Patent Publication Number: US-2023136727-A1

Title: Vehicle based wireless communications

Description:
CROSS REFERENCES 
     The present Application for Patent claims priority to U.S. patent application Ser. No. 16/900,410 by BALASUBRAMANIAN et al., entitled “TECHNIQUES FOR VEHICLE BASED WIRELESS COMMUNICATIONS,” filed Jun. 12, 2020, which is assigned to the assignee hereof and which is expressly incorporated by reference herein. 
    
    
     FIELD OF TECHNOLOGY 
     The following relates generally to wireless communications and more specifically to vehicle based wireless communications. 
     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 frequency division multiple access (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). 
     SUMMARY 
     The described techniques relate to improved methods, systems, devices, and apparatuses vehicle based wireless communications. Generally, the described techniques provide various proposals that support techniques in a vehicle-based wireless communication system, e.g., in a vehicle-to-pedestrian (V2P), pedestrian-to-pedestrian (P2P), and/or pedestrian-to-vehicle (P2V) wireless communication system. The vehicle based wireless communication system may perform wireless V2P/P2P/P2V transmissions over a sidelink channel, such as a PSCCH and/or PSSCH. Broadly, aspects of such techniques may include a first pedestrian user equipment (PUE) (or first UE in this example) adopting the identity of a second PUE (or second UE in this example) within a threshold range of the first PUE for a certain period of a discontinuous transmission (DTX) cycle. For example, the first PUE (or first UE) may detect transmission(s) (e.g., broadcast transmission(s)) from other PUE(s) (second UE(s) in this example) that carries or otherwise conveys location information of the transmitting PUE. Based on the detected transmission, the first UE may identify or otherwise determine that a second PUE is located within the threshold distance (d) of the first UE, e.g., within d feet, meters, etc. Accordingly, the first PUE may adopt the identity of the second PUE and monitor, during a subsequent transmission period of the DTX cycle, for a transmission, e.g., such as from a vehicle UE (VUE) transmitting an alert message) using the identifier of the second PUE (a second identifier in this example). That is, the first PUE may use its identifier (a first identifier in this example) with the identifier of the second PUE for N subsequent transmission period(s) of the DTX cycle. In some aspects, the first PUE may also monitor for the transmission using its own identifier (the first identifier) during the subsequent transmission period(s) of the DTX cycle. This may allow the first PUE to refrain from transmitting for N transmission periods of the DTX cycle, which may result in considerable power savings at the PUE. Once the second PUE is no longer within the threshold distance d and/or the N transmission periods of the DTX cycle have passed, the first PUE may return to monitoring for transmissions using its own identifier and/or search for a new neighboring PUE within the threshold distance d to adopt its identity. 
     Additionally and/or alternatively, aspects of such techniques may include a VUE sending a paging indicator message that uses location information to address any PUE(s) located within the location. That is, the VUE (or simply a UE in this example) may determine that it needs to send a group paging indicator to any PUE (or one or more additional UE in this example). For example, the VUE may determine that it needs to send a BSM, TIM, and the like, to PUE(s) located within a geographic area (e.g., to avoid a potential collision between the vehicle and the pedestrians associated with the PUE). Accordingly, the VUE may transmit the group paging indicator that carries or otherwise conveys an indication of the geographical area. Broadly, the indication of the geographical area may serve as the address list for the group paging indicator. The indication of the geographical area may include a point/radius indication, four coordinate indication (e.g., corners of a square, rectangle, etc.), and the like. Accordingly, any of the other UE (e.g., PUE) that receive the group paging indicator may determine whether or not they are located within the geographic area. If so, the PUE may determine that the group paging indicator is addressed to them and, therefore, monitor for a paging message from the VUE during a monitoring period of the DTX cycle. 
     A method for wireless communication at a first UE is descried. The method may include: detecting, during a first transmission period of a DTX cycle, a transmission over a sidelink channel from a second UE that is located within a threshold distance from the first UE, the first UE associated with a first identifier; determining, based at least in part on the transmission, a second identifier associated with the second UE, the second identifier being different from the first identifier; and using, based at least in part on the second UE being within the threshold distance, the first identifier and the second identifier during one or more subsequent transmission periods of the DTX cycle. 
     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 detect, during a first transmission period of a DTX cycle, a transmission over a sidelink channel from a second UE that is located within a threshold distance from the first UE, the first UE associated with a first identifier; determine, based at least in part on the transmission, a second identifier associated with the second UE, the second identifier being different from the first identifier; and use, based at least in part on the second UE being within the threshold distance, the first identifier and the second identifier during one or more subsequent transmission periods of the DTX cycle. 
     Another apparatus for wireless communication at a first UE is described. The apparatus may include means for detecting, during a first transmission period of a DTX cycle, a transmission over a sidelink channel from a second UE that is located within a threshold distance from the first UE, the first UE associated with a first identifier; determining, based at least in part on the transmission, a second identifier associated with the second UE, the second identifier being different from the first identifier; and using, based at least in part on the second UE being within the threshold distance, the first identifier and the second identifier during one or more subsequent transmission periods of the DTX cycle. 
     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 detect, during a first transmission period of a DTX cycle, a transmission over a sidelink channel from a second UE that is located within a threshold distance from the first UE, the first UE associated with a first identifier; determine, based at least in part on the transmission, a second identifier associated with the second UE, the second identifier being different from the first identifier; and use, based at least in part on the second UE being within the threshold distance, the first identifier and the second identifier during one or more subsequent transmission periods of the DTX cycle. 
     A method for wireless communications at a first UE is described. The method may include receiving, during a transmission period of a DTX cycle, a group paging indicator from a second UE over a sidelink channel; identifying a geographic area indicated in the group paging indicator; determining that a location of the first UE is within the geographical area; determining, based at least in part on the first UE being located within the geographical area, that the group paging indicator is addressed to the first UE; and receiving, during a monitoring period of the DTX cycle, a paging message from the second UE. 
     An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, during a transmission period of a DTX cycle, a group paging indicator from a second UE over a sidelink channel; identify a geographic area indicated in the group paging indicator; determine that a location of the first UE is within the geographical area; determine, based at least in part on the first UE being located within the geographical area, that the group paging indicator is addressed to the first UE; and receive, during a monitoring period of the DTX cycle, a paging message from the second UE. 
     Another apparatus for wireless communication at a UE is described. The apparatus may include means for receiving, during a transmission period of a DTX cycle, a group paging indicator from a second UE over a sidelink channel; identifying a geographic area indicated in the group paging indicator; determining that a location of the first UE is within the geographical area; determining, based at least in part on the first UE being located within the geographical area, that the group paging indicator is addressed to the first UE; and receiving, during a monitoring period of the DTX cycle, a paging message from the second UE. 
     A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to receive, during a transmission period of a DTX cycle, a group paging indicator from a second UE over a sidelink channel; identify a geographic area indicated in the group paging indicator; determine that a location of the first UE is within the geographical area; determine, based at least in part on the first UE being located within the geographical area, that the group paging indicator is addressed to the first UE; and receive, during a monitoring period of the DTX cycle, a paging message from the second UE. 
     A method for wireless communications at a UE is described. The method may include identifying a geographic area associated with transmitting a group paging indicator to one or more additional UE located within the geographic area; transmitting, over a sidelink channel associated with a DTX cycle, the group paging indicator indicating the geographical area, the indication of the geographical area indicating that the group paging indicator is addressed to the one or more additional UE that are located within the geographical area; and transmitting, during a monitoring period of the DTX cycle, a group paging message to the one or more additional UE. 
     An apparatus for wireless communication at a 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 identify a geographic area associated with transmitting a group paging indicator to one or more additional UE located within the geographic area; transmit, over a sidelink channel associated with a DTX cycle, the group paging indicator indicating the geographical area, the indication of the geographical area indicating that the group paging indicator is addressed to the one or more additional UE that are located within the geographical area; and transmit, during a monitoring period of the DTX cycle, a group paging message to the one or more additional UE. 
     Another apparatus for wireless communication at a UE is described. The apparatus may include means for identifying a geographic area associated with transmitting a group paging indicator to one or more additional UE located within the geographic area; transmitting, over a sidelink channel associated with a DTX cycle, the group paging indicator indicating the geographical area, the indication of the geographical area indicating that the group paging indicator is addressed to the one or more additional UE that are located within the geographical area; and transmitting, during a monitoring period of the DTX cycle, a group paging message to the one or more additional UE. 
     A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to identify a geographic area associated with transmitting a group paging indicator to one or more additional UE located within the geographic area; transmit, over a sidelink channel associated with a DTX cycle, the group paging indicator indicating the geographical area, the indication of the geographical area indicating that the group paging indicator is addressed to the one or more additional UE that are located within the geographical area; and transmit, during a monitoring period of the DTX cycle, a group paging message to the one or more additional UE. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates an example of a system for wireless communications that supports vehicle based wireless communications in accordance with aspects of the present disclosure. 
         FIG.  2    illustrates an example of a wireless communication system that supports vehicle based wireless communications in accordance with aspects of the present disclosure. 
         FIG.  3    illustrates an example of a wireless communication system that supports vehicle based wireless communications in accordance with aspects of the present disclosure. 
         FIG.  4    illustrates an example of a process that supports vehicle based wireless communications in accordance with aspects of the present disclosure. 
         FIG.  5    illustrates an example of a process that supports vehicle based wireless communications in accordance with aspects of the present disclosure. 
         FIGS.  6  and  7    show block diagrams of devices that supports vehicle based wireless communications in accordance with aspects of the present disclosure. 
         FIG.  8    shows a block diagram of a communications manager that supports vehicle based wireless communications in accordance with aspects of the present disclosure. 
         FIG.  9    shows a diagram of a system including a device that supports vehicle based wireless communications in accordance with aspects of the present disclosure. 
         FIGS.  10  through  14    show flowcharts illustrating methods that support vehicle based wireless communications in accordance with aspects of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Wireless communication systems may include or support networks used for vehicle-based communications, also referred to as vehicle-to-everything (V2X) networks, vehicle-to-vehicle (V2V) networks, cellular V2X (CV2X) networks, or other similar networks. Vehicle based communication networks may provide always on telematics where vehicle-based wireless devices, e.g., vehicle UEs (VUEs), communicate directly with the network (V2N), to pedestrian UEs (V2P), from pedestrian UEs (P2V), to infrastructure devices (V2I), and to other VUEs (e.g., via the network and/or directly). The vehicle-based communication networks may support a safe, always-connected driving experience by providing intelligent connectivity where traffic signal/timing, real-time traffic and routing, safety alerts to pedestrians/bicyclist, collision avoidance information, etc., are exchanged. Communications in vehicle-based networks may include transmissions of various safety-related messages (e.g., basic safety message (BSM) transmissions, traveler information message (TIM) transmissions, etc.). Vehicle based communications may occur over one or more sidelink channels, e.g., a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), and the like. 
     Aspects of the disclosure are initially described in the context of wireless communications systems. In certain instances, all or part of one or more of the described techniques may be implemented to improve power and/or paging operations/functions in a vehicle-based wireless communication system, e.g., in a V2P, pedestrian-to-pedestrian (P2P), and/or P2V wireless communication system. The vehicle based wireless communication system may perform wireless V2P/P2P/P2V transmissions over a sidelink channel, such as a PSCCH and/or PSSCH. Broadly, aspects of such techniques may include a first pedestrian user equipment (PUE) (or first UE in this example) adopting the identity of a second PUE (or second UE in this example) within a threshold range of the first PUE for a certain period of a discontinuous transmission (DTX) cycle. For example, the first PUE (or first UE) may detect transmission(s) (e.g., broadcast transmission(s)) from other PUE(s) (second UE(s) in this example) that carries or otherwise conveys location information of the transmitting PUE. Based on the detected transmission, the first UE may identify or otherwise determine that a second PUE is located within the threshold distance (d) of the first UE, e.g., within d feet, meters, etc. Accordingly, the first PUE may adopt the identity of the second PUE and monitor, during a subsequent transmission period of the DTX cycle, for a transmission, e.g., such as from a vehicle UE (VUE) transmitting an alert message) using the identifier of the second PUE (a second identifier in this example). That is, the first PUE may use its identifier (a first identifier in this example) and the identifier of the second PUE for N subsequent transmission period(s) of the DTX cycle. In some aspects, the first PUE may also monitor for the transmission using its own identifier (the first identifier) during the subsequent transmission period(s) of the DTX cycle. This may allow the first PUE to refrain from transmitting for N transmission periods of the DTX cycle, which may result in considerable power savings at the PUE. Once the second PUE is no longer within the threshold distance d and/or the N transmission periods of the DTX cycle have passed, the first PUE may return to monitoring for transmissions using its own identifier and/or search for a new neighboring PUE within the threshold distance d to adopt its identity. 
     Additionally and/or alternatively, aspects of such techniques may include a VUE sending a paging indicator message that uses location information to address any PUE(s) located within the location. That is, the VUE (or simply a UE in this example) may determine that it needs to send a group paging indicator to any PUE (or one or more additional UE in this example). For example, the VUE may determine that it needs to send a BSM, TIM, and the like, to PUE(s) located within a geographic area (e.g., to avoid a potential collision between the vehicle and the pedestrians associated with the PUE). Accordingly, the VUE may transmit the group paging indicator that carries or otherwise conveys an indication of the geographical area. Broadly, the indication of the geographical area may serve as the address list for the group paging indicator. The indication of the geographical area may include a point/radius indication, four coordinate indication (e.g., corners of a square, rectangle, etc.), and the like. Accordingly, any of the other UE (e.g., PUE) that receive the group paging indicator may determine whether or not they are located within the geographic area. If so, the may determine that the group paging indicator is addressed to them and, therefore, monitor for a paging message from the VUE during a monitoring period of the DTX cycle. 
     The techniques described herein may, for example, provide for improved power conservation of a UE, and/or paging mechanisms that may increase pedestrian safety. In particular, small wearable devices (e.g., PUEs) which may have even less available battery power than a traditional UE, may benefit from such techniques. 
     Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that may relate, at least in part, to possible power and/or paging improvements for vehicle based wireless communications. 
       FIG.  1    illustrates an example of a wireless communications system  100  that supports vehicle based wireless communications 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, a New Radio (NR) network, or a network operating in accordance with other systems and radio technologies, including future systems and radio technologies not explicitly mentioned herein. In some examples, the wireless communications system  100  may support enhanced broadband communications, ultra-reliable (e.g., mission critical) 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 geographic coverage area  110  over which the UEs  115  and the base station  105  may establish one or more communication links  125 . The geographic 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 the geographic 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   . 
     As described herein, a node of the wireless communications system  100 , which may be referred to as a network node, or a wireless node, may be a base station  105  (e.g., any network entity described herein), a UE  115  (e.g., any UE described herein), a network controller, an apparatus, a device, a computing system, one or more components, or another suitable processing entity configured to perform any of the techniques described herein. For example, a node may be a UE  115 . As another example, a node may be a network entity (e.g., a base station  105 ). As another example, a first node may be configured to communicate with a second node or a third node. In one aspect of this example, the first node may be a UE  115 , the second node may be a base station  105 , and the third node may be a UE  115 . In another aspect of this example, the first node may be a UE  115 , the second node may be a base station  105 , and the third node may be a base station  105 . In yet other aspects of this example, the first, second, and third nodes may be different relative to these examples. Similarly, reference to a UE  115 , network entity, base station  105 , apparatus, device, computing system, or the like may include disclosure of the UE  115 , network entity, base station  105 , apparatus, device, computing system, or the like being a node. For example, disclosure that a UE  115  is configured to receive information from a base station  105  also discloses that a first node is configured to receive information from a second node. 
     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 protocol). The base stations  105  may communicate with one another over the backhaul links  120  (e.g., via an X2, Xn, or other interface protocol) 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. In some examples, base stations  105  may communicate with one another via a midhaul communication link (e.g., in accordance with a midhaul interface protocol) or a fronthaul communication link (e.g., in accordance with a fronthaul interface protocol), or any combination thereof. The backhaul links  120 , midhaul communication links, or fronthaul communication links may be or include one or more wired links (e.g., an electrical link, an optical fiber link), one or more wireless links (e.g., a radio link, a wireless optical link), among other examples or various combinations thereof. A UE  115  may communicate with the core network  130  via a communication link. 
     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 NR 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 5G NB, a next-generation eNB (ng-eNB), a Home NodeB, a Home eNodeB, or other suitable terminology. In some examples, a network entity (e.g., a base station  105 ) may be implemented in an aggregated (e.g., monolithic, standalone) base station architecture, which may be configured to utilize a protocol stack that is physically or logically integrated within a single network entity (e.g., a single RAN node, such as a base station  105 ). 
     In some examples, a base station  105  may be implemented in a disaggregated architecture (e.g., a disaggregated base station architecture, a disaggregated RAN architecture), which may be configured to utilize a protocol stack that is physically or logically distributed among two or more network entities, such as an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance), or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN)). For example, a network entity (e.g., a base station)  105  may include one or more of a central unit (CU), a distributed unit (DU), a radio unit (RU), a RAN Intelligent Controller (RIC) (e.g., a Near-Real Time RIC (Near-RT RIC), a Non-Real Time RIC (Non-RT RIC)), a Service Management and Orchestration (SMO) system, or any combination thereof. An RU may also be referred to as a radio head, a smart radio head, a remote radio head (RRH), a remote radio unit (RRU), or a transmission reception point (TRP). One or more components of the base station  105  in a disaggregated RAN architecture may be co-located, or one or more components of the base stations  105  may be located in distributed locations (e.g., separate physical locations). In some examples, one or more base stations  105  of a disaggregated RAN architecture may be implemented as virtual units (e.g., a virtual CU (VCU), a virtual DU (VDU), a virtual RU (VRU)). 
     The split of functionality between a CU, a DU, and an RU is flexible and may support different functionalities depending on which functions (e.g., network layer functions, protocol layer functions, baseband functions, RF functions, and any combinations thereof) are performed at a CU, a DU, or an RU. For example, a functional split of a protocol stack may be employed between a CU and a DU such that the CU may support one or more layers of the protocol stack and the DU may support one or more different layers of the protocol stack. In some examples, the CU may host upper protocol layer (e.g., layer 3 (L3), layer 2 (L2)) functionality and signaling (e.g., Radio Resource Control (RRC), service data adaption protocol (SDAP), Packet Data Convergence Protocol (PDCP)). The CU may be connected to one or more DUs or RUs, and the one or more DUs or RUs may host lower protocol layers, such as layer 1 (L1) (e.g., physical (PHY) layer) or L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU. Additionally, or alternatively, a functional split of the protocol stack may be employed between a DU and an RU such that the DU may support one or more layers of the protocol stack and the RU may support one or more different layers of the protocol stack. The DU may support one or multiple different cells (e.g., via one or more RUs). In some cases, a functional split between a CU and a DU, or between a DU and an RU may be within a protocol layer (e.g., some functions for a protocol layer may be performed by one of a CU, a DU, or an RU, while other functions of the protocol layer are performed by a different one of the CU, the DU, or the RU). A CU may be functionally split further into CU control plane (CU-CP) and CU user plane (CU-UP) functions. A CU may be connected to one or more DUs via a midhaul communication link (e.g., F1, F1-c, F1-u), and a DU may be connected to one or more RUs via a fronthaul communication link (e.g., open fronthaul (FH) interface). In some examples, a midhaul communication link or a fronthaul communication link may be implemented in accordance with an interface (e.g., a channel) between layers of a protocol stack supported by respective base stations  105  that are in communication via such communication links. 
     In wireless communications systems (e.g., wireless communications system  100 ), infrastructure and spectral resources for radio access may support wireless backhaul link capabilities to supplement wired backhaul connections, providing an IAB network architecture (e.g., to a core network  130 ). In some cases, in an IAB network, one or more base stations  105  (e.g., IAB nodes) may be partially controlled by each other. One or more IAB nodes may be referred to as a donor entity or an IAB donor. One or more DUs or one or more RUs may be partially controlled by one or more CUs associated with a donor network entity (e.g., a donor base station  105 ). The one or more donor network entities (e.g., IAB donors) may be in communication with one or more additional network entities (e.g., IAB nodes) via supported access and backhaul links (e.g., backhaul links  120 ). IAB nodes may include an IAB mobile termination (IAB-MT) controlled (e.g., scheduled) by DUs of a coupled IAB donor. An IAB-MT may include an independent set of antennas for relay of communications with UEs  115 , or may share the same antennas (e.g., of an RU) of an IAB node used for access via the DU of the IAB node (e.g., referred to as virtual IAB-MT (vIAB-MT)). In some examples, the IAB nodes may include DUs that support communication links with additional entities (e.g., IAB nodes, UEs  115 ) within the relay chain or configuration of the access network (e.g., downstream). In such cases, one or more components of the disaggregated RAN architecture (e.g., one or more IAB nodes or components of IAB nodes) may be configured to operate according to the techniques described herein. 
     For instance, an access network (AN) or RAN may include communications between access nodes (e.g., an IAB donor), IAB nodes, and one or more UEs  115 . The IAB donor may facilitate connection between the core network  130  and the AN (e.g., via a wired or wireless connection to the core network  130 ). That is, an IAB donor may refer to a RAN node with a wired or wireless connection to core network  130 . The IAB donor may include a CU and at least one DU (e.g., and RU), in which case the CU may communicate with the core network  130  via an interface (e.g., a backhaul link). IAB donor and IAB nodes may communicate via an F1 interface according to a protocol that defines signaling messages (e.g., an F1 AP protocol). Additionally, or alternatively, the CU may communicate with the core network via an interface, which may be an example of a portion of backhaul link, and may communicate with other CUs (e.g., a CU associated with an alternative IAB donor) via an Xn-C interface, which may be an example of a portion of a backhaul link. 
     An IAB node may refer to a RAN node that provides IAB functionality (e.g., access for UEs  115 , wireless self-backhauling capabilities). A DU may act as a distributed scheduling node towards child nodes associated with the IAB node, and the IAB-MT may act as a scheduled node towards parent nodes associated with the IAB node. That is, an IAB donor may be referred to as a parent node in communication with one or more child nodes (e.g., an IAB donor may relay transmissions for UEs through one or more other IAB nodes). Additionally, or alternatively, an IAB node may also be referred to as a parent node or a child node to other IAB nodes, depending on the relay chain or configuration of the AN. Therefore, the IAB-MT entity of IAB nodes may provide a Uu interface for a child IAB node to receive signaling from a parent IAB node, and the DU interface (e.g., DUs) may provide a Uu interface for a parent IAB node to signal to a child IAB node or UE  115 . 
     For example, IAB node may be referred to as a parent node that supports communications for a child IAB node, or referred to as a child IAB node associated with an IAB donor, or both. The IAB donor may include a CU with a wired or wireless connection (e.g., a backhaul links  120 ) to the core network  130  and may act as parent node to IAB nodes. For example, the DU of IAB donor may relay transmissions to UEs  115  through IAB nodes, or may directly signal transmissions to a UE  115 , or both. The CU of IAB donor may signal communication link establishment via an F1 interface to IAB nodes, and the IAB nodes may schedule transmissions (e.g., transmissions to the UEs  115  relayed from the IAB donor) through the DUs. That is, data may be relayed to and from IAB nodes via signaling via an NR Uu interface to MT of the IAB node. Communications with IAB node may be scheduled by a DU of IAB donor and communications with IAB node may be scheduled by DU of IAB node. 
     In the case of the techniques described herein applied in the context of a disaggregated RAN architecture, one or more components of the disaggregated RAN architecture may be configured to support zero-delay gap period SRS transmissions with antenna switching as described herein. For example, some operations described as being performed by a UE  115  or a network entity (e.g., a base station  105 ) may additionally, or alternatively, be performed by one or more components of the disaggregated RAN architecture (e.g., IAB nodes, DUs, CUs, RUs, RIC, SMO). 
     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. Communication between a base station  105  and other devices may refer to communication between the devices and any portion (e.g., entity, sub-entity) of a base station  105 . For example, the terms “transmitting,” “receiving,” or “communicating,” when referring to a base station  105 , may refer to any portion of a base station  105  (e.g., a network entity, a CU, a DU, a RU) of a RAN communicating with another device (e.g., directly or via one or more other base stations  105 ). 
     In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers. A carrier may be associated with a frequency channel (e.g., an evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN)) and may be positioned according to a channel raster for discovery by the UEs  115 . A carrier may be operated in a standalone mode where initial acquisition and connection may be conducted by the UEs  115  via the carrier, or the carrier may be operated in a non-standalone mode where a connection is anchored using a different carrier (e.g., of the same or a different radio access technology). 
     The communication links  125  shown in the wireless communications system  100  may include uplink transmissions from a UE  115  to a base station  105 , or downlink transmissions from a base station  105  to a UE  115 . Carriers may carry downlink or uplink communications (e.g., in an FDD mode) or may be configured to carry downlink and uplink communications (e.g., in a TDD mode). 
     A carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some examples the carrier bandwidth may be referred to as a “system bandwidth” of the carrier or the wireless communications system  100 . For example, the carrier bandwidth may be one of a number of determined bandwidths for carriers of a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz)). Devices of the wireless communications system  100  (e.g., the base stations  105 , the UEs  115 , or both) may have hardware configurations that support communications over a particular carrier bandwidth or may be configurable to support communications over one of a set of carrier bandwidths. In some examples, the wireless communications system  100  may include base stations  105  or UEs  115  that support simultaneous communications via carriers associated with multiple carrier bandwidths. In some examples, each served UE  115  may be configured for operating over portions (e.g., a sub-band, a BWP) or all of a carrier bandwidth. 
     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 consist of 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 . 
     One or more numerologies for a carrier may be supported, where a numerology may include a subcarrier spacing (Δf) and a cyclic prefix. A carrier may be divided into one or more BWPs having the same or different numerologies. In some examples, a UE  115  may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time and communications for the UE  115  may be restricted to one or more active BWPs. 
     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 , such as MTC or IoT devices, may be low cost or low complexity devices and may provide for automated communication between machines (e.g., via Machine-to-Machine (M2M) communication). M2M communication or MTC may refer to data communication technologies that allow devices to communicate with one another or a base station  105  without human intervention. In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay such information to a central server or application program that makes use of the information or presents the information to humans interacting with the application program. Some UEs  115  may be designed to collect information or enable automated behavior of machines or other devices. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging. 
     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) or mission critical communications. The UEs  115  may be designed to support ultra-reliable, low-latency, or important functions (e.g., mission critical functions). Ultra-reliable communications may include private communication or group communication and may be supported by one or more mission critical services such as mission critical push-to-talk (MCPTT), mission critical video (MCVideo), or mission critical data (MCData). Support for mission critical functions may include prioritization of services, and mission critical services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission critical, 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 . 
     In some systems, the D2D communication link  135  may be an example of a communication channel, such as a sidelink communication channel, between vehicles (e.g., UEs  115 ). In some examples, vehicles may communicate using vehicle-to-everything (V2X) communications, vehicle-to-vehicle (V2V) communications, or some combination of these. A vehicle may signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure, such as roadside units, or with the network via one or more network nodes (e.g., base stations  105 ) using vehicle-to-network (V2N) communications, or with both. 
     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 (MME), 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 the network operators IP services  150 . The operators 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 access network transmission entity  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 also operate in a super high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as the centimeter band, or in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz), also known as the millimeter band. In some examples, the wireless communications system  100  may support millimeter wave (mmW) communications between the UEs  115  and the base stations  105 , and EHF antennas of the respective devices may be smaller and more closely spaced than UHF antennas. In some examples, this may facilitate use of antenna arrays within a device. The propagation of EHF transmissions, however, may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body. 
     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. 
     The base stations  105  or the UEs  115  may use MIMO communications to exploit multipath signal propagation and increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such techniques may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO), where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO), where multiple spatial layers are transmitted to multiple devices. 
     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). 
     A base station  105  or a UE  115  may use beam sweeping techniques as part of beam forming operations. For example, a base station  105  may use multiple antennas or antenna arrays (e.g., antenna panels) to conduct beamforming operations for directional communications with a UE  115 . Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station  105  multiple times in different directions. For example, the base station  105  may transmit a signal according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by a transmitting device, such as a base station  105 , or by a receiving device, such as a UE  115 ) a beam direction for later transmission or reception by the base station  105 . 
     Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station  105  in a single beam direction (e.g., a direction associated with the receiving device, such as a UE  115 ). In some examples, the beam direction associated with transmissions along a single beam direction may be determined based on a signal that was transmitted in one or more beam directions. For example, a UE  115  may receive one or more of the signals transmitted by the base station  105  in different directions and may report to the base station  105  an indication of the signal that the UE  115  received with a highest signal quality or an otherwise acceptable signal quality. 
     In some examples, transmissions by a device (e.g., by a base station  105  or a UE  115 ) may be performed using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (e.g., from a base station  105  to a UE  115 ). The UE  115  may report feedback that indicates precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across a system bandwidth or one or more sub-bands. The base station  105  may transmit a reference signal (e.g., a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS)), which may be precoded or unprecoded. The UE  115  may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook). Although these techniques are described with reference to signals transmitted in one or more directions by a base station  105 , a UE  115  may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE  115 ) or for transmitting a signal in a single direction (e.g., for transmitting data to a receiving device). 
     A receiving device (e.g., a UE  115 ) may try multiple receive configurations (e.g., directional listening) when receiving various signals from the base station  105 , such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive configurations or receive directions. In some examples, a receiving device may use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal). The single receive configuration may be aligned in a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio (SNR), or otherwise acceptable signal quality based on listening according to multiple beam directions). 
     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. 
     The UEs  115  and the base stations  105  may support retransmissions of data to increase the likelihood that data is received successfully. Hybrid automatic repeat request (HARQ) feedback is one technique for increasing the likelihood that data is received correctly over a communication link  125 . HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ may improve throughput at the MAC layer in poor radio conditions (e.g., low signal-to-noise conditions). In some examples, a device may support same-slot HARQ feedback, where the device may provide HARQ feedback in a specific slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in a subsequent slot, or according to some other time interval. 
     A UE  115  (e.g., a first UE, such as a first PUE in this example) may detect, during a first transmission period of a DTX cycle, a transmission over a sidelink channel from a second UE  115  (e.g., a second PUE in this example) that is located within a threshold distance from the first UE, the first UE  115  associated with a first identifier. The UE  115  may determine, based at least in part on the transmission, a second identifier associated with the second UE  115 , the second identifier being different from the first identifier. The UE  115  may use, based at least in part on the second UE  115  being within the threshold distance, the first identifier and the second identifier during one or more subsequent transmission periods of the DTX cycle. 
     A UE  115  (e.g., a first UE, such as a PUE) may receive, during a transmission period of a DTX cycle, a group paging indicator from a second UE  115  (e.g., a second UE, such as a VUE in this example) over a sidelink channel. The UE  115  may identify a geographic area indicated in the group paging indicator. The UE  115  may determine that a location of the first UE  115  is within the geographical area. The UE  115  may determine, based at least in part on the first UE  115  being located within the geographical area, that the group paging indicator is addressed to the first UE  115 . The UE  115  may receive, during a monitoring period of the DTX cycle, a paging message from the second UE  115 . 
     A UE  115  (e.g., a VUE in this example) may identify a geographic area associated with transmitting a group paging indicator to one or more additional UE  115  (e.g., additional PUE(s)) located within the geographic area. The UE  115  may transmit, over a sidelink channel associated with a DTX cycle, the group paging indicator indicating the geographical area, the indication of the geographical area indicating that the group paging indicator is addressed to the one or more additional UE  115  that are located within the geographical area. The UE  115  may transmit, during a monitoring period of the DTX cycle, a group paging message to the one or more additional UE  115 . 
       FIG.  2    illustrates an example of a wireless communication system  200  that supports vehicle based wireless communications in accordance with aspects of the present disclosure. In some examples, wireless communication system  200  may implement aspects of wireless communications system  100 . Aspects of wireless communication system  200  may be implemented by VUE  205  and/or one or more PUE  210 , which may be examples of corresponding devices described herein. In some aspects, VUE  205  may be an example of a vehicle equipped or otherwise configured to support cellular communications over a wireless network. In some aspects, PUE  210  may be examples of any UE associated with a pedestrian, such as a traditional UE, a wearable device, and IOT device, and the like. 
     Broadly, VUE  205  may communicate with PUE  210 - a , PUE  210 - b , PUE  210 - c , and/or PUE  210 - d  over a sidelink channel (e.g., a PSCCH and/or PSSCH). It is to be understood that VUE  205  may communicate with more than the four PUE  210  shown by way of example only in  FIG.  2   . The communications may include V2P communications where VUE  205  performs a transmission over the sidelink channel to a PUE  210  and/or P2V communications where a PUE  210  performs a transmission over a sidelink channel to VUE  205 . Such communications may be implemented according to a DTX cycle over one or more paging occasions  220  (with paging occasion  220 - a , paging occasion  220 - b , and paging occasion  220 - c  being shown by way of example only). Each paging occasion  220  may be associated with the common paging pool (e.g., a pool of resources for V2P/P2V communications during a paging occasion  220 ). 
     Each PUE  210  may be associated with a corresponding radius  215 . That is, PUE  210 - a  may be associated with radius  215 - a , PUE  210 - b  may be associated with radius  215 - b , PUE  210 - c  may be associated with radius  215 - c , and PUE  210 - d  may be associated with radius  215 - d . Broadly, radius  215  may refer to the threshold distance (e.g., d) within which a first PUE  210  may adopt the identifier of a second PUE  210 . Radius  215  may be the same for each corresponding PUE  210 , or each PUE  210  may have a different radius  215 . 
     When two pedestrians are close to each other (e.g., within threshold distance d corresponding to radius  215 , such as when the pedestrians are walking near each other, standing at a corner together waiting to cross, etc.) and if one pedestrian is on a collision course (e.g., with respect to VUE  205 ), there may be a high probability that the other pedestrian may also be on the collision course due to their proximity to the pedestrian on the collision course. It may become redundant if the other PUE  210  perform their P2V transmissions during the paging occasion  220  to transmit their IDs/location information. That is, as these pedestrians are within a threshold distance (e.g., radius  215 ) from each other, it may be inefficient for all of the PUE  210  to transmit their ID/location information as each PUE  210  would otherwise be signaled with the same alert message transmission to avoid a collision. Accordingly, aspects of the described techniques provide a mechanism where, if the distance between two PUE  210  is within a threshold distance (e.g., d, which corresponds to radius  215 ), the PUE  210  of the other pedestrians may adopt the ID of the PUE  210  of the pedestrian on the collision course, although these techniques may also be adopted without the first pedestrian being on the collision course. 
     For example, power consumption by PUE  210  (e.g., wearable devices, reduced capability devices, etc.) may be an important factor given their small size/limited battery life. This is particularly important because PUE  210  may be expected to transmit their ID/location information during paging occasions  220 , e.g., to provide situational awareness to try and avoid a vehicle-to-pedestrian collision. Aspects of the described techniques allow PUE  210  that are located with a certain distance of another PUE  210  to adopt that PUE&#39;s  210  ID for N V2P paging occasions, e.g., if a first PUE is within its radius  215  from a second PUE, it may use the identification of the second PUE for a certain amount of time. This permits the adopting PUE to refrain from transmitting such broadcast signals during transmission periods of the DTX cycle. That is, PUE1 (e.g., PUE  210 - b  and PUE  210 - c  in this example) may adopt the ID of PUE2 (e.g., PUE  210 - a  in this example) during N paging occasions  220  of the DTX cycle since PUE  210 - a  is within radius  215 - b  of PUE  210 - b  and also within radius  215 - c  of PUE  210 - c.    
     In some aspects, this may include PUE  210 - b  and PUE  210 - c  detecting a transmission from PUE  210 - a  over a sidelink channel. For example, the transmission may be the transmission configured during a paging occasion where PUE  210 - a  broadcasts its ID/location information. Of course, PUE  210 - b , PUE  210 - c , and PUE  210 - d  may also broadcast their ID/location information during the paging occasion  220 . PUE  210 - b  and PUE  210 - c  may, based on the transmission detected from PUE  210 - a  , determine that PUE  210 - a  is within their respective threshold distance (e.g., their respective radius  215 ), e.g., the separation distance between each PUE  210 . PUE  210 - d  may determine that there are no other PUE  210  within radius  215 - d  of PUE  210 - d  and, therefore, continue to communicate according to the DTX cycle. 
     In response to PUE  210 - a  being within radius  215 - b  of PUE  210 - b  and within radius  215 - c  of PUE  210 - c , PUE  210 - b  and PUE  210 - c  may adopt the ID of PUE  210 - a . In some aspects, this may include using their own ID with the ID of PUE  210 - a . For example, PUE  210 - b  and PUE  210 - c  may monitor for transmissions addressed to the ID of PUE  210 - a  (as well as their own ID) during N paging occasions  220 . In some aspects, this may include adding the ID of PUE  210 - a  to their own ID. For example, PUE  210 - b  and PUE  210 - c  may monitor for transmissions addressed to the ID of PUE  210 - a  as well as their own ID during the N paging occasions  220 . 
     In some aspects, this may include PUE  210 - b  and PUE  210 - c  transmitting an indication to PUE  210 - a  that each PUE  210  has adopted the ID of PUE  210 - a . For example, PUE  210 - b  and PUE  210 - c  may transmit the indication during a P2V period (e.g., a transmission period of a previous paging occasion  220 ) and/or may occur during a V2P receive period (e.g., a PUE  210  monitoring period) of a paging occasion  220 . Accordingly, PUE  210 - a  may know that it cannot adopt the ID of another PUE for N paging occasions  220  since PUE  210 - b  and PUE  210 - c  are relying on PUE  210 - a  to transmit its ID/location information during paging occasions  220  so that all of PUE  210 - a , PUE  210 - b , and PUE  210 - c  can receive any relevant alert message associated with their location. As discussed, these techniques are not limited to ensuring alert messages are received, but may be implemented in order to conserve battery power of PUE  210 - b  and PUE  210 - c.    
     In some aspects, PUE  210 - b  and PUE  210 - c  may identify or otherwise determine a use period for adopting the ID of PUE  210 - a , e.g., N. In some aspects, the use period (e.g., N) may be configured for a set number of paging occasions  220 , e.g., N is definite. In the non-limiting example illustrated in  FIG.  2   , N spans three paging occasions  220 . In some aspects, the use period (e.g., N) may be based on the threshold distance (e.g., d). That is, PUE  210 - b  and PUE  210 - c  may adopt the ID of PUE  210 - a  as long as PUE  210 - a  is within the threshold distance d, e.g., N is indefinite. Moreover, the use period may be different for each PUE  210 . For example, PUE  210 - b  may adopt the ID of PUE  210 - a  for three paging occasions  220 , but PUE  210 - c  may adopt the ID of PUE  210 - a  for more or less than three paging occasions  220 . 
     PUE2 (e.g., PUE  210 - a  in this example) may still transmit its location/ID information during transmission periods of the paging occasions  220 , but PUE1 (e.g., PUE  210 - b  and PUE  210 - c  in this example) do not have to. Instead, PUE1 (e.g., PUE  210 - b  and/or PUE  210 - c ) may monitor for alert messages using its (their) own ID and the ID of PUE2 during a monitoring portion of the paging occasion  220 . This enables PUE1 to still be safe (as its located near PUE2 that broadcasts its location information), but not have to transmit during every paging occasion  220 , e.g., may conserve power. 
       FIG.  3    illustrates an example of a wireless communication system  300  that supports vehicle based wireless communications in accordance with aspects of the present disclosure. In some examples, wireless communication system  300  may implement aspects of wireless communications systems  100  and/or  200 . Aspects of wireless communication system  300  may be implemented by VUE  305  and/or one or more PUE  310 , which may be examples of corresponding devices described herein. In some aspects, VUE  305  may be an example of a vehicle equipped or otherwise configured to support cellular communications over a wireless network. In some aspects, PUE  310  may be examples of any UE associated with a pedestrian, such as a traditional UE, a wearable device, and IOT device, and the like. 
     Broadly, VUE  305  may communicate with PUE  310 - a , PUE  310 - b , PUE  310 - c , PUE  310 - d  and/or PUE  310 - e  over a sidelink channel (e.g., a PSCCH and/or PSSCH). It is to be understood that VUE  305  may communicate with more than the five PUE  310  shown by way of example only in  FIG.  3   . The communications may include V2P communications where VUE  305  performs a transmission over the sidelink channel to a PUE  310  and/or P2V communications where a PUE  310  performs a transmission over a sidelink channel to VUE  305 . Such communications may be implemented according to a DTX cycle over one or more paging occasions  320 . Each paging occasion  320  may be associated with the common paging pool (e.g., a pool of resources for V2P/P2V communications during a paging occasion  320 ). For example, each paging occasion  320  may be configured or otherwise associated with a P2V resource pool  325 , a paging indicator pool  330 , and a V2P resource pool  335 . The P2V resource pool  325  may define a pool of allocated or otherwise configured resources (e.g., time, frequency, code and/or spatial resources) over which PUE  310  may transmit information, e.g., transmit their ID/location information to VUE  305  and/or other PUE  310 , as well as any other information being transmitted by a PUE  310 . VUE  305  may monitor for transmissions from PUE  310  during the P2V resource pool  325 . 
     The paging indicator pool  330  may define a pool of allocated or otherwise configured resources (e.g., time, frequency, code and/or spatial resources) over which VUE  305  may transmit information, e.g., alert messages to PUE  310 , paging indicator messages to PUE  310 , as well as any other information being transmitted by a VUE  305 . PUE  310  may monitor for transmissions from VUE  305  during the paging indicator pool  330 , e.g., to see if VUE  305  sends a paging indicator to those PUE  310 . In some aspects, the paging indicator pool  330  may be considered a transmission period from the perspective of PUE  310  as they monitor for transmissions from VUE  305 . 
     The V2P resource pool  335  may define a pool of allocated or otherwise configured resources (e.g., time, frequency, code and/or spatial resources) over which VUE  305  may transmit information, e.g., alert messages to PUE  310 , paging messages to PUE  310 , as well as any other information being transmitted by a VUE  305 . PUE  310  may monitor for transmissions from VUE  305  during the V2P resource pool  335 . For example, a PUE  310  receiving a paging indicator during the transmission period of the DTX cycle (e.g., during the paging indicator pool  330 ) may monitor for a paging message during the P2V resource pool  325 . In some aspects, the paging indicator pool  330  may be considered a monitoring period from the perspective of PUE  310  as they monitor for transmissions from VUE  305 . 
     Paging operations according to the described techniques relate to a VUE  305  including a location/region indication in its group paging indicator (e.g., VUE  305  sends a group paging indicator to PUE  310  located within a particular region, such as geographic area). The indication of the geographic area  315  information in the paging indicator provides the list of PUE  310  addressed by the paging indicator. The geographic area  315  indication may include a point/radius indication, four-corner coordinate indications (as shown in the non-limiting example of  FIG.  3   ), and the like. This approach improves paging techniques by the VUE  305 , e.g., VUE  305  does not have to identify individual PUE  310  within the geographic area  315  and then address paging message(s) to individual PUE  310 . This approach also improves pedestrian safety in that the VUE  305  can simply identify a geographic area  315  that has PUE  310  (e.g., pedestrians) in the geographic area  315  and that may collide with the VUE  305  and then page any PUE  310  in that area with a single group paging indicator (much quicker process). 
     This may be a particularly important safety matter. A vehicle approaching an intersection where pedestrians are crossing (and therefore in a potential collision zone) may be required to send an alert message to each pedestrian to avoid a collision. In some situations, this may include a large crowd crossing a busy street at the same time, and therefore in a potential collision zone (e.g., lots of PUE  310  located in a relatively small geographic area  315 ). VUE  305  would otherwise be required to monitor the P2V resource pool  325  (e.g., a V2P paging occasion) to receive broadcast messages from each PUE  310 , determine (based on the location information in each PUE  310  broadcast message), which PUE  310  are located in the collision area (e.g., which PUE  310  are located within the crosswalk example defining the geographic area  315 ), and then separately address a paging indicator to those PUE  310  (e.g., unicast or groupcast) to avoid collisions. Instead, the described techniques allow VUE  305  to simply determine that there are PUE  310  in a potential collision area (e.g., based on previous PUE  310  broadcast messages, using a vehicle mounted camera or other sensor, and the like) and then send a more generic group paging indicator where the indication of the geographic area  315  serves as the address for the group paging indicator. That is, the described techniques permit VUE  305  to be able to page a particular region/location to address all PUE  310  (pedestrians) in that region. This greatly reduces processing requirements and makes this process much quicker, thereby improving safety for pedestrians and vehicles alike. 
     Accordingly, VUE  305  may determine or otherwise identify the geographic area  315 . For example, based on the travel speed/direction of VUE  305 , VUE  305  may determine that it will pass over the example crosswalk corresponding to geographic are  315 . VUE  305  may also determine that one or more PUE  310  are, or may be located within geographic are  315  (e.g., based on previous PUE  310  transmissions, based on a vehicle mounted camera or other sensor, based on receiving a message from a roadside unit (RSU) or other traffic management entity indicating that PUE  310  are or will be crossing the geographic area, and the like. 
     VUE  305  may then identify the geographic area  315  in which to transmit the group paging indicator. VUE  305  may configure the group paging indicator transmitted over the sidelink channel to identify or otherwise indicate the geographic area  315 . The indication of the geographic area  315  may include, but is not limited to, an indication of a point and associated radius from the point, an indication of three or four corners (e.g., coordinates corresponding to a triangle, square, rectangle, rhombus, etc.), an indication of two coordinates and a corresponding radius (e.g., start and end coordinates of a line with a radius from the line), and the like. 
     VUE  305  may transmit the group paging indicator during the paging indicator pool  330  (e.g., using a resource from the paging indicator pool  330 ) of the DTX cycle. PUE  310  may monitor the paging indicator pool  330  for a paging indicator message from VUE  305  addressed to them. If the paging indicator is addressed to a PUE  310 , that PUE  310  may then monitor for a paging message (e.g., alert message) during the V2P resource pool  335 . 
     Accordingly, PUE  310  may receive the group paging indicator from VUE  305  during the paging indicator pool  330 . Each PUE  310  may identify the geographic area  315  indicated in the group paging indicator and then determine whether they are located within the geographic area  315 . In the non-limiting example illustrated in FIG.  3 , PUE  310 - a , PUE  310 - b , PUE  310 - c , and PUE  310 - d  may determine that they are located within the geographic area and, therefore, the group paging indicator is addressed to them. PUE  310 - e  may determine that it is not located in the geographic area  315  and, therefore, that the group paging indicator is not addressed to it. 
     PUE  310 - a , PUE  310 - b , PUE  310 - c , and PUE  310 - d  may, since the group paging indicator is addressed to them, monitor the V2P resource pool  335  for a paging message from VUE  305 . Accordingly, each addressed PUE  310  may receive the paging message from VUE  305  during a monitoring period (e.g., V2P resource pool  335 ) of the DTX cycle. 
       FIG.  4    illustrates an example of a process  400  that supports vehicle based wireless communications in accordance with aspects of the present disclosure. In some examples, process  400  may implement aspects of wireless communications systems  100 ,  200 , and/or  300 . Process  400  may be implemented by a first PUE  405  and/or a second PUE  410 , which may be examples of the corresponding devices described herein. 
     At  415 , first PUE  405  may detect a transmission over a sidelink channel from second PUE  410 . First PUE  405  may detect the transmission during a first transmission period of the DTX cycle, e.g., during a P2V resource pool period of a paging occasion in the DTX cycle. The transmission may carry or otherwise location information for second PUE  410 . In some aspects, this may include first PUE  405  being within a threshold distance (e.g., d) from second PUE  410 . For example, first PUE  405  may compare its location information with the location information of second PUE  410  indicated in the transmission to determine or otherwise identify that second PUE  410  is within the threshold distance d of first PUE  405 . 
     At  420 , first PUE  405  may determine or otherwise identify the ID of second PUE  410  (e.g., a second identifier in this example) based on the transmission. The ID of second PUE  410  may be different from the ID of first PUE  405  (e.g., a first identifier in this example). For example, first PUE  405  may decode and recover the ID of second PUE  410  from the transmission. 
     At  425 , first PUE  405  may use, based on second PUE  410  being located within the threshold distance d from first PUE  405 , the ID of second PUE  410  and the ID of first PUE  405  during one or more subsequent transmission periods of the DTX cycle (e.g., for N paging occasions). This may include first PUE  405  refraining from transmitting its own transmissions of its ID/location information during the N subsequent transmission periods (e.g., during the P2V resource pool periods of N paging occasions). Instead, first PUE  405  may monitor for an alert message (e.g., paging message or any other message) using its own ID in addition to the ID of second PUE  410  during the subsequent transmission periods. 
     In some aspects, this may include first PUE  405  transmitting or otherwise conveying an indication to second PUE  410  that first PUE  405  is using the ID of second PUE  410  during the subsequent transmission periods, e.g., a transmission over the sidelink channel. 
     In some aspects, this may include first PUE  405  identifying or otherwise determining a use period for using the ID of second PUE  410  and its own ID. The use period may generally correspond to N paging occasions in which first PUE  405  may use or otherwise adopt the ID of second PUE  410 . For example, the use period may be based on the separation distance between second PUE  410  and first PUE  405 , the travel speed/direction of first PUE  405  and/or second PUE  410 , and the like. Accordingly, the use period may be indefinite (e.g., so long as second PUE  410  is within the threshold distance d from first PUE  405 ) and/or may be more definite (e.g., based on a configurable use period, based on a fixed use period, and the like). 
       FIG.  5    illustrates an example of a process  500  that supports vehicle based wireless communications in accordance with aspects of the present disclosure. In some examples, process  500  may implement aspects of wireless communications systems  100 ,  200 , and/or  300 , and/or process  400 . Process  500  may be implemented by VUE  505  and/or PUE  510 , which may be examples of the corresponding devices described herein. In some examples, PUE  510  may be an example of a first UE and/or an additional UE and VUE  505  may be an example of a second UE. 
     At  515 , VUE  505  may identify a geographic area associated with transmitting a group paging indicator to one or more additional UE (e.g., which may include PUE  510 ) located within the geographic area. For example, VUE  505  may be approaching a crosswalk, corner, or some other area in which the additional UE(s) are located. It is to be understood that the geographic area is not limited to any particular crosswalk, corner, etc. Instead, the geographic area may simply be that VUE  505  determines that there is a PUE located on a collision course with VUE  505  (e.g., a pedestrian with an associated PUE is in, or likely to enter the path of travel of VUE  505 ). Accordingly, VUE  505  may determine that it needs to alert the PUE (such as PUE  510 ) to avoid a collision. 
     Accordingly and at  520 , VUE  505  may transmit (and PUE  510  may receive) a group paging indicator indicating the geographic area. The group paging indicator may be transmitted over a sidelink channel and during a DTX cycle. The indication of the geographic area in the group paging indicator may serve as the address list for the group paging indicator. That is, the indication of the geographic area in the group paging indicator may carry or otherwise convey an indication that the group paging indicator is addressed to the one or more additional UE (e.g., any UE/PUE) that are located within the geographic area. 
     In some aspects, the indication of the geographic area may include, but is not limited to, an indication of a point and associated radius from the point, an indication of three or four corners (e.g., coordinates corresponding to a triangle, square, rectangle, rhombus, etc.), an indication of two coordinates and a corresponding radius (e.g., start and end coordinates of a line with a radius from the line), and the like. 
     At  525 , PUE  510  may identify the geographic area from the indication conveyed in the group paging indicator. At  530 , PUE  510  may determine that it is within the geographic area indicated in the group paging indicator. For example, PUE  510  may identify or otherwise determine its location and then determine whether it is within the geographic area based on its location being within the geographic area. Therefore and at  535 , PUE  510  may determine that the group paging indicator is addressed to PUE  510  based on PUE  510  being located within the geographic area. 
     At  540 , VUE  505  may transmit (and PUE  510  may receive) a paging message during a monitoring period of the DTX cycle. That is, PUE  510  may monitor for the paging message since it has determined that it is located within the geographic area indicated in the group paging indicator. 
       FIG.  6    shows a block diagram  600  of a device  605  that supports vehicle based wireless communications in accordance with aspects of the present disclosure. The device  605  may be an example of aspects of a UE  115  as described herein. The device  605  may include a receiver  610 , a communications manager  615 , and a transmitter  620 . The device  605  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  610  may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to vehicle based wireless communications, etc.). Information may be passed on to other components of the device  605 . The receiver  610  may be an example of aspects of the transceiver  920  described with reference to  FIG.  9   . The receiver  610  may utilize a single antenna or a set of antennas. 
     The communications manager  615  may detect, during a first transmission period of a discontinuous transmission cycle, a transmission over a sidelink channel from a second UE that is located within a threshold distance from the first UE, the first UE associated with a first identifier, determine, based on the transmission, a second identifier associated with the second UE, the second identifier being different from the first identifier, and use, based on the second UE being within the threshold distance, the first identifier and the second identifier during one or more subsequent transmission periods of the discontinuous transmission cycle. 
     The communications manager  615  may also receive, during a transmission period of a discontinuous transmission cycle, a group paging indicator from a second UE over a sidelink channel, identify a geographic area indicated in the group paging indicator, determine that a location of the first UE is within the geographical area, determine, based on the first UE being located within the geographical area, that the group paging indicator is addressed to the first UE, and receive, during a monitoring period of the discontinuous transmission cycle, a paging message from the second UE. 
     The communications manager  615  may also identify a geographic area associated with transmitting a group paging indicator to one or more additional UE located within the geographic area, transmit, over a sidelink channel associated with a discontinuous transmission cycle, the group paging indicator indicating the geographical area, the indication of the geographical area indicating that the group paging indicator is addressed to the one or more additional UE that are located within the geographical area, and transmit, during a monitoring period of the discontinuous transmission cycle, a group paging message to the one or more additional UE. The communications manager  615  may be an example of aspects of the communications manager  910  described herein. 
     The communications manager  615 , or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager  615 , or its sub-components may be executed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. 
     The communications manager  615 , or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager  615 , or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager  615 , or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure. 
     The transmitter  620  may transmit signals generated by other components of the device  605 . In some examples, the transmitter  620  may be collocated with a receiver  610  in a transceiver. For example, the transmitter  620  may be an example of aspects of the transceiver  920  described with reference to  FIG.  9   . The transmitter  620  may utilize a single antenna or a set of antennas. 
       FIG.  7    shows a block diagram  700  of a device  705  that supports vehicle based wireless communications in accordance with aspects of the present disclosure. The device  705  may be an example of aspects of a device  605 , or a UE  115  as described herein. The device  705  may include a receiver  710 , a communications manager  715 , and a transmitter  730 . The device  705  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  710  may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to vehicle based wireless communications, etc.). Information may be passed on to other components of the device  705 . The receiver  710  may be an example of aspects of the transceiver  920  described with reference to  FIG.  9   . The receiver  710  may utilize a single antenna or a set of antennas. 
     The communications manager  715  may be an example of aspects of the communications manager  615  as described herein. The communications manager  715  may include an ID use manager  720  and a location based paging manager  725 . The communications manager  715  may be an example of aspects of the communications manager  910  described herein. 
     The ID use manager  720  may detect, during a first transmission period of a discontinuous transmission cycle, a transmission over a sidelink channel from a second UE that is located within a threshold distance from the first UE, the first UE associated with a first identifier, determine, based on the transmission, a second identifier associated with the second UE, the second identifier being different from the first identifier, and use, based on the second UE being within the threshold distance, the first identifier and the second identifier during one or more subsequent transmission periods of the discontinuous transmission cycle. 
     The location based paging manager  725  may receive, during a transmission period of a discontinuous transmission cycle, a group paging indicator from a second UE over a sidelink channel, identify a geographic area indicated in the group paging indicator, determine that a location of the first UE is within the geographical area, determine, based on the first UE being located within the geographical area, that the group paging indicator is addressed to the first UE, and receive, during a monitoring period of the discontinuous transmission cycle, a paging message from the second UE. 
     The location based paging manager  725  may identify a geographic area associated with transmitting a group paging indicator to one or more additional UE located within the geographic area, transmit, over a sidelink channel associated with a discontinuous transmission cycle, the group paging indicator indicating the geographical area, the indication of the geographical area indicating that the group paging indicator is addressed to the one or more additional UE that are located within the geographical area, and transmit, during a monitoring period of the discontinuous transmission cycle, a group paging message to the one or more additional UE. 
     The transmitter  730  may transmit signals generated by other components of the device  705 . In some examples, the transmitter  730  may be collocated with a receiver  710  in a transceiver. For example, the transmitter  730  may be an example of aspects of the transceiver  920  described with reference to  FIG.  9   . The transmitter  730  may utilize a single antenna or a set of antennas. 
       FIG.  8    shows a block diagram  800  of a communications manager  805  that supports vehicle based wireless communications in accordance with aspects of the present disclosure. The communications manager  805  may be an example of aspects of a communications manager  615 , a communications manager  715 , or a communications manager  910  described herein. The communications manager  805  may include an ID use manager  810 , an ID/location transmission manager  815 , a separation distance manager  820 , an alert manager  825 , an use indication manager  830 , an use period manager  835 , a location based paging manager  840 , and a geographic area indication manager  845 . Each of these components may communicate, directly or indirectly, with one another (e.g., via one or more buses). 
     The ID use manager  810  may detect, during a first transmission period of a discontinuous transmission cycle, a transmission over a sidelink channel from a second UE that is located within a threshold distance from the first UE, the first UE associated with a first identifier. In some examples, the ID use manager  810  may determine, based on the transmission, a second identifier associated with the second UE, the second identifier being different from the first identifier. In some examples, the ID use manager  810  may use, based on the second UE being within the threshold distance, the first identifier and the second identifier during one or more subsequent transmission periods of the discontinuous transmission cycle. In some cases, the transmission periods of the discontinuous transmission cycle includes V2P paging occasions. In some cases, the first UE and the second UE include pedestrian UEs. 
     The location based paging manager  840  may receive, during a transmission period of a discontinuous transmission cycle, a group paging indicator from a second UE over a sidelink channel. In some examples, the location based paging manager  840  may identify a geographic area indicated in the group paging indicator. In some examples, the location based paging manager  840  may determine that a location of the first UE is within the geographical area. In some examples, the location based paging manager  840  may determine, based on the first UE being located within the geographical area, that the group paging indicator is addressed to the first UE. In some examples, the location based paging manager  840  may receive, during a monitoring period of the discontinuous transmission cycle, a paging message from the second UE. 
     In some examples, the location based paging manager  840  may identify a geographic area associated with transmitting a group paging indicator to one or more additional UE located within the geographic area. In some examples, the location based paging manager  840  may transmit, over a sidelink channel associated with a discontinuous transmission cycle, the group paging indicator indicating the geographical area, the indication of the geographical area indicating that the group paging indicator is addressed to the one or more additional UE that are located within the geographical area. In some examples, the location based paging manager  840  may transmit, during a monitoring period of the discontinuous transmission cycle, a group paging message to the one or more additional UE. In some cases, the first UE includes a pedestrian UE and the second UE includes a vehicle based UE. In some cases, the UE includes a vehicle based UE and the one or more additional UE include one or more pedestrian UEs. 
     The ID/location transmission manager  815  may refrain, based on the using, from performing transmissions over the sidelink channel during the one or more subsequent transmission periods of the discontinuous transmission cycle. 
     The separation distance manager  820  may determine, based on the transmission, a separation distance between the second UE and the first UE, where the second UE being within the threshold distance from the first UE is based on the separation distance. 
     The alert manager  825  may monitor, during the one or more subsequent transmission periods, for an alert message associated with the first identifier and the second identifier. 
     The use indication manager  830  may transmit an indication to the second UE that the first UE has used the second identifier during the one or more subsequent transmission periods. 
     The use period manager  835  may determine a use period for using the first identifier with the second identifier, where the one or more subsequent transmission periods are based on the use period. In some cases, the use period is determined based on at least one of a separation distance between the second UE and the first UE, a travel speed of the first UE, a travel speed of the second UE, a travel direction of the first UE, a travel direction of the second UE, or a combination thereof. 
     The geographic area indication manager  845  may identify a coordinate and associated radius indicated in the group paging indicator. In some examples, the geographic area indication manager  845  may determine that the location of the first UE is within the radius of the coordinate. In some examples, the geographic area indication manager  845  may identify a set of coordinates defining the geographical area. In some examples, the geographic area indication manager  845  may determine, based on the set of coordinates, that the location of the first UE is within the geographic area. In some examples, configuring the group paging indicator to identify a coordinate and associated radius indicated in the group paging indicator to indicate the geographical area, where the one or more additional UE located within the radius of the coordinate includes the one or more additional UE being within the geographical area. In some examples, configuring the group paging indicator to identify a set of coordinates defining the geographical area, where the one or more additional UE located within the set of coordinates includes the one or more additional UE being within the geographical area. 
       FIG.  9    shows a diagram of a system  900  including a device  905  that supports vehicle based wireless communications in accordance with aspects of the present disclosure. The device  905  may be an example of or include the components of device  605 , device  705 , or a UE  115  as described herein. The device  905  may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager  910 , an I/O controller  915 , a transceiver  920 , an antenna  925 , memory  930 , and a processor  940 . These components may be in electronic communication via one or more buses (e.g., bus  945 ). 
     The communications manager  910  may detect, during a first transmission period of a discontinuous transmission cycle, a transmission over a sidelink channel from a second UE that is located within a threshold distance from the first UE, the first UE associated with a first identifier, determine, based on the transmission, a second identifier associated with the second UE, the second identifier being different from the first identifier, and use, based on the second UE being within the threshold distance, the first identifier and the second identifier during one or more subsequent transmission periods of the discontinuous transmission cycle. 
     The communications manager  910  may also receive, during a transmission period of a discontinuous transmission cycle, a group paging indicator from a second UE over a sidelink channel, identify a geographic area indicated in the group paging indicator, determine that a location of the first UE is within the geographical area, determine, based on the first UE being located within the geographical area, that the group paging indicator is addressed to the first UE, and receive, during a monitoring period of the discontinuous transmission cycle, a paging message from the second UE. 
     The communications manager  910  may also identify a geographic area associated with transmitting a group paging indicator to one or more additional UE located within the geographic area, transmit, over a sidelink channel associated with a discontinuous transmission cycle, the group paging indicator indicating the geographical area, the indication of the geographical area indicating that the group paging indicator is addressed to the one or more additional UE that are located within the geographical area, and transmit, during a monitoring period of the discontinuous transmission cycle, a group paging message to the one or more additional UE. 
     The I/O controller  915  may manage input and output signals for the device  905 . The I/O controller  915  may also manage peripherals not integrated into the device  905 . In some cases, the I/O controller  915  may represent a physical connection or port to an external peripheral. In some cases, the I/O controller  915  may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. In other cases, the I/O controller  915  may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller  915  may be implemented as part of a processor. In some cases, a user may interact with the device  905  via the I/O controller  915  or via hardware components controlled by the I/O controller  915 . 
     The transceiver  920  may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver  920  may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver  920  may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas. 
     In some cases, the wireless device may include a single antenna  925 . However, in some cases the device may have more than one antenna  925 , which may be capable of concurrently transmitting or receiving multiple wireless transmissions. 
     The memory  930  may include random access memory (RAM) and read-only memory (ROM). The memory  930  may store computer-readable, computer-executable code  935  including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory  930  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  940  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  940  may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor  940 . The processor  940  may be configured to execute computer-readable instructions stored in a memory (e.g., the memory  930 ) to cause the device  905  to perform various functions (e.g., functions or tasks supporting vehicle based wireless communications). 
     The code  935  may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code  935  may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code  935  may not be directly executable by the processor  940  but may cause a computer (e.g., when compiled and executed) to perform functions described herein. 
       FIG.  10    shows a flowchart illustrating a method  1000  that supports vehicle based wireless communications in accordance with aspects of the present disclosure. The operations of method  1000  may be implemented by a UE  115  or its components as described herein. For example, the operations of method  1000  may be performed by a communications manager as described with reference to  FIGS.  6  through  9   . In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware. 
     At  1005 , the UE may detect, during a first transmission period of a discontinuous transmission cycle, a transmission over a sidelink channel from a second UE that is located within a threshold distance from the first UE, the first UE associated with a first identifier. The operations of  1005  may be performed according to the methods described herein. In some examples, aspects of the operations of  1005  may be performed by an ID use manager as described with reference to  FIGS.  6  through  9   . 
     At  1010 , the UE may determine, based on the transmission, a second identifier associated with the second UE, the second identifier being different from the first identifier. The operations of  1010  may be performed according to the methods described herein. In some examples, aspects of the operations of  1010  may be performed by an ID use manager as described with reference to  FIGS.  6  through  9   . 
     At  1015 , the UE may use, based on the second UE being within the threshold distance, the first identifier and the second identifier during one or more subsequent transmission periods of the discontinuous transmission cycle. The operations of  1015  may be performed according to the methods described herein. In some examples, aspects of the operations of  1015  may be performed by an ID use manager as described with reference to  FIGS.  6  through  9   . 
       FIG.  11    shows a flowchart illustrating a method  1100  that supports vehicle based wireless communications in accordance with aspects of the present disclosure. The operations of method  1100  may be implemented by a UE  115  or its components as described herein. For example, the operations of method  1100  may be performed by a communications manager as described with reference to  FIGS.  6  through  9   . In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware. 
     At  1105 , the UE may detect, during a first transmission period of a discontinuous transmission cycle, a transmission over a sidelink channel from a second UE that is located within a threshold distance from the first UE, the first UE associated with a first identifier. The operations of  1105  may be performed according to the methods described herein. In some examples, aspects of the operations of  1105  may be performed by an ID use manager as described with reference to  FIGS.  6  through  9   . 
     At  1110 , the UE may determine, based on the transmission, a second identifier associated with the second UE, the second identifier being different from the first identifier. The operations of  1110  may be performed according to the methods described herein. In some examples, aspects of the operations of  1110  may be performed by an ID use manager as described with reference to  FIGS.  6  through  9   . 
     At  1115 , the UE may use, based on the second UE being within the threshold distance, the first identifier and the second identifier during one or more subsequent transmission periods of the discontinuous transmission cycle. The operations of  1115  may be performed according to the methods described herein. In some examples, aspects of the operations of  1115  may be performed by an ID use manager as described with reference to  FIGS.  6  through  9   . 
     At  1120 , the UE may refrain, based on the using, from performing transmissions over the sidelink channel during the one or more subsequent transmission periods of the discontinuous transmission cycle. The operations of  1120  may be performed according to the methods described herein. In some examples, aspects of the operations of  1120  may be performed by an ID/location transmission manager as described with reference to  FIGS.  6  through  9   . 
       FIG.  12    shows a flowchart illustrating a method  1200  that supports vehicle based wireless communications in accordance with aspects of the present disclosure. The operations of method  1200  may be implemented by a UE  115  or its components as described herein. For example, the operations of method  1200  may be performed by a communications manager as described with reference to  FIGS.  6  through  9   . In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware. 
     At  1205 , the UE may detect, during a first transmission period of a discontinuous transmission cycle, a transmission over a sidelink channel from a second UE that is located within a threshold distance from the first UE, the first UE associated with a first identifier. The operations of  1205  may be performed according to the methods described herein. In some examples, aspects of the operations of  1205  may be performed by an ID use manager as described with reference to  FIGS.  6  through  9   . 
     At  1210 , the UE may determine, based on the transmission, a second identifier associated with the second UE, the second identifier being different from the first identifier. The operations of  1210  may be performed according to the methods described herein. In some examples, aspects of the operations of  1210  may be performed by an ID use manager as described with reference to  FIGS.  6  through  9   . 
     At  1215 , the UE may use, based on the second UE being within the threshold distance, the first identifier and the second identifier during one or more subsequent transmission periods of the discontinuous transmission cycle. The operations of  1215  may be performed according to the methods described herein. In some examples, aspects of the operations of  1215  may be performed by an ID use manager as described with reference to  FIGS.  6  through  9   . 
     At  1220 , the UE may monitor, during the one or more subsequent transmission periods, for an alert message associated with the first identifier and the second identifier. The operations of  1220  may be performed according to the methods described herein. In some examples, aspects of the operations of  1220  may be performed by an alert manager as described with reference to  FIGS.  6  through  9   . 
       FIG.  13    shows a flowchart illustrating a method  1300  that supports vehicle based wireless communications in accordance with aspects of the present disclosure. The operations of method  1300  may be implemented by a UE  115  or its components as described herein. For example, the operations of method  1300  may be performed by a communications manager as described with reference to  FIGS.  6  through  9   . In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware. 
     At  1305 , the UE may receive, during a transmission period of a discontinuous transmission cycle, a group paging indicator from a second UE over a sidelink channel. The operations of  1305  may be performed according to the methods described herein. In some examples, aspects of the operations of  1305  may be performed by a location based paging manager as described with reference to  FIGS.  6  through  9   . 
     At  1310 , the UE may identify a geographic area indicated in the group paging indicator. The operations of  1310  may be performed according to the methods described herein. In some examples, aspects of the operations of  1310  may be performed by a location based paging manager as described with reference to  FIGS.  6  through  9   . 
     At  1315 , the UE may determine that a location of the first UE is within the geographical area. The operations of  1315  may be performed according to the methods described herein. In some examples, aspects of the operations of  1315  may be performed by a location based paging manager as described with reference to  FIGS.  6  through  9   . 
     At  1320 , the UE may determine, based on the first UE being located within the geographical area, that the group paging indicator is addressed to the first UE. The operations of  1320  may be performed according to the methods described herein. In some examples, aspects of the operations of  1320  may be performed by a location based paging manager as described with reference to  FIGS.  6  through  9   . 
     At  1325 , the UE may receive, during a monitoring period of the discontinuous transmission cycle, a paging message from the second UE. The operations of  1325  may be performed according to the methods described herein. In some examples, aspects of the operations of  1325  may be performed by a location based paging manager as described with reference to  FIGS.  6  through  9   . 
       FIG.  14    shows a flowchart illustrating a method  1400  that supports vehicle based wireless communications in accordance with aspects of the present disclosure. The operations of method  1400  may be implemented by a UE  115  or its components as described herein. For example, the operations of method  1400  may be performed by a communications manager as described with reference to  FIGS.  6  through  9   . In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware. 
     At  1405 , the UE may identify a geographic area associated with transmitting a group paging indicator to one or more additional UE located within the geographic area. The operations of  1405  may be performed according to the methods described herein. In some examples, aspects of the operations of  1405  may be performed by a location based paging manager as described with reference to  FIGS.  6  through  9   . 
     At  1410 , the UE may transmit, over a sidelink channel associated with a discontinuous transmission cycle, the group paging indicator indicating the geographical area, the indication of the geographical area indicating that the group paging indicator is addressed to the one or more additional UE that are located within the geographical area. The operations of  1410  may be performed according to the methods described herein. In some examples, aspects of the operations of  1410  may be performed by a location based paging manager as described with reference to  FIGS.  6  through  9   . 
     At  1415 , the UE may transmit, during a monitoring period of the discontinuous transmission cycle, a group paging message to the one or more additional UE. The operations of  1415  may be performed according to the methods described herein. In some examples, aspects of the operations of  1415  may be performed by a location based paging manager as described with reference to  FIGS.  6  through  9   . 
     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 non-transitory computer storage media. 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 random-access memory (RAM), read-only memory (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. 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. 
     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.” 
     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.