Signaling of joint alignment of Uu DRX and SL DRX

Aspects present herein relate to methods and devices for wireless communication including an apparatus, e.g., a UE and/or a base station. The apparatus may receive a first indication of assistance information associated with a Uu DRX configuration and an SL DRX configuration. The apparatus may also transmit a second indication of the assistance information associated with the Uu DRX configuration and the SL DRX configuration. Additionally, the apparatus may receive an indication of the Uu DRX configuration and an indication of the SL DRX configuration.

TECHNICAL FIELD

The present disclosure relates generally to communication systems, and more particularly, to discontinuous reception (DRX) configurations in wireless communications.

INTRODUCTION

BRIEF SUMMARY

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a user equipment (UE). The apparatus may receive a first indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration. The apparatus may also transmit a second indication of the assistance information associated with the Uu DRX configuration and the SL DRX configuration. Additionally, the apparatus may receive an indication of the Uu DRX configuration and an indication of the SL DRX configuration.

In another aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a base station. The apparatus may receive, from a user equipment (UE), an indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration. The apparatus may also configure the SL DRX configuration and the Uu DRX configuration based on the indication of the assistance information. Further, the apparatus may transmit, to the UE, an indication of the SL DRX configuration and an indication of the Uu DRX configuration.

DETAILED DESCRIPTION

Referring again toFIG.1, in certain aspects, the UE104may include a reception component198configured to receive a first indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration. Reception component198may also be configured to transmit a second indication of the assistance information associated with the Uu DRX configuration and the SL DRX configuration. Reception component198may also be configured to receive an indication of the Uu DRX configuration and an indication of the SL DRX configuration.

Referring again toFIG.1, in certain aspects, the base station180may include a transmission component199configured to receive, from a user equipment (UE), an indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration. Transmission component199may also be configured to configure the SL DRX configuration and the Uu DRX configuration based on the indication of the assistance information. Transmission component199may also be configured to transmit, to the UE, an indication of the SL DRX configuration and an indication of the Uu DRX configuration.

FIG.4is a diagram400illustrating example aspects of sidelink communication between devices. For example, the UE402may transmit a sidelink transmission414, e.g., including a control channel (e.g., a physical sidelink control channel (PSCCH)) and/or a corresponding data channel (e.g., a physical sidelink shared channel (PSSCH)), that may be received by UEs404,406,408. A control channel may include information (e.g., sidelink control information (SCI)) for decoding the data channel including reservation information, such as information about time and/or frequency resources that are reserved for the data channel transmission. For example, the SCI may indicate a number of TTIs, as well as the RBs that will be occupied by the data transmission. The SCI may also be used by receiving devices to avoid interference by refraining from transmitting on the reserved resources. The UEs402,404,406,408may each be capable of sidelink transmission in addition to sidelink reception. Thus, UEs404,406,408are illustrated as transmitting sidelink transmissions413,415,416,420. The sidelink transmissions413,414,415,416,420may be unicast, broadcast, or multicast to nearby devices. For example, UE404may transmit transmissions413,415intended for receipt by other UEs within a range401of UE404, and UE406may transmit transmission416. Additionally, RSU407may receive communication from and/or transmit transmission418to UEs402,404,406,408. One or more of the UEs402,404,406,408or the RSU407may include an SL component440.

Sidelink communication may be based on different types or modes of resource allocation mechanisms. In a first resource allocation mode (which may be referred to herein as “Mode 1”), centralized resource allocation may be provided by a network entity. For example, a base station may determine resources for sidelink communication and may allocate resources to different UEs to use for sidelink transmissions. In this first mode, a UE receives the allocation of sidelink resources from the base station. In a second resource allocation mode (which may be referred to herein as “Mode 2”), distributed resource allocation may be provided. In Mode 2, each UE may autonomously determine resources to use for sidelink transmission. In order to coordinate the selection of sidelink resources by individual UEs, each UE may use a sensing technique to monitor for resource reservations by other sidelink UEs and may select resources for sidelink transmissions from unreserved resources. Devices communicating based on sidelink may determine one or more radio resources in the time and frequency domain that are used by other devices in order to select transmission resources that avoid collisions with other devices. The sidelink transmission and/or the resource reservation may be periodic or aperiodic, where a UE may reserve resources for transmission in a current slot and up to two future slots (as discussed below). Thus, in the second mode (e.g., Mode 2), individual UEs may autonomously select resources for sidelink transmission, e.g., without a central entity such as a base station indicating the resources for the device. A first UE may reserve the selected resources in order to inform other UEs about the resources that the first UE intends to use for sidelink transmission(s).

In some examples, the resource selection for sidelink communication may be based on a sensing-based mechanism. For instance, before selecting a resource for a data transmission, a UE may first determine whether resources have been reserved by other UEs. For example, as part of a sensing mechanism for resource allocation mode 2, the UE may determine (e.g., sense) whether the selected sidelink resource has been reserved by other UE(s) before selecting a sidelink resource for a data transmission. If the UE determines that the sidelink resource has not been reserved by other UEs, the UE may use the selected sidelink resource for transmitting the data, e.g., in a PSSCH transmission. The UE may estimate or determine which radio resources (e.g., sidelink resources) may be in-use and/or reserved by others by detecting and decoding sidelink control information (SCI) transmitted by other UEs. The UE may use a sensing-based resource selection algorithm to estimate or determine which radio resources are in-use and/or reserved by others. The UE may receive SCI from another UE that includes reservation information based on a resource reservation field included in the SCI. The UE may continuously monitor for (e.g., sense) and decode SCI from peer UEs. The SCI may include reservation information, e.g., indicating slots and RBs that a particular UE has selected for a future transmission. The UE may exclude resources that are used and/or reserved by other UEs from a set of candidate resources for sidelink transmission by the UE, and the UE may select/reserve resources for a sidelink transmission from the resources that are unused and therefore form the set of candidate resources. The UE may continuously perform sensing for SCI with resource reservations in order to maintain a set of candidate resources from which the UE may select one or more resources for a sidelink transmission. Once the UE selects a candidate resource, the UE may transmit SCI indicating its own reservation of the resource for a sidelink transmission. The number of resources (e.g., sub-channels per subframe) reserved by the UE may depend on the size of data to be transmitted by the UE. Although the example is described for a UE receiving reservations from another UE, the reservations may also be received from an RSU or other device communicating based on sidelink.

FIG.5is diagram500illustrating an example of time and frequency resources showing reservations for sidelink transmissions. The resources may be included in a sidelink resource pool, for example. The resource allocation for each UE may be in units of one or more sub-channels in the frequency domain (e.g., sub-channels SC 1 to SC 4), and may be based on one slot in the time domain. The UE may also use resources in the current slot to perform an initial transmission, and may reserve resources in future slots for retransmissions. In this example, two different future slots are being reserved by UE1 and UE2 for retransmissions. The resource reservation may be limited to a window of pre-defined slots and sub-channels, such as a window including 8 time slots by 4 sub-channels, as shown in diagram500, which provides32available resource blocks in total. This window may also be referred to as a resource selection window.

A first UE (UE1) may reserve a sub-channel (e.g., SC 1) in a current slot (e.g., slot 1) for its initial data transmission502, and may reserve additional future slots within the window for data retransmissions (e.g.,504and506). For example, UE1 may reserve sub-channels SC 3 at slot 3 and SC 2 at slot 4 for future retransmissions as shown byFIG.4. UE1 may then transmit information regarding which resources are being used and/or reserved by it to other UE(s). UE1 may do so by including the reservation information in the reservation resource field of the SCI, e.g., a first stage SCI.

FIG.5illustrates that a second UE (UE2) reserves resources in sub-channels SC 3 and SC 4 at time slot 1 for its current data transmission508, and reserve first data retransmission510at time slot 4 using sub-channels SC 3 and SC 4, and reserve second data retransmission512at time slot 7 using sub-channels SC 1 and SC 2 as shown byFIG.5. Similarly, UE2 may transmit the resource usage and reservation information to other UE(s), such as using the reservation resource field in SCI.

A third UE may consider resources reserved by other UEs within the resource selection window to select resources to transmit its data. The third UE may first decode SCIS within a time period to identify which resources are available (e.g., candidate resources). For example, the third UE may exclude the resources reserved by UE1 and UE2 and may select other available sub-channels and time slots from the candidate resources for its transmission and retransmissions, which may be based on a number of adjacent sub-channels in which the data (e.g., packet) to be transmitted can fit. WhileFIG.5illustrates resources being reserved for an initial transmission and two retransmissions, the reservation may be for an initial transmission and a single transmission or for an initial transmission.

The UE may determine an associated signal measurement (such as RSRP) for each resource reservation received by another UE. The UE may consider resources reserved in a transmission for which the UE measures an RSRP below a threshold to be available for use by the UE. A UE may perform a signal/channel measurement for a sidelink resource that has been reserved and/or used by other UE(s), such as by measuring the RSRP of the message (e.g., the SCI) that reserves the sidelink resource. Based at least in part on the signal/channel measurement, the UE may consider using/reusing the sidelink resource that has been reserved by other UE(s). For example, the UE may exclude the reserved resources from a candidate resource set if the measured RSRP meets or exceeds the threshold, and the UE may consider a reserved resource to be available if the measured RSRP for the message reserving the resource is below the threshold. The UE may include the resources in the candidate resources set and may use/reuse such reserved resources when the message reserving the resources has an RSRP below the threshold, because the low RSRP indicates that the other UE is distant and a reuse of the resources is less likely to cause interference to that UE. A higher RSRP indicates that the transmitting UE that reserved the resources is potentially closer to the UE and may experience higher levels of interference if the UE selected the same resources.

For example, in a first step, the UE may determine a set of candidate resources (e.g., by monitoring SCI from other UEs and removing resources from the set of candidate resources that are reserved by other UEs in a signal for which the UE measures an RSRP above a threshold value). In a second step, the UE may select N resources for transmissions and/or retransmissions of a TB. As an example, the UE may randomly select the N resources from the set of candidate resources determined in the first step. In a third step, for each transmission, the UE may reserve future time and frequency resources for an initial transmission and up to two retransmissions. The UE may reserve the resources by transmitting SCI indicating the resource reservation. For example, in the example inFIG.5, the UE may transmit SCI reserving resources for data transmission508and data retransmissions510and512.

In some aspects of wireless communications, e.g., 5G new radio (NR), a UE may be configured by a base station for a discontinuous reception (DRX) mode. In some instances, when there is no data to be transmitted between the UE and base station in either direction (e.g., no uplink or downlink transmissions) the UE may enter the DRX mode in which the UE may monitor a control channel discontinuously using a sleep and awake cycle. Moreover, the DRX mode may conserve battery power at the UE. Without DRX, the UE may need to monitor the control channel in each subframe in order to determine whether there is data for the UE. Continuous monitoring of the control channel may place a demand on the UE's battery power.

A UE and a base station may communicate during a reception cycle. In some aspects, this may occur when the UE is configured by the base station for a DRX mode. Accordingly, the reception cycle may be a DRX cycle. In some aspects, a DRX cycle may be a reception cycle during which the UE and a base station communicate while the UE is in a DRX mode. Also, the UE may receive a configuration for the reception cycle from the base station. During the DRX cycle between the base station and the UE, the base station may send a wake-up signal (WUS) monitoring occasion (MO).

In some instances, the base station may send a WUS to the UE when the base station will transmit communication to the UE. Accordingly, the base station may send a WUS to the UE during the reception cycle. In some aspects, during the reception cycle, the UE may determine whether to monitor for a WUS during a WUS time resource. If the UE receives a WUS, the UE may wake-up by preparing to receive the communication. If the UE does not receive a WUS, the UE may return to sleep mode.

In some modes of operation, a UE may be constantly awake and monitor for a PDCCH in each subframe. This means that the UE may be awake all of the time since the UE may not know exactly when the network will transmit data. By monitoring the PDCCH, the UE may monitor instructions from the network or base station. However, this PDCCH monitoring may consume a lot of power on the UE side. As mentioned above, DRX is a mechanism in which a UE transitions to sleep mode for a certain period of time and wakes-up for another period of time. One purpose of DRX may be to save power at the UE, such as by monitoring for a wake-up signal (WUS), which may reduce the amount of power utilized by the UE. So the DRX cycle may help to reduce power utilized at the UE by not continuously monitoring for the PDCCH. During a DRX cycle there may be multiple UE settings, such as an ‘ON’ time, i.e., where the UE monitors for the PDCCH, and an ‘OFF’ time, i.e., where the UE is not monitoring for the PDCCH and saving power.

There are a number of different parameters associated with DRX. As indicated above, the DRX cycle is the duration of one ON time and one OFF time. In some instances, the DRX cycle may be calculated by the subframe time and a longdrx-CycleStartOffset parameter. Also, the DRX cycle may not be explicitly specified in RRC messages. The onDurationTimer may be the duration of the ON time within one DRX cycle, e.g., the amount of time the UE monitors for the PDCCH. The drx-Inactivity timer may specify the amount of time the UE may remain ON after the reception of a PDCCH. When the drx-Inactivity timer is on, the UE may remain in an ON state which may extend the UE ON period into the period which is otherwise an OFF period. The drx-Retransmission timer may specify the maximum number of consecutive PDCCH subframes that the UE may remain active to wait for an incoming retransmission after the first available retransmission time. The shortDRX-Cycle may be a DRX cycle that may be implemented within the OFF period of a long DRX cycle. Also, the drxShortCycleTimer may be the consecutive number of subframes that the UE follows the short DRX cycle after the DRX inactivity timer has expired.

Some aspects of wireless communication may utilize different types of DRX configurations. For instance, for communications between a UE and a universal mobile telecommunications system terrestrial radio access network (UTRAN) (i.e., via a UE-UTRAN (Uu) interface), aspects of wireless communication may utilize Uu DRX configurations. For communications between UEs, aspects of wireless communication may utilize sidelink (SL) DRX configurations. Additionally, aspects of wireless communications may align Uu DRX configurations with SL DRX configurations. In some instances, the alignment of Uu DRX configurations and SL DRX configurations may be utilized for UEs, e.g., a transmitting (Tx) UE and a receiving (Rx) UE, in different radio resource control (RRC) modes, e.g., RRC IDLE mode, RRC INACTIVE mode, and/or RRC CONNECTED mode. Some alignment between a Tx UE's Uu DRX configuration and an Rx UE's SL DRX configurations may be considered to ensure that an SL grant scheduled for the Tx UE during its Uu DRX active time falls into the SL DRX active time of the Rx UE.

FIG.6is a diagram600illustrating an example communication between base stations and UEs (e.g., a Tx UE and an Rx UE). As shown inFIG.6, diagram600includes base station (BS)610, base station612, Tx UE620, and Rx UE622. More specifically, diagram600depicts Tx UE620and Rx UE622are connected via sidelink, while base station610and Tx UE620are connected via a Uu interface and base station612and Rx UE622are connected via a Uu interface. Indeed, Tx UE620and Rx UE622are connected on sidelink, and each UE610/612is connected with base station610/612, respectively, via a Uu interface. In some aspects, base station610(i.e., the base station for Tx UE620) and base station612(i.e., the base station for Rx UE622) may be responsible for the alignment of SL DRX and Uu DRX configurations.

FIG.7is a diagram700illustrating an example of Uu DRX and SL DRX configuration timing before alignment. As shown inFIG.7, diagram700includes a timing for Uu DRX configuration702(i.e., the Uu DRX configuration of a Tx UE), Uu DRX configuration704(i.e., the Uu DRX configuration of an Rx UE), and SL DRX configuration706(i.e., the SL DRX configuration of the Rx UE). More specifically, diagram700depicts the timing for Uu DRX configuration702, Uu DRX configuration704, and SL DRX configuration706before they are aligned with each other.FIG.7also displays a short DRX cycle, a long DRX cycle, an inactivity timer, a time when a data transfer is completed, active times, slot offsets (e.g., drx-Slot-Offset and sl-drx-Slot-Offset), and times when certain conditions (e.g., condition 1 and condition 2) are satisfied.

FIG.8is a diagram800illustrating an example of Uu DRX and SL DRX configuration timing after alignment. As shown inFIG.8, diagram800includes a timing for Uu DRX configuration802(i.e., the Uu DRX configuration of a Tx UE), Uu DRX configuration804(i.e., the Uu DRX configuration of an Rx UE), and SL DRX configuration806(i.e., the SL DRX configuration of the Rx UE). More specifically, diagram800depicts the timing for Uu DRX configuration802, Uu DRX configuration804, and SL DRX configuration806after they are aligned with each other.FIG.8also displays a short DRX cycle, a long DRX cycle, an inactivity timer, a time when a data transfer is completed, active times, slot offsets (e.g., drx-Slot-Offset and sl-drx-Slot-Offset), times when certain conditions (e.g., condition 1 and condition 2) are satisfied, and the alignment of each of the configurations.

Some types of wireless communication may utilize different types of alignment between Uu DRX and SL DRX configurations. For instance, there may be an alignment of Uu DRX and SL DRX configurations for an Rx UE. Also, there may be an alignment of an Rx UE's SL DRX configuration with a Tx UE's Uu DRX configuration. In some instances, if both a Tx UE's Uu DRX configuration and an Rx UE's Uu DRX configuration are aligned with an Rx UE's SL DRX configuration, then all 3 of these DRX cycles may be aligned. By aligning all 3 configurations, the signaling may be optimized and a unified procedure may be present if the signaling covers all of these configurations.

As indicated herein, there may be different RRC states for DRX configuration alignments. For instance, a Tx UE may be in an RRC connected state, an RRC inactive state, or an RRC idle state. Also, an Rx UE may be in an RRC connected state. In some instances, DRX alignment scenarios may include both a Tx UE and an Rx UE in RRC connected mode. Also, DRX alignment scenarios may include a Tx UE in RRC inactive/idle mode and an Rx UE in RRC connected mode.

DRX alignment scenarios may also utilize different information elements, e.g., an RRC information element (IE). The individual contents of an information element may be referred to as a field. Also, a structural element containing single or multiple fields may be referred to as an information element. An RRC IE may be contained in RRC messages and utilized to convey information. One type of RRC IE is DRX-Config, which may define an entire DRX configuration and may be utilized in the Uu interface between a base station and a UE. Another type of RRC IE is sl-DRX-Config, which may define an entire SL DRX configuration and may be utilized in the PC5 interface (i.e., the interface between UE/vehicles and other devices).

As indicated herein, some types of wireless communication may utilize inefficient types of DRX alignment, such as certain types of alignment for Uu DRX and SL DRX configurations. For example, some RRC IEs (e.g., DRX-Config and sl-DRX-Config) may convey the entire Uu DRX or SL DRX configuration, which may be an inefficient type of DRX alignment. As such, it may be beneficial to more efficiently align a Uu DRX configuration and an SL DRX configuration. For instance, it may be beneficial to utilize certain types of RRC IEs to efficiently align the Uu DRX configuration or the SL DRX configuration. Additionally, it may be beneficial to utilize different types of signaling between base stations and UEs to facilitate the procedure for Uu DRX and SL DRX alignment.

Aspects of the present disclosure may more efficiently align a Uu DRX configuration and an SL DRX configuration. For instance, aspects of the present disclosure may utilize certain types of RRC IEs (e.g., DRX-Config-Alignment and/or sl-DRX-Config-Alignment) to efficiently align the Uu DRX configuration and the SL DRX configuration. Additionally, in some instances, aspects of the present disclosure may utilize different types of signaling between base stations and UEs to facilitate the procedure for Uu DRX and SL DRX alignment. More specifically, aspects of the present disclosure may utilize layer 1 (L1), layer 2 (L2), and/or layer 3 (L3) signaling between base stations and UEs to facilitate the procedure for Uu DRX and SL DRX alignment.

In order to align the Uu DRX configuration and the SL DRX configuration, aspects of the present disclosure may use certain types of RRC IEs (e.g., DRX-Config, DRX-Config-Alignment, sl-DRX-Config, and/or sl-DRX-Config-Alignment). For instance, the base station and UE may utilize DRX-Config or DRX-Config-Alignment to convey the parameters in the Uu DRX configuration. Also, the base station and UE may utilize either sl-DRX-Config or sl-DRX-Config-Alignment to convey the parameters in the SL DRX configuration. These RRC IEs may be contained in certain messages (e.g., assistance information message, SL DRX configuration message, or Uu DRX configuration message) that are transmitted between the base station and UEs. In some instances, certain RRC IEs may define the parameters that are related to a corresponding alignment. For example, DRX-Config-Alignment may define the parameters that are related to the Uu DRX configuration alignment, while sl-DRX-Config-Alignment may define the parameters that are related to the SL DRX configuration alignment.

FIG.9is a diagram900illustrating an example communication flow between base stations and UEs (e.g., an Rx UE and a Tx UE). As shown inFIG.9, diagram900includes base station902, Tx UE904, Rx UE906, and base station908. More specifically, diagram900depicts example communication flow between Tx UE904and its corresponding base station (e.g., base station902) and Rx UE906and its corresponding base station (e.g., base station908). As illustrated inFIG.9, base stations902/908and UEs904/906may transmit different types of message between one another. For instance, base stations902/908and UEs904/906may transmit assistance information (e.g., an assistance information message/indication), an SL DRX configuration (e.g., SL DRX configuration message/indication), and/or a Uu DRX configuration (e.g., a Uu DRX configuration message/indication).

As shown inFIG.9, at910, base station908may send assistance information (e.g., an assistance information message and/or an indication of assistance information), to Rx UE906. At920, Rx UE906may transmit the assistance information (e.g., an assistance information message and/or an indication of assistance information) to Tx UE904. At930, Tx UE904may transmit/report the assistance information (e.g., an assistance information message and/or an indication of assistance information) to base station902. After receiving the assistance information, base station902may determine or configure an SL DRX configuration and/or a Uu DRX configuration. For example, base station902may determine or configure an SL DRX configuration for Rx UE906and/or a Uu DRX configuration for Tx UE904.

At940, after determining or configuration the SL DRX configuration and/or Uu DRX configuration, the base station902may transmit the SL DRX configuration (e.g., an SL DRX configuration message and/or an indication of the SL DRX configuration) and/or the Uu DRX configuration (e.g., a Uu DRX configuration message and/or an indication of the Uu DRX configuration) to Tx UE904. At950, Tx UE904may send/forward the SL DRX configuration (e.g., an SL DRX configuration message and/or an indication of the SL DRX configuration) to the Rx UE906. At960, Rx UE906may send/report the SL DRX configuration (e.g., an SL DRX configuration message and/or an indication of the SL DRX configuration) to the base station908. After receiving the SL DRX configuration, base station908may adjust/configure a Uu DRX configuration for Rx UE906in order to achieve the alignment with the SL DRX configuration. At970, base station908may transmit the adjusted/configured Uu DRX configuration to Rx UE906.

As depicted inFIG.9, a base station for a Tx UE may determine/configuration an SL DRX configuration for an Rx UE and/or a Uu DRX configuration for a Tx UE based on assistance information. The assistance information may contain a variety of information including at least one of: the Rx UE's Uu DRX configuration, a list of the Rx UE's available Uu DRX configurations, existing SL DRX configurations from other Tx UEs, or a suitable SL DRX configuration from the Rx UE or Rx UE's base station. Regarding the Rx UE's Uu DRX configuration, the Tx UE's base station may select the SL DRX configuration that is aligned with the Rx UE's Uu DRX configuration. For the list of the Rx UE's available Uu DRX configurations, the Tx UE's base station may align the Uu DRX configuration with one of the available Uu DRX configurations. Concerning the existing SL DRX configurations from other Tx UEs, the Tx UE's base station may select an SL DRX configuration that does not overlap with existing SL DRX configurations from other Tx UEs. For the suitable SL DRX configuration from the Rx UE or Rx UE's base station, the Rx UE may take into account its Uu DRX configuration when requesting the suitable SL DRX configuration.

In some aspects, the assistance information may include the Uu DRX configuration (e.g., the Rx UE's Uu DRX configuration) and may be transmitted via layer 3 (L3) signaling. For instance, an RRC message may contain the Uu DRX configuration. This message may contain the whole Uu DRX configuration, e.g., using RRC IE DRX-Config. The message may also contain a subset of the Uu DRX configuration which is related to alignment, e.g., using RRC IE DRX-Config-Alignment.

The Uu DRX configuration (e.g., the Rx UE's Uu DRX configuration) may also be transmitted via layer 1 (L1) or layer 2 (L2) signaling. For L2 signaling, a MAC-CE may convey the relevant Uu DRX configuration (e.g., drx-LongCycleStartOffset, drx-Short-Cycle, or drx-SlotOffset). In some instances, short DRX information may be included if it is configured for Uu as a short DRX cycle.FIG.10Ais a diagram1000illustrating an example MAC-CE format, e.g., the MAC-CE format that may convey the relevant Uu DRX configuration. As shown inFIG.10A, the MAC-CE may be designed such that it has a variable length. The MAC-CE inFIG.10Aincludes several octets (Oct), e.g., a first Oct (Oct1), a second Oct (Oct2), and a third Oct (Oct3). The base station may also set a subset of values for the update, e.g., drx-Slot-Offset may have 32 values, such that the base station may inform UEs that the updated value in the MAC-CE is one of 8 values in a subset. Additionally, for L1/L2 signaling, the RRC message may configure a set of values for a relevant Uu DRX configuration (e.g., drx-LongCycleStartOffset, shortDRX, or drx-SlotOffset) and L1/L2 signaling may be used to point to one of these values. For example, this may be a pointer to a list to minimize the overhead.

In some aspects, the assistance information may include a list of available Uu DRX configurations for the Rx UE. For instance, instead of a single Uu DRX configuration in the assistance information, the assistance information may include a list of possible Uu DRX configurations, so that the Tx UE's base station may align with one of the Uu DRX configurations. Because the selected SL DRX configuration may align with one of the Uu DRX configurations provided by Rx UE's base station, the Rx UE's base station may be able to align the Uu DRX configuration with the selected SL DRX configuration. Also, the list of Uu DRX configurations may be sorted in order of suitability, e.g., a descending or ascending order of suitability.

The assistance information may include the list of available Uu DRX configurations for the Rx UE and may be transmitted via L3 signaling. For instance, an RRC message may contain the Uu DRX configuration candidates. This message may contain the whole Uu DRX configuration and candidates. The message may also contain the parameters related to alignment.

The list of available Uu DRX configurations for the Rx UE may also be transmitted via L1 or L2 signaling. For L2 signaling, a MAC-CE may convey the relevant Uu DRX configuration candidates (e.g., drx-LongCycleStartOffset, drx-Short-Cycle, or drx-SlotOffset). In some instances, the short DRX information may be included if it is configured for Uu as a short DRX cycle.FIG.10Bis a diagram1020illustrating an example MAC-CE format, e.g., the MAC-CE format that may convey the list of available Uu DRX configurations. As shown inFIG.10B, the MAC-CE may be designed such that it has a variable length. The base station may also set a subset of values for the update, e.g., drx-Slot-Offset may have 32 values, such that the base station may inform UEs that the updated value in the MAC-CE is one of 8 values in a subset. For L1/L2 signaling, the RRC message may configure a set of values for relevant Uu DRX configuration candidates (e.g., drx-LongCycleStartOffset, shortDRX, or drx-SlotOffset) and L1/L2 signaling may be used to point to one of these values. For example, this may be a pointer to a list to minimize the overhead.

Additionally, the assistance information may include existing SL DRX configurations from other Tx UEs. For instance, the Rx UE may have SL connections with multiple Tx UEs, where each Tx UE may set an SL DRX configuration for the Rx UE. The Tx UE may need to set an SL DRX configuration based on existing SL DRX configurations and the UE's capability. If the Rx UE cannot monitor signaling/message from different Tx UEs simultaneously, the active times of each SL DRX configuration may not overlap (e.g., this may work on FR2 and/or a single panel). If the Rx UE monitors the signaling/message from different Tx UEs simultaneously, the active times of different SL DRX configurations may overlap (e.g., this may work on FR1 or multiple panels). Also, the Tx UE's base station may select the SL DRX configuration that does not overlap with existing SL DRX configurations from other Tx UEs.

The assistance information may include the existing SL DRX configurations from other Tx UEs and may be transmitted via L3 signaling. For instance, an RRC message may contain the existing SL DRX configurations from other Tx UEs. This message may contain the whole SL DRX configuration and candidates. The message may also contain the parameters related to alignment.

The existing SL DRX configurations from other Tx UEs may also be transmitted via L1 or L2 signaling. For L2 signaling, a MAC-CE may convey the relevant SL DRX configurations (e.g., sl-drx-StartOffset, sl-drx-Cycle, or sl-drx-SlotOffset).FIG.10Cis a diagram1040illustrating an example MAC-CE format, e.g., the MAC-CE format that may convey the existing SL DRX configurations from other Tx UEs. As shown inFIG.10C, the MAC-CE may be designed such that it has a variable length. The base station may also set a subset of values for the update, e.g., sl-drx-Slot-Offset may have 32 values, such that the base station may inform UEs that the updated value in the MAC-CE is one of 8 values in a subset. For L1/L2 signaling, the RRC message may configure a set of values for relevant SL DRX configurations (e.g., sl-drx-StartOffset, sl-drx-Cycle, or sl-drx-SlotOffset) and L1/L2 signaling may be used to point to one of these values. For example, this may be a pointer to a list to minimize the overhead.

Moreover, the assistance information may include a suitable SL DRX configuration from the Rx UE or Rx UE's base station. For instance, the Rx UE's base station may provide a list of the suitable SL DRX configurations, which may be compatible with the Rx UE's Uu DRX configuration. The suitable SL DRX configuration may be aligned with a current Rx UE's Uu DRX configuration. Also, in some instances, the suitable SL DRX configuration may not be aligned with current Rx UE's Uu DRX, but it may be possible for Rx UE's base station to align the Rx UE's Uu DRX configuration with the SL DRX configuration, as it may be provided by the Rx UE's base station.

The assistance information may include the suitable SL DRX configurations from the Rx UE or Rx UE's base station via L3 signaling. For instance, an RRC message may contain the list of suitable SL DRX configurations. This message may contain the whole SL DRX configuration and candidates. The message may also contain the parameters related to alignment. Also, the suitable SL DRX configurations from the Rx UE or Rx UE's base station may be transmitted via L1 or L2 signaling. For L2 signaling, a MAC-CE (e.g., the MAC-CE inFIG.10C) may convey the relevant SL DRX configurations (e.g., sl-drx-StartOffset, sl-drx-Cycle, or sl-drx-SlotOffset). For L1/L2 signaling, the RRC message may configure a set of values for relevant SL DRX configurations (e.g., sl-drx-StartOffset, sl-drx-Cycle, or sl-drx-SlotOffset) and L1/L2 signaling may be used to point to one of these values.

The SL DRX configuration message (or indication of the SL DRX configuration) may be transmitted from a Tx UE's base station to a Tx UE, transmitted from a Tx UE to an Rx UE, or transmitted from an Rx UE to the Rx UE's base station. The Tx UE's base station may make decisions for the Rx UE's SL DRX configuration, and the Tx UE may forward this SL DRX configuration to the Rx UE. The Rx UE may then report its SL DRX configuration to its corresponding base station. The SL DRX configuration message (or indication of the SL DRX configuration) may contain the SL DRX configuration for the Rx UE, including the SL DRX parameters related to the alignment between the SL DRX configuration and the Uu DRX configuration (e.g., sl-drx-StartOffset, sl-drx-Cycle, and/or sl-drx-SlotOffset).

The SL DRX configuration message (or indication of the SL DRX configuration) may be transmitted via L3 signaling. For instance, an RRC message may contain the SL DRX configuration. This message may contain the whole SL DRX configuration, i.e., using SL RRC IE sl-DRX-Config. The message may also contain a subset of SL DRX configuration which is related to alignment, i.e., using SL RRC IE sl-DRX-Config-Alignment.

The SL DRX configuration message (or indication of the SL DRX configuration) may also be transmitted via L1 or L2 signaling. For L2 signaling, a MAC-CE may convey the relevant SL DRX configurations (e.g., sl-drx-StartOffset, sl-drx-Cycle, or sl-drx-SlotOffset).FIG.10Dis a diagram1060illustrating an example MAC-CE format, e.g., the MAC-CE format that may convey the SL DRX configuration. As shown inFIG.10D, the MAC-CE may be designed such that it has a variable length. The base station may also set a subset of values for the update, e.g., sl-drx-Slot-Offset may have 32 values, such that the base station may inform UEs that the updated value in the MAC-CE is one of 8 values in a subset. For L1/L2 signaling, the RRC message may configure a set of values for relevant SL DRX configurations (e.g., sl-drx-StartOffset, sl-drx-Cycle, or sl-drx-SlotOffset) and L1/L2 signaling may be used to point to one of these values. For example, this may be a pointer to a list to minimize the overhead.

The Uu DRX configuration message (or indication of the Uu DRX configuration) may be transmitted from a Tx UE's base station to a Tx UE and/or transmitted from an Rx UE's base station to an Rx UE. The Tx UE and the Rx UE may receive their Uu DRX configuration from their corresponding base stations, respectively. The Uu DRX configuration message (or indication of the Uu DRX configuration) may contain the Uu DRX configuration for the UE, including the Uu DRX parameters related to the alignment between the SL DRX configuration and the Uu DRX configuration (e.g., drx-LongCycleStartOffset, shortDRX, drx-ShortCycle, drx-ShortCycleTimer, and/or drx-SlotOffset).

The Uu DRX configuration message (or indication of the Uu DRX configuration) may be transmitted via L3 signaling. For instance, an RRC message may contain the Uu DRX configuration. This message may contain the whole Uu DRX configuration, i.e., using RRC IE DRX-Config. The message may also contain a subset of the Uu DRX configuration which is related to alignment, i.e., using RRC IE DRX-Config-Alignment. Also, the Uu DRX configuration message (or indication of the Uu DRX configuration) may be transmitted via L1 or L2 signaling. For L2 signaling, a MAC-CE may convey the relevant Uu DRX configuration (e.g., drx-LongCycleStartOffset, drx-ShortCycle, and/or drx-SlotOffset), such as the MAC-CE inFIG.10A. The short DRX information may be included if it is configured for Uu, as in some instances the short DRX cycle may not be included. For L1/L2 signaling, the RRC message may configure a set of values for relevant Uu DRX configurations (e.g., drx-LongCycleStartOffset, shortDRX, or drx-SlotOffset) and L1/L2 signaling may be used to point to one of these values.

In some aspects, L1/L2 signaling may be used after the initial DRX configuration setup based on L3 signaling. For instance, the UE may make a decision on changing the DRX configuration among RRC configured options and then notify the base station via L1/L2 signaling. Additionally, for the alignment of the Tx UE's Uu DRX configuration and the Rx UE's SL DRX configuration, an on-time duration (onDuration) of active times may be optimized. In some instances, the length of the Rx UE's onDuration may be no less than the Tx UE's Uu DRX onDuration. This may be performed to ensure that the SL grant scheduled for the TX UE during its Uu DRX active time falls into the SL DRX active time of the peer RX UE. Also, the drx-onDuration Timer may be included in the DRX-Config-Alignment and the sl-drx-onDurationTimer may be included in the sl-DRX-Config-Alignment, so that the Tx UE or the Tx UE's base station may adjust the SL DRX configuration and the Rx UE's base station may adjust the Uu DRX configuration.

FIG.11is a diagram1100illustrating example communication between a UE1102and a base station1104.

At1110, UE1102may receive a first indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration.

At1120, UE1102may transmit a second indication of the assistance information associated with the Uu DRX configuration and the SL DRX configuration (e.g., indication1132).

In some aspects, the first indication may be received from a base station and the second indication may be transmitted to at least one other UE. Also, the first indication may be received from at least one other UE and the second indication may be transmitted to a base station. The first indication may be received via layer 3 (L3) signaling or a radio resource control (RRC) message, and the second indication may be transmitted via the L3 signaling or the RRC message. Further, the first indication may be received via layer 1 (L1) signaling, layer 2 (L2) signaling, or a medium access control (MAC) control element (MAC-CE), and the second indication may be transmitted via the L1 signaling, the L2 signaling, or the MAC-CE.

The assistance information associated with the Uu DRX configuration and the SL DRX configuration may correspond to at least one of: (1) a current Uu DRX configuration of the UE, (2) a list of available Uu DRX configurations of the UE, (3) one or more existing SL DRX configurations of at least one other UE, or (4) at least one suitable SL DRX configuration for the UE. The list of the available Uu DRX configurations may include all of the available Uu DRX configurations or a subset of the available Uu DRX configurations. The current Uu DRX configuration may be associated with a long DRX cycle, a short DRX cycle, a DRX slot offset, or a starting offset of the long DRX cycle. The Uu DRX configuration may be adjusted to align with the SL DRX configuration based on at least one available Uu DRX configuration of the list of available Uu DRX configurations. The list of the available Uu DRX configurations may be based on a suitability of each of the available Uu DRX configurations. The SL DRX configuration may be based on the one or more existing SL DRX configurations and a capability of the UE, and the SL DRX configuration may not overlap with the one or more existing SL DRX configurations. The at least one suitable SL DRX configuration for the UE may be aligned with the current Uu DRX configuration of the UE.

At1130, base station1104may receive, from a UE (e.g., UE1102), an indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration (e.g., indication1132).

At1140, base station1104may configure the SL DRX configuration and the Uu DRX configuration based on the indication of the assistance information.

At1150, base station1104may transmit, to the UE (e.g., UE1102), an indication of the SL DRX configuration and an indication of the Uu DRX configuration (e.g., indication1162).

At1160, UE1102may receive an indication of the Uu DRX configuration and an indication of the SL DRX configuration (e.g., indication1162).

In some aspects, the indication of the SL DRX configuration may be received from at least one other UE and the indication of the Uu DRX configuration may be received from a base station. Further, the indication of the Uu DRX configuration and the indication of the SL DRX configuration may be received from a base station. The indication of the Uu DRX configuration and the indication of the SL DRX configuration may be received via layer 3 (L3) signaling or a radio resource control (RRC) message. Also, the indication of the Uu DRX configuration and the indication of the SL DRX configuration may be received via layer 1 (L1) signaling, layer 2 (L2) signaling, or a medium access control (MAC) control element (MAC-CE).

Additionally, the indication of the SL DRX configuration may include one or more SL DRX parameters associated with an alignment of the Uu DRX configuration and the SL DRX configuration. The one or more SL DRX parameters may include at least one of: an SL DRX cycle, an SL DRX starting offset, or an SL DRX slot offset. Further, the indication of the Uu DRX configuration may include one or more Uu DRX parameters associated with an alignment of the Uu DRX configuration and the SL DRX configuration. The one or more Uu DRX parameters may include at least one of: a Uu DRX long cycle, a starting offset for the Uu DRX long cycle, a Uu DRX short cycle, a timer for the Uu DRX short cycle, or a Uu DRX slot offset.

FIG.12is a flowchart1200of a method of wireless communication. The method may be performed by a UE or a component of a UE (e.g., the UE104,350,620,622,904,906,1102; the apparatus1602). The methods described herein may provide a number of benefits, such as improving communication signaling, resource utilization, and/or power savings.

At1202, the UE may receive a first indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration, as described in connection with the examples inFIGS.4-11. For example, UE1102may receive a first indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration, as described in connection with1110inFIG.11. Further,1202may be performed by determination component1640inFIG.16.

At1204, the UE may transmit a second indication of the assistance information associated with the Uu DRX configuration and the SL DRX configuration, as described in connection with the examples inFIGS.4-11. For example, UE1102may transmit a second indication of the assistance information associated with the Uu DRX configuration and the SL DRX configuration, as described in connection with1120inFIG.11. Further,1204may be performed by determination component1640inFIG.16.

In some aspects, the first indication may be received from a base station and the second indication may be transmitted to at least one other UE. Also, the first indication may be received from at least one other UE and the second indication may be transmitted to a base station. The first indication may be received via layer 3 (L3) signaling or a radio resource control (RRC) message, and the second indication may be transmitted via the L3 signaling or the RRC message. Further, the first indication may be received via layer 1 (L1) signaling, layer 2 (L2) signaling, or a medium access control (MAC) control element (MAC-CE), and the second indication may be transmitted via the L1 signaling, the L2 signaling, or the MAC-CE.

The assistance information associated with the Uu DRX configuration and the SL DRX configuration may correspond to at least one of: (1) a current Uu DRX configuration of the UE, (2) a list of available Uu DRX configurations of the UE, (3) one or more existing SL DRX configurations of at least one other UE, or (4) at least one suitable SL DRX configuration for the UE. The list of the available Uu DRX configurations may include all of the available Uu DRX configurations or a subset of the available Uu DRX configurations. The current Uu DRX configuration may be associated with a long DRX cycle, a short DRX cycle, a DRX slot offset, or a starting offset of the long DRX cycle. The Uu DRX configuration may be adjusted to align with the SL DRX configuration based on at least one available Uu DRX configuration of the list of available Uu DRX configurations. The list of the available Uu DRX configurations may be based on a suitability of each of the available Uu DRX configurations. The SL DRX configuration may be based on the one or more existing SL DRX configurations and a capability of the UE, and the SL DRX configuration may not overlap with the one or more existing SL DRX configurations. The at least one suitable SL DRX configuration for the UE may be aligned with the current Uu DRX configuration of the UE.

At1206, the UE may receive an indication of the Uu DRX configuration and an indication of the SL DRX configuration, as described in connection with the examples inFIGS.4-11. For example, UE1102may receive an indication of the Uu DRX configuration and an indication of the SL DRX configuration, as described in connection with1160inFIG.11. Further,1206may be performed by determination component1640inFIG.16.

In some aspects, the indication of the SL DRX configuration may be received from at least one other UE and the indication of the Uu DRX configuration may be received from a base station. Further, the indication of the Uu DRX configuration and the indication of the SL DRX configuration may be received from a base station. The indication of the Uu DRX configuration and the indication of the SL DRX configuration may be received via layer 3 (L3) signaling or a radio resource control (RRC) message. Also, the indication of the Uu DRX configuration and the indication of the SL DRX configuration may be received via layer 1 (L1) signaling, layer 2 (L2) signaling, or a medium access control (MAC) control element (MAC-CE).

Additionally, the indication of the SL DRX configuration may include one or more SL DRX parameters associated with an alignment of the Uu DRX configuration and the SL DRX configuration. The one or more SL DRX parameters may include at least one of: an SL DRX cycle, an SL DRX starting offset, or an SL DRX slot offset. Further, the indication of the Uu DRX configuration may include one or more Uu DRX parameters associated with an alignment of the Uu DRX configuration and the SL DRX configuration. The one or more Uu DRX parameters may include at least one of: a Uu DRX long cycle, a starting offset for the Uu DRX long cycle, a Uu DRX short cycle, a timer for the Uu DRX short cycle, or a Uu DRX slot offset.

FIG.13is a flowchart1300of a method of wireless communication. The method may be performed by a UE or a component of a UE (e.g., the UE104,350,620,622,904,906,1102; the apparatus1602). The methods described herein may provide a number of benefits, such as improving communication signaling, resource utilization, and/or power savings.

At1302, the UE may receive a first indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration, as described in connection with the examples inFIGS.4-11. For example, UE1102may receive a first indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration, as described in connection with1110inFIG.11. Further,1302may be performed by determination component1640inFIG.16.

At1304, the UE may transmit a second indication of the assistance information associated with the Uu DRX configuration and the SL DRX configuration, as described in connection with the examples inFIGS.4-11. For example, UE1102may transmit a second indication of the assistance information associated with the Uu DRX configuration and the SL DRX configuration, as described in connection with1120inFIG.11. Further,1304may be performed by determination component1640inFIG.16.

In some aspects, the first indication may be received from a base station and the second indication may be transmitted to at least one other UE. Also, the first indication may be received from at least one other UE and the second indication may be transmitted to a base station. The first indication may be received via layer 3 (L3) signaling or a radio resource control (RRC) message, and the second indication may be transmitted via the L3 signaling or the RRC message. Further, the first indication may be received via layer 1 (L1) signaling, layer 2 (L2) signaling, or a medium access control (MAC) control element (MAC-CE), and the second indication may be transmitted via the L1 signaling, the L2 signaling, or the MAC-CE.

As shown at1310, the assistance information associated with the Uu DRX configuration and the SL DRX configuration may correspond to at least one of: (1) a current Uu DRX configuration of the UE, (2) a list of available Uu DRX configurations of the UE, (3) one or more existing SL DRX configurations of at least one other UE, or (4) at least one suitable SL DRX configuration for the UE. The list of the available Uu DRX configurations may include all of the available Uu DRX configurations or a subset of the available Uu DRX configurations. The current Uu DRX configuration may be associated with a long DRX cycle, a short DRX cycle, a DRX slot offset, or a starting offset of the long DRX cycle. The Uu DRX configuration may be adjusted to align with the SL DRX configuration based on at least one available Uu DRX configuration of the list of available Uu DRX configurations. The list of the available Uu DRX configurations may be based on a suitability of each of the available Uu DRX configurations. The SL DRX configuration may be based on the one or more existing SL DRX configurations and a capability of the UE, and the SL DRX configuration may not overlap with the one or more existing SL DRX configurations. The at least one suitable SL DRX configuration for the UE may be aligned with the current Uu DRX configuration of the UE.

At1306, the UE may receive an indication of the Uu DRX configuration and an indication of the SL DRX configuration, as described in connection with the examples inFIGS.4-11. For example, UE1102may receive an indication of the Uu DRX configuration and an indication of the SL DRX configuration, as described in connection with1160inFIG.11. Further,1306may be performed by determination component1640inFIG.16.

In some aspects, the indication of the SL DRX configuration may be received from at least one other UE and the indication of the Uu DRX configuration may be received from a base station. Further, the indication of the Uu DRX configuration and the indication of the SL DRX configuration may be received from a base station. The indication of the Uu DRX configuration and the indication of the SL DRX configuration may be received via layer 3 (L3) signaling or a radio resource control (RRC) message. Also, the indication of the Uu DRX configuration and the indication of the SL DRX configuration may be received via layer 1 (L1) signaling, layer 2 (L2) signaling, or a medium access control (MAC) control element (MAC-CE).

As shown at1320, the indication of the SL DRX configuration may include one or more SL DRX parameters associated with an alignment of the Uu DRX configuration and the SL DRX configuration. The one or more SL DRX parameters may include at least one of: an SL DRX cycle, an SL DRX starting offset, or an SL DRX slot offset. As further shown at1320, the indication of the Uu DRX configuration may include one or more Uu DRX parameters associated with an alignment of the Uu DRX configuration and the SL DRX configuration. The one or more Uu DRX parameters may include at least one of: a Uu DRX long cycle, a starting offset for the Uu DRX long cycle, a Uu DRX short cycle, a timer for the Uu DRX short cycle, or a Uu DRX slot offset.

FIG.14is a flowchart1400of a method of wireless communication. The method may be performed by a base station or a component of a base station (e.g., the base station102,180,310,610,612,902,908,1104; the apparatus1702). The methods described herein may provide a number of benefits, such as improving communication signaling, resource utilization, and/or power savings.

At1402, the base station may receive, from a user equipment (UE), an indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration, as described in connection with the examples inFIGS.4-11. For example, base station1104may receive, from a user equipment (UE), an indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration, as described in connection with1130inFIG.11. Further,1402may be performed by determination component1740inFIG.17.

The assistance information associated with the Uu DRX configuration and the SL DRX configuration may correspond to at least one of: (1) a current Uu DRX configuration of the UE, (2) a list of available Uu DRX configurations of the UE, (3) one or more existing SL DRX configurations of at least one other UE, or (4) at least one suitable SL DRX configuration for the UE. The list of the available Uu DRX configurations may include all of the available Uu DRX configurations or a subset of the available Uu DRX configurations. The current Uu DRX configuration may be associated with a long DRX cycle, a short DRX cycle, a DRX slot offset, or a starting offset of the long DRX cycle. The Uu DRX configuration may be adjusted to align with the SL DRX configuration based on at least one available Uu DRX configuration of the list of available Uu DRX configurations. The list of the available Uu DRX configurations may be based on a suitability of each of the available Uu DRX configurations. The SL DRX configuration may be based on the one or more existing SL DRX configurations and a capability of the UE, and the SL DRX configuration may not overlap with the one or more existing SL DRX configurations. The at least one suitable SL DRX configuration for the UE may be aligned with the current Uu DRX configuration of the UE. In some aspects, the indication of the assistance information may be received via layer 3 (L3) signaling or a radio resource control (RRC) message. Also, the indication of the assistance information may be received via layer 1 (L1) signaling, layer 2 (L2) signaling, or a medium access control (MAC) control element (MAC-CE).

At1404, the base station may configure the SL DRX configuration and the Uu DRX configuration based on the indication of the assistance information, as described in connection with the examples inFIGS.4-11. For example, base station1104may configure the SL DRX configuration and the Uu DRX configuration based on the indication of the assistance information, as described in connection with1140inFIG.11. Further,1404may be performed by determination component1740inFIG.17.

At1406, the base station may transmit, to the UE, an indication of the SL DRX configuration and an indication of the Uu DRX configuration, as described in connection with the examples inFIGS.4-11. For example, base station1104may transmit, to the UE, an indication of the SL DRX configuration and an indication of the Uu DRX configuration, as described in connection with1150inFIG.11. Further,1406may be performed by determination component1740inFIG.17.

In some instances, the indication of the Uu DRX configuration and the indication of the SL DRX configuration may be transmitted via layer 3 (L3) signaling or a radio resource control (RRC) message. Also, the indication of the Uu DRX configuration and the indication of the SL DRX configuration may be transmitted via layer 1 (L1) signaling, layer 2 (L2) signaling, or a medium access control (MAC) control element (MAC-CE). Further, the indication of the SL DRX configuration may include one or more SL DRX parameters associated with an alignment of the Uu DRX configuration and the SL DRX configuration. The one or more SL DRX parameters may include at least one of: an SL DRX cycle, an SL DRX starting offset, or an SL DRX slot offset. Further, the indication of the Uu DRX configuration may include one or more Uu DRX parameters associated with an alignment of the Uu DRX configuration and the SL DRX configuration. The one or more Uu DRX parameters may include at least one of: a Uu DRX long cycle, a starting offset for the Uu DRX long cycle, a Uu DRX short cycle, a timer for the Uu DRX short cycle, or a Uu DRX slot offset.

FIG.15is a flowchart1500of a method of wireless communication. The method may be performed by a base station or a component of a base station (e.g., the base station102,180,310,610,612,902,908,1104; the apparatus1702). The methods described herein may provide a number of benefits, such as improving communication signaling, resource utilization, and/or power savings.

At1502, the base station may receive, from a user equipment (UE), an indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration, as described in connection with the examples inFIGS.4-11. For example, base station1104may receive, from a user equipment (UE), an indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration, as described in connection with1130inFIG.11. Further,1502may be performed by determination component1740inFIG.17.

As shown at1510, the assistance information associated with the Uu DRX configuration and the SL DRX configuration may correspond to at least one of: (1) a current Uu DRX configuration of the UE, (2) a list of available Uu DRX configurations of the UE, (3) one or more existing SL DRX configurations of at least one other UE, or (4) at least one suitable SL DRX configuration for the UE. The list of the available Uu DRX configurations may include all of the available Uu DRX configurations or a subset of the available Uu DRX configurations. The current Uu DRX configuration may be associated with a long DRX cycle, a short DRX cycle, a DRX slot offset, or a starting offset of the long DRX cycle. The Uu DRX configuration may be adjusted to align with the SL DRX configuration based on at least one available Uu DRX configuration of the list of available Uu DRX configurations. The list of the available Uu DRX configurations may be based on a suitability of each of the available Uu DRX configurations. The SL DRX configuration may be based on the one or more existing SL DRX configurations and a capability of the UE, and the SL DRX configuration may not overlap with the one or more existing SL DRX configurations. The at least one suitable SL DRX configuration for the UE may be aligned with the current Uu DRX configuration of the UE. In some aspects, the indication of the assistance information may be received via layer 3 (L3) signaling or a radio resource control (RRC) message. Also, the indication of the assistance information may be received via layer 1 (L1) signaling, layer 2 (L2) signaling, or a medium access control (MAC) control element (MAC-CE).

At1504, the base station may configure the SL DRX configuration and the Uu DRX configuration based on the indication of the assistance information, as described in connection with the examples inFIGS.4-11. For example, base station1104may configure the SL DRX configuration and the Uu DRX configuration based on the indication of the assistance information, as described in connection with1140inFIG.11. Further,1504may be performed by determination component1740inFIG.17.

At1506, the base station may transmit, to the UE, an indication of the SL DRX configuration and an indication of the Uu DRX configuration, as described in connection with the examples inFIGS.4-11. For example, base station1104may transmit, to the UE, an indication of the SL DRX configuration and an indication of the Uu DRX configuration, as described in connection with1150inFIG.11. Further,1506may be performed by determination component1740inFIG.17.

In some instances, the indication of the Uu DRX configuration and the indication of the SL DRX configuration may be transmitted via layer 3 (L3) signaling or a radio resource control (RRC) message. Also, the indication of the Uu DRX configuration and the indication of the SL DRX configuration may be transmitted via layer 1 (L1) signaling, layer 2 (L2) signaling, or a medium access control (MAC) control element (MAC-CE). As shown at1520, the indication of the SL DRX configuration may include one or more SL DRX parameters associated with an alignment of the Uu DRX configuration and the SL DRX configuration. The one or more SL DRX parameters may include at least one of: an SL DRX cycle, an SL DRX starting offset, or an SL DRX slot offset. As further shown at1520, the indication of the Uu DRX configuration may include one or more Uu DRX parameters associated with an alignment of the Uu DRX configuration and the SL DRX configuration. The one or more Uu DRX parameters may include at least one of: a Uu DRX long cycle, a starting offset for the Uu DRX long cycle, a Uu DRX short cycle, a timer for the Uu DRX short cycle, or a Uu DRX slot offset.

FIG.16is a diagram1600illustrating an example of a hardware implementation for an apparatus1602. The apparatus1602may be a UE, a component of a UE, or may implement UE functionality. In some aspects, the apparatus1602may include a cellular baseband processor1604(also referred to as a modem) coupled to a cellular RF transceiver1622. In some aspects, the apparatus1602may further include one or more subscriber identity modules (SIM) cards1620, an application processor1606coupled to a secure digital (SD) card1608and a screen1610, a Bluetooth module1612, a wireless local area network (WLAN) module1614, a Global Positioning System (GPS) module1616, or a power supply1618. The cellular baseband processor1604communicates through the cellular RF transceiver1622with the UE104and/or BS102/180. The cellular baseband processor1604may include a computer-readable medium/memory. The computer-readable medium/memory may be non-transitory. The cellular baseband processor1604is responsible for general processing, including the execution of software stored on the computer-readable medium/memory. The software, when executed by the cellular baseband processor1604, causes the cellular baseband processor1604to perform the various functions described supra. The computer-readable medium/memory may also be used for storing data that is manipulated by the cellular baseband processor1604when executing software. The cellular baseband processor1604further includes a reception component1630, a communication manager1632, and a transmission component1634. The communication manager1632includes the one or more illustrated components. The components within the communication manager1632may be stored in the computer-readable medium/memory and/or configured as hardware within the cellular baseband processor1604. The cellular baseband processor1604may be a component of the UE350and may include the memory360and/or at least one of the TX processor368, the RX processor356, and the controller/processor359. In one configuration, the apparatus1602may be a modem chip and include just the baseband processor1604, and in another configuration, the apparatus1602may be the entire UE (e.g., see350ofFIG.3) and include the additional modules of the apparatus1602.

The communication manager1632includes a determination component1640that is configured to receive a first indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration, e.g., as described in connection with step1202above. Determination component1640may also be configured to transmit a second indication of the assistance information associated with the Uu DRX configuration and the SL DRX configuration, e.g., as described in connection with step1204above. Determination component1640may also be configured to receive an indication of the Uu DRX configuration and an indication of the SL DRX configuration, e.g., as described in connection with step1206above.

As shown, the apparatus1602may include a variety of components configured for various functions. In one configuration, the apparatus1602, and in particular the cellular baseband processor1604, includes means for receiving a first indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration; means for transmitting a second indication of the assistance information associated with the Uu DRX configuration and the SL DRX configuration; and means for receiving an indication of the Uu DRX configuration and an indication of the SL DRX configuration. The means may be one or more of the components of the apparatus1602configured to perform the functions recited by the means. As described supra, the apparatus1602may include the TX Processor368, the RX Processor356, and the controller/processor359. As such, in one configuration, the means may be the TX Processor368, the RX Processor356, and the controller/processor359configured to perform the functions recited by the means.

FIG.17is a diagram1700illustrating an example of a hardware implementation for an apparatus1702. The apparatus1702may be a base station, a component of a base station, or may implement base station functionality. In some aspects, the apparatus1702may include a baseband unit1704. The baseband unit1704may communicate through a cellular RF transceiver1722with the UE104. The baseband unit1704may include a computer-readable medium/memory. The baseband unit1704is responsible for general processing, including the execution of software stored on the computer-readable medium/memory. The software, when executed by the baseband unit1704, causes the baseband unit1704to perform the various functions described supra. The computer-readable medium/memory may also be used for storing data that is manipulated by the baseband unit1704when executing software. The baseband unit1704further includes a reception component1730, a communication manager1732, and a transmission component1734. The communication manager1732includes the one or more illustrated components. The components within the communication manager1732may be stored in the computer-readable medium/memory and/or configured as hardware within the baseband unit1704. The baseband unit1704may be a component of the base station310and may include the memory376and/or at least one of the TX processor316, the RX processor370, and the controller/processor375.

The communication manager1732includes a determination component1740that is configured to receive, from a user equipment (UE), an indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration, e.g., as described in connection with step1402above. Determination component1740may also be configured to configure the SL DRX configuration and the Uu DRX configuration based on the indication of the assistance information, e.g., as described in connection with step1404above. Determination component1740may also be configured to transmit, to the UE, an indication of the SL DRX configuration and an indication of the Uu DRX configuration, e.g., as described in connection with step1406above.

As shown, the apparatus1702may include a variety of components configured for various functions. In one configuration, the apparatus1702, and in particular the baseband unit1704, includes means for receiving, from a user equipment (UE), an indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration; means for configuring the SL DRX configuration and the Uu DRX configuration based on the indication of the assistance information; and means for transmitting, to the UE, an indication of the SL DRX configuration and an indication of the Uu DRX configuration. The means may be one or more of the components of the apparatus1702configured to perform the functions recited by the means. As described supra, the apparatus1702may include the TX Processor316, the RX Processor370, and the controller/processor375. As such, in one configuration, the means may be the TX Processor316, the RX Processor370, and the controller/processor375configured to perform the functions recited by the means.

Aspect 1 is an apparatus for wireless communication at a UE including at least one processor coupled to a memory and configured to: receive a first indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration; transmit a second indication of the assistance information associated with the Uu DRX configuration and the SL DRX configuration; and receive an indication of the Uu DRX configuration and an indication of the SL DRX configuration.

Aspect 2 is the apparatus of aspect 1, where the first indication is received from a base station and the second indication is transmitted to at least one other UE.

Aspect 3 is the apparatus of any of aspects 1 and 2, where the indication of the SL DRX configuration is received from at least one other UE and the indication of the Uu DRX configuration is received from a base station.

Aspect 4 is the apparatus of any of aspects 1 to 3, where the first indication is received from at least one other UE and the second indication is transmitted to a base station.

Aspect 5 is the apparatus of any of aspects 1 to 4, where the indication of the Uu DRX configuration and the indication of the SL DRX configuration are received from a base station.

Aspect 6 is the apparatus of any of aspects 1 to 5, where the first indication is received via layer 3 (L3) signaling or a radio resource control (RRC) message, and where the second indication is transmitted via the L3 signaling or the RRC message.

Aspect 7 is the apparatus of any of aspects 1 to 6, where the indication of the Uu DRX configuration and the indication of the SL DRX configuration are received via layer 3 (L3) signaling or a radio resource control (RRC) message.

Aspect 8 is the apparatus of any of aspects 1 to 7, where the first indication is received via layer 1 (L1) signaling, layer 2 (L2) signaling, or a medium access control (MAC) control element (MAC-CE), and where the second indication is transmitted via the L1 signaling, the L2 signaling, or the MAC-CE.

Aspect 9 is the apparatus of any of aspects 1 to 8, where the indication of the Uu DRX configuration and the indication of the SL DRX configuration are received via layer 1 (L1) signaling, layer 2 (L2) signaling, or a medium access control (MAC) control element (MAC-CE).

Aspect 10 is the apparatus of any of aspects 1 to 9, where the assistance information associated with the Uu DRX configuration and the SL DRX configuration corresponds to at least one of: (1) a current Uu DRX configuration of the UE, (2) a list of available Uu DRX configurations of the UE, (3) one or more existing SL DRX configurations of at least one other UE, or (4) at least one suitable SL DRX configuration for the UE.

Aspect 11 is the apparatus of any of aspects 1 to 10, where the list of the available Uu DRX configurations includes all of the available Uu DRX configurations or a subset of the available Uu DRX configurations.

Aspect 12 is the apparatus of any of aspects 1 to 11, where the current Uu DRX configuration is associated with a long DRX cycle, a short DRX cycle, a DRX slot offset, or a starting offset of the long DRX cycle.

Aspect 13 is the apparatus of any of aspects 1 to 12, where the Uu DRX configuration is adjusted to align with the SL DRX configuration based on at least one available Uu DRX configuration of the list of available Uu DRX configurations.

Aspect 14 is the apparatus of any of aspects 1 to 13, where the list of the available Uu DRX configurations is based on a suitability of each of the available Uu DRX configurations.

Aspect 15 is the apparatus of any of aspects 1 to 14, where the SL DRX configuration is based on the one or more existing SL DRX configurations and a capability of the UE, and where the SL DRX configuration does not overlap with the one or more existing SL DRX configurations.

Aspect 16 is the apparatus of any of aspects 1 to 15, where the at least one suitable SL DRX configuration for the UE is aligned with the current Uu DRX configuration of the UE.

Aspect 17 is the apparatus of any of aspects 1 to 16, where the indication of the SL DRX configuration includes one or more SL DRX parameters associated with an alignment of the Uu DRX configuration and the SL DRX configuration.

Aspect 18 is the apparatus of any of aspects 1 to 17, where the one or more SL DRX parameters include at least one of: an SL DRX cycle, an SL DRX starting offset, or an SL DRX slot offset.

Aspect 19 is the apparatus of any of aspects 1 to 18, where the indication of the Uu DRX configuration includes one or more Uu DRX parameters associated with an alignment of the Uu DRX configuration and the SL DRX configuration.

Aspect 20 is the apparatus of any of aspects 1 to 19, where the one or more Uu DRX parameters include at least one of: a Uu DRX long cycle, a starting offset for the Uu DRX long cycle, a Uu DRX short cycle, a timer for the Uu DRX short cycle, or a Uu DRX slot offset.

Aspect 21 is the apparatus of any of aspects 1 to 20, further including a transceiver or an antenna coupled to the at least one processor.

Aspect 22 is a method of wireless communication for implementing any of aspects 1 to 21.

Aspect 23 is an apparatus for wireless communication including means for implementing any of aspects 1 to 21.

Aspect 25 is an apparatus for wireless communication at a base station including at least one processor coupled to a memory and configured to: receive, from a user equipment (UE), an indication of assistance information associated with a UE-universal mobile telecommunications system terrestrial radio access network (UTRAN) (Uu) discontinuous reception (DRX) configuration and a sidelink (SL) DRX configuration; configure the SL DRX configuration and the Uu DRX configuration based on the indication of the assistance information; and transmit, to the UE, an indication of the SL DRX configuration and an indication of the Uu DRX configuration.

Aspect 26 is the apparatus of aspect 25, where the indication of the assistance information is received via layer 3 (L3) signaling or a radio resource control (RRC) message.

Aspect 27 is the apparatus of any of aspects 25 and 26, where the indication of the Uu DRX configuration and the indication of the SL DRX configuration are transmitted via layer 3 (L3) signaling or a radio resource control (RRC) message.

Aspect 28 is the apparatus of any of aspects 25 to 27, where the indication of the assistance information is received via layer 1 (L1) signaling, layer 2 (L2) signaling, or a medium access control (MAC) control element (MAC-CE).

Aspect 29 is the apparatus of any of aspects 25 to 28, where the indication of the Uu DRX configuration and the indication of the SL DRX configuration are transmitted via layer 1 (L1) signaling, layer 2 (L2) signaling, or a medium access control (MAC) control element (MAC-CE).

Aspect 30 is the apparatus of any of aspects 25 to 29, where the assistance information associated with the Uu DRX configuration and the SL DRX configuration corresponds to at least one of: (1) a current Uu DRX configuration of the UE, (2) a list of available Uu DRX configurations of the UE, (3) one or more existing SL DRX configurations of at least one other UE, or (4) at least one suitable SL DRX configuration for the UE.

Aspect 31 is the apparatus of any of aspects 25 to 30, where the list of the available Uu DRX configurations includes all of the available Uu DRX configurations or a subset of the available Uu DRX configurations.

Aspect 32 is the apparatus of any of aspects 25 to 31, where the current Uu DRX configuration is associated with a long DRX cycle, a short DRX cycle, a DRX slot offset, or a starting offset of the long DRX cycle.

Aspect 33 is the apparatus of any of aspects 25 to 32, where the Uu DRX configuration is adjusted to align with the SL DRX configuration based on at least one available Uu DRX configuration of the list of available Uu DRX configurations.

Aspect 34 is the apparatus of any of aspects 25 to 33, where the list of the available Uu DRX configurations is based on a suitability of each of the available Uu DRX configurations.

Aspect 35 is the apparatus of any of aspects 25 to 34, where the SL DRX configuration is based on the one or more existing SL DRX configurations and a capability of the UE, and where the SL DRX configuration does not overlap with the one or more existing SL DRX configurations.

Aspect 36 is the apparatus of any of aspects 25 to 35, where the at least one suitable SL DRX configuration for the UE is aligned with the current Uu DRX configuration of the UE.

Aspect 37 is the apparatus of any of aspects 25 to 36, where the indication of the SL DRX configuration includes one or more SL DRX parameters associated with an alignment of the Uu DRX configuration and the SL DRX configuration.

Aspect 38 is the apparatus of any of aspects 25 to 37, where the one or more SL DRX parameters include at least one of: an SL DRX cycle, an SL DRX starting offset, or an SL DRX slot offset.

Aspect 39 is the apparatus of any of aspects 25 to 38, where the indication of the Uu DRX configuration includes one or more Uu DRX parameters associated with an alignment of the Uu DRX configuration and the SL DRX configuration.

Aspect 40 is the apparatus of any of aspects 25 to 39, where the one or more Uu DRX parameters include at least one of: a Uu DRX long cycle, a starting offset for the Uu DRX long cycle, a Uu DRX short cycle, a timer for the Uu DRX short cycle, or a Uu DRX slot offset.

Aspect 41 is the apparatus of any of aspects 25 to 40, further including a transceiver or an antenna coupled to the at least one processor.

Aspect 42 is a method of wireless communication for implementing any of aspects 25 to 41.

Aspect 43 is an apparatus for wireless communication including means for implementing any of aspects 25 to 41.