Patent Publication Number: US-2023164872-A1

Title: Coordination for access link discontinuous reception and sidelink alignment

Description:
FIELD OF TECHNOLOGY 
     The following relates to wireless communications, including coordination during access link discontinuous reception and sidelink alignment. 
     BACKGROUND 
     Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). 
     Some wireless communications devices may implement discontinuous reception (DRX) methods to conserve battery power, where the device cycles through periods of activity and inactivity according to a DRX periodicity. In some cases, however, multiple DRX configured devices may perform DRX alignment procedures to coordinate these periods of activity and inactivity. 
     SUMMARY 
     The described techniques relate to improved methods, systems, devices, and apparatuses that support coordination during access link discontinuous reception (DRX) and sidelink alignment. Generally, the described techniques support techniques for sidelink DRX coordination. In some wireless communications systems, base stations may configure communications and alignment for user equipment (UE) operating in a DRX mode. For example, in cases where UEs communicate with one another using sidelink DRX communications, the UEs may perform DRX alignment so that an active time of one UE does not align with an active time of another UE. To support efficient DRX alignment and reduced sidelink signaling overhead, in some cases, a base station or base station component such as a centralized unit (CU) or a distributed unit (DU) may determine the DRX configurations and coordinate with one another via a direct link (e.g., an Xn or F1 interface) or a wired backhaul link. Such implementations may reduce power expenditure at the UE level, and free up sidelink resources that the UEs may use for transmitting data. In some cases, a UE may transmit assistance information to a base station, and the base station may use the assistance information to coordinate with a second base station to determine a sidelink DRX configuration for the UE and a second UE, along with an access link for the UE. 
     A method for wireless communication at a first base station is described. The method may include receiving, from a first UE, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE, transmitting, to a second base station, the assistance information message received from the first UE, communicating, with the second base station via an interface between the first base station and the second base station, an indication of the sidelink DRX configuration for the first UE, and transmitting, to the first UE, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration for the first UE based on the communicating. 
     An apparatus for wireless communication at a first base station 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, from a first UE, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE, transmit, to a second base station, the assistance information message received from the first UE, communicate, with the second base station via an interface between the first base station and the second base station, an indication of the sidelink DRX configuration for the first UE, and transmit, to the first UE, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration for the first UE based on the communicating. 
     Another apparatus for wireless communication at a first base station is described. The apparatus may include means for receiving, from a first UE, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE, means for transmitting, to a second base station, the assistance information message received from the first UE, means for communicating, with the second base station via an interface between the first base station and the second base station, an indication of the sidelink DRX configuration for the first UE, and means for transmitting, to the first UE, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration for the first UE based on the communicating. 
     A non-transitory computer-readable medium storing code for wireless communication at a first base station is described. The code may include instructions executable by a processor to receive, from a first UE, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE, transmit, to a second base station, the assistance information message received from the first UE, communicate, with the second base station via an interface between the first base station and the second base station, an indication of the sidelink DRX configuration for the first UE, and transmit, to the first UE, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration for the first UE based on the communicating. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, communicating with the second base station via the interface may include operations, features, means, or instructions for transmitting the assistance information message between the first base station and the second base station via a connection between a first CU of the first base station and a second CU of the second base station. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for relaying the indication of the sidelink DRX configuration and the indication of the access link DRX configuration from a first CU of the first base station to a first DU of the first base station and transmitting, to the first UE, the indication of the sidelink DRX configuration and the indication of the access link DRX configuration via an access link between the first UE and the first DU. 
     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 assistance information message to the second base station, the assistance information message including a field including one or more additional sidelink DRX configurations associated with one or more additional sidelink UEs, and a field including the indication of the access link DRX configuration for the first UE. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the sidelink DRX configuration for the first UE includes one or more sidelink DRX alignment parameters. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the access link DRX configuration for the second UE includes one or more access link DRX alignment parameters. 
     A method for wireless communication at a second base station is described. The method may include receiving, from a first base station, an assistance information message from a first UE, the assistance information message for determining a sidelink DRX configuration for communications between the first UE and a second UE, transmitting, to the first base station, an indication of the sidelink DRX configuration determined for the first UE via an interface between the first base station and the second base station, and transmitting, to the second UE, an indication of an access link DRX configuration for communications between the second UE and the second base station. 
     An apparatus for wireless communication at a second base station 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, from a first base station, an assistance information message from a first UE, the assistance information message for determining a sidelink DRX configuration for communications between the first UE and a second UE, transmit, to the first base station, an indication of the sidelink DRX configuration determined for the first UE via an interface between the first base station and the second base station, and transmit, to the second UE, an indication of an access link DRX configuration for communications between the second UE and the second base station. 
     Another apparatus for wireless communication at a second base station is described. The apparatus may include means for receiving, from a first base station, an assistance information message from a first UE, the assistance information message for determining a sidelink DRX configuration for communications between the first UE and a second UE, means for transmitting, to the first base station, an indication of the sidelink DRX configuration determined for the first UE via an interface between the first base station and the second base station, and means for transmitting, to the second UE, an indication of an access link DRX configuration for communications between the second UE and the second base station. 
     A non-transitory computer-readable medium storing code for wireless communication at a second base station is described. The code may include instructions executable by a processor to receive, from a first base station, an assistance information message from a first UE, the assistance information message for determining a sidelink DRX configuration for communications between the first UE and a second UE, transmit, to the first base station, an indication of the sidelink DRX configuration determined for the first UE via an interface between the first base station and the second base station, and transmit, to the second UE, an indication of an access link DRX configuration for communications between the second UE and the second base station. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, communicating with the first base station via the interface may include operations, features, means, or instructions for receiving the assistance information message from the first base station via a connection between a first CU of the first base station and a second CU of the second base station. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining the sidelink DRX configuration for the first UE and the access link DRX configuration for the second UE, transmitting, to the first base station, the indication of the sidelink DRX configuration for the first UE via the interface between the second base station and the first base station, and transmitting, to the second UE, the indication of the access link DRX configuration for the second UE based on the determining. 
     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 assistance information message from the first base station, the assistance information message including a field including one or more additional sidelink DRX configurations associated with one or more additional sidelink UEs, and a field including the indication of the access link DRX configuration for the first UE. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the sidelink DRX configuration for the first UE includes one or more sidelink DRX alignment parameters. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the access link DRX configuration for the second UE includes one or more access link DRX alignment parameters. 
     A method for wireless communication is described. The method may include receiving, from a first UE, a first assistance information message at a first DU, the first assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE, receiving, at a CU, the first assistance information message relayed by the first DU to the CU, communicating, between the CU and at least the first DU, an indication of the sidelink DRX configuration for the first UE and an indication of a first access link DRX configuration for the first UE, and transmitting, to the first UE, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based on the communicating. 
     An apparatus for wireless communication 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, from a first UE, a first assistance information message at a first DU, the first assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE, receive, at a CU, the first assistance information message relayed by the first DU to the CU, communicate, between the CU and at least the first DU, an indication of the sidelink DRX configuration for the first UE and an indication of a first access link DRX configuration for the first UE, and transmit, to the first UE, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based on the communicating. 
     Another apparatus for wireless communication is described. The apparatus may include means for receiving, from a first UE, a first assistance information message at a first DU, the first assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE, means for receiving, at a CU, the first assistance information message relayed by the first DU to the CU, means for communicating, between the CU and at least the first DU, an indication of the sidelink DRX configuration for the first UE and an indication of a first access link DRX configuration for the first UE, and means for transmitting, to the first UE, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based on the communicating. 
     A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to receive, from a first UE, a first assistance information message at a first DU, the first assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE, receive, at a CU, the first assistance information message relayed by the first DU to the CU, communicate, between the CU and at least the first DU, an indication of the sidelink DRX configuration for the first UE and an indication of a first access link DRX configuration for the first UE, and transmit, to the first UE, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based on the communicating. 
     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 second UE, a second assistance information message at a second DU, receiving, at the CU, the second assistance information message relayed by the second DU to the CU, communicating, between the CU and the second DU, an indication of a second access link DRX configuration for the second UE, and transmitting, to the second UE, the indication of the first access link DRX configuration based on the communicating. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, at the first DU and a second DU, one or more pre-configurations for determining one or more DRX configurations for the first UE and the second UE, transmitting, to the first UE via the first DU, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based on the one or more pre-configurations, and transmitting, to the second UE via the second DU, an indication of a second access link DRX configuration based on the one or more pre-configurations. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for communicating, between the first DU and the second DU, the one or more DRX configurations for the first UE and the second UE based on the one or more pre-configurations. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for communicating, between the first DU and a second DU, the first assistance information message, the indication of the sidelink DRX configuration, the indication of the first access link DRX configuration, or any combination thereof. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the CU determines the sidelink DRX configuration for the first UE, the first access link DRX configuration for the first UE, and the second access link DRX configuration for the second UE. 
     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 second UE, a second assistance information message at the first DU, receiving, at the CU, the second assistance information message relayed by the first DU to the CU, communicating, between the CU and the first DU, an indication of a second access link DRX configuration for the second UE, and transmitting, to the second UE, the indication of the first access link DRX configuration based on the communicating. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, at the first DU, one or more pre-configurations for determining one or more DRX configurations for the first UE and the second UE, transmitting, to the first UE via the first DU, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based on the one or more pre-configurations, and transmitting, to the second UE via the first DU, an indication of a second access link DRX configuration based on the one or more pre-configurations. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for communicating, between the CU and the first DU, the one or more DRX configurations for the first UE and the second UE based on the one or more pre-configurations. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for communicating, between the CU and the first DU and a second DU, the first assistance information message, the indication of the sidelink DRX configuration, the indication of the first access link DRX configuration, or any combination thereof. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first assistance information message includes one or more additional indications of sidelink connected mode DRX configurations established between the first UE and one or more other sidelink UEs. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for communicating via layer-1 signaling, layer-2 signaling, layer-3 signaling, or any combination thereof. 
     A method for wireless communication at a first UE is described. The method may include transmitting, to a base station, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE, receiving, from the base station, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration, communicating with the second UE via a sidelink in accordance with the received sidelink DRX configuration, and communicating with the base station via an access link in accordance with the received access link DRX configuration. 
     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 transmit, to a base station, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE, receive, from the base station, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration, communicate with the second UE via a sidelink in accordance with the received sidelink DRX configuration, and communicate with the base station via an access link in accordance with the received access link DRX configuration. 
     Another apparatus for wireless communication at a first UE is described. The apparatus may include means for transmitting, to a base station, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE, means for receiving, from the base station, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration, means for communicating with the second UE via a sidelink in accordance with the received sidelink DRX configuration, and means for communicating with the base station via an access link in accordance with the received access link DRX configuration. 
     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 transmit, to a base station, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE, receive, from the base station, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration, communicate with the second UE via a sidelink in accordance with the received sidelink DRX configuration, and communicate with the base station via an access link in accordance with the received access link DRX configuration. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, via a first DU of the base station, the indication of the sidelink DRX configuration and the indication of the access link DRX configuration based on one or more pre-configurations. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the assistance information message may include operations, features, means, or instructions for transmitting the assistance information message via the access link to a first DU of the base station. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the assistance information message includes one or more additional indications of sidelink connected mode DRX configurations established between the first UE and one or more other sidelink UEs. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for communicating via layer-1 signaling, layer-2 signaling, layer-3 signaling, or any combination thereof. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for refraining from transmitting the sidelink DRX configuration to the second UE based on receiving the indication of the sidelink DRX configuration from the base station. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS.  1  through  3    illustrate example wireless communications systems that support coordination during access link discontinuous reception (DRX) and sidelink alignment in accordance with aspects of the present disclosure. 
         FIG.  4    illustrates an example of a process flow that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. 
         FIG.  5    illustrates an example of a wireless communications system that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. 
         FIGS.  6  and  7    illustrate example process flows that support coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. 
         FIG.  8    illustrates an example of a wireless communications system that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. 
         FIGS.  9  and  10    illustrate example process flows that support coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. 
         FIGS.  11  and  12    show block diagrams of devices that support coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. 
         FIG.  13    shows a block diagram of a communications manager that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. 
         FIG.  14    shows a diagram of a system including a device that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. 
         FIGS.  15  and  16    show block diagrams of devices that support coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. 
         FIG.  17    shows a block diagram of a communications manager that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. 
         FIG.  18    shows a diagram of a system including a device that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. 
         FIGS.  19  through  24    show flowcharts illustrating methods that support coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In some wireless communications systems, network devices such as base stations may communicate or share information to coordinate signaling between connected devices such as user equipment (UE). For example, base stations may configure communications and alignment for UEs operating in a discontinuous reception (DRX) mode. For example, in cases where UEs communicate with one another using sidelink DRX communications, the UEs may perform DRX alignment such that the sidelink grant from one of the UEs during its DRX active time does not overlap with the DRX active time of another UE. In some cases, the UEs may communicate with one another directly using sidelink resources, and with each respective base station in order to determine a sidelink DRX configuration that effectively coordinates the active DRX times. In some cases, however, this DRX alignment which relies on sidelink communications between the UEs may increase signaling overhead and power expenditure for the UEs. 
     To support more efficient DRX alignment and reduced sidelink signaling overhead, in some cases, a base station or base station component such as a centralized unit (CU) or a distributed unit (DU) may determine the DRX configurations and coordinate with one another via an Xn link or backhaul link. Such implementations may reduce power expenditure at the UE level, and free up sidelink resources that the UEs may use for transmitting data. 
     In some examples, a receiving UE and a transmitting UE may be connected to respective base stations via different CUs and DUs. The receiving UE may transmit assistance information to a first base station, and the first base station may relay the assistance information on to a second base station. The second base station then may determine a sidelink DRX configuration for the receiving UE, and transmits the configuration to the first base station, which then transmits the sidelink DRX configuration along with a Uu DRX configuration to the receiving UE. In such examples, the coordination of sidelink DRX configurations occurs between the first and second base stations, such that the base stations may exchange information directly via an Xn interface between them. 
     In some other examples, the receiving UE and the transmitting UE may be connected to different DUs, but a common CU. In such cases, the DUs may communicate indirectly between the CU to determine the sidelink DRX configuration, or the DUs may communicate directly between one another. In either case, the sidelink DRX configuration (and in some cases) the Uu DRX configuration is signaled between DUs, and transmitted to respective UEs. In some other examples, the receiving UE and the transmitting UE may be connected to a common CU and a common DU. In such cases, the assistance information provided by the receiving UE is used to determine sidelink DRX configurations and Uu configurations for the transmitting UE and the receiving UE by the CU. 
     Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, process flows, and flowcharts that relate to coordination during access link DRX and sidelink alignment. 
       FIG.  1    illustrates an example of a wireless communications system  100  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The wireless communications system  100  may include one or more base stations  105 , one or more UEs  115 , and a core network  130 . In some examples, the wireless communications system  100  may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communications system  100  may support enhanced broadband communications, ultra-reliable communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof. 
     The base stations  105  may be dispersed throughout a geographic area to form the wireless communications system  100  and may be devices in different forms or having different capabilities. The base stations  105  and the UEs  115  may wirelessly communicate via one or more communication links  125 . Each base station  105  may provide a coverage area  110  over which the UEs  115  and the base station  105  may establish one or more communication links  125 . The coverage area  110  may be an example of a geographic area over which a base station  105  and a UE  115  may support the communication of signals according to one or more radio access technologies. 
     The UEs  115  may be dispersed throughout a coverage area  110  of the wireless communications system  100 , and each UE  115  may be stationary, or mobile, or both at different times. The UEs  115  may be devices in different forms or having different capabilities. Some example UEs  115  are illustrated in  FIG.  1   . The UEs  115  described herein may be able to communicate with various types of devices, such as other UEs  115 , the base stations  105 , or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment), as shown in  FIG.  1   . 
     In some examples, one or more components of the wireless communications system  100  may operate as or be referred to as a network node. As used herein, a network node may refer to any UE  115 , base station  105 , entity of a core network  130 , apparatus, device, or computing system configured to perform any techniques described herein. For example, a network node may be a UE  115 . As another example, a network node may be a base station  105 . 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 UE  115 , the second network node may be a base station  105 , and the third network node may be a UE  115 . In another aspect of this example, the first network node may be a UE  115 , the second network node may be a base station  105 , and the third network node may be a base station  105 . In yet other aspects of this example, the first, second, and third network nodes may be different. Similarly, reference to a UE  115 , a base station  105 , an apparatus, a device, or a computing system may include disclosure of the UE  115 , base station  105 , apparatus, device, or computing system being a network node. For example, disclosure that a UE  115  is configured to receive information from a base station  105  also discloses that a first network node is configured to receive information from a second network node. In this example, in accordance with this disclosure, the first network node may refer to a first UE  115 , a first base station  105 , 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 UE  115 , a second base station  105 , a second apparatus, a second device, or a second computing system 
     The base stations  105  may communicate with the core network  130 , or with one another, or both. For example, the base stations  105  may interface with the core network  130  through one or more backhaul links  120  (e.g., via an S1, N2, N3, or other interface). The base stations  105  may communicate with one another over the backhaul links  120  (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations  105 ), or indirectly (e.g., via core network  130 ), or both. In some examples, the backhaul links  120  may be or include one or more wireless links. 
     One or more of the base stations  105  described herein may include or may be referred to by a person having ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or a giga-NodeB (either of which may be referred to as a gNB), a Home NodeB, a Home eNodeB, or other suitable terminology. 
     A UE  115  may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples. A UE  115  may also include or may be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, a UE  115  may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, or vehicles, meters, among other examples. 
     The UEs  115  described herein may be able to communicate with various types of devices, such as other UEs  115  that may sometimes act as relays as well as the base stations  105  and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in  FIG.  1   . 
     The UEs  115  and the base stations  105  may wirelessly communicate with one another via one or more communication links  125  over one or more carriers. The term “carrier” may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication links  125 . For example, a carrier used for a communication link  125  may include a portion of a radio frequency spectrum band (e.g., a bandwidth part (BWP)) that is operated according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling that coordinates operation for the carrier, user data, or other signaling. The wireless communications system  100  may support communication with a UE  115  using carrier aggregation or multi-carrier operation. A UE  115  may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers. 
     Signal waveforms transmitted over a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element may include one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both). Thus, the more resource elements that a UE  115  receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE  115 . A wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers or beams), and the use of multiple spatial layers may further increase the data rate or data integrity for communications with a UE  115 . 
     The time intervals for the base stations  105  or the UEs  115  may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of T s =1/(Δf max ·N f ) seconds, where Δf max  may represent the maximum supported subcarrier spacing, and N f  may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023). 
     Each frame may include multiple consecutively numbered subframes or slots, and each subframe or slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a number of slots. Alternatively, each frame may include a variable number of slots, and the number of slots may depend on subcarrier spacing. Each slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period). In some wireless communications systems  100 , a slot may further be divided into multiple mini-slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., N f ) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation. 
     A subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system  100  and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communications system  100  may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)). 
     Physical channels may be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) for a physical control channel may be defined by a number of symbol periods and may extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) may be configured for a set of the UEs  115 . For example, one or more of the UEs  115  may monitor or search control regions for control information according to one or more search space sets, and each search space set may include one or multiple control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to a number of control channel resources (e.g., control channel elements (CCEs)) associated with encoded information for a control information format having a given payload size. Search space sets may include common search space sets configured for sending control information to multiple UEs  115  and UE-specific search space sets for sending control information to a specific UE  115 . 
     Each base station  105  may provide communication coverage via one or more cells, for example a macro cell, a small cell, a hot spot, or other types of cells, or any combination thereof. The term “cell” may refer to a logical communication entity used for communication with a base station  105  (e.g., over a carrier) and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID), or others). In some examples, a cell may also refer to a geographic coverage area  110  or a portion of a geographic coverage area  110  (e.g., a sector) over which the logical communication entity operates. Such cells may range from smaller areas (e.g., a structure, a subset of structure) to larger areas depending on various factors such as the capabilities of the base station  105 . For example, a cell may be or include a building, a subset of a building, or exterior spaces between or overlapping with geographic coverage areas  110 , among other examples. 
     A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by the UEs  115  with service subscriptions with the network provider supporting the macro cell. A small cell may be associated with a lower-powered base station  105 , as compared with a macro cell, and a small cell may operate in the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to the UEs  115  with service subscriptions with the network provider or may provide restricted access to the UEs  115  having an association with the small cell (e.g., the UEs  115  in a closed subscriber group (CSG), the UEs  115  associated with users in a home or office). A base station  105  may support one or multiple cells and may also support communications over the one or more cells using one or multiple component carriers. 
     In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)) that may provide access for different types of devices. 
     In some examples, a base station  105  may be movable and therefore provide communication coverage for a moving geographic coverage area  110 . In some examples, different geographic coverage areas  110  associated with different technologies may overlap, but the different geographic coverage areas  110  may be supported by the same base station  105 . In other examples, the overlapping geographic coverage areas  110  associated with different technologies may be supported by different base stations  105 . The wireless communications system  100  may include, for example, a heterogeneous network in which different types of the base stations  105  provide coverage for various geographic coverage areas  110  using the same or different radio access technologies. 
     The wireless communications system  100  may support synchronous or asynchronous operation. For synchronous operation, the base stations  105  may have similar frame timings, and transmissions from different base stations  105  may be approximately aligned in time. For asynchronous operation, the base stations  105  may have different frame timings, and transmissions from different base stations  105  may, in some examples, not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations. 
     Some UEs  115  may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception simultaneously). In some examples, half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for the UEs  115  include entering a power saving deep sleep mode when not engaging in active communications, operating over a limited bandwidth (e.g., according to narrowband communications), or a combination of these techniques. For example, some UEs  115  may be configured for operation using a narrowband protocol type that is associated with a defined portion or range (e.g., set of subcarriers or resource blocks (RBs)) within a carrier, within a guard-band of a carrier, or outside of a carrier. 
     The wireless communications system  100  may be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system  100  may be configured to support ultra-reliable low-latency communications (URLLC). The UEs  115  may be designed to support ultra-reliable, low-latency, or critical functions. Ultra-reliable communications may include private communication or group communication and may be supported by one or more services such as push-to-talk, video, or data. Support for ultra-reliable, low-latency functions may include prioritization of services, and such services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, and ultra-reliable low-latency may be used interchangeably herein. 
     In some examples, a UE  115  may also be able to communicate directly with other UEs  115  over a device-to-device (D2D) communication link  135  (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs  115  utilizing D2D communications may be within the geographic coverage area  110  of a base station  105 . Other UEs  115  in such a group may be outside the geographic coverage area  110  of a base station  105  or be otherwise unable to receive transmissions from a base station  105 . In some examples, groups of the UEs  115  communicating via D2D communications may utilize a one-to-many (1:M) system in which each UE  115  transmits to every other UE  115  in the group. In some examples, a base station  105  facilitates the scheduling of resources for D2D communications. In other cases, D2D communications are carried out between the UEs  115  without the involvement of a base station  105 . 
     The core network  130  may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network  130  may be an evolved packet core (EPC) or 5G core (5GC), which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MIME), an access and mobility management function (AMF)) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a Packet Data Network (PDN) gateway (P-GW), or a user plane function (UPF)). The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs  115  served by the base stations  105  associated with the core network  130 . User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to IP services  150  for one or more network operators. The IP services  150  may include access to the Internet, Intranet(s), an IP Multimedia Subsystem (IMS), or a Packet-Switched Streaming Service. 
     Some of the network devices, such as a base station  105 , may include subcomponents such as an access network entity  140 , which may be an example of an access node controller (ANC). Each access network entity  140  may communicate with the UEs  115  through one or more other access network transmission entities  145 , which may be referred to as radio heads, smart radio heads, or transmission/reception points (TRPs). Each access network transmission entity  145  may include one or more antenna panels. In some configurations, various functions of each access network entity  140  or base station  105  may be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., a base station  105 ). 
     The wireless communications system  100  may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. The UHF waves may be blocked or redirected by buildings and environmental features, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs  115  located indoors. The transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz. 
     The wireless communications system  100  may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communications system  100  may employ License Assisted Access (LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in unlicensed radio frequency spectrum bands, devices such as the base stations  105  and the UEs  115  may employ carrier sensing for collision detection and avoidance. In some examples, operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA). Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples. 
     A base station  105  or a UE  115  may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a base station  105  or a UE  115  may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with a base station  105  may be located in diverse geographic locations. A base station  105  may have an antenna array with a number of rows and columns of antenna ports that the base station  105  may use to support beamforming of communications with a UE  115 . Likewise, a UE  115  may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, an antenna panel may support radio frequency beamforming for a signal transmitted via an antenna port. 
     Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station  105 , a UE  115 ) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that some signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying amplitude offsets, phase offsets, or both to signals carried via the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation). 
     The wireless communications system  100  may be a packet-based network that operates according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate over logical channels. A Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use error detection techniques, error correction techniques, or both to support retransmissions at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE  115  and a base station  105  or a core network  130  supporting radio bearers for user plane data. At the physical layer, transport channels may be mapped to physical channels. 
     In some cases, a UE  115  may be configured for sidelink communications, and may receive a sidelink configuration message indicating a configuration for communicating via a sidelink or a PC5 link with another sidelink UE  115 . For example, the sidelink configuration message may include a number of parameters related to the alignment of the sidelink transmissions, for example a DRX starting time offset parameter (e.g., sl-drx-StartOffset), a DRX cycle parameter (e.g., sl-drx-Cycle), and a DRX slot offset parameter (e.g., sl-drx-SlotOffset). In some examples, the sidelink DRX configuration (e.g., SL C-DRX configuration) may be transmitted via layer-3 signaling or via an RRC message. In some cases, the RRC message may contain the entire SL DRX configuration (e.g., using the sidelink RRC information element sl-DRX-Config), or the message may contain a subset of SL DRX configuration which is related to alignment (e.g., using the sidelink RRC information element sl-DRX-Config-Alignment). In addition, one or more parameters associated with the sidelink DRX configuration may be included in a MAC-CE for layer-2 signaling. For example, the MAC CE may include one or more sidelink DRX parameters such as various offset parameters and DRX cycle parameters (e.g., drx-StartOffset, sl-DRX-Cycle, sl-drx-SlotOffset). In some cases, the MAC CE format used to convey the sidelink DRX configuration may have variable length. Additionally or alternatively, the base station may indicate a subset of values for an update to the sidelink DRX configuration (e.g., a first parameter sl-drx-Slot-Offset has 32 values, and the base station may inform the UEs that the updated value in the MAC CE is one of 8 values in a subset). In such cases, the base station may use layer 3 signaling (e.g., RRC) to configure a set of values for various parameters in the sidelink DRX configuration, and then may use layer 1/layer 2 signaling to indicate one of the parameters. In some examples, sidelink DRX configuration messages may be transmitted between serving base stations (e.g., via an Xn interface) to reduce sidelink signaling overhead for the two sidelink UEs. 
     In some examples, a receiving UE  115  may have a sidelink connection with multiple transmitting UEs  115 , and each transmitting UE  115  may set a different sidelink DRX configuration for the receiving UE  115 . For example, the transmitting UE  115  may set the sidelink DRX configuration based on existing sidelink DRX configurations and capabilities of the receiving UE  115 . In cases that the receiving UE  115  cannot monitor signaling or messaging from different transmitting UEs  115  simultaneously, the active times of each SL DRX may not overlap (works on FR2 and single panel). If the receiving UE  115  may monitor the signaling or messaging from different transmitting UEs  115  simultaneously, the active times of different SL DRX configurations may overlap (works on FR1 or multiple panels). 
     The wireless communications system  100  may support layer-3 signaling (e.g., RRC signaling) of existing sidelink C-DRX configurations from other transmitting UEs  115 . In some examples, the sidelink configuration signaling may include the whole sidelink DRX configuration, or the sidelink configuration signaling may include parameters related to sidelink alignment. 
     In addition, a UE  115  may be configured to communicate via a direct link with a base station  105 , for example, via a Uu link. The UE  115  may receive a Uu DRX configuration message indicating a configuration for communicating via an access link or a Uu link with the base station  105 - a . For example, the Uu DRX configuration message may include a number of parameters related to the alignment of the transmissions on the access link, for example a DRX starting time offset parameter (e.g., drx-LongCycleStartOffset), a number of DRX parameters associated with DRX cycle length (e.g., shortDRX, drx-ShortCycle, drx-ShortCycleTimer), and a DRX slot offset parameter (e.g., drx-SlotOffset). In some examples, the Uu DRX configuration (e.g., Uu C-DRX configuration) may be transmitted in layer-3 signaling or via an RRC message. In some cases, the RRC message may contain the entire DRX configuration (e.g., using the sidelink RRC information element DRX-Config), or the message may contain a subset of DRX configuration which is related to alignment (e.g., using the sidelink RRC information element DRX-Config-Alignment). In addition, one or more parameters associated with the Uu DRX configuration may be included in a MAC-CE for layer-2 signaling. For example, the MAC CE may include one or more Uu DRX parameters such as various offset parameters and DRX cycle parameters (e.g., drx-LongCycleStartOffset, DRX-Short-Cycle, drx-SlotOffset). In some cases, the MAC CE format used to convey the sidelink DRX configuration may have variable length. Additionally or alternatively, the base station may indicate a subset of values for an update to the DRX configuration (e.g., a first parameter drx-Slot-Offset has 32 values, and the base station may inform the UEs that the updated value in the MAC CE is one of 8 values in a subset). In such cases, the base station may use layer 3 signaling (e.g., RRC) to configure a set of values for various parameters in the sidelink DRX configuration, and then may use layer 1/layer 2 signaling to indicate one of the parameters. In some examples, the DRX configuration messages may be transmitted between serving base stations (e.g., via an Xn interface) to reduce sidelink signaling overhead for the two UEs. 
     In some wireless communications systems, base stations  105  may configure communications and alignment for UEs  115  operating in a DRX mode. For example, in cases where UEs  115  communicate with one another using sidelink DRX communications, the UEs may perform DRX alignment so that an active time of one UE  115  does not align with an active time of another UE  115 . In some cases, the UEs  115  may communicate with one another directly using sidelink resources, and with each respective base station  105  in order to determine a sidelink DRX configuration that effectively coordinates the active DRX times. In some cases, however, this DRX alignment which relies on sidelink communications between the UEs may increase signaling overhead and power expenditure 
     To support more efficient DRX alignment and reduced sidelink signaling overhead, in some cases, a base station  105  or base station component such as a CU or a DU may determine the DRX configurations and coordinate with one another via an Xn link or backhaul link. Such implementations may reduce power expenditure at the UE level, and free up sidelink resources that the UEs  115  may use for transmitting data. 
       FIG.  2    illustrates an example of a wireless communications system  200  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. For example, wireless communications system  200  may support signaling between a UE  205 - a , a UE  205 - b , a base station  210 - a , a base station  210 - b , or any combination thereof. 
     In some wireless communications systems, base stations  210  (e.g., gNBs) may communicate or share information in order to coordinate signaling between connected devices in the network. For example, base stations  210  may configure communications for UEs  205  operating in a DRX mode (e.g., an idle mode DRX or connected mode DRX), and may perform various alignments for DRX operations between UEs  205 . For example, the UE  205 - a  may communicate with the base station  210 - a  using a first access link (e.g., Uu link  215 - a ), and the UE  205 - b  may communicate with the base station  210 - b  using a second access link (e.g., Uu link  215 - b ). In addition, the UEs  205 - a  and  205 - b  may communicate with one another using sidelink signaling  220 . In order to communicate via sidelink DRX, the UEs  205  may perform alignment so that the sidelink grant from one of the UEs  205  during a Uu active time does not overlap with the active time of the other UE  205 . In some cases, the UE  205 - a  and the UE  205 - b  may communicate directly with one another using sidelink resources, and with each respective base station  210  in order to determine a sidelink DRX configuration. In some cases, however, this DRX alignment which relies on sidelink communications between the UEs  205 - a  and  205 - b  may increase signaling overhead and power expenditure for the UEs. 
     To support more efficient DRX alignment and reduced sidelink signaling overhead, in some cases, a base station or base station component may determine the DRX configurations and coordinate with one another via an Xn link  225  or backhaul link. Such implementations may reduce power expenditure at the UE level, and free up sidelink resources that the UEs  205  may use for transmitting data. 
     In some examples, the UE  205 - a  (e.g., a receiving UE) and the UE  205 - b  (e.g., a transmitting UE) may be connected to base stations  210 - a  and  210 - b , respectively, with different CUs and different DUs. The UE  205 - a  may transmit assistance information to the base station  210 - a , which the base station  210 - a  may send to the base station  210 - b . The base station  210 - b  then determines a sidelink DRX configuration for the UE  205 - a , and transmits the configuration to the base station  210 - a , which then transmits the sidelink DRX configuration along with a Uu DRX configuration to the UE  205 - a . The coordination of sidelink DRX configurations occurs between base stations, where the base stations  210 - a  and  210 - b  may exchange information directly via an Xn interface  225  between them. 
     In some other examples, the UE  205 - a  and the UE  205 - b  may be connected to different DUs, but a common CU. In such cases, the DUs may communicate indirectly between the CU to determine the sidelink DRX configuration, or the DUs may communicate directly between one another. In either case, the sidelink DRX configuration (and in some cases) the Uu DRX configuration is signaled between DUs, and transmitted to respective UEs. 
     In some other examples, the UE  205 - a  and the UE  205 - b  may be connected to a common CU and a common DU. In such cases, the assistance information provided by the UE  205 - a  is used to determine sidelink DRX configurations and Uu configurations for the UE  205 - b  and the UE  205 - b  at the CU. 
       FIG.  3    illustrates an example of a wireless communications system  300  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. For example, wireless communications system  300  may support a signaling configuration in which one or more wireless user devices (such as a UE  305 - a  and UE  305 - b ) are connected to or otherwise associated with two different DUs and two different CUs of two different base stations (e.g., gNodeBs) such as base stations  310 - a  and  310 - b . The base station  310 - a  may include a CU  320 - a  and a DU  315 - a , and the base station  310 - b  may include a CU  320 - b  and a DU  315 - b . The UEs  305 - a  and  305 - b , along with the base station  310 - a  and  310 - b  may be examples of corresponding devices described with reference to  FIGS.  1  and  2   . 
     In some examples, the UE  305 - a  may be a transmitting UE (e.g., a Tx UE) and the UE  305 - b  may be a receiving UE (e.g., a Rx UE). The transmitting UE  305 - a  may be connected to the base station  310 - a  via the DU  315 - a , and the receiving UE  305 - b  may be connected to the base station  310 - b  via the DU  315 - b . The UEs  305 - a  and  305 - b  may be connected with each respective DU  315 - a  and  315 - b  using a Uu interface  325 - a  and  325 - b , which may serve as direct links between the UEs  305  and each respective base station  310 . In addition, the DU  305 - b  may be associated with a CU  320 - a , and the DU  305 - b  may be associated with the CU  320 - b . Devices in wireless communications system  300  may communicate via direct links (e.g., access links) or sidelinks. For example, the UEs  305  may communicate with the base stations  310  using direct links or Uu links  325 , or the UEs may communicate with one another using sidelink signaling on the sidelink  330 . In some cases, the sidelink signaling may occur via a PC5 interface between UEs  305 . Additionally or alternatively, the base stations  310  may communicate with one another using a direct link or via the Xn interface  335   
     In some implementations, the UE  305 - a  and the UE  305 - b  may exchange sidelink information such as sidelink DRX configuration information via the sidelink signaling  330 . In some cases, however, the configuration signaling may occupy a relatively large number of wireless resources between the UE  305 - a  and the UE  305 - b , and may increase sidelink signaling overhead. To reduce such signaling overhead for the sidelink  330 , in some examples, the base station  310 - a  and the base station  310 - b  may communicate directly via an Xn interface  330  to exchange the sidelink DRX information for the UEs  305 - a  and  305 - b , which may reduce the signaling overhead and increase throughput for sidelink communications between the UEs  305 - a  and  305 - b . For example, the base station  310 - a  and the base station  310 - b  may use the Xn interface  330  to exchange information directly (e.g., sidelink DRX information, Uu configuration information, etc.) between CUs without involving communications between user devices. In some examples, communications between the base stations on the Xn interface  330  may be performed through wired (e.g., an IAB connected) communications. 
     To facilitate sidelink alignment between UE  305 - a  and UE  305 - b , the base station  310 - b  may receive assistance information from the receiving UE  305 - b  which includes a Uu DRX configuration of the receiving UE  305 - b . Additionally or alternatively, the assistance information from the receiving UE  305 - b  may include additional sidelink DRX configurations of receiving UE  305 - b  with transmitting UE  305 - a , or other existing sidelink DRX configurations of receiving UE  305 - b  with other transmitting UEs. The base station  310 - b  may transmit the assistance information it receives from the receiving UE  305 - b  to the base station  310 - a  via the Xn interface  335 , and the base station  310 - a  may determine the receiving UE&#39;s sidelink DRX configuration, which it may transmit to the base station  310 - b  via the Xn interface. The base station  310 - b  may then relay the sidelink DRX configuration to the receiving UE  305 - b . In such examples, the receiving UE  305 - b  may receive the sidelink DRX configuration (for configuring sidelink communications between itself and the transmitting UE  305 - a ), without directly communicating with the transmitting UE  305 - a.    
       FIG.  4    illustrates an example of a process flow  400  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The process flow  400  may implement aspects of wireless communications systems  100  through  300 , or may be implemented by aspects of the wireless communications system  100  through  300 . For example, the process flow  400  may illustrate operations between a UE  405 - a , a UE  405 - b , a base station  410 - a  and a base station  410 - b , which may be examples of corresponding devices described with reference to  FIGS.  1  and  2   . In the following description of the process flow  400 , the operations between the devices may be transmitted in a different order than the example order shown, or the operations may be performed in different orders or at different times or by different devices. Additionally or alternatively, some operations may also be omitted from the process flow  400 , and other operations may be added to the process flow  400 . 
     At  415 , the receiving UE  405 - a  may transmit or report assistance information to the base station  410 - a  which is associated with the receiving UE  405 - a . In some examples, the assistance information may include information which is unknown to the base station  410 - a . For example, the assistance information may include existing SL DRX (e.g., C-DRX) configurations of receiving UE  405 - a  with other transmitting UEs. In such examples, the assistance information may provide information which allows the base station  410 - a  to select a configuration (e.g., a SL C-DRX configuration) that does not overlap with existing configurations used by the receiving UE  405 - a  or by other UEs in the system. The assistance information may optionally include a Uu DRX configuration between the receiving UE  405 - a  and the base station  410 - a , but in some cases, the base station  410 - a  may know the Uu DRX configuration for the UE  405 - a  without the assistance information. 
     At  420 , the base station  410 - a  may transmit the assistance information received from the receiving UE  405 - a  to the base station  410 - b . In some examples, the signaling may be performed through wired (e.g., an IAB connection) communications. In some examples, the communication of assistance information between base stations may occur via an Xn interface between two CUs of the base stations. The assistance information may include the information transmitted to base station  410 - a  at  415  by receiving UE  405 - a , such as existing SL C-DRX configurations of receiving UE  405 - a , and may further include one or more additional information fields. In some cases, this information may allow the base station  410 - b  to select sidelink DRX configurations for the receiving UE  405 - a  that do not overlap with these existing sidelink configurations. The assistance information may further include the Uu DRX configuration of the receiving UE  405 - a , which may be a connected mode DRX (C-DRX) or idle mode DRX (I-DRX) configuration. Since the Uu DRX configuration of receiving UE  405 - a  is known to base station  410 - a , when preparing the assistance information to send to the base station  410 - b , the base station  410 - a  may append the Uu DRX configuration to the assistance information received from the receiving UE  405 - a.    
     At  425 , the base station  410 - b  may determine DRX configurations for the receiving UE  405 - a  and for the transmitting UE  405 - b . The base station  410 - b  may determine the DRX configurations based on the assistance information received from base station  410 - a . The configurations determined by the base station  410 - b  may include a sidelink DRX configuration (e.g., SL C-DRX or I-DRX) for the receiving UE  405 - a  to use in communications with transmitting UE  405 - b . The base station  410 - b  may select the sidelink DRX configuration such that the sidelink communications between the UE  405 - a  and the UE  405 - b  do not overlap with existing sidelink C DRX configurations configured for the receiving UE  405 - a  and other transmitting UEs. For example, if the receiving UE  405 - a  does not have the capability to monitor signaling from different transmitting UEs simultaneously, then the base station  410 - b  may coordinate the sidelink configurations such that the active times of each SL DRX do not overlap with each other. Additionally or alternatively, the base station  410 - b  may select a sidelink configuration (e.g., SL C-DRX or I-DRX) that is aligned with the Uu DRX configuration of receiving UE  405 - a  by including sidelink DRX parameters related to the alignment. For example, some alignment parameters may include sl-drx-StartOffset, sl-drx-Cycle, and sl-drx-SlotOffset. The selection of the SL DRX configuration may be facilitated by the assistance information received from base station  410 - a . In addition, the base station  410 - b  may determine one or more configurations (such as a Uu DRX configuration) for the transmitting UE  405 - b  to use in communications with base station  410 - b . In such cases, the configurations for the transmitting UE  405 - b  may be aligned with the configurations determined for the receiving UE  405 - a . For example, the configurations may support coordinated communications between the UE  405 - a  and  405 - b , such that the configurations support signaling that does not overlap or otherwise interfere. 
     At  430 , the base station  410 - b  may transmit the determined SL DRX configuration (for the UE  405 - a ) to base station  410 - a  via a direct link between the base station  410 - a  and  410 - b  (e.g., via the Xn interface). In some examples, the signaling may be performed through wired (e.g., an IAB connection) communications between the base station  410 - a  and  410 - b.    
     At  435 , the base station  410 - a  may determine a Uu configuration for receiving UE  405 - a  to use in communications with base station  410 - a . In some examples, the base station  410 - a  may use the assistance information received from receiving UE  405 - a  at  415  to determine the Uu configuration. 
     At  440 - a , the base station  410 - a  may transmit the SL DRX configuration determined by the base station  410 - b  and the Uu DRX configuration determined by the base station  410 - a  to the receiving UE  405 - a.    
     At  440 - b , the base station  410 - b  may transmit the Uu DRX configuration determined by the base station  410 - b  to the transmitting UE  405 - b.    
       FIG.  5    illustrates an example of a wireless communications system  500  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. For example, the wireless communication system  500  may include communications between a UE  505 - a , a UE  505 - b  a DU  510 - a , a DU  510 - b , and a CU  515 . Wireless communications system  500  may also support a configuration in which transmitting and a receiving user devices such as UE  505  are associated with two different DUs and each associated with the same CU. In some examples, the DUs and CU may form part of a single base station (e.g., gNB) or different base stations. 
     The DU  510 - a  may be associated with or connected to a transmitting UE  505 - a , and the UE  505 - a  and the DU  510 - a  may exchange information through the Uu interface  520 - a . The DU  510 - b  may be associated with or otherwise connected to a receiving UE  505 - b , and the UE  505 - b  and the DU  510 - b  may exchange information through the Uu interface  520 - b.    
     In wireless communications system  500 , the CU  515  and DU  510 - b  may communicate with the DU  510 - a  and DU  510 - b  through an F1 interface  525 , which may be an example on an Xn interface or a direct link between base stations or base station components as described herein. In some cases, the Xn interface  525  may allow the CU  515  to directly exchange information with DU  510 - a  and DU  510 - b  without involving communications between user devices on the sidelink or PC5 link  530 . For example, the direct communication between DUs  510 - a  and  510 - b  may allow the wireless communication system  500  to avoid using sidelink signaling  530  for exchanging sidelink or Uu link configuration information. 
     The DU  510 - a , the DU  510 - b , and the CU  515  may transmit additional signaling via the Xn interface  525  to further facilitate alignment between devices or device components. For example, this additional signaling may include assistance information carrying Uu DRX configuration of the receiving UE  505 - b , the sidelink DRX configuration of receiving UE  505 - b  with transmitting UE  505 - a , and other existing SL DRX configurations of receiving UE  505 - b  with other transmitting UEs. 
     In some cases, the DU  510 - a  and the DU  510 - b  may coordinate with one another in order to support communications between the UEs  505 - a  and  505 - b . For example, in some cases, the DU  510 - a  and  510 - b  may communicate indirectly through the CU  515 . In such examples, the DU  510 - a  and the DU  510 - b  may transmit information to the CU  515 , and the CU  515  may use the information from each DU to coordinate and determine DRX configurations for the DUs. In some other examples, the DUs  510 - a  and  510 - b  may communicate directly between one another. In such examples, the CU  515  may transmit one or more pre-configurations to the DUs  510 - a  and  510 - b , and the DUs  510 - a  and  510 - b  may determine respective DRX configurations for UEs  505 - a  and  505 - b  using the pre-configurations received from the CU. In some cases, if the pre-configurations are unsuccessful, the DUs  510 - a  and  510 - b  may communicate directly through the CU  515 . 
     The direct or indirect communication between DUs  510 - a  may include the transmission of assistance information (e.g., including assistance information received from one or more connected UEs, among other information), and one or more sidelink DRX or Uu DRX configurations for the UE  505 - a.    
       FIG.  6    illustrates an example of a process flow  600  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The process flow  600  may implement aspects of wireless communications systems  100 ,  200 , and  500 , or may be implemented by aspects of the wireless communications systems  100 ,  200 , and  500 . For example, the process flow  400  may illustrate operations between a UE  605 - a , a UE  605 - b , a CU  615 , a DU  610 - a , and a DU  610 - b , which may be examples of corresponding devices described with reference to  FIGS.  1 ,  2 , and  5   . In the following description of the process flow  600 , the operations between the devices may be transmitted in a different order than the example order shown, or the operations may be performed in different orders or at different times or by different devices. Additionally or alternatively, some operations may also be omitted from the process flow  600 , and other operations may be added to the process flow  600 . In some examples, process flow  600  may illustrate indirect communication between DUs  610 - a  and  610 - b  via the CU  615 . 
     At  620 , the receiving UE  605 - a  may transmit assistance information to the DU  610 - a  (e.g., the DU that is associated with or otherwise connected to the receiving UE  605 - a ). The assistance information may include information that is unknown to the DU  610 - a  that the DU  610 - a  may use for determining DRX configurations for UEs  605 - a  and  605 - b . For example, the assistance information may include existing sidelink DRX (e.g., C-DRX, I-DRX) configurations established or configured at the receiving UE  605 - a  with other transmitting UEs. 
     At  625 , the DU  610 - a  may transmit the assistance information to the CU  615  (e.g., the CU which is connected with both the DU  610 - a  and a DU  610 - b ). The assistance information may include information transmitted to DU  610 - a  at  620  by receiving UE  605 - a , such as existing sidelink C-DRX configurations of receiving UE  605 - a  with other transmitting UEs. Since the Uu DRX configuration of receiving UE  605 - a  is known to base station  610 - a , it may also include the Uu DRX configuration with the assistance information received from the receiving UE  605 - a.    
     At  630 , the CU  615  may determine DRX configurations for receiving UE  605 - a  and transmitting UE  605 - b . For example, the CU  615  may determine the DRX configurations based on the assistance information received from DU  610 - a . The determined configurations may include a sidelink DRX configuration (e.g., SL C-DRX) for the receiving UE  605 - a  to use in communications with transmitting UE  605 - b . The CU  615  may ensure the selected SL DRX configuration does not overlap with existing SL C-DRX configurations from receiving UE  605 - a  with other transmitting UEs. For example, if the receiving UE  605 - a  does not have the capability to monitor signaling from different transmitting UEs simultaneously, then the CU  615  may determine the sidelink configuration such that the active times of each SL DRX do not overlap with each other. The CU  615  may also select a sidelink configuration (e.g., SL C-DRX) that is aligned with the Uu DRX configuration of receiving UE  605 - a  by including sidelink DRX parameters related to the alignment. These parameters may include sl-drx-StartOffset, sl-drx-Cycle, and sl-drx-SlotOffset, for example. In addition, the CU  615  may determine one or more configurations (such as a Uu DRX configuration) for the transmitting UE  605 - b  to use in communications with DU  610 - b . In such cases, the configurations for the transmitting UE  605 - b  may be aligned with the configurations determined for the receiving UE  605 - a . For example, the configurations may support coordinated communications between the UE  610 - a  and  605 - b , such that the configurations support signaling that does not overlap or otherwise interfere. 
     At  635 , the CU  615  may transmit the determined sidelink DRX configuration and the Uu DRX configuration for the receiving UE  605 - a  to the DU  610 - a , and may transmit the determined Uu configuration for transmitting UE  605 - b  to DU  610 - b.    
     At  640 - a , the DU  610 - a  may transmit the sidelink DRX configuration and the Uu DRX configuration determined by the CU  615  to the receiving UE  605 - a.    
     At  640 - b , the DU  610 - b  may transmit the Uu DRX configuration determined by the CU  615  to transmitting UE  605 - b . As described in  FIG.  6   , the indirect communication between DUs  610 - a  and  610 - b  through CU  615  may reduce excess signaling and resource usage between UEs  605 - a  and  605 - b  communicating via sidelink DRX. 
       FIG.  7    illustrates an example of a process flow  700  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The process flow  700  may implement aspects of wireless communications systems  100 ,  200 , and  500 , or may be implemented by aspects of the wireless communications systems  100 ,  200 , and  500 . For example, the process flow  700  may illustrate operations between a UE  705 - a , a UE  705 - b , a DU  710 - a , and a DU  710 - b , which may be examples of corresponding devices described with reference to  FIGS.  1 ,  2 , and  5   . In the following description of the process flow  700 , the operations between the devices may be transmitted in a different order than the example order shown, or the operations may be performed in different orders or at different times or by different devices. Additionally or alternatively, some operations may also be omitted from the process flow  700 , and other operations may be added to the process flow  700 . In some examples, process flow  700  may illustrate direct communication between DUs  710 - a  and  710 - b.    
     At  715 , the receiving UE  705 - a  may transmit assistance information to the DU  710 - a  (e.g., the DU that is associated with or otherwise connected to the receiving UE  705 - a ). The assistance information may include information that is unknown to the DU  710 - a  that the DU  710 - a  may use for determining DRX configurations for UEs  705 - a  and  705 - b . For example, the assistance information may include existing sidelink DRX (e.g., C-DRX, I-DRX) configurations established or configured at the receiving UE  705 - a  with other transmitting UEs. 
     At  720 , the DU  710 - a  may transmit the assistance information to the DU  710 - b  (e.g., the DU that is connected to the transmitting UE  705 - b ). The assistance information may include information transmitted to DU  710 - a  at  715  by receiving UE  705 - a , such as existing sidelink C-DRX configurations of receiving UE  705 - a  with other transmitting UEs. Since the Uu DRX configuration of receiving UE  705 - a  is known to base station  710 - a , it may also include the Uu DRX configuration with the assistance information received from the receiving UE  705 - a  by appending the Uu DRX configuration with the assistance information. 
     At  725 , the DU  710 - b  may determine DRX configurations for receiving UE  705 - a  and transmitting UE  705 - b . For example, the DU  710 - b  may determine the DRX configurations based on the assistance information received from DU  710 - a . The determined configurations may include a sidelink DRX configuration (e.g., SL C-DRX) for the receiving UE  705 - a  to use in communications with transmitting UE  705 - b . The DU  710 - b  may also select a sidelink configuration (e.g., SL C-DRX) that is aligned with the Uu DRX configuration of receiving UE  705 - a . In addition, the DU  710 - b  may determine one or more configurations (such as a Uu DRX configuration) for the transmitting UE  705 - b  to use in communications with DU  710 - b . In such cases, the configurations for the transmitting UE  705 - b  may be aligned with the configurations determined for the receiving UE  705 - a.    
     In some other examples, the DUs  710 - a  and  710 - b  may receive one or more pre-configurations from a CU, which each DU may use to determine one or more DRX configurations for communications between the UEs  705 - a  and  705 - b . The pre-configurations may include a number of parameters or additional information that the DUs  710 - a  and  710 - b  may use to determine one or more sidelink or Uu DRX configurations, and coordinate the configurations with one another. 
     At  730 , the DU  710 - b  may transmit the determined SL DRX configuration and the Uu DRX configuration for the receiving UE  705 - a  to the DU  710 - a . In some examples, the sidelink DRX configuration and the Uu DRX configuration may be based on the one or more pre-configurations received from the CU. 
     At  735 - a , the DU  710 - a  may transmit the SL DRX configuration and the Uu DRX configuration to the receiving UE  705 - a , and at  735 - b , the DU  710 - b  may transmit the Uu DRX configuration to transmitting UE  705 - b . As described in  FIG.  7   , the direct communication between DUs  710 - a  and  710 - b  may reduce excess signaling and resource usage between UEs  705 - a  and  705 - b  communicating via sidelink DRX. 
       FIG.  8    illustrates an example of a wireless communications system  800  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. For example, the wireless communication system  800  may include an example configuration in which transmitting and a receiving user devices such as UE are associated with a same DU and a same CU. In some examples, the DU and CU may form part of a single base station (e.g., gNB) or different base stations. The base station (including the CU  815  and the DU  810 ) and UEs  805 - a  and  8 - 5 - b  may be examples of corresponding devices described with reference to  FIGS.  1  and  2   . 
     Based on sharing the CU  815  and the DU  815 , the UEs  805 - a  and  805 - b  may also share common control layers from their respective serving cells with a common decision making place for determining layer-1, layer-2, or layer 3 signaling. The DU  810  may be associated with or connected to a transmitting UE  805 - a  and a receiving UE and the UE  805 - a  and the DU  810  may exchange information with the UE  805 - a  through the Uu interface  820 - a , and may exchange information with the UE  805 - b  through the Uu interface  820 - b.    
     In wireless communications system  800 , the CU  815  and DU  810  may communicate via an F1 interface  825 , which may be an example on an Xn interface or a direct link between base stations or base station components as described herein. In some cases, the Xn interface  825  may allow the CU  815  to directly exchange information with the DU  810  without involving communications between user devices on the sidelink or PC5 link  830 . For example, the direct communication between the CU  815  and the DU  810  may allow the wireless communication system  800  to avoid using sidelink signaling  830  for exchanging sidelink or Uu link configuration information. 
     In some examples, the DU  810  and the CU  815  may transmit additional signaling via the Xn interface  825  to further facilitate communications between devices or device components. For example, this additional signaling may include assistance information from one or more of the UEs  805 - a  and  805 - b , the Uu DRX configuration of the receiving UE  805 - b , the sidelink DRX configuration of receiving UE  805 - b  with transmitting UE  805 - a , and other existing SL DRX configurations of receiving UE  805 - b  with other transmitting UEs. 
     In some cases, based on the assistance information received from the DU  810 , the CU  815  may determine the Uu DRX configuration of the receiving UE  805 - b , the sidelink DRX configuration of receiving UE  805 - b  with transmitting UE  805 - a , and the Uu DRX configuration for the transmitting UE  805 - a . The CU  815  may transmit this information to the DU  810 , and the DU  810  may transmit the respective configurations to the UEs  805 - a  and  805 - b . In some other examples, the CU  815  may transmit one or more pre-configurations to the DU  810 , and the DU  810  may determine respective DRX configurations for UEs  805 - a  and  805 - b  using the one or more pre-configurations received from the CU  815 . In some cases, if the pre-configurations are unsuccessful, the DU  810  may request configurations from the CU  815 . 
       FIG.  9    illustrates an example of a process flow  900  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The process flow  900  may implement aspects of wireless communications systems  100 ,  200 , and  800 , or may be implemented by aspects of the wireless communications systems  100 ,  200 , and  500 . For example, the process flow  900  may illustrate operations between a UE  905 - a , a UE  905 - b , a CU  915 , and a DU  910 , which may be examples of corresponding devices described with reference to  FIGS.  1 ,  2 , and  8   . In the following description of the process flow  900 , the operations between the devices may be transmitted in a different order than the example order shown, or the operations may be performed in different orders or at different times or by different devices. Additionally or alternatively, some operations may also be omitted from the process flow  900 , and other operations may be added to the process flow  900 . 
     In some examples, process flow  900  may illustrate communications in which UEs  905 - a  and  905 - b  are both connected to the DU  910  and the CU  915 . At  920 , the receiving UE  905 - b  may transmit assistance information to the DU  910  (e.g., the DU that is associated with or otherwise connected to the receiving UE  905 - b ). The assistance information may include information that is unknown to the DU  910  that the DU  910  or the CU  915  may use for determining one or more DRX configurations for UEs  905 - a  and  905 - b . For example, the assistance information may include existing sidelink DRX (e.g., C-DRX, I-DRX) configurations established or configured at the receiving UE  905 - b  with other transmitting UEs. 
     At  925 , the DU  910  may transmit the assistance information to the CU  915  (e.g., the CU which is connected with both the DU  910 ) via a direct connection with the CU  915 . The assistance information may include information transmitted to DU  910  at  920  by receiving UE  905 - b , such as existing sidelink C-DRX configurations of receiving UE  905 - a  with other transmitting UEs. 
     At  930 , the CU  915  may determine DRX configurations for receiving UE  905 - a  and transmitting UE  905 - b . For example, the CU  915  may determine the DRX configurations based on the assistance information received from DU  910 . The determined configurations may include a sidelink DRX configuration (e.g., SL C-DRX) for the receiving UE  905 - b  to use in communications with transmitting UE  905 - a . In addition, the CU  915  may determine one or more configurations (such as a Uu DRX configuration) for the transmitting UE  905 - a  to use in communications with DU  910 . In such cases, the configurations for the transmitting UE  905 - a  may be aligned with the configurations determined for the receiving UE  905 - b . For example, the configurations may support coordinated communications between the UE  910 - a  and  905 - b , such that the configurations support signaling that does not overlap or otherwise interfere. 
     At  935 , the CU  915  may transmit the determined SL DRX configuration and the Uu DRX configuration for the receiving UE  905 - b  to the DU, and at  940 , the DU  910  may transmit the SL DRX configuration and the Uu DRX configuration determined by the CU  915  to the receiving UE  905 - b.    
     At  945 , the DU  910  may transmit the Uu DRX configuration determined by the CU  915  to transmitting UE  905 - a . As described in  FIG.  9   , the direct communication between DU  910  and CU  915  may reduce excess signaling and resource usage between UEs  905 - a  and  905 - b  communicating via sidelink DRX. In addition, the CU  915  may determine the DRX configurations for both the UEs  905 - a  and  905 - b , which may reduce excess sidelink resource consumption for the UEs  905 - a  and  905 - b , while increasing coordination between devices. 
       FIG.  10    illustrates an example of a process flow  1000  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The process flow  1000  may implement aspects of wireless communications systems  100  and  200 , or may be implemented by aspects of the wireless communications systems  100  and  200 . For example, the process flow  1000  may illustrate operations between a UE  1005 - a , a UE  1005 - b , and a DU  1010 , which may be examples of corresponding devices described with reference to  FIGS.  1  and  2   . In the following description of the process flow  1000 , the operations between the devices may be transmitted in a different order than the example order shown, or the operations may be performed in different orders or at different times or by different devices. Additionally or alternatively, some operations may also be omitted from the process flow  1000 , and other operations may be added to the process flow  1000 . In some examples, process flow  1000  may illustrate communications in which UEs  1005 - a  and  1005 - b  are both connected to the DU  1010 . 
     At  1015 , the receiving UE  1005 - b  may transmit assistance information to the DU  1010 . The assistance information may include information that is unknown to the DU  1010  that the DU  1010  may use for determining one or more DRX configurations for UEs  1005 - a  and  1005 - b . For example, the assistance information may include existing sidelink DRX (e.g., C-DRX, I-DRX) configurations established or configured at the receiving UE  1005 - b  with other transmitting UEs. 
     At  1020 , the DU  1010  may determine DRX configurations for receiving UE  1005 - a  and transmitting UE  1005 - b . For example, the DU  1010  may determine the DRX configurations based on the assistance information received from receiving UE  1005 - b . The determined configurations may include a sidelink DRX configuration (e.g., SL C-DRX) for the receiving UE  1005 - b  to use in communications with transmitting UE  1005 - a . In addition, the DU  1010  may determine one or more configurations (such as a Uu DRX configuration) for the transmitting UE  1005 - a  to use in communications with DU  1010 . In such cases, the configurations for the transmitting UE  1005 - a  may be aligned with the configurations determined for the receiving UE  1005 - b . For example, the configurations may support coordinated communications between the UE  1010 - a  and  1005 - b , such that the configurations support signaling that does not overlap or otherwise interfere. 
     At  1025 , the DU  1010  may transmit the determined SL DRX configuration and the Uu DRX configuration to the receiving UE  1005 - b , and at  1030 , the DU  1010  may transmit the determined Uu DRX configuration to the transmitting UE  1005 . 
       FIG.  11    shows a block diagram  1100  of a device  1105  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The device  1105  may be an example of aspects of a base station  105  as described herein. The device  1105  may include a receiver  1110 , a transmitter  1115 , and a communications manager  1120 . The device  1105  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). 
     The receiver  1110  may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to coordination during access link DRX and sidelink alignment). Information may be passed on to other components of the device  1105 . The receiver  1110  may utilize a single antenna or a set of multiple antennas. 
     The transmitter  1115  may provide a means for transmitting signals generated by other components of the device  1105 . For example, the transmitter  1115  may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to coordination during access link DRX and sidelink alignment). In some examples, the transmitter  1115  may be co-located with a receiver  1110  in a transceiver module. The transmitter  1115  may utilize a single antenna or a set of multiple antennas. 
     The communications manager  1120 , the receiver  1110 , the transmitter  1115 , or various combinations thereof or various components thereof may be examples of means for performing various aspects of coordination during access link DRX and sidelink alignment as described herein. For example, the communications manager  1120 , the receiver  1110 , the transmitter  1115 , 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 manager  1120 , the receiver  1110 , the transmitter  1115 , or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry). The hardware may include a processor, a DSP, an ASIC, an FPGA or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some examples, a processor and memory coupled with the processor may be configured to perform one or more of the functions described herein (e.g., by executing, by the processor, instructions stored in the memory). 
     Additionally or alternatively, in some examples, the communications manager  1120 , the receiver  1110 , the transmitter  1115 , or various combinations or components thereof may be implemented in code (e.g., as communications management software or firmware) executed by a processor. If implemented in code executed by a processor, the functions of the communications manager  1120 , the receiver  1110 , the transmitter  1115 , or various combinations or components thereof may be performed by a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination of these or other programmable logic devices (e.g., configured as or otherwise supporting a means for performing the functions described in the present disclosure). 
     In some examples, the communications manager  1120  may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver  1110 , the transmitter  1115 , or both. For example, the communications manager  1120  may receive information from the receiver  1110 , send information to the transmitter  1115 , or be integrated in combination with the receiver  1110 , the transmitter  1115 , or both to receive information, transmit information, or perform various other operations as described herein. 
     The communications manager  1120  may support wireless communication at a first base station in accordance with examples as disclosed herein. For example, the communications manager  1120  may be configured as or otherwise support a means for receiving, from a first UE, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The communications manager  1120  may be configured as or otherwise support a means for transmitting, to a second base station, the assistance information message received from the first UE. The communications manager  1120  may be configured as or otherwise support a means for communicating, with the second base station via an interface between the first base station and the second base station, an indication of the sidelink DRX configuration for the first UE. The communications manager  1120  may be configured as or otherwise support a means for transmitting, to the first UE, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration for the first UE based on the communicating. 
     Additionally or alternatively, the communications manager  1120  may support wireless communication at a second base station in accordance with examples as disclosed herein. For example, the communications manager  1120  may be configured as or otherwise support a means for receiving, from a first base station, an assistance information message from a first UE, the assistance information message for determining a sidelink DRX configuration for communications between the first UE and a second UE. The communications manager  1120  may be configured as or otherwise support a means for transmitting, to the first base station, an indication of the sidelink DRX configuration determined for the first UE via an interface between the first base station and the second base station. The communications manager  1120  may be configured as or otherwise support a means for transmitting, to the second UE, an indication of an access link DRX configuration for communications between the second UE and the second base station. 
     Additionally or alternatively, the communications manager  1120  may support wireless communication in accordance with examples as disclosed herein. For example, the communications manager  1120  may be configured as or otherwise support a means for receiving, from a first UE, a first assistance information message at a first DU, the first assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The communications manager  1120  may be configured as or otherwise support a means for receiving, at a CU, the first assistance information message relayed by the first DU to the CU. The communications manager  1120  may be configured as or otherwise support a means for communicating, between the CU and at least the first DU, an indication of the sidelink DRX configuration for the first UE and an indication of a first access link DRX configuration for the first UE. The communications manager  1120  may be configured as or otherwise support a means for transmitting, to the first UE, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based on the communicating. 
     By including or configuring the communications manager  1120  in accordance with examples as described herein, the device  1105  (e.g., a processor controlling or otherwise coupled to the receiver  1110 , the transmitter  1115 , the communications manager  1120 , or a combination thereof) may support techniques for reduced processing, reduced power consumption, and more efficient utilization of communication resources. 
       FIG.  12    shows a block diagram  1200  of a device  1205  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The device  1205  may be an example of aspects of a device  1105  or a base station  105  as described herein. The device  1205  may include a receiver  1210 , a transmitter  1215 , and a communications manager  1220 . The device  1205  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). 
     The receiver  1210  may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to coordination during access link DRX and sidelink alignment). Information may be passed on to other components of the device  1205 . The receiver  1210  may utilize a single antenna or a set of multiple antennas. 
     The transmitter  1215  may provide a means for transmitting signals generated by other components of the device  1205 . For example, the transmitter  1215  may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to coordination during access link DRX and sidelink alignment). In some examples, the transmitter  1215  may be co-located with a receiver  1210  in a transceiver module. The transmitter  1215  may utilize a single antenna or a set of multiple antennas. 
     The device  1205 , or various components thereof, may be an example of means for performing various aspects of coordination during access link DRX and sidelink alignment as described herein. For example, the communications manager  1220  may include an assistance information receiving component  1225 , a base station interface communication component  1230 , a DRX configuration signaling component  1235 , a CU-DU communication component  1240 , or any combination thereof. The communications manager  1220  may be an example of aspects of a communications manager  1120  as described herein. In some examples, the communications manager  1220 , or various components thereof, may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver  1210 , the transmitter  1215 , or both. For example, the communications manager  1220  may receive information from the receiver  1210 , send information to the transmitter  1215 , or be integrated in combination with the receiver  1210 , the transmitter  1215 , or both to receive information, transmit information, or perform various other operations as described herein. 
     The communications manager  1220  may support wireless communication at a first base station in accordance with examples as disclosed herein. The assistance information receiving component  1225  may be configured as or otherwise support a means for receiving, from a first UE, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The base station interface communication component  1230  may be configured as or otherwise support a means for transmitting, to a second base station, the assistance information message received from the first UE. The base station interface communication component  1230  may be configured as or otherwise support a means for communicating, with the second base station via an interface between the first base station and the second base station, an indication of the sidelink DRX configuration for the first UE. The DRX configuration signaling component  1235  may be configured as or otherwise support a means for transmitting, to the first UE, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration for the first UE based on the communicating. 
     Additionally or alternatively, the communications manager  1220  may support wireless communication at a second base station in accordance with examples as disclosed herein. The assistance information receiving component  1225  may be configured as or otherwise support a means for receiving, from a first base station, an assistance information message from a first UE, the assistance information message for determining a sidelink DRX configuration for communications between the first UE and a second UE. The base station interface communication component  1230  may be configured as or otherwise support a means for transmitting, to the first base station, an indication of the sidelink DRX configuration determined for the first UE via an interface between the first base station and the second base station. The DRX configuration signaling component  1235  may be configured as or otherwise support a means for transmitting, to the second UE, an indication of an access link DRX configuration for communications between the second UE and the second base station. 
     Additionally or alternatively, the communications manager  1220  may support wireless communication in accordance with examples as disclosed herein. The assistance information receiving component  1225  may be configured as or otherwise support a means for receiving, from a first UE, a first assistance information message at a first DU, the first assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The CU-DU communication component  1240  may be configured as or otherwise support a means for receiving, at a CU, the first assistance information message relayed by the first DU to the CU. The CU-DU communication component  1240  may be configured as or otherwise support a means for communicating, between the CU and at least the first DU, an indication of the sidelink DRX configuration for the first UE and an indication of a first access link DRX configuration for the first UE. The DRX configuration signaling component  1235  may be configured as or otherwise support a means for transmitting, to the first UE, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based on the communicating. 
       FIG.  13    shows a block diagram  1300  of a communications manager  1320  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The communications manager  1320  may be an example of aspects of a communications manager  1120 , a communications manager  1220 , or both, as described herein. The communications manager  1320 , or various components thereof, may be an example of means for performing various aspects of coordination during access link DRX and sidelink alignment as described herein. For example, the communications manager  1320  may include an assistance information receiving component  1325 , a base station interface communication component  1330 , a DRX configuration signaling component  1335 , a CU-DU communication component  1340 , a CU-CU communication component  1345 , a DRX configuration determination component  1350 , a DRX pre-configuration component  1355 , a DU-DU communication component  1360 , 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 manager  1320  may support wireless communication at a first base station in accordance with examples as disclosed herein. The assistance information receiving component  1325  may be configured as or otherwise support a means for receiving, from a first UE, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The base station interface communication component  1330  may be configured as or otherwise support a means for transmitting, to a second base station, the assistance information message received from the first UE. In some examples, the base station interface communication component  1330  may be configured as or otherwise support a means for communicating, with the second base station via an interface between the first base station and the second base station, an indication of the sidelink DRX configuration for the first UE. The DRX configuration signaling component  1335  may be configured as or otherwise support a means for transmitting, to the first UE, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration for the first UE based on the communicating. 
     In some examples, to support communicating with the second base station via the interface, the CU-CU communication component  1345  may be configured as or otherwise support a means for transmitting the assistance information message between the first base station and the second base station via a connection between a first CU of the first base station and a second CU of the second base station. 
     In some examples, the CU-DU communication component  1340  may be configured as or otherwise support a means for relaying the indication of the sidelink DRX configuration and the indication of the access link DRX configuration from a first CU of the first base station to a first DU of the first base station. In some examples, the DRX configuration signaling component  1335  may be configured as or otherwise support a means for transmitting, to the first UE, the indication of the sidelink DRX configuration and the indication of the access link DRX configuration via an access link between the first UE and the first DU. 
     In some examples, the base station interface communication component  1330  may be configured as or otherwise support a means for transmitting the assistance information message to the second base station, the assistance information message including a field including one or more additional sidelink DRX configurations associated with one or more additional sidelink UEs, and a field including the indication of the access link DRX configuration for the first UE. 
     In some examples, the sidelink DRX configuration for the first UE includes one or more sidelink DRX alignment parameters. 
     In some examples, the access link DRX configuration for the second UE includes one or more access link DRX alignment parameters. 
     Additionally or alternatively, the communications manager  1320  may support wireless communication at a second base station in accordance with examples as disclosed herein. In some examples, the assistance information receiving component  1325  may be configured as or otherwise support a means for receiving, from a first base station, an assistance information message from a first UE, the assistance information message for determining a sidelink DRX configuration for communications between the first UE and a second UE. In some examples, the base station interface communication component  1330  may be configured as or otherwise support a means for transmitting, to the first base station, an indication of the sidelink DRX configuration determined for the first UE via an interface between the first base station and the second base station. In some examples, the DRX configuration signaling component  1335  may be configured as or otherwise support a means for transmitting, to the second UE, an indication of an access link DRX configuration for communications between the second UE and the second base station. 
     In some examples, to support communicating with the first base station via the interface, the CU-CU communication component  1345  may be configured as or otherwise support a means for receiving the assistance information message from the first base station via a connection between a first CU of the first base station and a second CU of the second base station. 
     In some examples, the DRX configuration determination component  1350  may be configured as or otherwise support a means for determining the sidelink DRX configuration for the first UE and the access link DRX configuration for the second UE. In some examples, the base station interface communication component  1330  may be configured as or otherwise support a means for transmitting, to the first base station, the indication of the sidelink DRX configuration for the first UE via the interface between the second base station and the first base station. In some examples, the DRX configuration signaling component  1335  may be configured as or otherwise support a means for transmitting, to the second UE, the indication of the access link DRX configuration for the second UE based on the determining. 
     In some examples, the assistance information receiving component  1325  may be configured as or otherwise support a means for receiving the assistance information message from the first base station, the assistance information message including a field including one or more additional sidelink DRX configurations associated with one or more additional sidelink UEs, and a field including the indication of the access link DRX configuration for the first UE. 
     In some examples, the sidelink DRX configuration for the first UE includes one or more sidelink DRX alignment parameters. 
     In some examples, the access link DRX configuration for the second UE includes one or more access link DRX alignment parameters. 
     Additionally or alternatively, the communications manager  1320  may support wireless communication in accordance with examples as disclosed herein. In some examples, the assistance information receiving component  1325  may be configured as or otherwise support a means for receiving, from a first UE, a first assistance information message at a first DU, the first assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The CU-DU communication component  1340  may be configured as or otherwise support a means for receiving, at a CU, the first assistance information message relayed by the first DU to the CU. In some examples, the CU-DU communication component  1340  may be configured as or otherwise support a means for communicating, between the CU and at least the first DU, an indication of the sidelink DRX configuration for the first UE and an indication of a first access link DRX configuration for the first UE. In some examples, the DRX configuration signaling component  1335  may be configured as or otherwise support a means for transmitting, to the first UE, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based on the communicating. 
     In some examples, the assistance information receiving component  1325  may be configured as or otherwise support a means for receiving, from the second UE, a second assistance information message at a second DU. In some examples, the assistance information receiving component  1325  may be configured as or otherwise support a means for receiving, at the CU, the second assistance information message relayed by the second DU to the CU. In some examples, the CU-DU communication component  1340  may be configured as or otherwise support a means for communicating, between the CU and the second DU, an indication of a second access link DRX configuration for the second UE. In some examples, the DRX configuration signaling component  1335  may be configured as or otherwise support a means for transmitting, to the second UE, the indication of the first access link DRX configuration based on the communicating. 
     In some examples, the DRX pre-configuration component  1355  may be configured as or otherwise support a means for receiving, at the first DU and a second DU, one or more pre-configurations for determining one or more DRX configurations for the first UE and the second UE. In some examples, the DRX configuration signaling component  1335  may be configured as or otherwise support a means for transmitting, to the first UE via the first DU, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based on the one or more pre-configurations. In some examples, the DRX configuration signaling component  1335  may be configured as or otherwise support a means for transmitting, to the second UE via the second DU, an indication of a second access link DRX configuration based on the one or more pre-configurations. 
     In some examples, the DU-DU communication component  1360  may be configured as or otherwise support a means for communicating, between the first DU and the second DU, the one or more DRX configurations for the first UE and the second UE based on the one or more pre-configurations. 
     In some examples, the DU-DU communication component  1360  may be configured as or otherwise support a means for communicating, between the first DU and a second DU, the first assistance information message, the indication of the sidelink DRX configuration, the indication of the first access link DRX configuration, or any combination thereof. 
     In some examples, the CU determines the sidelink DRX configuration for the first UE, the first access link DRX configuration for the first UE, and the second access link DRX configuration for the second UE. 
     In some examples, the assistance information receiving component  1325  may be configured as or otherwise support a means for receiving, from the second UE, a second assistance information message at the first DU. In some examples, the CU-DU communication component  1340  may be configured as or otherwise support a means for receiving, at the CU, the second assistance information message relayed by the first DU to the CU. In some examples, the CU-DU communication component  1340  may be configured as or otherwise support a means for communicating, between the CU and the first DU, an indication of a second access link DRX configuration for the second UE. In some examples, the DRX configuration signaling component  1335  may be configured as or otherwise support a means for transmitting, to the second UE, the indication of the first access link DRX configuration based on the communicating. 
     In some examples, the DRX pre-configuration component  1355  may be configured as or otherwise support a means for receiving, at the first DU, one or more pre-configurations for determining one or more DRX configurations for the first UE and the second UE. In some examples, the DRX configuration signaling component  1335  may be configured as or otherwise support a means for transmitting, to the first UE via the first DU, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based on the one or more pre-configurations. In some examples, the DRX configuration signaling component  1335  may be configured as or otherwise support a means for transmitting, to the second UE via the first DU, an indication of a second access link DRX configuration based on the one or more pre-configurations. 
     In some examples, the CU-DU communication component  1340  may be configured as or otherwise support a means for communicating, between the CU and the first DU, the one or more DRX configurations for the first UE and the second UE based on the one or more pre-configurations. 
     In some examples, the CU-DU communication component  1340  may be configured as or otherwise support a means for communicating, between the CU and the first DU and a second DU, the first assistance information message, the indication of the sidelink DRX configuration, the indication of the first access link DRX configuration, or any combination thereof. 
     In some examples, the first assistance information message includes one or more additional indications of sidelink connected mode DRX configurations established between the first UE and one or more other sidelink UEs. 
     In some examples, the DRX configuration signaling component  1335  may be configured as or otherwise support a means for communicating via layer-1 signaling, layer-2 signaling, layer-3 signaling, or any combination thereof. 
       FIG.  14    shows a diagram of a system  1400  including a device  1405  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The device  1405  may be an example of or include the components of a device  1105 , a device  1205 , or a base station  105  as described herein. The device  1405  may communicate wirelessly with one or more base stations  105 , UEs  115 , or any combination thereof. The device  1405  may include components for bi-directional voice and data communications including components for transmitting and receiving communications, such as a communications manager  1420 , a network communications manager  1410 , a transceiver  1415 , an antenna  1425 , a memory  1430 , code  1435 , a processor  1440 , and an inter-station communications manager  1445 . These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus  1450 ). 
     The network communications manager  1410  may manage communications with a core network  130  (e.g., via one or more wired backhaul links). For example, the network communications manager  1410  may manage the transfer of data communications for client devices, such as one or more UEs  115 . 
     In some cases, the device  1405  may include a single antenna  1425 . However, in some other cases the device  1405  may have more than one antenna  1425 , which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver  1415  may communicate bi-directionally, via the one or more antennas  1425 , wired, or wireless links as described herein. For example, the transceiver  1415  may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver  1415  may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas  1425  for transmission, and to demodulate packets received from the one or more antennas  1425 . The transceiver  1415 , or the transceiver  1415  and one or more antennas  1425 , may be an example of a transmitter  1115 , a transmitter  1215 , a receiver  1110 , a receiver  1210 , or any combination thereof or component thereof, as described herein. 
     The memory  1430  may include RAM and ROM. The memory  1430  may store computer-readable, computer-executable code  1435  including instructions that, when executed by the processor  1440 , cause the device  1405  to perform various functions described herein. The code  1435  may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code  1435  may not be directly executable by the processor  1440  but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some cases, the memory  1430  may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices. 
     The processor  1440  may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor  1440  may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the processor  1440 . The processor  1440  may be configured to execute computer-readable instructions stored in a memory (e.g., the memory  1430 ) to cause the device  1405  to perform various functions (e.g., functions or tasks supporting coordination during access link DRX and sidelink alignment). For example, the device  1405  or a component of the device  1405  may include a processor  1440  and memory  1430  coupled to the processor  1440 , the processor  1440  and memory  1430  configured to perform various functions described herein. 
     The inter-station communications manager  1445  may manage communications with other base stations  105 , and may include a controller or scheduler for controlling communications with UEs  115  in cooperation with other base stations  105 . For example, the inter-station communications manager  1445  may coordinate scheduling for transmissions to UEs  115  for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager  1445  may provide an X2 interface within an LTE/LTE-A wireless communications network technology to provide communication between base stations  105 . 
     The communications manager  1420  may support wireless communication at a first base station in accordance with examples as disclosed herein. For example, the communications manager  1420  may be configured as or otherwise support a means for receiving, from a first UE, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The communications manager  1420  may be configured as or otherwise support a means for transmitting, to a second base station, the assistance information message received from the first UE. The communications manager  1420  may be configured as or otherwise support a means for communicating, with the second base station via an interface between the first base station and the second base station, an indication of the sidelink DRX configuration for the first UE. The communications manager  1420  may be configured as or otherwise support a means for transmitting, to the first UE, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration for the first UE based on the communicating. 
     Additionally or alternatively, the communications manager  1420  may support wireless communication at a second base station in accordance with examples as disclosed herein. For example, the communications manager  1420  may be configured as or otherwise support a means for receiving, from a first base station, an assistance information message from a first UE, the assistance information message for determining a sidelink DRX configuration for communications between the first UE and a second UE. The communications manager  1420  may be configured as or otherwise support a means for transmitting, to the first base station, an indication of the sidelink DRX configuration determined for the first UE via an interface between the first base station and the second base station. The communications manager  1420  may be configured as or otherwise support a means for transmitting, to the second UE, an indication of an access link DRX configuration for communications between the second UE and the second base station. 
     Additionally or alternatively, the communications manager  1420  may support wireless communication in accordance with examples as disclosed herein. For example, the communications manager  1420  may be configured as or otherwise support a means for receiving, from a first UE, a first assistance information message at a first DU, the first assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The communications manager  1420  may be configured as or otherwise support a means for receiving, at a CU, the first assistance information message relayed by the first DU to the CU. The communications manager  1420  may be configured as or otherwise support a means for communicating, between the CU and at least the first DU, an indication of the sidelink DRX configuration for the first UE and an indication of a first access link DRX configuration for the first UE. The communications manager  1420  may be configured as or otherwise support a means for transmitting, to the first UE, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based on the communicating. 
     By including or configuring the communications manager  1420  in accordance with examples as described herein, the device  1405  may support techniques 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, increased throughput, and increased utilization of available sidelink resources. 
     In some examples, the communications manager  1420  may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the transceiver  1415 , the one or more antennas  1425 , or any combination thereof. Although the communications manager  1420  is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager  1420  may be supported by or performed by the processor  1440 , the memory  1430 , the code  1435 , or any combination thereof. For example, the code  1435  may include instructions executable by the processor  1440  to cause the device  1405  to perform various aspects of coordination during access link DRX and sidelink alignment as described herein, or the processor  1440  and the memory  1430  may be otherwise configured to perform or support such operations. 
       FIG.  15    shows a block diagram  1500  of a device  1505  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The device  1505  may be an example of aspects of a UE  115  as described herein. The device  1505  may include a receiver  1510 , a transmitter  1515 , and a communications manager  1520 . The device  1505  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). 
     The receiver  1510  may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to coordination during access link DRX and sidelink alignment). Information may be passed on to other components of the device  1505 . The receiver  1510  may utilize a single antenna or a set of multiple antennas. 
     The transmitter  1515  may provide a means for transmitting signals generated by other components of the device  1505 . For example, the transmitter  1515  may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to coordination during access link DRX and sidelink alignment). In some examples, the transmitter  1515  may be co-located with a receiver  1510  in a transceiver module. The transmitter  1515  may utilize a single antenna or a set of multiple antennas. 
     The communications manager  1520 , the receiver  1510 , the transmitter  1515 , or various combinations thereof or various components thereof may be examples of means for performing various aspects of coordination during access link DRX and sidelink alignment as described herein. For example, the communications manager  1520 , the receiver  1510 , the transmitter  1515 , 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 manager  1520 , the receiver  1510 , the transmitter  1515 , or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry). The hardware may include a processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some examples, a processor and memory coupled with the processor may be configured to perform one or more of the functions described herein (e.g., by executing, by the processor, instructions stored in the memory). 
     Additionally or alternatively, in some examples, the communications manager  1520 , the receiver  1510 , the transmitter  1515 , or various combinations or components thereof may be implemented in code (e.g., as communications management software or firmware) executed by a processor. If implemented in code executed by a processor, the functions of the communications manager  1520 , the receiver  1510 , the transmitter  1515 , or various combinations or components thereof may be performed by a general-purpose processor, a DSP, a central processing unit (CPU), an ASIC, an FPGA, or any combination of these or other programmable logic devices (e.g., configured as or otherwise supporting a means for performing the functions described in the present disclosure). 
     In some examples, the communications manager  1520  may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver  1510 , the transmitter  1515 , or both. For example, the communications manager  1520  may receive information from the receiver  1510 , send information to the transmitter  1515 , or be integrated in combination with the receiver  1510 , the transmitter  1515 , or both to receive information, transmit information, or perform various other operations as described herein. 
     The communications manager  1520  may support wireless communication at a first UE in accordance with examples as disclosed herein. For example, the communications manager  1520  may be configured as or otherwise support a means for transmitting, to a base station, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The communications manager  1520  may be configured as or otherwise support a means for receiving, from the base station, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration. The communications manager  1520  may be configured as or otherwise support a means for communicating with the second UE via a sidelink in accordance with the received sidelink DRX configuration. The communications manager  1520  may be configured as or otherwise support a means for communicating with the base station via an access link in accordance with the received access link DRX configuration. 
     By including or configuring the communications manager  1520  in accordance with examples as described herein, the device  1505  (e.g., a processor controlling or otherwise coupled to the receiver  1510 , the transmitter  1515 , the communications manager  1520 , or a combination thereof) may support techniques for reduced processing, reduced power consumption, and more efficient utilization of communication resources. 
       FIG.  16    shows a block diagram  1600  of a device  1605  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The device  1605  may be an example of aspects of a device  1505  or a UE  115  as described herein. The device  1605  may include a receiver  1610 , a transmitter  1615 , and a communications manager  1620 . The device  1605  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). 
     The receiver  1610  may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to coordination during access link DRX and sidelink alignment). Information may be passed on to other components of the device  1605 . The receiver  1610  may utilize a single antenna or a set of multiple antennas. 
     The transmitter  1615  may provide a means for transmitting signals generated by other components of the device  1605 . For example, the transmitter  1615  may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to coordination during access link DRX and sidelink alignment). In some examples, the transmitter  1615  may be co-located with a receiver  1610  in a transceiver module. The transmitter  1615  may utilize a single antenna or a set of multiple antennas. 
     The device  1605 , or various components thereof, may be an example of means for performing various aspects of coordination during access link DRX and sidelink alignment as described herein. For example, the communications manager  1620  may include an assistance information transmitting component  1625 , a DRX configuration receiving component  1630 , a sidelink communication component  1635 , an access link communication component  1640 , or any combination thereof. The communications manager  1620  may be an example of aspects of a communications manager  1520  as described herein. In some examples, the communications manager  1620 , or various components thereof, may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver  1610 , the transmitter  1615 , or both. For example, the communications manager  1620  may receive information from the receiver  1610 , send information to the transmitter  1615 , or be integrated in combination with the receiver  1610 , the transmitter  1615 , or both to receive information, transmit information, or perform various other operations as described herein. 
     The communications manager  1620  may support wireless communication at a first UE in accordance with examples as disclosed herein. The assistance information transmitting component  1625  may be configured as or otherwise support a means for transmitting, to a base station, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The DRX configuration receiving component  1630  may be configured as or otherwise support a means for receiving, from the base station, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration. The sidelink communication component  1635  may be configured as or otherwise support a means for communicating with the second UE via a sidelink in accordance with the received sidelink DRX configuration. The access link communication component  1640  may be configured as or otherwise support a means for communicating with the base station via an access link in accordance with the received access link DRX configuration. 
       FIG.  17    shows a block diagram  1700  of a communications manager  1720  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The communications manager  1720  may be an example of aspects of a communications manager  1520 , a communications manager  1620 , or both, as described herein. The communications manager  1720 , or various components thereof, may be an example of means for performing various aspects of coordination during access link DRX and sidelink alignment as described herein. For example, the communications manager  1720  may include an assistance information transmitting component  1725 , a DRX configuration receiving component  1730 , a sidelink communication component  1735 , an access link communication component  1740 , 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 manager  1720  may support wireless communication at a first UE in accordance with examples as disclosed herein. The assistance information transmitting component  1725  may be configured as or otherwise support a means for transmitting, to a base station, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The DRX configuration receiving component  1730  may be configured as or otherwise support a means for receiving, from the base station, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration. The sidelink communication component  1735  may be configured as or otherwise support a means for communicating with the second UE via a sidelink in accordance with the received sidelink DRX configuration. The access link communication component  1740  may be configured as or otherwise support a means for communicating with the base station via an access link in accordance with the received access link DRX configuration. 
     In some examples, the DRX configuration receiving component  1730  may be configured as or otherwise support a means for receiving, via a first DU of the base station, the indication of the sidelink DRX configuration and the indication of the access link DRX configuration based on one or more pre-configurations. 
     In some examples, to support transmitting the assistance information message, the assistance information transmitting component  1725  may be configured as or otherwise support a means for transmitting the assistance information message via the access link to a first DU of the base station. 
     In some examples, the assistance information message includes one or more additional indications of sidelink connected mode DRX configurations established between the first UE and one or more other sidelink UEs. 
     In some examples, the DRX configuration receiving component  1730  may be configured as or otherwise support a means for communicating via layer-1 signaling, layer-2 signaling, layer-3 signaling, or any combination thereof. 
     In some examples, the sidelink communication component  1735  may be configured as or otherwise support a means for refraining from transmitting the sidelink DRX configuration to the second UE based on receiving the indication of the sidelink DRX configuration from the base station. 
       FIG.  18    shows a diagram of a system  1800  including a device  1805  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The device  1805  may be an example of or include the components of a device  1505 , a device  1605 , or a UE  115  as described herein. The device  1805  may communicate wirelessly with one or more base stations  105 , UEs  115 , or any combination thereof. The device  1805  may include components for bi-directional voice and data communications including components for transmitting and receiving communications, such as a communications manager  1820 , an input/output (I/O) controller  1810 , a transceiver  1815 , an antenna  1825 , a memory  1830 , code  1835 , and a processor  1840 . These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus  1845 ). 
     The I/O controller  1810  may manage input and output signals for the device  1805 . The I/O controller  1810  may also manage peripherals not integrated into the device  1805 . In some cases, the I/O controller  1810  may represent a physical connection or port to an external peripheral. In some cases, the I/O controller  1810  may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. Additionally or alternatively, the I/O controller  1810  may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller  1810  may be implemented as part of a processor, such as the processor  1840 . In some cases, a user may interact with the device  1805  via the I/O controller  1810  or via hardware components controlled by the I/O controller  1810 . 
     In some cases, the device  1805  may include a single antenna  1825 . However, in some other cases, the device  1805  may have more than one antenna  1825 , which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver  1815  may communicate bi-directionally, via the one or more antennas  1825 , wired, or wireless links as described herein. For example, the transceiver  1815  may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver  1815  may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas  1825  for transmission, and to demodulate packets received from the one or more antennas  1825 . The transceiver  1815 , or the transceiver  1815  and one or more antennas  1825 , may be an example of a transmitter  1515 , a transmitter  1615 , a receiver  1510 , a receiver  1610 , or any combination thereof or component thereof, as described herein. 
     The memory  1830  may include random access memory (RAM) and read-only memory (ROM). The memory  1830  may store computer-readable, computer-executable code  1835  including instructions that, when executed by the processor  1840 , cause the device  1805  to perform various functions described herein. The code  1835  may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code  1835  may not be directly executable by the processor  1840  but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some cases, the memory  1830  may contain, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices. 
     The processor  1840  may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor  1840  may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the processor  1840 . The processor  1840  may be configured to execute computer-readable instructions stored in a memory (e.g., the memory  1830 ) to cause the device  1805  to perform various functions (e.g., functions or tasks supporting coordination during access link DRX and sidelink alignment). For example, the device  1805  or a component of the device  1805  may include a processor  1840  and memory  1830  coupled to the processor  1840 , the processor  1840  and memory  1830  configured to perform various functions described herein. 
     The communications manager  1820  may support wireless communication at a first UE in accordance with examples as disclosed herein. For example, the communications manager  1820  may be configured as or otherwise support a means for transmitting, to a base station, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The communications manager  1820  may be configured as or otherwise support a means for receiving, from the base station, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration. The communications manager  1820  may be configured as or otherwise support a means for communicating with the second UE via a sidelink in accordance with the received sidelink DRX configuration. The communications manager  1820  may be configured as or otherwise support a means for communicating with the base station via an access link in accordance with the received access link DRX configuration. 
     By including or configuring the communications manager  1820  in accordance with examples as described herein, the device  1805  may support techniques 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, increased throughput, and increased utilization of available sidelink resources. 
     In some examples, the communications manager  1820  may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the transceiver  1815 , the one or more antennas  1825 , or any combination thereof. Although the communications manager  1820  is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager  1820  may be supported by or performed by the processor  1840 , the memory  1830 , the code  1835 , or any combination thereof. For example, the code  1835  may include instructions executable by the processor  1840  to cause the device  1805  to perform various aspects of coordination during access link DRX and sidelink alignment as described herein, or the processor  1840  and the memory  1830  may be otherwise configured to perform or support such operations. 
       FIG.  19    shows a flowchart illustrating a method  1900  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The operations of the method  1900  may be implemented by a base station or its components as described herein. For example, the operations of the method  1900  may be performed by a base station  105  as described with reference to  FIGS.  1  through  14   . In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the described functions. Additionally or alternatively, the base station may perform aspects of the described functions using special-purpose hardware. 
     At  1905 , the method may include receiving, from a first UE, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The operations of  1905  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  1905  may be performed by an assistance information receiving component  1325  as described with reference to  FIG.  13   . 
     At  1910 , the method may include transmitting, to a second base station, the assistance information message received from the first UE. The operations of  1910  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  1910  may be performed by a base station interface communication component  1330  as described with reference to  FIG.  13   . 
     At  1915 , the method may include communicating, with the second base station via an interface between the first base station and the second base station, an indication of the sidelink DRX configuration for the first UE. The operations of  1915  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  1915  may be performed by a base station interface communication component  1330  as described with reference to  FIG.  13   . 
     At  1920 , the method may include transmitting, to the first UE, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration for the first UE based on the communicating. The operations of  1920  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  1920  may be performed by a DRX configuration signaling component  1335  as described with reference to  FIG.  13   . 
       FIG.  20    shows a flowchart illustrating a method  2000  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The operations of the method  2000  may be implemented by a base station or its components as described herein. For example, the operations of the method  2000  may be performed by a base station  105  as described with reference to  FIGS.  1  through  14   . In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the described functions. Additionally or alternatively, the base station may perform aspects of the described functions using special-purpose hardware. 
     At  2005 , the method may include receiving, from a first UE, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The operations of  2005  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2005  may be performed by an assistance information receiving component  1325  as described with reference to  FIG.  13   . 
     At  2010 , the method may include transmitting, to a second base station, the assistance information message received from the first UE. The operations of  2010  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2010  may be performed by a base station interface communication component  1330  as described with reference to  FIG.  13   . 
     At  2015 , the method may include transmitting the assistance information message between the first base station and the second base station via a connection between a first CU of the first base station and a second CU of the second base station. The operations of  2015  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2015  may be performed by a CU-CU communication component  1345  as described with reference to  FIG.  13   . 
     At  2020 , the method may include communicating, with the second base station via an interface between the first base station and the second base station, an indication of the sidelink DRX configuration for the first UE. The operations of  2020  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2020  may be performed by a base station interface communication component  1330  as described with reference to  FIG.  13   . 
     At  2025 , the method may include transmitting, to the first UE, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration for the first UE based on the communicating. The operations of  2025  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2025  may be performed by a DRX configuration signaling component  1335  as described with reference to  FIG.  13   . 
       FIG.  21    shows a flowchart illustrating a method  2100  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The operations of the method  2100  may be implemented by a base station or its components as described herein. For example, the operations of the method  2100  may be performed by a base station  105  as described with reference to  FIGS.  1  through  14   . In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the described functions. Additionally or alternatively, the base station may perform aspects of the described functions using special-purpose hardware. 
     At  2105 , the method may include receiving, from a first base station, an assistance information message from a first UE, the assistance information message for determining a sidelink DRX configuration for communications between the first UE and a second UE. The operations of  2105  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2105  may be performed by an assistance information receiving component  1325  as described with reference to  FIG.  13   . 
     At  2110 , the method may include transmitting, to the first base station, an indication of the sidelink DRX configuration determined for the first UE via an interface between the first base station and the second base station. The operations of  2110  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2110  may be performed by a base station interface communication component  1330  as described with reference to  FIG.  13   . 
     At  2115 , the method may include transmitting, to the second UE, an indication of an access link DRX configuration for communications between the second UE and the second base station. The operations of  2115  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2115  may be performed by a DRX configuration signaling component  1335  as described with reference to  FIG.  13   . 
       FIG.  22    shows a flowchart illustrating a method  2200  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The operations of the method  2200  may be implemented by a base station or its components as described herein. For example, the operations of the method  2200  may be performed by a base station  105  as described with reference to  FIGS.  1  through  14   . In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the described functions. Additionally or alternatively, the base station may perform aspects of the described functions using special-purpose hardware. 
     At  2205 , the method may include receiving, from a first UE, a first assistance information message at a first DU, the first assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The operations of  2205  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2205  may be performed by an assistance information receiving component  1325  as described with reference to  FIG.  13   . 
     At  2210 , the method may include receiving, at a CU, the first assistance information message relayed by the first DU to the CU. The operations of  2210  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2210  may be performed by a CU-DU communication component  1340  as described with reference to  FIG.  13   . 
     At  2215 , the method may include communicating, between the CU and at least the first DU, an indication of the sidelink DRX configuration for the first UE and an indication of a first access link DRX configuration for the first UE. The operations of  2215  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2215  may be performed by a CU-DU communication component  1340  as described with reference to  FIG.  13   . 
     At  2220 , the method may include transmitting, to the first UE, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based on the communicating. The operations of  2220  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2220  may be performed by a DRX configuration signaling component  1335  as described with reference to  FIG.  13   . 
       FIG.  23    shows a flowchart illustrating a method  2300  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The operations of the method  2300  may be implemented by a base station or its components as described herein. For example, the operations of the method  2300  may be performed by a base station  105  as described with reference to  FIGS.  1  through  14   . In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the described functions. Additionally or alternatively, the base station may perform aspects of the described functions using special-purpose hardware. 
     At  2305 , the method may include receiving, from a first UE, a first assistance information message at a first DU, the first assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The operations of  2305  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2305  may be performed by an assistance information receiving component  1325  as described with reference to  FIG.  13   . 
     At  2310 , the method may include receiving, at a CU, the first assistance information message relayed by the first DU to the CU. The operations of  2310  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2310  may be performed by a CU-DU communication component  1340  as described with reference to  FIG.  13   . 
     At  2315 , the method may include communicating, between the CU and at least the first DU, an indication of the sidelink DRX configuration for the first UE and an indication of a first access link DRX configuration for the first UE. The operations of  2315  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2315  may be performed by a CU-DU communication component  1340  as described with reference to  FIG.  13   . 
     At  2320 , the method may include communicating, between the first DU and a second DU, the first assistance information message, the indication of the sidelink DRX configuration, the indication of the first access link DRX configuration, or any combination thereof. The operations of  2320  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2320  may be performed by a DU-DU communication component  1360  as described with reference to  FIG.  13   . 
     At  2325 , the method may include transmitting, to the first UE, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based on the communicating. The operations of  2325  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2325  may be performed by a DRX configuration signaling component  1335  as described with reference to  FIG.  13   . 
       FIG.  24    shows a flowchart illustrating a method  2400  that supports coordination during access link DRX and sidelink alignment in accordance with aspects of the present disclosure. The operations of the method  2400  may be implemented by a UE or its components as described herein. For example, the operations of the method  2400  may be performed by a UE  115  as described with reference to  FIGS.  1  through  10  and  15  through  18   . 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. 
     At  2405 , the method may include transmitting, to a base station, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE. The operations of  2405  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2405  may be performed by an assistance information transmitting component  1725  as described with reference to  FIG.  17   . 
     At  2410 , the method may include receiving, from the base station, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration. The operations of  2410  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2410  may be performed by a DRX configuration receiving component  1730  as described with reference to  FIG.  17   . 
     At  2415 , the method may include communicating with the second UE via a sidelink in accordance with the received sidelink DRX configuration. The operations of  2415  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2415  may be performed by a sidelink communication component  1735  as described with reference to  FIG.  17   . 
     At  2420 , the method may include communicating with the base station via an access link in accordance with the received access link DRX configuration. The operations of  2420  may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of  2420  may be performed by an access link communication component  1740  as described with reference to  FIG.  17   . 
     The following provides an overview of aspects of the present disclosure: 
     Aspect 1: A method for wireless communication at a first base station, comprising: receiving, from a first UE, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE; transmitting, to a second base station, the assistance information message received from the first UE; communicating, with the second base station via an interface between the first base station and the second base station, an indication of the sidelink DRX configuration for the first UE; and transmitting, to the first UE, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration for the first UE based at least in part on the communicating. 
     Aspect 2: The method of aspect 1, wherein communicating with the second base station via the interface further comprises: transmitting the assistance information message between the first base station and the second base station via a connection between a first CU of the first base station and a second CU of the second base station. 
     Aspect 3: The method of any of aspects 1 through 2, further comprising: relaying the indication of the sidelink DRX configuration and the indication of the access link DRX configuration from a first CU of the first base station to a first DU of the first base station; and transmitting, to the first UE, the indication of the sidelink DRX configuration and the indication of the access link DRX configuration via an access link between the first UE and the first DU. 
     Aspect 4: The method of any of aspects 1 through 3, further comprising: transmitting the assistance information message to the second base station, the assistance information message comprising a field including one or more additional sidelink DRX configurations associated with one or more additional sidelink UEs, and a field including the indication of the access link DRX configuration for the first UE. 
     Aspect 5: The method of any of aspects 1 through 4, wherein the sidelink DRX configuration for the first UE comprises one or more sidelink DRX alignment parameters. 
     Aspect 6: The method of any of aspects 1 through 5, wherein the access link DRX configuration for the second UE comprises one or more access link DRX alignment parameters. 
     Aspect 7: A method for wireless communication at a second base station, comprising: receiving, from a first base station, an assistance information message from a first UE, the assistance information message for determining a sidelink DRX configuration for communications between the first UE and a second UE; transmitting, to the first base station, an indication of the sidelink DRX configuration determined for the first UE via an interface between the first base station and the second base station; and transmitting, to the second UE, an indication of an access link DRX configuration for communications between the second UE and the second base station. 
     Aspect 8: The method of aspect 7, wherein communicating with the first base station via the interface further comprises: receiving the assistance information message from the first base station via a connection between a first CU of the first base station and a second CU of the second base station. 
     Aspect 9: The method of any of aspects 7 through 8, further comprising: determining the sidelink DRX configuration for the first UE and the access link DRX configuration for the second UE; and transmitting, to the first base station, the indication of the sidelink DRX configuration for the first UE via the interface between the second base station and the first base station; and transmitting, to the second UE, the indication of the access link DRX configuration for the second UE based at least in part on the determining. 
     Aspect 10: The method of any of aspects 7 through 9, further comprising: receiving the assistance information message from the first base station, the assistance information message comprising a field including one or more additional sidelink DRX configurations associated with one or more additional sidelink UEs, and a field including the indication of the access link DRX configuration for the first UE. 
     Aspect 11: The method of any of aspects 7 through 10, wherein the sidelink DRX configuration for the first UE comprises one or more sidelink DRX alignment parameters. 
     Aspect 12: The method of any of aspects 7 through 11, wherein the access link DRX configuration for the second UE comprises one or more access link DRX alignment parameters. 
     Aspect 13: A method for wireless communication, comprising: receiving, from a first UE, a first assistance information message at a first DU, the first assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE; receiving, at a CU, the first assistance information message relayed by the first DU to the CU; communicating, between the CU and at least the first DU, an indication of the sidelink DRX configuration for the first UE and an indication of a first access link DRX configuration for the first UE; and transmitting, to the first UE, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based at least in part on the communicating. 
     Aspect 14: The method of aspect 13, further comprising: receiving, from the second UE, a second assistance information message at a second DU; receiving, at the CU, the second assistance information message relayed by the second DU to the CU; communicating, between the CU and the second DU, an indication of a second access link DRX configuration for the second UE; and transmitting, to the second UE, the indication of the first access link DRX configuration based at least in part on the communicating. 
     Aspect 15: The method of any of aspects 13 through 14, further comprising: receiving, at the first DU and a second DU, one or more pre-configurations for determining one or more DRX configurations for the first UE and the second UE; transmitting, to the first UE via the first DU, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based at least in part on the one or more pre-configurations; and transmitting, to the second UE via the second DU, an indication of a second access link DRX configuration based at least in part on the one or more pre-configurations. 
     Aspect 16: The method of aspect 15, further comprising: communicating, between the first DU and the second DU, the one or more DRX configurations for the first UE and the second UE based at least in part on the one or more pre-configurations. 
     Aspect 17: The method of any of aspects 13 through 16, further comprising: communicating, between the first DU and a second DU, the first assistance information message, the indication of the sidelink DRX configuration, the indication of the first access link DRX configuration, or any combination thereof. 
     Aspect 18: The method of any of aspects 13 through 17, wherein the CU determines the sidelink DRX configuration for the first UE, the first access link DRX configuration for the first UE, and the second access link DRX configuration for the second UE. 
     Aspect 19: The method of any of aspects 13 through 18, further comprising: receiving, from the second UE, a second assistance information message at the first DU; receiving, at the CU, the second assistance information message relayed by the first DU to the CU; communicating, between the CU and the first DU, an indication of a second access link DRX configuration for the second UE; and transmitting, to the second UE, the indication of the first access link DRX configuration based at least in part on the communicating. 
     Aspect 20: The method of aspect 19, further comprising: receiving, at the first DU, one or more pre-configurations for determining one or more DRX configurations for the first UE and the second UE; transmitting, to the first UE via the first DU, the indication of the sidelink DRX configuration and the indication of the first access link DRX configuration based at least in part on the one or more pre-configurations; and transmitting, to the second UE via the first DU, an indication of a second access link DRX configuration based at least in part on the one or more pre-configurations. 
     Aspect 21: The method of aspect 20, further comprising: communicating, between the CU and the first DU, the one or more DRX configurations for the first UE and the second UE based at least in part on the one or more pre-configurations. 
     Aspect 22: The method of any of aspects 13 through 21, further comprising: communicating, between the CU and the first DU and a second DU, the first assistance information message, the indication of the sidelink DRX configuration, the indication of the first access link DRX configuration, or any combination thereof. 
     Aspect 23: The method of any of aspects 13 through 22, wherein the first assistance information message comprises one or more additional indications of sidelink connected mode DRX configurations established between the first UE and one or more other sidelink UEs. 
     Aspect 24: The method of any of aspects 13 through 23, further comprising: communicating via layer-1 signaling, layer-2 signaling, layer-3 signaling, or any combination thereof. 
     Aspect 25: A method for wireless communication at a first UE, comprising: transmitting, to a base station, an assistance information message associated with a sidelink DRX configuration for communications between the first UE and a second UE; receiving, from the base station, an indication of the sidelink DRX configuration and an indication of an access link DRX configuration; communicating with the second UE via a sidelink in accordance with the received sidelink DRX configuration; and communicating with the base station via an access link in accordance with the received access link DRX configuration. 
     Aspect 26: The method of aspect 25, further comprising: receiving, via a first DU of the base station, the indication of the sidelink DRX configuration and the indication of the access link DRX configuration based at least in part on one or more pre-configurations. 
     Aspect 27: The method of any of aspects 25 through 26, wherein transmitting the assistance information message further comprises: transmitting the assistance information message via the access link to a first DU of the base station. 
     Aspect 28: The method of any of aspects 25 through 27, wherein the assistance information message comprises one or more additional indications of sidelink connected mode DRX configurations established between the first UE and one or more other sidelink UEs. 
     Aspect 29: The method of any of aspects 25 through 28, further comprising: communicating via layer-1 signaling, layer-2 signaling, layer-3 signaling, or any combination thereof. 
     Aspect 30: The method of any of aspects 25 through 29, further comprising: refraining from transmitting the sidelink DRX configuration to the second UE based at least in part on receiving the indication of the sidelink DRX configuration from the base station. 
     Aspect 31: An apparatus for wireless communication at a first base station, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 1 through 6. 
     Aspect 32: An apparatus for wireless communication at a first base station, comprising at least one means for performing a method of any of aspects 1 through 6. 
     Aspect 33: A non-transitory computer-readable medium storing code for wireless communication at a first base station, the code comprising instructions executable by a processor to perform a method of any of aspects 1 through 6. 
     Aspect 34: An apparatus for wireless communication at a second base station, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 7 through 12. 
     Aspect 35: An apparatus for wireless communication at a second base station, comprising at least one means for performing a method of any of aspects 7 through 12. 
     Aspect 36: A non-transitory computer-readable medium storing code for wireless communication at a second base station, the code comprising instructions executable by a processor to perform a method of any of aspects 7 through 12. 
     Aspect 37: An apparatus for wireless communication, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 13 through 24. 
     Aspect 38: An apparatus for wireless communication, comprising at least one means for performing a method of any of aspects 13 through 24. 
     Aspect 39: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform a method of any of aspects 13 through 24. 
     Aspect 40: An apparatus for wireless communication at a first UE, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 25 through 30. 
     Aspect 41: An apparatus for wireless communication at a first UE, comprising at least one means for performing a method of any of aspects 25 through 30. 
     Aspect 42: A non-transitory computer-readable medium storing code for wireless communication at a first UE, the code comprising instructions executable by a processor to perform a method of any of aspects 25 through 30. 
     It should be noted that the methods described herein describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined. 
     Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communications systems such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, as well as other systems and radio technologies not explicitly mentioned herein. 
     Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. 
     The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration). 
     The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. 
     Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media. 
     As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of”) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on.” 
     The term “determine” or “determining” encompasses a wide variety of actions and, therefore, “determining” can include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, a database or another data structure), ascertaining and the like. Also, “determining” can include receiving (such as receiving information), accessing (such as accessing data in a memory) and the like. Also, “determining” can include resolving, selecting, choosing, establishing and other such similar actions. 
     In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label. 
     The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples. 
     The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.