transmitted during at least a portion of a first time interval of the COT and the second control information and the second data to be transmitted during at least a portion of a second time interval of the COT subsequent to the first time interval, transmit, during at least the portion of the first time interval and to a second UE, the first control information and the first data over a sidelink shared channel, the first control information indicating the second time interval, and transmit, during at least the portion of the second time interval, the second control information and the second data over the sidelink shared channel.

Another apparatus for wireless communication at a first UE is described. The apparatus may include means for obtaining a COT in an unlicensed frequency spectrum band for transmitting first control information and first data and second control information and second data, the first control information and the first data to be transmitted during at least a portion of a first time interval of the COT and the second control information and the second data to be transmitted during at least a portion of a second time interval of the COT subsequent to the first time interval, means for transmitting, during at least the portion of the first time interval and to a second UE, the first control information and the first data over a sidelink shared channel, the first control information indicating the second time interval, and means for transmitting, during at least the portion of the second time interval, the second control information and the second data over the sidelink shared channel.

A non-transitory computer-readable medium storing code for wireless communication at a first UE is described. The code may include instructions executable by a processor to obtain a COT in an unlicensed frequency spectrum band for transmitting first control information and first data and second control information and second data, the first control information and the first data to be transmitted during at least a portion of a first time interval of the COT and the second control information and the second data to be transmitted during at least a portion of a second time interval of the COT subsequent to the first time interval, transmit, during at least the portion of the first time interval and to a second UE, the first control information and the first data over a sidelink shared channel, the first control information indicating the second time interval, and transmit, during at least the portion of the second time interval, the second control information and the second data over the sidelink shared channel.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting sidelink control information (SCI) to configure the second UE with a list of subchannels associated with the sidelink shared channel, each subchannel in the list of subchannels being within the second time interval, where the first control information includes the SCI.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for selecting one or more subchannels associated with a same frequency domain resource allocation (FDRA) as the sidelink shared channel, within a listen-before-talk subband occupied by the sidelink shared channel, or both and transmitting the list of subchannels based on selecting the one or more subchannels, where the list of subchannels includes the one or more subchannels.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting the SCI based on a relationship between the first UE and the second UE, where the relationship corresponds to the first UE and the second UE being within a same zone, the first UE and the second UE being within a same UE group, or both.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for establishing the relationship via sidelink radio resource control (RRC) signaling, according to a resource pool, or both.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the SCI includes stage-one SCI or stage-two SCI.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting the first control information indicating the second time interval based on a resource pool of the first UE, the second UE, or both, where the first control information includes a FDRA field.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the FDRA field indicates a set of multiple frequency domain resources associated with a set of multiple subchannels used to transmit the first data over the sidelink shared channel and the method, apparatuses, and non-transitory computer-readable medium may include further operations, features, means, or instructions for transmitting the second data over the set of multiple subchannels using the set of multiple frequency domain resources.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the FDRA field indicates a set of multiple frequency domain resources for the second data and the method, apparatuses, and non-transitory computer-readable medium may include further operations, features, means, or instructions for transmitting the second data using the set of multiple frequency domain resources.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting the first control information including an indicator corresponding to a use of the second time interval or one or more time domain resource allocations (TDRAs), where a number of bits of the indicator corresponds to a number of TDRAs of the one or more TDRAs.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting SCI indicating the second time interval for transmission of the second control information and the second data and a TDRA indication for a retransmission of the first control information and the first data, where the first control information includes the SCI and the TDRA indication.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting the retransmission according to the TDRA indication prior to the second control information and the second data.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting a TDRA indicating the second time interval and a third time interval for a retransmission of the first control information and the first data, where the first control information includes the TDRA.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving signaling configuring a resource pool for the first UE and the second UE, where the TDRA corresponds to the resource pool.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining to perform COT sharing with the second UE based on the second time interval, a COT length, a channel access priority class, or any combination thereof and transmitting, to the second UE, an indication of the COT sharing, where the first control information includes the indication.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting first SCI including the second time interval and transmitting second SCI including the indication.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting SCI including the second time interval and the indication.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining to perform COT sharing may include operations, features, means, or instructions for determining the first UE and the second UE may be within a same zone, share a unicast connection, or both.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first control information indicates a third time interval associated with third control information and third data and the method, apparatuses, and non-transitory computer-readable medium may include further operations, features, means, or instructions for transmitting, during at least a portion of the third time interval and subsequent to the second time interval, the third control information and the third data over the sidelink shared channel, where the second control information indicates the third time interval.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, obtaining the COT may include operations, features, means, or instructions for performing a channel access procedure to obtain the COT, where the channel access procedure includes a listen before talk (LBT) procedure.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a time delay between an end of the first time interval and a beginning of the second time interval exceeds a threshold amount of time and applying a cyclic prefix extension to the second control information based on the time delay exceeding the threshold amount of time.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting the second control information to the second UE or to another UE.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the second data includes a retransmission of the first data.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the second data may be different from the first data.

A method for wireless communication at a first UE is described. The method may include receiving, during at least a portion of a first time interval and from a second UE, first control information and first data over a sidelink shared channel during a COT in an unlicensed frequency spectrum band, the first control information indicating a second time interval subsequent to the first time interval and selectively performing communications during at least a portion of the second time interval based on receiving the first control information.

An apparatus for wireless communication at a first UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, during at least a portion of a first time interval and from a second UE, first control information and first data over a sidelink shared channel during a COT in an unlicensed frequency spectrum band, the first control information indicating a second time interval subsequent to the first time interval and selectively perform communications during at least a portion of the second time interval based on receiving the first control information.

Another apparatus for wireless communication at a first UE is described. The apparatus may include means for receiving, during at least a portion of a first time interval and from a second UE, first control information and first data over a sidelink shared channel during a COT in an unlicensed frequency spectrum band, the first control information indicating a second time interval subsequent to the first time interval and means for selectively performing communications during at least a portion of the second time interval based on receiving the first control information.

A non-transitory computer-readable medium storing code for wireless communication at a first UE is described. The code may include instructions executable by a processor to receive, during at least a portion of a first time interval and from a second UE, first control information and first data over a sidelink shared channel during a COT in an unlicensed frequency spectrum band, the first control information indicating a second time interval subsequent to the first time interval and selectively perform communications during at least a portion of the second time interval based on receiving the first control information.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving SCI to configure the first UE with a list of subchannels associated with the sidelink shared channel, each subchannel in the list of subchannels being within the second time interval, where the first control information includes the SCI and identifying one or more subchannels in the list of subchannels as unavailable for the communications based on receiving the SCI.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving the SCI based on a relationship between the first UE and the second UE, where the relationship corresponds to the first UE and the second UE being within a same zone, the first UE and the second UE being within a same UE group, or both.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for establishing the relationship via sidelink RRC signaling, according to a resource pool, or both.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the SCI includes stage-one SCI or stage-two SCI.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving the first control information indicating the second time interval based on a resource pool of the first UE, the second UE, or both, where the first control information includes a FDRA field.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving the first control information including an indicator corresponding to a use of the second time interval or one or more TDRAs, where a number of bits of the indicator corresponds to a number of TDRAs of the one or more TDRAs.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving SCI indicating the second time interval and a TDRA indication for a retransmission of the first control information and the first data, where the first control information includes the SCI and the TDRA indication and determining to perform the communications based on receiving the SCI, where the communications include receiving the retransmission of the first control information and the first data according to the TDRA indication.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a TDRA indicating the second time interval and a third time interval for a retransmission of the first control information and the first data, where the first control information includes the TDRA and determining to perform the communications based on receiving the TDRA, where the communications include receiving, during the third time interval, the retransmission of the first control information and the first data according to the TDRA.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, from the first UE, an indication of COT sharing including the second time interval, a COT length, a channel access priority class, or any combination thereof, where the first control information includes the indication and determining to perform the communications during the COT based on receiving the indication, where the communications include receiving signaling, transmitting signaling, or both in accordance with the COT sharing.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving first SCI including the second time interval and receiving second SCI including the indication.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving SCI including the second time interval and the indication.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, for the second time interval, second control information and second data over the sidelink shared channel.

DETAILED DESCRIPTION

In some wireless communications systems, such as vehicle-to-everything (V2X) systems, a wireless device may transmit control information and data to another wireless device in a sidelink shared channel. To reduce or mitigate resource collision, a base station may facilitate centralized coordination of time-frequency resource reservation for scheduling transmissions. The reservation information may be carried between wireless devices in sidelink control information (SCI) in a time domain resource allocation (TDRA) field and a frequency domain resource allocation (FDRA) field. The SCI may include resource reservation for one or two scheduled transmissions. However, a wireless device may transmit continuous control information and data transmissions during a channel occupancy time (COT), which may cause resource collision due to lack of scheduling.

As described herein, a wireless device, such as a user equipment (UE), may continuously transmit for a duration, or one or more time intervals, to other wireless devices to prevent resource collision for the continuous transmissions. For example, the UE obtains a COT in an unlicensed frequency spectrum band by performing a listen-before-talk (LBT) procedure. The UE transmits control information and data to another UE during a slot (e.g., duration or time interval) of the COT. The control information includes an indication of a time interval for one or more continuous transmissions. If the UE schedules multiple back-to-back transmissions, the control information in the first transmission indicates the time interval of those back-to-back transmissions. The other UE knows that the resources during that time interval are occupied, and refrains from transmitting using the resources. Otherwise, the UE indicates to the other UE to perform COT sharing, such that the other UE continues to transmit and receive signaling. The UE transmits the continuous transmissions during the time interval.

Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are further described in the context of resource diagrams and process flows. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to continuous channel reservation for sidelink communication.

In some examples, one or more components of the wireless communications system100may operate as or be referred to as a network node. As used herein, a network node may refer to any UE115, base station105, entity of a core network130, apparatus, device, or computing system configured to perform any techniques described herein. For example, a network node may be a UE115. As another example, a network node may be a base station105. As another example, a first network node may be configured to communicate with a second network node or a third network node. In one aspect of this example, the first network node may be a UE115, the second network node may be a base station105, and the third network node may be a UE115. In another aspect of this example, the first network node may be a UE115, the second network node may be a base station105, and the third network node may be a base station105. In yet other aspects of this example, the first, second, and third network nodes may be different. Similarly, reference to a UE115, a base station105, an apparatus, a device, or a computing system may include disclosure of the UE115, base station105, apparatus, device, or computing system being a network node. For example, disclosure that a UE115is configured to receive information from a base station105also discloses that a first network node is configured to receive information from a second network node. In this example, consistent with this disclosure, the first network node may refer to a first UE115, a first base station105, a first apparatus, a first device, or a first computing system configured to receive the information; and the second network node may refer to a second UE115, a second base station105, a second apparatus, a second device, or a second computing system.

In some examples, a wireless device in the wireless communications system100, such as a UE115, may continuously transmit for a duration, or one or more time intervals, to other wireless devices to prevent resource collision for the continuous transmissions. For example, the UE115may obtain a COT in an unlicensed frequency spectrum band by performing an LBT procedure. The UE115may transmit control information and data to another UE115during a slot (e.g., duration or time interval) of the COT. The control information may include an indication of a time interval for one or more continuous transmissions. If the UE115schedules multiple back-to-back transmissions, the control information in the first transmission indicates the time interval of those back-to-back transmissions. The other UE115may know that the resources during that time interval are occupied, and may refrain from transmitting using the resources. Otherwise, the UE115may indicate to the other UE115to perform COT sharing, such that the other UE115may continue to transmit and receive signaling. The UE115may transmit the continuous transmissions during the time interval.

FIG.2illustrates an example of a wireless communications system200that supports continuous channel reservation for sidelink communication in accordance with various aspects of the present disclosure. In some examples, wireless communications system200may implement aspects of wireless communications system100and may include a UE115-a, a UE115-b, a UE115-c, a UE115-d, and a base station105, which may be examples of UEs115and a base station105as described with reference toFIG.1. In some examples, the base station105and UEs115, such as UE115-a, may communicate control information, data, or both using a communication link125. Similarly, the UE115-amay communicate control information, data, or both with another UE115, or multiple UEs115, such as UE115-b, UE115-c, UE115-d, or a combination thereof, using one or more sidelink communication links205. For example, UE115-amay transmit a time interval for continuous channel reservation to UE115-b, UE115-c, UE115-d, or a combination thereof via one or more sidelink communication links205.

In some examples, one or more UEs may communicate with each other, which may be referred to as sidelink communications. For example, in a V2X system, UEs115may perform sidelink communications to exchange periodic messages between nearby UEs115, which may be vehicles, over one or more frequency bands (e.g., sub-6 Hz intelligent transport system (ITS) or licensed frequency bands). In some cases, a wireless device (e.g., UE115or base station105) may perform resource allocation according to different communication modes (e.g., mode 1 and mode 2 resource allocation). For example, mode 2 resource allocation may support standalone sidelink deployment (e.g., in the absence of a base station105to facilitate centralized control or coordination). A UE115may reserve one or more time-frequency resources to mitigate resource collision for distributed channel access.

The UE115may include the reservation information in SCI210, such as stage-one SCI (SCI-1). Specifically, the SCI210may include a codepoint of a TDRA as part of the reservation information. When a resource pool supports one time-frequency resource reservation, the TDRA may be a number of bits (e.g., 5-bits) to indicate the index of a slot215that may be reserved, the slot215being within future slots (e.g.,32future slots). In some examples, a slot215may be a dynamic scheduling unit that refers to a duration for one or more transmissions. Each slot215may be divided into multiple symbols. When a resource pool supports two time-frequency resource reservations, the TDRA may be a greater number of bits than if the resource pool supports one time-frequency resource reservation (e.g., 9-bits), to indicate indices of the two future reserved slots. Similarly, the resource pool may support any number of time-frequency resource reservations, and the TDRA may be a corresponding number of bits.

In some examples, sidelink communications between UEs115may be supported by DRX for battery-powered UEs115, inter-UE coordination for improved reliability (e.g., for mode 2 communications), and the like. Further, sidelink communications may be deployed over one or more frequency bands (e.g., sub-6 GHz ITS or licensed frequency bands). Deployment over the one or more frequency bands may include the Frequency Range 1 (FR1) unlicensed spectrum (e.g., sub-6 GHz frequency bands) for both mode 1 and mode 2 communications, where base station105to UE115communication, which may be referred to as Uu operation, for mode 1 communications may be over a licensed spectrum. Sidelink communication and operation may occur on one or more unlicensed frequency spectrum bands, which may involve channel access and changes to channel structures and procedures. Thus, a UE115may perform continuous channel access within a COT to improve channel access overhead. The UE115may also co-exist with other radio access technologies (RATs) over one or more unlicensed frequency spectrum bands (e.g., FR1 unlicensed spectrum), which may be imposed with LBT (e.g., by local regulations).

For example, LBT may be imposed by local regulators for co-existence among different RATs over one or more unlicensed frequency spectrum bands (e.g., 5 GHz and 6 GHz unlicensed bands). There may be multiple types of LBT procedures, such as a Type 1 LBT (e.g., Cat 1 LBT) procedure in which a wireless device may not perform sensing, a Type 2 LBT (e.g., Cat 2 LBT) procedure in which the wireless device may have a fixed sensing period, and additional LBT procedures (e.g., Cat 3 and Cat 4 LBT procedures) with variable sensing periods and random back-offs. Specifically, a node, such as a UE115, may perform an LBT procedure (e.g., a Type 1 LBT procedure), within a threshold random interval (e.g., up to 9 ms), to reserve a COT for continuous transmission (e.g., up to 10 ms). The reserved COT may be shared via COT-sharing with other UEs115for transmissions during any remaining time. In some examples, there may be multiple RATs operating within the COT, such as Wi-Fi, LTE-license assisted access (LAA), NR-Unlicensed (NR-U), and the like. Each RAT may be capable of performing continuous transmission within the COT as well as COT sharing. For example, for NR-U, both a base station105and a UE115may continuously transmit over one or more slots215, which may be allocated by the base station105, after passing an LBT procedure (e.g., Type 1 LBT procedure).

In some examples, a base station105may include a COT structure indication (COT-SI) in control information to one or more UEs115. For example, the base station105may transmit a COT-SI to UE115-avia communication link125in downlink control information (DCI), such as DCI format 2_0 (e.g., DCI 2_0). The one or more UEs115, may determine a remaining duration of the COT reserved by the base station based on the COT-SI. Additionally or alternatively, the one or more UEs115may determine a COT sharing opportunity (e.g., from the base station105to the UEs115) over one or more symbols, one or more slots215, or the like which are indicated as uplink. In some examples, a UE115may transmit a configured grant-uplink control information (CG-UCI) message to a base station105that may include COT sharing information. The base station105may determine a duration of the COT reserved by a UE115as well as an offset for a COT sharing opportunity (e.g., from the UE115to the base station105). In some examples, there may not be a configuration or signaling for sidelink communication over an unlicensed frequency spectrum band for co-existence with other RATs over the unlicensed spectrum (e.g., 5 GHz or 6 GHz).

In some examples, a UE115may use a TDRA including an indication for continuous channel reservation for improved channel access over one or more unlicensed frequency spectrum bands (e.g., FR1 in the unlicensed spectrum). In some cases, a UE115, such as UE115-a, may include an indicator of a time interval for continuous transmissions in control information. For example, at220, UE115-amay obtain a COT225for performing back-to-back transmission. UE115-amay perform a clear channel assessment (CCA)230to obtain the COT225for sidelink transmission235-a, sidelink transmission235-b, and sidelink transmission235-c. In some examples, sidelink transmission235-athrough sidelink transmission235-cmay be for a same UE115, or for different UEs115. For example, UE115-amay transmit sidelink transmission235-ato UE115-b, sidelink transmission235-bto UE115-c, and sidelink transmission235-cto UE115-d. In some other examples, UE115-amay transmit sidelink transmission235-aand sidelink transmission235-bto UE115-band sidelink transmission235-cto UE115-cor UE115-d. UE115-amay transmit sidelink transmission235-a, sidelink transmission235-b, sidelink transmission235-c, or a combination thereof to any combination of UE115-b, UE115-c, and UE115-d. An SCI210-amay schedule a sidelink transmission235-a, an SCI210-bmay schedule a sidelink transmission235-b, and an SCI210-cmay schedule a sidelink transmission235-c.

In some examples, the indication of time interval240-ain SCI210-aand the indication of time interval240-bin SCI210-bmay reserve one or more time resources for transmission bursts (e.g., sidelink transmission235-band sidelink transmission235-c). Additionally or alternatively, UE115-amay over reserve one or more time-frequency resources to control leakage among interlaced channels. For example, UE115-amay reserve an entire LBT sub-band even if UE115-amay use a portion of available channels in the sub-band. In some cases, the indication of time interval240-aand the indication of time interval240-bmay be used for COT sharing, to communicate information on a COT length, channel access priority class (CAPC), or the like. A sensing UE115(e.g., a UE115performing a CCA230, such as by performing an LBT procedure), may learn about COT sharing opportunities earlier. For example, UE115-amay indicate to UE115-b, UE115-c, UE115-d, or a combination thereof to perform COT sharing, prior to the UEs115performing a CCA230. UE115-b, UE115-c, UE115-d, or a combination thereof may jump in during one of sidelink transmission235-a, sidelink transmission235-b, or sidelink transmission235-cfor transmitting according to the COT sharing (e.g., at an appropriate instance and with a right burst length).

In some cases, the SCI210, such as SCI210-aand SCI210-b, may include a control field for resource reservation. For example, the control field may indicate the duration of a train of control channels and shared channels (e.g., a physical sidelink control channel (PSCCH) and PSSCH pair) transmitted back-to-back in an unlicensed frequency spectrum band according to LBT. Other UEs115may perform collision avoidance accordingly. For example, UE115-b, UE115-c, and UE115-dmay perform collision avoidance when transmitting and receiving control signaling or data during the COT225. In some examples, UE115-amay indicate the resources for sidelink transmission235-a, sidelink transmission235-b, and sidelink transmission235-cto UE115-b, UE115-c, UE115-d, or a combination thereof using an FDRA mechanism, which is described in further detail with respect toFIGS.3A,3B, and3C. In some other examples, UE115-amay indicate the resources for sidelink transmission235-a, sidelink transmission235-b, and sidelink transmission235-cto UE115-b, UE115-c, UE115-d, or a combination thereof using an TDRA mechanism, which is described in further detail with respect toFIGS.4A and4B.

In some examples, the FDRA may indicate a current sidelink shared channel for an entire transmission burst (e.g., time interval240-ain SCI210-aand time interval240-bin SCI210-b). However, the FDRA may not predictably reserve resources for a retransmission of the current sidelink shared channel (e.g., with a consistent radio frequency footprint). Thus, UE115-b, UE115-c, UE115-d, or a combination thereof may not use spatial reuse based on a measurement of the current sidelink shared channel. Thus, UE115-amy enforce back-off for a defined set of sub-channels within the indication of a time interval240without interference measurement and prediction at UE115-b, UE115-c, and UE115-d.

When a UE115performs back-to-back sidelink control channel and sidelink shared channel transmissions, the UE115may carry an indication of a time interval240of the transmission bursts after a current transmission in SCI210. For example, UE115-amay transmit PSCCH and PSSCH pairs, the PSCCH carrying SCI210, such as SCI210-aand SCI210-b. The back-to-back transmission may occur after UE115-aobtains a COT, at220. The COT may be in an unlicensed frequency band imposed with LBT. UE115-amy perform the LBT procedure (e.g., Type 1 LBT), or the LBT procedure outcome may be shared from another UE115or from the base station105via the communication link125. In some cases, UE115-amay perform cycle prefix (CP) extension on the first automatic gain control (AGC) symbol of each following sidelink control channel and sidelink shared channel transmission to avoid leaving a gap greater than a threshold (e.g., equal to or greater than 16 micro seconds (μs)) from the proceeding transmission. In some examples, UE115-amay transmit the set of PSCCH and PSSCH pairs to a same destination or to respective destinations (e.g., to one of UE115-b, UE115-c, or UE115-d, or to each of UE115-b, UE115-c, and UE115-d). Each pair may be used for either a new transmission with new data or a retransmission of a previous transmission. Time interval240-aand time interval240-bmay be with respect to a number of slots215. In some examples, UE115-amay select a subcarrier spacing (SCS) for sidelink transmission235-a, sidelink transmission235-b, and sidelink transmission235-cbased on the duration of the COT225. For example, for a 30 kHz and 15 kHz SCS, UE115-amay use a 5-bit or 4-bit indicator for the time intervals240for a COT of 10 ms.

In some examples, UE115-amay transmit sidelink transmission235-band sidelink transmission235-cduring time interval240-a. UE115-amay transmit sidelink transmission240-cduring time interval240-b. UE115-b, UE115-c, and UE115-dmay selectively perform transmissions during time interval240-aand time interval240-bbased on a COT sharing status, one or more available sub-channels, or the like.

FIGS.3A,3B, and3Cillustrate examples of a resource diagrams300that supports continuous channel reservation for sidelink communication in accordance with various aspects of the present disclosure. In some examples, resource diagram300-a, resource diagram300-b, and resource diagram300-c, may implement aspects of wireless communications system100and wireless communications system200. For example, as illustrated in resource diagram300-a, a UE, which may be an example of a UE115as described inFIGS.1and2, may transmit control information including an FDRA305-athat indicates frequency resources for a current transmission and a duration indication310-ato another UE. In some other examples, as illustrated in resource diagram300-band resource diagram300-c, a UE may transmit control information including an FDRA305-band FDRA305-c, respectively, that indicates frequency resources for one or more subsequent transmissions and a duration indication310-band310-cto another UE.

In some examples, a UE may transmit control information, such as SCI315to another UE. The SCI315may be SCI-1. The UE may include the SCI315in a sidelink control channel, and the SCI315may schedule a sidelink shared channel. The sidelink control channel and sidelink shared channel pair may be referred to as a sidelink transmission320. The SCI315may include an FDRA305indicating one or more frequency resources and a duration indication310indicating one or more time resources for communication, which may replace a TDRA. The duration indication310may be configured according to a resource pool. For example, a network entity (e.g., a base station) may configure a UE by resource pool to carry an indication (e.g., a one bit indication) in the SCI315to dynamically switch between using the duration indication310and a TDRA to indicate the time resources.

In some cases, as illustrated in resource diagram300-a, SCI315-amay indicate FDRA305-aand duration indication310-a. The duration indication310-amay indicate time interval325-a, which may be a duration of back-to-back transmissions including sidelink transmission320-b, sidelink transmission320-c, sidelink transmission320-d, or a combination thereof. FDRA305-amay indicate a number of sub-channels used by a current sidelink shared channel for sidelink transmission320-a. The following sidelink transmissions320, including sidelink transmission320-b, sidelink transmission320-c, sidelink transmission320-d, or a combination thereof may use same frequency domain resources as the current sidelink transmission320-a.

In some other cases, as illustrated in resource diagram300-b, SCI315-bmay indicate FDRA305-band duration indication310-b. The duration indication310-bmay indicate time interval325-b, which may be a duration of back-to-back transmissions including sidelink transmission320-b, sidelink transmission320-c, sidelink transmission320-d, or a combination thereof. FDRA305-bmay indicate one or more frequency resources used by following bursts of sidelink transmissions320, including sidelink transmission320-b, sidelink transmission320-c, sidelink transmission320-d, or a combination thereof. That is, each subsequent sidelink transmission320to sidelink transmission320-amay use a same number of sub-channels as a current sidelink shared channel for sidelink transmission320-a, but at different frequency domain locations as indicated by the FDRA codepoint.

Similarly, as illustrated in resource diagram300-c, SCI315-cmay indicate FDRA305-cand duration indication310-c. The duration indication310-cmay indicate time interval325-c, which may be a duration of back-to-back transmissions including sidelink transmission320-b, sidelink transmission320-c, sidelink transmission320-d, or a combination thereof. FDRA305-cmay indicate one or more frequency resources used by following bursts of sidelink transmissions320, including sidelink transmission320-b, sidelink transmission320-c, sidelink transmission320-d, or a combination thereof. The UE may include an explicit indication of an FDRA305, such as FDRA305-c, to indicate different frequency resources for subsequent sidelink transmissions (e.g., instead of that of a current sidelink shared channel). For example, FDRA305-cmay indicate different frequency resources for sidelink transmission320-b, sidelink transmission320-c, and sidelink transmission320-d.

FIGS.4A and4Billustrate examples of resource diagrams400that support continuous channel reservation for sidelink communication in accordance with various aspects of the present disclosure. In some examples, resource diagram400-aand resource diagram400-bmay implement aspects of wireless communications system100and wireless communications system200. For example, as illustrated in resource diagram400-a, a UE, which may be an example of a UE115as described inFIGS.1and2, may transmit control information including a TDRA405-athat indicates time resources for a retransmission of a current transmission and a duration indication410to another UE. In some other examples, as illustrated in resource diagram400-b, a UE may transmit control information including a TDRA405-bthat indicates both a duration of continuous reservation and non-continuous reservations.

In some examples, a UE may transmit control information, such as SCI415to another UE. The SCI415may be SCI-1. The UE may include the SCI415in a sidelink control channel, and the SCI415may schedule a sidelink shared channel. The sidelink control channel and sidelink shared channel pair may be referred to as a sidelink transmission420. The SCI415may include a TDRA405, a duration indication410, or both indicating one or more time resources for communication. Together with an FDRA, as described with respect toFIGS.3A through3C, one or more UEs may perform collision avoidance. Specifically, after decoding a duration indication410, such as in SCI415-a, a receiving UE (e.g., sensing UE) may be configured to mark a set of subchannels within the indicated duration (e.g., sub-channel1,2,3, and4) as unavailable. In some examples, a UE transmitting SCI415-amay define the set of sub-channels as any sub-channel having a same FDRA as a sidelink shared channel carrying SCI415-aor a number of sub-channels within one or more LBT sub-bands occupied by the sidelink shared channel carrying SCI415-a(e.g., where the number is all of the sub-channels). In some other examples, the UE may indicate one of the two options or may provide for a receiving UE to choose between the two options in SCI415-a.

In some cases, if the UE defines the set of sub-channels as any sub-channel having a same FDRA, one or more sub-channels may be left empty. One or more other UEs may use the frequency domain resources not occupied by one or more sidelink transmissions420. For example, if the other UEs are configured to perform COT sharing, the UEs may use the resources. UE-to-UE sharing may occur according to a defined procedure. To use the FDM resource, other UEs may use an LBT procedure (e.g., Cat 2 LBT) if COT sharing to another sidelink transmission is supported. Additionally or alternatively, the UEs may use a Cat 4 LBT procedure, in which the other UE may acquire a COT, while the UE backs-off from the resources. For both Cat 2 and Cat 4 LBT, if the other UE is too close to the transmitting UE, the LBT may fail due to the energy transmitted from the transmitting UE, which may prevent or reduce FDM resource reuse when UEs are too close.

In some other examples, instead of using a duration indication410and FDRA to perform collision avoidance, the collision avoidance behavior at a receiving or sensing UE may be configured to be UE-dependent (e.g., according to resource pool). Specifically, a sensing UE may be configured to perform collision avoidance when there is a defined relationship between the sensing UE and a source or destination UE in SCI415-a. For example, the sensing UE may execute a back-off if the sensing UE is located within a same zone of a source UE, a same zone of a destination UE, or both. Additionally or alternatively, the sensing UE may execute a back-off if the sensing UE is within a group (e.g., layer 2 (L2) group) including a source UE, a destination UE, or both. Instead of being configured according to a resource pool, the UE-dependent reservation may be agreed between a pair of unicast UEs via sidelink control signaling, such as sidelink RRC (PC5-RRC) signaling. The sidelink control signaling may be semi-static or dynamic via an indication in SCI415(e.g., a layer 1 (L1) indication in SCI type 2 (SCI-2)). In some cases, SCI415-amay be SCI-2.

In some cases, as illustrated in resource diagram400-a, SCI415-amay indicate TDRA405-aand duration indication410in parallel to reserve both a burst for one or more additional sidelink transmissions420and one or more (e.g., up to 2) non-continuous transmission slots for a retransmission425of a current sidelink transmission420-aon a sidelink shared channel. In some cases, the duration indication410may indicate time interval430-a, time interval430-b, or both, which may be durations of back-to-back transmissions including one or more sidelink transmission420. The duration indication410may be configured to apply after the slots reserved for retransmission425-aand retransmission425-b(e.g., to indicate reservation of transmission bursts in the future).

In some other cases, as illustrated in resource diagram400-b, SCI415-bmay indicate TDRA405-b, which may include a new type of indication for both a duration of a continuous reservation and a non-continuous reservation. For example, a UE may use a start and length indicator (SLIV)435for a time domain allocation. The UE may encode TDRA405-baccording to the SLIV435for one or more reservations (e.g., two, where sl-MAxNumPerReserve=3). The UE may use a same encoding approach to indicate a burst duration, such as time interval430-c, and an isolated reservation for sidelink transmission420-b, which may include a new transmission. Similarly, same FDRA entries in an FDRA codepoint may indicate a non-continuous reservation, while different FDRA entries may indicate a continuous reservation. In some examples, TDRA405-bmay be configured according to a resource pool. In some cases, a UE may configure two candidate time domain resource allocations in L2 and may introduce a one bit parameter in SCI415-bto switch between the two candidates. In some other cases, a UE may configure three candidate time domain resource allocations in L3 and may introduce a two bit parameter in SCI415-bto switch among them.

In some cases, a UE may use a duration indication410together with COT information (e.g., COT length and CAPC) to indicate COT sharing opportunities to other UEs. For example, the UE may encode the duration indication410and the COT information separately, with the duration indication in SCI-1 and COT information in SCI-2. In some other examples, the UE may encode the duration indication410and the COT information jointly, in SCI-1 or SCI-2. The UE may perform the joint encoding of the duration indication410, the COT information, and CAPC according to an encoding scheme. In some cases, the UE may use a number of bits to achieve a granularity (e.g., 11 bits to arrive at a granularity of 0.25 ms). The UE may use a reduced number of bits according to one or more SCSs (e.g., 15 kHz and 30 kHz).

In some examples, UE-to-UE COT sharing may be defined such that a UE may share a COT with another UE when they are in a same zone or a defined set of zones. The UEs may share a COT when they have a unicast connection. A control field or codepoint of a remaining COT and CAPC may be encoded as an index according to a configured set or list of valid combinations of remaining COT and CAPC values (e.g., for 18 or 19 remaining COT slots, use 3 or 4 for CAPC, and for 5 or 6 remaining COT slots, use 2, 3, or 4 for CAPC).

In some examples, for mode 1 communications, a wireless device may include a TDRA in a DCI message, such as a DCI format 3 (DCI 3_0) message. Similarly, the duration indication410together with an FDRA may be used in an enhance DCI 3_0 message for a scheduling grant of sidelink resources.

FIG.5illustrates an example of a process flow500that supports continuous channel reservation for sidelink communication in accordance with various aspects of the present disclosure. In some examples, the process flow500may implement aspects of wireless communications system100, wireless communications system200, and resource diagrams300-athrough400-b. The process flow500may illustrate an example of a UE115-eindicating a time interval to UE115-f, UE115-g, or both for one or more sidelink transmission during a COT in an unlicensed frequency spectrum band. UE115-ethrough UE115-gmay be examples of UEs115as described with reference toFIGS.1and2. Alternative examples of the following may be implemented, where some processes are performed in a different order than described or are not performed. In some cases, processes may include additional features not mentioned below, or further processes may be added.

At505, UE115-emay obtain a COT in an unlicensed frequency spectrum band. The COT may be for transmitting one or more pairs of sidelink control conformation and data over a sidelink shared channel. For example, UE115-emay obtain the COT to transmit an initial pair of sidelink control information and data during at least a portion of an initial time interval and one or more additional pairs of sidelink control information and data during at least a portion of subsequent time intervals. UE115-emay perform a channel access procedure to obtain the COT, such as an LBT procedure.

At510, UE115-emay select one or more sub-channels associated with a same FDRA as the sidelink shared channel, within an LBT subband occupied by the sidelink shared channel, or both.

At515, UE115-emay transmit the list of selected sub-channels to UE115-f, UE115-g, or both.

At520, UE115-emay determine to perform COT sharing with UE115-f, UE115-g, or both based on the subsequent time intervals, a COT length, a CAPC, or any combination thereof. For example, UE115-emay determine to perform COT sharing based on UE115-eand UE115-f, or UE115-gbeing within a same zone, sharing a unicast connection, or both.

At525, UE115-emay transmit control information and data over the sidelink shared channel. The control information may indicate one or more subsequent time intervals for additional transmissions over the sidelink shared channel. UE115-emay include the time interval indication in a sidelink control channel and sidelink shared channel pair (e.g., a PSCCH and PSSCH pair). In some examples, the control information may include SCI, such as SCI-1, SCI-2, or both. The SCI may configure UE115-f, UE115-g, or both with the list of sub-channels of the sidelink shared channel. Each sub-channel in the list may be within the subsequent time interval in the time interval indication.

In some cases, UE115-emay transmit the SCI based on a relationship between UE115-eand UE115-for UE115-g. The relationship may be based on the UEs115being within a same zone or set of zones, within a same group, or both. UE115-emay establish the relationship via sidelink RRC signaling (e.g., PC5-RRC signaling), according to a resource pool, or both.

In some examples, UE115-emay transmit the time interval indication based on a resource pool of UE115-e, UE115-f, UE115-g, or a combination thereof. The control information may include an FDRA field. In some cases, the FDRA field may indicate multiple frequency domain resources, which may be for sub-channels used to transmit data over the sidelink shared channel in a sidelink transmission paired with the control information.

In some examples, the control information may include an indicator for a use of the subsequent time interval or one or more TDRAs, where a number of bits of the indicator is based on a number of TDRAs. In some cases, UE115-emay transmit SCI indicating the subsequent time interval for the additional transmission and a TDRA for a retransmission of a current transmission. UE115-emay transmit the retransmission according to the TDRA indication prior to the additional transmission.

In some cases, UE115-emay transmit a time interval indication for each sidelink transmission (e.g., sidelink control information and data pair), until a continuous transmission ends. One or more of the time intervals may be for a retransmission of early data. UE115-emay include a TDRA in the control information including a TDRA indicating both a time interval for a new transmission and a time interval for a retransmission. The TDRA may be based on a resource pool configured at UE115-e. For example, a base station may configure UE115-ewith a resource pool, and UE115-emay send the TDRA based on the resource pool.

In some examples, the control information may include an indication for UE115-f, UE115-g, or both to perform COT sharing. In some cases, UE115-emay indicate the COT sharing in the initial control information or in subsequent control information and in SCI.

At530, UE115-emay transmit at least one additional transmission to UE115-f, UE115-g, or both during at least a portion of an indicated time interval. The additional transmission may be a sidelink control channel and sidelink shared channel pair including control information and data. In some cases, UE115-emay transmit the data for the additional transmission using the sub-channels, the frequency domain resources, or both indicated in the FDRA in the control signaling at525.

In some examples, UE115-emay determine a time delay between an end of an initial time interval and a beginning of a subsequent time interval exceeds a threshold amount of time. UE115-emay apply a cyclic prefix extension to the additional control information based on the time delay exceeding the threshold amount of time.

In some examples, UE115-emay transmit the additional control information to UE115-f, UE115-g, or both. In some cases, the additional data may include a retransmission of previous data. In some other cases, the additional data may include different data than previous data (e.g., new data).

At535, UE115-fmay selectively perform communications during at least a portion of the subsequent time interval based on receiving the initial control information. For example, at540, UE115-fmay identify one or more sub-channels are unavailable for communications, and may refrain from communicating using the subchannels. In some other examples, UE115-fmay determine to perform the communications based on receiving SCI at525, the SCI including a TDRA, a COT sharing status, or the like.

FIG.6shows a block diagram600of a device605that supports continuous channel reservation for sidelink communication in accordance with various aspects of the present disclosure. The device605may be an example of aspects of a UE115as described herein. The device605may include a receiver610, a transmitter615, and a communications manager620. The device605may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

The communications manager620, the receiver610, the transmitter615, or various combinations thereof or various components thereof may be examples of means for performing various aspects of continuous channel reservation for sidelink communication as described herein. For example, the communications manager620, the receiver610, the transmitter615, or various combinations or components thereof may support a method for performing one or more of the functions described herein.

In some examples, the communications manager620may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver610, the transmitter615, or both. For example, the communications manager620may receive information from the receiver610, send information to the transmitter615, or be integrated in combination with the receiver610, the transmitter615, or both to receive information, transmit information, or perform various other operations as described herein.

The communications manager620may support wireless communication at a first UE in accordance with examples as disclosed herein. For example, the communications manager620may be configured as or otherwise support a means for obtaining a COT in an unlicensed frequency spectrum band for transmitting first control information and first data and second control information and second data, the first control information and the first data to be transmitted during at least a portion of a first time interval of the COT and the second control information and the second data to be transmitted during at least a portion of a second time interval of the COT subsequent to the first time interval. The communications manager620may be configured as or otherwise support a means for transmitting, during at least the portion of the first time interval and to a second UE, the first control information and the first data over a sidelink shared channel, the first control information indicating the second time interval. The communications manager620may be configured as or otherwise support a means for transmitting, during at least the portion of the second time interval, the second control information and the second data over the sidelink shared channel.

Additionally or alternatively, the communications manager620may support wireless communication at a first UE in accordance with examples as disclosed herein. For example, the communications manager620may be configured as or otherwise support a means for receiving, during at least a portion of a first time interval and from a second UE, first control information and first data over a sidelink shared channel during a COT in an unlicensed frequency spectrum band, the first control information indicating a second time interval subsequent to the first time interval. The communications manager620may be configured as or otherwise support a means for selectively performing communications during at least a portion of the second time interval based on receiving the first control information.

By including or configuring the communications manager620in accordance with examples as described herein, the device605(e.g., a processor controlling or otherwise coupled to the receiver610, the transmitter615, the communications manager620, or a combination thereof) may support techniques for a UE115to indicate a time interval to another UE115for one or more sidelink transmission during a COT in an unlicensed frequency spectrum band, which may provide for reduced processing, reduced power consumption, more efficient utilization of communication resources, and the like at the UEs115.

The device705, or various components thereof, may be an example of means for performing various aspects of continuous channel reservation for sidelink communication as described herein. For example, the communications manager720may include a COT component725, a time interval component730, a data component735, or any combination thereof. The communications manager720may be an example of aspects of a communications manager620as described herein. In some examples, the communications manager720, or various components thereof, may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver710, the transmitter715, or both. For example, the communications manager720may receive information from the receiver710, send information to the transmitter715, or be integrated in combination with the receiver710, the transmitter715, or both to receive information, transmit information, or perform various other operations as described herein.

The communications manager720may support wireless communication at a first UE in accordance with examples as disclosed herein. The COT component725may be configured as or otherwise support a means for obtaining a COT in an unlicensed frequency spectrum band for transmitting first control information and first data and second control information and second data, the first control information and the first data to be transmitted during at least a portion of a first time interval of the COT and the second control information and the second data to be transmitted during at least a portion of a second time interval of the COT subsequent to the first time interval. The time interval component730may be configured as or otherwise support a means for transmitting, during at least the portion of the first time interval and to a second UE, the first control information and the first data over a sidelink shared channel, the first control information indicating the second time interval. The data component735may be configured as or otherwise support a means for transmitting, during at least the portion of the second time interval, the second control information and the second data over the sidelink shared channel.

Additionally or alternatively, the communications manager720may support wireless communication at a first UE in accordance with examples as disclosed herein. The time interval component730may be configured as or otherwise support a means for receiving, during at least a portion of a first time interval and from a second UE, first control information and first data over a sidelink shared channel during a COT in an unlicensed frequency spectrum band, the first control information indicating a second time interval subsequent to the first time interval. The data component735may be configured as or otherwise support a means for selectively performing communications during at least a portion of the second time interval based on receiving the first control information.

FIG.8shows a block diagram800of a communications manager820that supports continuous channel reservation for sidelink communication in accordance with various aspects of the present disclosure. The communications manager820may be an example of aspects of a communications manager620, a communications manager720, or both, as described herein. The communications manager820, or various components thereof, may be an example of means for performing various aspects of continuous channel reservation for sidelink communication as described herein. For example, the communications manager820may include a COT component825, a time interval component830, a data component835, a resource allocation component840, a UE relationship component845, or any combination thereof. Each of these components may communicate, directly or indirectly, with one another (e.g., via one or more buses).

The communications manager820may support wireless communication at a first UE in accordance with examples as disclosed herein. The COT component825may be configured as or otherwise support a means for obtaining a COT in an unlicensed frequency spectrum band for transmitting first control information and first data and second control information and second data, the first control information and the first data to be transmitted during at least a portion of a first time interval of the COT and the second control information and the second data to be transmitted during at least a portion of a second time interval of the COT subsequent to the first time interval. The time interval component830may be configured as or otherwise support a means for transmitting, during at least the portion of the first time interval and to a second UE, the first control information and the first data over a sidelink shared channel, the first control information indicating the second time interval. The data component835may be configured as or otherwise support a means for transmitting, during at least the portion of the second time interval, the second control information and the second data over the sidelink shared channel.

In some examples, the resource allocation component840may be configured as or otherwise support a means for transmitting SCI to configure the second UE with a list of subchannels associated with the sidelink shared channel, each subchannel in the list of subchannels being within the second time interval, where the first control information includes the SCI.

In some examples, the resource allocation component840may be configured as or otherwise support a means for selecting one or more subchannels associated with a same frequency domain resource allocation as the sidelink shared channel, within a listen-before-talk subband occupied by the sidelink shared channel, or both. In some examples, the resource allocation component840may be configured as or otherwise support a means for transmitting the list of subchannels based on selecting the one or more subchannels, where the list of subchannels includes the one or more subchannels.

In some examples, the UE relationship component845may be configured as or otherwise support a means for transmitting the SCI based on a relationship between the first UE and the second UE, where the relationship corresponds to the first UE and the second UE being within a same zone, the first UE and the second UE being within a same UE group, or both.

In some examples, the UE relationship component845may be configured as or otherwise support a means for establishing the relationship via sidelink RRC signaling, according to a resource pool, or both.

In some examples, the SCI includes stage-one SCI or stage-two SCI.

In some examples, the resource allocation component840may be configured as or otherwise support a means for transmitting the first control information indicating the second time interval based on a resource pool of the first UE, the second UE, or both, where the first control information includes a frequency domain resource allocation field.

In some examples, the frequency domain resource allocation field indicates a set of multiple frequency domain resources associated with a set of multiple subchannels used to transmit the first data over the sidelink shared channel, and the resource allocation component840may be configured as or otherwise support a means for transmitting the second data over the set of multiple subchannels using the set of multiple frequency domain resources.

In some examples, the frequency domain resource allocation field indicates a set of multiple frequency domain resources for the second data, and the resource allocation component840may be configured as or otherwise support a means for transmitting the second data using the set of multiple frequency domain resources.

In some examples, the resource allocation component840may be configured as or otherwise support a means for transmitting the first control information including an indicator corresponding to a use of the second time interval or one or more time domain resource allocations, where a number of bits of the indicator corresponds to a number of time domain resource allocations of the one or more time domain resource allocations.

In some examples, the resource allocation component840may be configured as or otherwise support a means for transmitting SCI indicating the second time interval for transmission of the second control information and the second data and a time domain resource allocation indication for a retransmission of the first control information and the first data, where the first control information includes the SCI and the time domain resource allocation indication.

In some examples, the resource allocation component840may be configured as or otherwise support a means for transmitting the retransmission according to the time domain resource allocation indication prior to the second control information and the second data.

In some examples, the resource allocation component840may be configured as or otherwise support a means for transmitting a time domain resource allocation indicating the second time interval and a third time interval for a retransmission of the first control information and the first data, where the first control information includes the time domain resource allocation.

In some examples, the resource allocation component840may be configured as or otherwise support a means for receiving signaling configuring a resource pool for the first UE and the second UE, where the time domain resource allocation corresponds to the resource pool.

In some examples, the COT component825may be configured as or otherwise support a means for determining to perform COT sharing with the second UE based on the second time interval, a COT length, a channel access priority class, or any combination thereof. In some examples, the COT component825may be configured as or otherwise support a means for transmitting, to the second UE, an indication of the COT sharing, where the first control information includes the indication.

In some examples, the time interval component830may be configured as or otherwise support a means for transmitting first SCI including the second time interval. In some examples, the time interval component830may be configured as or otherwise support a means for transmitting second SCI including the indication.

In some examples, the time interval component830may be configured as or otherwise support a means for transmitting SCI including the second time interval and the indication.

In some examples, to support determining to perform COT sharing, the UE relationship component845may be configured as or otherwise support a means for determining the first UE and the second UE are within a same zone, share a unicast connection, or both.

In some examples, the first control information indicates a third time interval associated with third control information and third data, and the time interval component830may be configured as or otherwise support a means for transmitting, during at least a portion of the third time interval and subsequent to the second time interval, the third control information and the third data over the sidelink shared channel, where the second control information indicates the third time interval.

In some examples, to support obtaining the COT, the COT component825may be configured as or otherwise support a means for performing a channel access procedure to obtain the COT, where the channel access procedure includes a listen before talk procedure.

In some examples, the time interval component830may be configured as or otherwise support a means for determining a time delay between an end of the first time interval and a beginning of the second time interval exceeds a threshold amount of time.

In some examples, the time interval component830may be configured as or otherwise support a means for applying a cyclic prefix extension to the second control information based on the time delay exceeding the threshold amount of time.

In some examples, the time interval component830may be configured as or otherwise support a means for transmitting the second control information to the second UE or to another UE.

In some examples, the second data includes a retransmission of the first data.

In some examples, the second data is different from the first data.

Additionally or alternatively, the communications manager820may support wireless communication at a first UE in accordance with examples as disclosed herein. In some examples, the time interval component830may be configured as or otherwise support a means for receiving, during at least a portion of a first time interval and from a second UE, first control information and first data over a sidelink shared channel during a COT in an unlicensed frequency spectrum band, the first control information indicating a second time interval subsequent to the first time interval. In some examples, the data component835may be configured as or otherwise support a means for selectively performing communications during at least a portion of the second time interval based on receiving the first control information.

In some examples, the resource allocation component840may be configured as or otherwise support a means for receiving SCI to configure the first UE with a list of subchannels associated with the sidelink shared channel, each subchannel in the list of subchannels being within the second time interval, where the first control information includes the SCI. In some examples, the resource allocation component840may be configured as or otherwise support a means for identifying one or more subchannels in the list of subchannels as unavailable for the communications based on receiving the SCI.

In some examples, the UE relationship component845may be configured as or otherwise support a means for receiving the SCI based on a relationship between the first UE and the second UE, where the relationship corresponds to the first UE and the second UE being within a same zone, the first UE and the second UE being within a same UE group, or both.

In some examples, the UE relationship component845may be configured as or otherwise support a means for establishing the relationship via sidelink RRC signaling, according to a resource pool, or both.

In some examples, the SCI includes stage-one SCI or stage-two SCI.

In some examples, the resource allocation component840may be configured as or otherwise support a means for receiving the first control information indicating the second time interval based on a resource pool of the first UE, the second UE, or both, where the first control information includes a frequency domain resource allocation field.

In some examples, the resource allocation component840may be configured as or otherwise support a means for receiving the first control information including an indicator corresponding to a use of the second time interval or one or more time domain resource allocations, where a number of bits of the indicator corresponds to a number of time domain resource allocations of the one or more time domain resource allocations.

In some examples, the resource allocation component840may be configured as or otherwise support a means for receiving SCI indicating the second time interval and a time domain resource allocation indication for a retransmission of the first control information and the first data, where the first control information includes the SCI and the time domain resource allocation indication. In some examples, the resource allocation component840may be configured as or otherwise support a means for determining to perform the communications based on receiving the SCI, where the communications include receiving the retransmission of the first control information and the first data according to the time domain resource allocation indication.

In some examples, the resource allocation component840may be configured as or otherwise support a means for receiving a time domain resource allocation indicating the second time interval and a third time interval for a retransmission of the first control information and the first data, where the first control information includes the time domain resource allocation. In some examples, the resource allocation component840may be configured as or otherwise support a means for determining to perform the communications based on receiving the time domain resource allocation, where the communications include receiving, during the third time interval, the retransmission of the first control information and the first data according to the time domain resource allocation.

In some examples, the COT component825may be configured as or otherwise support a means for receiving, from the first UE, an indication of COT sharing including the second time interval, a COT length, a channel access priority class, or any combination thereof, where the first control information includes the indication. In some examples, the COT component825may be configured as or otherwise support a means for determining to perform the communications during the COT based on receiving the indication, where the communications include receiving signaling, transmitting signaling, or both in accordance with the COT sharing.

In some examples, the time interval component830may be configured as or otherwise support a means for receiving first SCI including the second time interval. In some examples, the time interval component830may be configured as or otherwise support a means for receiving second SCI including the indication.

In some examples, the time interval component830may be configured as or otherwise support a means for receiving SCI including the second time interval and the indication.

In some examples, the time interval component830may be configured as or otherwise support a means for receiving, for the second time interval, second control information and second data over the sidelink shared channel.

The communications manager920may support wireless communication at a first UE in accordance with examples as disclosed herein. For example, the communications manager920may be configured as or otherwise support a means for obtaining a COT in an unlicensed frequency spectrum band for transmitting first control information and first data and second control information and second data, the first control information and the first data to be transmitted during at least a portion of a first time interval of the COT and the second control information and the second data to be transmitted during at least a portion of a second time interval of the COT subsequent to the first time interval. The communications manager920may be configured as or otherwise support a means for transmitting, during at least the portion of the first time interval and to a second UE, the first control information and the first data over a sidelink shared channel, the first control information indicating the second time interval. The communications manager920may be configured as or otherwise support a means for transmitting, during at least the portion of the second time interval, the second control information and the second data over the sidelink shared channel.

Additionally or alternatively, the communications manager920may support wireless communication at a first UE in accordance with examples as disclosed herein. For example, the communications manager920may be configured as or otherwise support a means for receiving, during at least a portion of a first time interval and from a second UE, first control information and first data over a sidelink shared channel during a COT in an unlicensed frequency spectrum band, the first control information indicating a second time interval subsequent to the first time interval. The communications manager920may be configured as or otherwise support a means for selectively performing communications during at least a portion of the second time interval based on receiving the first control information.

By including or configuring the communications manager920in accordance with examples as described herein, the device905may support techniques for a UE115to indicate a time interval to another UE115for one or more sidelink transmission during a COT in an unlicensed frequency spectrum band, which may provide for improved communication reliability, reduced latency, improved user experience related to reduced processing, reduced power consumption, more efficient utilization of communication resources, improved coordination between devices, longer battery life, improved utilization of processing capability, and the like at the UEs115

At1005, the method may include obtaining a COT in an unlicensed frequency spectrum band for transmitting first control information and first data and second control information and second data, the first control information and the first data to be transmitted during at least a portion of a first time interval of the COT and the second control information and the second data to be transmitted during at least a portion of a second time interval of the COT subsequent to the first time interval. The operations of1005may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1005may be performed by a COT component825as described with reference toFIG.8.

At1010, the method may include transmitting, during at least the portion of the first time interval and to a second UE, the first control information and the first data over a sidelink shared channel, the first control information indicating the second time interval. The operations of1010may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1010may be performed by a time interval component830as described with reference toFIG.8.

At1015, the method may include transmitting, during at least the portion of the second time interval, the second control information and the second data over the sidelink shared channel. The operations of1015may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1015may be performed by a data component835as described with reference toFIG.8.

At1105, the method may include obtaining a COT in an unlicensed frequency spectrum band for transmitting first control information and first data and second control information and second data, the first control information and the first data to be transmitted during at least a portion of a first time interval of the COT and the second control information and the second data to be transmitted during at least a portion of a second time interval of the COT subsequent to the first time interval. The operations of1105may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1105may be performed by a COT component825as described with reference toFIG.8.

At1110, the method may include transmitting, during at least the portion of the first time interval and to a second UE, the first control information and the first data over a sidelink shared channel, the first control information indicating the second time interval. The operations of1110may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1110may be performed by a time interval component830as described with reference toFIG.8.

At1115, the method may include transmitting SCI to configure the second UE with a list of subchannels associated with the sidelink shared channel, each subchannel in the list of subchannels being within the second time interval, where the first control information includes the SCI. The operations of1115may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1115may be performed by a resource allocation component840as described with reference toFIG.8.

At1120, the method may include transmitting, during at least the portion of the second time interval, the second control information and the second data over the sidelink shared channel. The operations of1120may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1120may be performed by a data component835as described with reference toFIG.8.

At1205, the method may include obtaining a COT in an unlicensed frequency spectrum band for transmitting first control information and first data and second control information and second data, the first control information and the first data to be transmitted during at least a portion of a first time interval of the COT and the second control information and the second data to be transmitted during at least a portion of a second time interval of the COT subsequent to the first time interval. The operations of1205may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1205may be performed by a COT component825as described with reference toFIG.8.

At1210, the method may include transmitting, during at least the portion of the first time interval and to a second UE, the first control information and the first data over a sidelink shared channel, the first control information indicating the second time interval. The operations of1210may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1210may be performed by a time interval component830as described with reference toFIG.8.

At1215, the method may include transmitting the first control information indicating the second time interval based on a resource pool of the first UE, the second UE, or both, where the first control information includes a frequency domain resource allocation field. The operations of1215may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1215may be performed by a resource allocation component840as described with reference toFIG.8.

At1220, the method may include transmitting, during at least the portion of the second time interval, the second control information and the second data over the sidelink shared channel. The operations of1220may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1220may be performed by a data component835as described with reference toFIG.8.

At1305, the method may include receiving, during at least a portion of a first time interval and from a second UE, first control information and first data over a sidelink shared channel during a COT in an unlicensed frequency spectrum band, the first control information indicating a second time interval subsequent to the first time interval. The operations of1305may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1305may be performed by a time interval component830as described with reference toFIG.8.

At1310, the method may include selectively performing communications during at least a portion of the second time interval based on receiving the first control information. The operations of1310may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1310may be performed by a data component835as described with reference toFIG.8.

FIG.14shows a flowchart illustrating a method1400that supports continuous channel reservation for sidelink communication in accordance with various aspects of the present disclosure. The operations of the method1400may be implemented by a UE or its components as described herein. For example, the operations of the method1400may be performed by a UE115as described with reference toFIGS.1through9. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.

At1405, the method may include receiving, during at least a portion of a first time interval and from a second UE, first control information and first data over a sidelink shared channel during a COT in an unlicensed frequency spectrum band, the first control information indicating a second time interval subsequent to the first time interval. The operations of1405may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1405may be performed by a time interval component830as described with reference toFIG.8.

At1410, the method may include receiving SCI to configure the first UE with a list of subchannels associated with the sidelink shared channel, each subchannel in the list of subchannels being within the second time interval, where the first control information includes the SCI. The operations of1410may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1410may be performed by a resource allocation component840as described with reference toFIG.8.

At1415, the method may include identifying one or more subchannels in the list of subchannels as unavailable for the communications based on receiving the SCI. The operations of1415may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1415may be performed by a resource allocation component840as described with reference toFIG.8.

At1420, the method may include selectively performing communications during at least a portion of the second time interval based on receiving the first control information. The operations of1420may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1420may be performed by a data component835as described with reference toFIG.8.

Aspect 1: A method for wireless communication at a first UE, comprising: obtaining a channel occupancy time in an unlicensed frequency spectrum band for transmitting first control information and first data and second control information and second data, the first control information and the first data to be transmitted during at least a portion of a first time interval of the channel occupancy time and the second control information and the second data to be transmitted during at least a portion of a second time interval of the channel occupancy time subsequent to the first time interval; transmitting, during at least the portion of the first time interval and to a second UE, the first control information and the first data over a sidelink shared channel, the first control information indicating the second time interval; and transmitting, during at least the portion of the second time interval, the second control information and the second data over the sidelink shared channel.

Aspect 2: The method of aspect 1 further comprising: transmitting sidelink control information to configure the second UE with a list of subchannels associated with the sidelink shared channel, each subchannel in the list of subchannels being within the second time interval, wherein the first control information comprises the sidelink control information.

Aspect 3: The method of aspect 2 further comprising: selecting one or more subchannels associated with a same frequency domain resource allocation as the sidelink shared channel, within a listen-before-talk subband occupied by the sidelink shared channel, or both; and transmitting the list of subchannels based at least in part on selecting the one or more subchannels, wherein the list of subchannels comprises the one or more subchannels.

Aspect 4: The method of any of aspects 2 through 3 further comprising: transmitting the sidelink control information based at least in part on a relationship between the first UE and the second UE, wherein the relationship corresponds to the first UE and the second UE being within a same zone, the first UE and the second UE being within a same UE group, or both.

Aspect 5: The method of aspect 4 further comprising: establishing the relationship via sidelink radio resource control signaling, according to a resource pool, or both.

Aspect 6: The method of any of aspects 2 through 5, wherein the sidelink control information comprises stage-one sidelink control information or stage-two sidelink control information.

Aspect 7: The method of any of aspects 1 through 6 further comprising: transmitting the first control information indicating the second time interval based at least in part on a resource pool of the first UE, the second UE, or both, wherein the first control information comprises a frequency domain resource allocation field.

Aspect 8: The method of aspect 7, wherein the frequency domain resource allocation field indicates a plurality of frequency domain resources associated with a plurality of subchannels used to transmit the first data over the sidelink shared channel, the method further comprising: transmitting the second data over the plurality of subchannels using the plurality of frequency domain resources.

Aspect 9: The method of any of aspects 7 through 8, wherein the frequency domain resource allocation field indicates a plurality of frequency domain resources for the second data, the method further comprising: transmitting the second data using the plurality of frequency domain resources.

Aspect 10: The method of any of aspects 1 through 9 further comprising: transmitting the first control information comprising an indicator corresponding to a use of the second time interval or one or more time domain resource allocations, wherein a number of bits of the indicator corresponds to a number of time domain resource allocations of the one or more time domain resource allocations.

Aspect 11: The method of any of aspects 1 through 10 further comprising: transmitting sidelink control information indicating the second time interval for transmission of the second control information and the second data and a time domain resource allocation indication for a retransmission of the first control information and the first data, wherein the first control information comprises the sidelink control information and the time domain resource allocation indication.

Aspect 12: The method of aspect 11 further comprising: transmitting the retransmission according to the time domain resource allocation indication prior to the second control information and the second data.

Aspect 13: The method of any of aspects 1 through 12 further comprising: transmitting a time domain resource allocation indicating the second time interval and a third time interval for a retransmission of the first control information and the first data, wherein the first control information comprises the time domain resource allocation.

Aspect 14: The method of aspect 13 further comprising: receiving signaling configuring a resource pool for the first UE and the second UE, wherein the time domain resource allocation corresponds to the resource pool.

Aspect 15: The method of any of aspects 1 through 14 further comprising: determining to perform channel occupancy time sharing with the second UE based at least in part on the second time interval, a channel occupancy time length, a channel access priority class, or any combination thereof; and transmitting, to the second UE, an indication of the channel occupancy time sharing, wherein the first control information comprises the indication.

Aspect 16: The method of aspect 15 further comprising: transmitting first sidelink control information comprising the second time interval; and transmitting second sidelink control information comprising the indication.

Aspect 17: The method of any of aspects 15 through 16 further comprising: transmitting sidelink control information comprising the second time interval and the indication.

Aspect 18: The method of any of aspects 15 through 17, wherein determining to perform channel occupancy time sharing comprises: determining the first UE and the second UE are within a same zone, share a unicast connection, or both.

Aspect 19: The method of any of aspects 1 through 18, wherein the first control information indicates a third time interval associated with third control information and third data, the method further comprising: transmitting, during at least a portion of the third time interval and subsequent to the second time interval, the third control information and the third data over the sidelink shared channel, wherein the second control information indicates the third time interval.

Aspect 20: The method of any of aspects 1 through 19, wherein obtaining the channel occupancy time further comprises: performing a channel access procedure to obtain the channel occupancy time, wherein the channel access procedure comprises a listen before talk procedure.

Aspect 21: The method of any of aspects 1 through 20 further comprising: determining a time delay between an end of the first time interval and a beginning of the second time interval exceeds a threshold amount of time; and applying a cyclic prefix extension to the second control information based at least in part on the time delay exceeding the threshold amount of time.

Aspect 22: The method of any of aspects 1 through 21 further comprising: transmitting the second control information to the second UE or to another UE.

Aspect 23: The method of any of aspects 1 through 22, wherein the second data comprises a retransmission of the first data.

Aspect 24: The method of any of aspects 1 through 22, wherein the second data is different from the first data.

Aspect 25: A method for wireless communication at a first UE, comprising: receiving, during at least a portion of a first time interval and from a second UE, first control information and first data over a sidelink shared channel during a channel occupancy time in an unlicensed frequency spectrum band, the first control information indicating a second time interval subsequent to the first time interval; and selectively performing communications during at least a portion of the second time interval based at least in part on receiving the first control information.

Aspect 26: The method of aspect 25 further comprising: receiving sidelink control information to configure the first UE with a list of subchannels associated with the sidelink shared channel, each subchannel in the list of subchannels being within the second time interval, wherein the first control information comprises the sidelink control information; and identifying one or more subchannels in the list of subchannels as unavailable for the communications based at least in part on receiving the sidelink control information.

Aspect 27: The method of aspect 26 further comprising: receiving the sidelink control information based at least in part on a relationship between the first UE and the second UE, wherein the relationship corresponds to the first UE and the second UE being within a same zone, the first UE and the second UE being within a same UE group, or both.

Aspect 28: The method of aspect 27 further comprising: establishing the relationship via sidelink radio resource control signaling, according to a resource pool, or both.

Aspect 29: The method of any of aspects 26 through 28, wherein the sidelink control information comprises stage-one sidelink control information or stage-two sidelink control information.

Aspect 30: The method of any of aspects 25 through 29 further comprising: receiving the first control information indicating the second time interval based at least in part on a resource pool of the first UE, the second UE, or both, wherein the first control information comprises a frequency domain resource allocation field.

Aspect 31: The method of any of aspects 25 through 30 further comprising: receiving the first control information comprising an indicator corresponding to a use of the second time interval or one or more time domain resource allocations, wherein a number of bits of the indicator corresponds to a number of time domain resource allocations of the one or more time domain resource allocations.

Aspect 32: The method of any of aspects 25 through 31 further comprising: receiving sidelink control information indicating the second time interval and a time domain resource allocation indication for a retransmission of the first control information and the first data, wherein the first control information comprises the sidelink control information and the time domain resource allocation indication; and determining to perform the communications based at least in part on receiving the sidelink control information, wherein the communications comprise receiving the retransmission of the first control information and the first data according to the time domain resource allocation indication.

Aspect 33: The method of any of aspects 25 through 32 further comprising: receiving a time domain resource allocation indicating the second time interval and a third time interval for a retransmission of the first control information and the first data, wherein the first control information comprises the time domain resource allocation; and determining to perform the communications based at least in part on receiving the time domain resource allocation, wherein the communications comprise receiving, during the third time interval, the retransmission of the first control information and the first data according to the time domain resource allocation.

Aspect 34: The method of any of aspects 25 through 33 further comprising: receiving, from the first UE, an indication of channel occupancy time sharing comprising the second time interval, a channel occupancy time length, a channel access priority class, or any combination thereof, wherein the first control information comprises the indication; and determining to perform the communications during the channel occupancy time based at least in part on receiving the indication, wherein the communications comprise receiving signaling, transmitting signaling, or both in accordance with the channel occupancy time sharing.

Aspect 35: The method of aspect 34 further comprising: receiving first sidelink control information comprising the second time interval; and receiving second sidelink control information comprising the indication.

Aspect 36: The method of any of aspects 34 through 35 further comprising: receiving sidelink control information comprising the second time interval and the indication.

Aspect 37: The method of any of aspects 25 through 36 further comprising: receiving, for the second time interval, second control information and second data over the sidelink shared channel.

Aspect 42: An apparatus for wireless communication at a first UE, comprising at least one means for performing a method of any of aspects 25 through 37.