Patent Publication Number: US-2023144860-A1

Title: Radar-assisted beam failure avoidance in nlos environments

Description:
INTRODUCTION 
     The present disclosure relates generally to communication systems, and more particularly, to beam failure avoidance techniques. 
     Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems. 
     These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G New Radio (NR). 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT)), and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low latency communication (URLLC). Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies. 
     BRIEF SUMMARY 
     The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later. 
     In an aspect of the disclosure, an apparatus for wireless communication at a first wireless device is provided. The apparatus includes a memory and at least one processor coupled to the memory, the memory and the at least one processor are configured to receive, from a second wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device; and perform radar detection for the potential obstruction to the set of one or more beams for the wireless communication with the second wireless device. 
     In another aspect of the disclosure, a method of wireless communication at a first wireless device is provided. The method includes receiving, from a second wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device; and performing radar detection for the potential obstruction to the set of one or more beams for the wireless communication with the second wireless device. 
     In another aspect of the disclosure, an apparatus for wireless communication at a first wireless device is provided. The apparatus includes means for receiving, from a second wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for the wireless communication with the second wireless device; and means for performing radar detection for the potential obstruction to the set of one or more beams for the wireless communication with the second wireless device. 
     In another aspect of the disclosure, a non-transitory computer-readable storage medium at a first wireless device is provided. The non-transitory computer-readable storage medium is configured to receive, from a second wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for the wireless communication with the second wireless device; and perform radar detection for the potential obstruction to the set of one or more beams for the wireless communication with the second wireless device. 
     In an aspect of the disclosure, an apparatus for wireless communication at a second wireless device is provided. The apparatus includes a memory and at least one processor coupled to the memory, the memory and the at least one processor are configured to transmit, to a first wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device; and receive, from the first wireless device, information based on radar measurement associated with the set of one or more beams for the wireless communication with the second wireless device. 
     In another aspect of the disclosure, a method of wireless communication at a second wireless device is provided. The method includes transmitting, to a first wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device; and receiving, from the first wireless device, information based on radar measurement associated with the set of one or more beams for the wireless communication with the second wireless device. 
     In another aspect of the disclosure, an apparatus for wireless communication at a second wireless device is provided. The apparatus includes means for transmitting, to a first wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device; and receive, from the first wireless device, information based on radar measurement associated with the set of one or more beams for the wireless communication with the second wireless device. 
     In another aspect of the disclosure, a non-transitory computer-readable storage medium at a second wireless device is provided. The non-transitory computer-readable storage medium is configured to transmit, to a first wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device; and receive, from the first wireless device, information based on radar measurement associated with the set of one or more beams for the wireless communication with the second wireless device. 
     To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a diagram illustrating an example of a wireless communications system and an access network, in accordance with aspects presented herein. 
         FIG.  2 A  is a diagram illustrating an example of a first frame, in accordance with various aspects of the present disclosure. 
         FIG.  2 B  is a diagram illustrating an example of downlink (DL) channels within a subframe, in accordance with various aspects of the present disclosure. 
         FIG.  2 C  is a diagram illustrating an example of a second frame, in accordance with various aspects of the present disclosure. 
         FIG.  2 D  is a diagram illustrating an example of uplink (UL) channels within a subframe, in accordance with various aspects of the present disclosure. 
         FIG.  3    is a diagram illustrating an example of a first wireless device and a second wireless device in an access network, in accordance with aspects presented herein. 
         FIG.  4    is a call flow diagram illustrating communications between a first wireless device and a second wireless device, in accordance with aspects presented herein. 
         FIGS.  5 A- 5 B  illustrate diagrams of a predicted future obstruction to a communication link between a UE and a base station, in accordance with aspects presented herein. 
         FIG.  6    illustrates a diagram associated with an obstruction that occurs within a line-of-sight (LoS) portion of a communication link of a base station, in accordance with aspects presented herein. 
         FIG.  7    illustrates a diagram associated with an obstruction that occurs within a non-line-of-sight (NLoS) portion of a communication link of a base station, in accordance with aspects presented herein. 
         FIG.  8    is a flowchart of a method of wireless communication at a first wireless device, in accordance with aspects presented herein. 
         FIG.  9    is a flowchart of a method of wireless communication at a first wireless device, in accordance with aspects presented herein. 
         FIG.  10    is a flowchart of a method of wireless communication at a second wireless device, in accordance with aspects presented herein. 
         FIG.  11    is a flowchart of a method of wireless communication at a second wireless device, in accordance with aspects presented herein. 
         FIG.  12    is a diagram illustrating an example of a hardware implementation for an example apparatus, in accordance with aspects presented herein. 
         FIG.  13    is a diagram illustrating an example of a hardware implementation for an example apparatus, in accordance with aspects presented herein. 
         FIG.  14    illustrates example aspects of radar detection, in accordance with aspects presented herein. 
     
    
    
     DETAILED DESCRIPTION 
     In dynamic communication environments, such as environments associated with vehicular networks, a first wireless device and a second wireless device may communicate with each other over a communication link having a path that reflects off an object within the communication environment. For example, a base station may transmit a beam in a beam direction that causes the beam to reflect off an object, such as a building, prior to being received by a user equipment (UE). A location at which the beam reflects off the object may be referred to herein as a “reflection point”. In some cases, the portion of the communication path that corresponds to locations after the reflection point of the beam may be non-line-of-sight (NLoS) portions of communication link for the base station. 
     Objects, such as vehicles, that move about the communication environment may occasionally cross the path of the communication link between the base station and the UE, which may cause a beam failure between the UE and the base station. In some configurations, the base station may include a radar device that may be utilized to predict that an object is going to block/obstruct the communication link between the base station and the UE. Based on the predicted obstruction, the base station may proactively switch to a different communication beam with the UE before the obstruction occurs in order to avoid a potential beam failure. 
     While a radar device at the base station may be used to predict a blockage/obstruction of the communication link, such predictions may only be performed for the LoS portion of the communication link. That is, the radar device at the base station may be unable to sense object trajectories that are not within a direct line-of-sight (LoS) of the radar device. 
     Aspects presented herein provide for improved beam management with a first wireless device and a second wireless device. As presented herein, the second wireless device, such as a base station, may configure the first wireless device, such as a UE, to monitor a set of receive beams of the UE from a perspective of the UE and to provide information to the base station about anticipated UE receive beam blockages. In further examples, the UE may monitor a set of transmit beams from a perspective of the UE to provide information to the base station about anticipated UE transmit beam blockages. The perspective of the UE may correspond to a field of view of the UE (e.g., for performing beam detection) based on a particular location/position of the UE in a communication environment. Thus, the perspective of the UE may change as the particular location/position of the UE changes within the communication environment. In an example, the perspective of the UE may allow the UE to receive a beam from the base station that includes a reflected portion of the beam that is not within a field of view of the base station upon transmission of the beam, as the base station may have a different perspective of the communication environment than the UE. 
     The UE may perform radar measurements to detect potential receive beam blockages, and if a potential receive beam blockage is detected from the UE&#39;s perspective, the UE may inform the base station so that the base station may switch to a different transmission beam for communicating with the UE. Beam blockage/beam blocking refers to an object that obstructs the communication path of the beams communicated between the first wireless device and the second wireless device, where the communication path may have a LoS portion and a NLoS portion that are separated via the reflection point of the communicated beams. Thus, the base station may adjust for a potential beam blockage that is not detected from the base station&#39;s perspective. For example, the base station may configure the UE to monitor a set of beams in a NLoS portion of the communication path. If the UE detects (e.g., based on a radar device located at the UE) that an object is predicted to block/obstruct the NLoS portion of the communication path, the UE may report such information to the base station. The base station may use the reported information to switch to a different communication beam with the UE (e.g., different base station transmit beam) prior to the obstruction occurring in association with the NLoS portion of the communication path, which may avoid a potential beam failure between the UE and the base station. Accordingly, such techniques may be performed to reduce a number of beam failures experienced between the base station and the UE, which may improve an overall reliability of such communications. 
     The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts. 
     Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. 
     By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. 
     Accordingly, in one or more examples, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer. 
     While aspects and implementations are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Aspects described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, implementations and/or uses may come about via integrated chip implementations and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, artificial intelligence (AI)-enabled devices, etc.). While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described aspects may occur. Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more aspects of the described aspects. In some practical settings, devices incorporating described aspects and features may also include additional components and features for implementation and practice of claimed and described aspect. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including antenna, RF-chains, power amplifiers, modulators, buffer, processor(s), interleaver, adders/summers, etc.). It is intended that aspects described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc. of varying sizes, shapes, and constitution. 
       FIG.  1    is a diagram illustrating an example of a wireless communications system and an access network  100 . The wireless communications system (also referred to as a wireless wide area network (WWAN)) includes base stations  102 , user equipments (UEs)  104 , an Evolved Packet Core (EPC)  160 , and another core network  190  (e.g., a 5G Core (5GC)). The base stations  102  may include macrocells (high power cellular base station) and/or small cells (low power cellular base station). The macrocells include base stations. The small cells include femtocells, picocells, and microcells. 
     The base stations  102  configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC  160  through first backhaul links  132  (e.g., S1 interface). The base stations  102  configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN)) may interface with core network  190  through second backhaul links  184 . In addition to other functions, the base stations  102  may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations  102  may communicate directly or indirectly (e.g., through the EPC  160  or core network  190 ) with each other over third backhaul links  134  (e.g., X2 interface). The first backhaul links  132 , the second backhaul links  184  (e.g., Xn interface), and the third backhaul links  134  may be wired or wireless. 
     In some aspects, a base station  102  or  180  may be referred as a RAN and may include aggregated or disaggregated components. As an example of a disaggregated RAN, a base station may include a central unit (CU)  106 , one or more distributed units (DU)  105 , and/or one or more remote units (RU)  109 , as illustrated in  FIG.  1   . A RAN may be disaggregated with a split between an RU  109  and an aggregated CU/DU. A RAN may be disaggregated with a split between the CU  106 , the DU  105 , and the RU  109 . A RAN may be disaggregated with a split between the CU  106  and an aggregated DU/RU. The CU  106  and the one or more DUs  105  may be connected via an F1 interface. A DU  105  and an RU  109  may be connected via a fronthaul interface. A connection between the CU  106  and a DU  105  may be referred to as a midhaul, and a connection between a DU  105  and an RU  109  may be referred to as a fronthaul. The connection between the CU  106  and the core network may be referred to as the backhaul. The RAN may be based on a functional split between various components of the RAN, e.g., between the CU  106 , the DU  105 , or the RU  109 . The CU may be configured to perform one or more aspects of a wireless communication protocol, e.g., handling one or more layers of a protocol stack, and the DU(s) may be configured to handle other aspects of the wireless communication protocol, e.g., other layers of the protocol stack. In different implementations, the split between the layers handled by the CU and the layers handled by the DU may occur at different layers of a protocol stack. As one, non-limiting example, a DU  105  may provide a logical node to host a radio link control (RLC) layer, a medium access control (MAC) layer, and at least a portion of a physical (PHY) layer based on the functional split. An RU may provide a logical node configured to host at least a portion of the PHY layer and radio frequency (RF) processing. A CU  106  may host higher layer functions, e.g., above the RLC layer, such as a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer. In other implementations, the split between the layer functions provided by the CU, DU, or RU may be different. 
     An access network may include one or more integrated access and backhaul (IAB) nodes  111  that exchange wireless communication with a UE  104  or other IAB node  111  to provide access and backhaul to a core network. In an IAB network of multiple IAB nodes, an anchor node may be referred to as an IAB donor. The IAB donor may be a base station  102  or  180  that provides access to a core network  190  or EPC  160  and/or control to one or more IAB nodes  111 . The IAB donor may include a CU  106  and a DU  105 . IAB nodes  111  may include a DU  105  and a mobile termination (MT). The DU  105  of an IAB node  111  may operate as a parent node, and the MT may operate as a child node. 
     The base stations  102  may wirelessly communicate with the UEs  104 . Each of the base stations  102  may provide communication coverage for a respective geographic coverage area  110 . There may be overlapping geographic coverage areas  110 . For example, the small cell  102 ′ may have a coverage area  110 ′ that overlaps the coverage area  110  of one or more macro base stations  102 . A network that includes both small cell and macrocells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG). The communication links  120  between the base stations  102  and the UEs  104  may include uplink (UL) (also referred to as reverse link) transmissions from a UE  104  to a base station  102  and/or downlink (DL) (also referred to as forward link) transmissions from a base station  102  to a UE  104 . The communication links  120  may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations  102 /UEs  104  may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL). The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell). 
     Certain UEs  104  may communicate with each other using device-to-device (D2D) communication link  158 . The D2D communication link  158  may use the DL/UL WWAN spectrum. The D2D communication link  158  may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication may be through a variety of wireless D2D communications systems, such as for example, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR. 
     Some examples of sidelink communication may include vehicle-based communication devices that can communicate from vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I) (e.g., from the vehicle-based communication device to road infrastructure nodes such as a roadside unit (RSU)), vehicle-to-network (V2N) (e.g., from the vehicle-based communication device to one or more network nodes, such as a base station), vehicle-to-pedestrian (V2P), cellular vehicle-to-everything (C-V2X), and/or a combination thereof and/or with other devices, which can be collectively referred to as vehicle-to-anything (V2X) communications. Sidelink communication may be based on V2X or other D2D communication, such as Proximity Services (ProSe), etc. In addition to UEs, sidelink communication may also be transmitted and received by other transmitting and receiving devices, such as RSU  107 , etc. Sidelink communication may be exchanged using a PC5 interface. 
     The wireless communications system may further include a Wi-Fi access point (AP)  150  in communication with Wi-Fi stations (STAs)  152  via communication links  154 , e.g., in a 5 GHz unlicensed frequency spectrum or the like. When communicating in an unlicensed frequency spectrum, the STAs  152 /AP  150  may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available. 
     The small cell  102 ′ may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell  102 ′ may employ NR and use the same unlicensed frequency spectrum (e.g., 5 GHz, or the like) as used by the Wi-Fi AP  150 . The small cell  102 ′, employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network. 
     The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz-300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band. 
     The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Recent 5G NR studies have identified an operating band for these mid-band frequencies as frequency range designation FR3 (7.125 GHz-24.25 GHz). Frequency bands falling within FR3 may inherit FR1 characteristics and/or FR2 characteristics, and thus may effectively extend features of FR1 and/or FR2 into mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operation beyond 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR2-2 (52.6 GHz-71 GHz), FR4 (52.6 GHz-114.25 GHz), and FR5 (114.25 GHz-300 GHz). Each of these higher frequency bands falls within the EHF band. 
     With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like if used herein may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, FR4, FR2-2, and/or FR5, or may be within the EHF band. 
     A base station  102 , whether a small cell  102 ′ or a large cell (e.g., macro base station), may include and/or be referred to as an eNB, gNodeB (gNB), or another type of base station. Some base stations, such as gNB may operate in a traditional sub 6 GHz spectrum, in millimeter wave frequencies, and/or near millimeter wave frequencies in communication with the UE  104 . When the gNB operates in millimeter wave or near millimeter wave frequencies, the gNB may be referred to as a millimeter wave base station. The millimeter wave base station  180  may utilize beamforming  182  with the UE  104  to compensate for the path loss and short range. The base station  180  and the UE  104  may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming. 
     The base station  180  may transmit a beamformed signal to the UE  104  in one or more transmit directions  182 ′. The UE  104  may receive the beamformed signal from the base station  180  in one or more receive directions  182 ″. The UE  104  may also transmit a beamformed signal to the base station  180  in one or more transmit directions. The base station  180  may receive the beamformed signal from the UE  104  in one or more receive directions. The base station  180 /UE  104  may perform beam training to determine the best receive and transmit directions for each of the base station  180 /UE  104 . The transmit and receive directions for the base station  180  may or may not be the same. The transmit and receive directions for the UE  104  may or may not be the same. 
     The EPC  160  may include a Mobility Management Entity (MME)  162 , other MMEs  164 , a Serving Gateway  166 , a Multimedia Broadcast Multicast Service (MBMS) Gateway  168 , a Broadcast Multicast Service Center (BM-SC)  170 , and a Packet Data Network (PDN) Gateway  172 . The MME  162  may be in communication with a Home Subscriber Server (HSS)  174 . The MME  162  is the control node that processes the signaling between the UEs  104  and the EPC  160 . Generally, the MME  162  provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway  166 , which itself is connected to the PDN Gateway  172 . The PDN Gateway  172  provides UE IP address allocation as well as other functions. The PDN Gateway  172  and the BM-SC  170  are connected to the IP Services  176 . The IP Services  176  may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, and/or other IP services. The BM-SC  170  may provide functions for MBMS user service provisioning and delivery. The BM-SC  170  may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway  168  may be used to distribute MBMS traffic to the base stations  102  belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information. 
     The core network  190  may include an Access and Mobility Management Function (AMF)  192 , other AMFs  193 , a Session Management Function (SMF)  194 , and a User Plane Function (UPF)  195 . The AMF  192  may be in communication with a Unified Data Management (UDM)  196 . The AMF  192  is the control node that processes the signaling between the UEs  104  and the core network  190 . Generally, the AMF  192  provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF  195 . The UPF  195  provides UE IP address allocation as well as other functions. The UPF  195  is connected to the IP Services  197 . The IP Services  197  may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a Packet Switch (PS) Streaming (PSS) Service, and/or other IP services. 
     The base station may include and/or be referred to as a gNB, Node B, eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit reception point (TRP), or some other suitable terminology. The base station  102  provides an access point to the EPC  160  or core network  190  for a UE  104 . Examples of UEs  104  include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs  104  may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc.). The UE  104  may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. In some scenarios, the term UE may also apply to one or more companion devices such as in a device constellation arrangement. One or more of these devices may collectively access the network and/or individually access the network. 
     Referring again to  FIG.  1   , in certain aspects, a first wireless device, such as the UE  104 , may include a beam monitoring component  198  configured to receive a configuration from a second wireless device, such as the base station  102 , UE  104 , RSU  107 , IAB node  111 , or other device, to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device; and perform radar detection for the potential obstruction to the set of one or more beams for the wireless communication with the second wireless device. As an example, a UE  104  may receive such a configuration when in a non-line of sight (NLOS) condition with the base station  102 . In certain aspects, the base station  180 , a UE  104 , an RSU  107 , or other device may include a NLoS configuration component  199  configured to transmit, to a first wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device; and receive, from the first wireless device, information based on radar measurement associated with the set of one or more beams for the wireless communication with the second wireless device. Although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies. 
       FIG.  2 A  is a diagram  200  illustrating an example of a first subframe within a 5G NR frame structure.  FIG.  2 B  is a diagram  230  illustrating an example of DL channels within a 5G NR subframe.  FIG.  2 C  is a diagram  250  illustrating an example of a second subframe within a 5G NR frame structure.  FIG.  2 D  is a diagram  280  illustrating an example of UL channels within a 5G NR subframe. The 5G NR frame structure may be frequency division duplexed (FDD) in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for either DL or UL, or may be time division duplexed (TDD) in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for both DL and UL. In the examples provided by  FIGS.  2 A,  2 C , the 5G NR frame structure is assumed to be TDD, with subframe 4 being configured with slot format 28 (with mostly DL), where D is DL, U is UL, and F is flexible for use between DL/UL, and subframe 3 being configured with slot format 1 (with all UL). While subframes 3, 4 are shown with slot formats 1, 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. UEs are configured with the slot format (dynamically through DL control information (DCI), or semi-statically/statically through radio resource control (RRC) signaling) through a received slot format indicator (SFI). Note that the description infra applies also to a 5G NR frame structure that is TDD. 
       FIGS.  2 A- 2 D  illustrate a frame structure, and the aspects of the present disclosure may be applicable to other wireless communication technologies, which may have a different frame structure and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms). Each subframe may include one or more time slots. Subframes may also include mini-slots, which may include 7, 4, or 2 symbols. Each slot may include 14 or 12 symbols, depending on whether the cyclic prefix (CP) is normal or extended. For normal CP, each slot may include 14 symbols, and for extended CP, each slot may include 12 symbols. The symbols on DL may be CP orthogonal frequency division multiplexing (OFDM) (CP-OFDM) symbols. The symbols on UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also referred to as single carrier frequency-division multiple access (SC-FDMA) symbols) (for power limited scenarios; limited to a single stream transmission). The number of slots within a subframe is based on the CP and the numerology. The numerology defines the subcarrier spacing (SCS) and, effectively, the symbol length/duration, which is equal to 1/SCS. 
     
       
         
           
               
               
               
             
               
                   
               
               
                   
                 SCS 
                   
               
               
                 μ 
                 Δf = 2 μ  · 15 [kHz] 
                 Cyclic prefix 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 0 
                 15 
                 Normal 
               
               
                 1 
                 30 
                 Normal 
               
               
                 2 
                 60 
                 Normal, 
               
               
                   
                   
                 Extended 
               
               
                 3 
                 120 
                 Normal 
               
               
                 4 
                 240 
                 Normal 
               
               
                   
               
            
           
         
       
     
     For normal CP (14 symbols/slot), different numerologies μ 0 to 4 allow for 1, 2, 4, 8, and 16 slots, respectively, per subframe. For extended CP, the numerology 2 allows for 4 slots per subframe. Accordingly, for normal CP and numerology μ, there are 14 symbols/slot and 2 μ  slots/subframe. The subcarrier spacing may be equal to 2 μ *15 kHz, where μ is the numerology 0 to 4. As such, the numerology μ=0 has a subcarrier spacing of 15 kHz and the numerology μ=4 has a subcarrier spacing of 240 kHz. The symbol length/duration is inversely related to the subcarrier spacing.  FIGS.  2 A- 2 D  provide an example of normal CP with 14 symbols per slot and numerology μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a set of frames, there may be one or more different bandwidth parts (BWPs) (see  FIG.  2 B ) that are frequency division multiplexed. Each BWP may have a particular numerology and CP (normal or extended). 
     A resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs)) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme. 
     As illustrated in  FIG.  2 A , some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include demodulation RS (DM-RS) (indicated as R for one particular configuration, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS), beam refinement RS (BRRS), and phase tracking RS (PT-RS). 
       FIG.  2 B  illustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs), each CCE including six RE groups (REGs), each REG including 12 consecutive REs in an OFDM symbol of an RB. A PDCCH within one BWP may be referred to as a control resource set (CORESET). A UE is configured to monitor PDCCH candidates in a PDCCH search space (e.g., common search space, UE-specific search space) during PDCCH monitoring occasions on the CORESET, where the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs may be located at greater and/or lower frequencies across the channel bandwidth. A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE  104  to determine subframe/symbol timing and a physical layer identity. A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the DM-RS. The physical broadcast channel (PBCH), which carries a master information block (MIB), may be logically grouped with the PSS and SSS to form a synchronization signal (SS)/PBCH block (also referred to as SS block (SSB)). The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs), and paging messages. 
     As illustrated in  FIG.  2 C , some of the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS may be transmitted in the first one or two symbols of the PUSCH. The PUCCH DM-RS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. The UE may transmit sounding reference signals (SRS). The SRS may be transmitted in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL. 
       FIG.  2 D  illustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and hybrid automatic repeat request (HARQ) acknowledgment (ACK) (HARQ-ACK) feedback (i.e., one or more HARQ ACK bits indicating one or more ACK and/or negative ACK (NACK)). The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and/or UCI. 
       FIG.  3    is a block diagram of a first wireless communication device  310  in communication with a second wireless communication device  350 . In some aspects, the first wireless device may be a base station, IAB node, RSU, or other network node in an access network, and the second wireless device may be a UE. In other aspects, the first wireless device may be a UE and the second wireless device may be a UE. The communication between the devices may be based on an access link, e.g., Uu interface, or sidelink, e.g., PC5 interface. In the DL, IP packets from the EPC  160  may be provided to a controller/processor  375 . The controller/processor  375  implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor  375  provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. 
     The transmit (TX) processor  316  and the receive (RX) processor  370  implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor  316  handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator  374  may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the device  350 . Each spatial stream may then be provided to a different antenna  320  via a separate transmitter  318  TX. Each transmitter  318  TX may modulate a radio frequency (RF) carrier with a respective spatial stream for transmission. 
     At the device  350 , each receiver  354  RX receives a signal through its respective antenna  352 . Each receiver  354  RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor  356 . The TX processor  368  and the RX processor  356  implement layer 1 functionality associated with various signal processing functions. The RX processor  356  may perform spatial processing on the information to recover any spatial streams destined for the device  350 . If multiple spatial streams are destined for the device  350 , they may be combined by the RX processor  356  into a single OFDM symbol stream. The RX processor  356  then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the device  310 . These soft decisions may be based on channel estimates computed by the channel estimator  358 . The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the device  310  on the physical channel. The data and control signals are then provided to the controller/processor  359 , which implements layer 3 and layer 2 functionality. 
     The controller/processor  359  can be associated with a memory  360  that stores program codes and data. The memory  360  may be referred to as a computer-readable medium. In the UL, the controller/processor  359  provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC  160 . The controller/processor  359  is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations. 
     Similar to the functionality described in connection with the DL transmission by the device  310 , the controller/processor  359  provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. 
     Channel estimates derived by a channel estimator  358  from a reference signal or feedback transmitted by the device  310  may be used by the TX processor  368  to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor  368  may be provided to different antenna  352  via separate transmitters  354 TX. Each transmitter  354 TX may modulate an RF carrier with a respective spatial stream for transmission. 
     The UL transmission is processed at the device  310  in a manner similar to that described in connection with the receiver function at the device  350 . Each receiver  318 RX receives a signal through its respective antenna  320 . Each receiver  318 RX recovers information modulated onto an RF carrier and provides the information to a RX processor  370 . 
     The controller/processor  375  can be associated with a memory  376  that stores program codes and data. The memory  376  may be referred to as a computer-readable medium. In the UL, the controller/processor  375  provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the device  350 . IP packets from the controller/processor  375  may be provided to the EPC  160 . The controller/processor  375  is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations. 
     At least one of the TX processor  368 , the RX processor  356 , and the controller/processor  359  may be configured to perform aspects in connection with the beam monitoring component  198  of  FIG.  1   . The device  350  may include a radar component  301 , or may receive information based on measurements of the radar component  301 . 
     At least one of the TX processor  316 , the RX processor  370 , and the controller/processor  375  may be configured to perform aspects in connection with the NLoS configuration component  199  of  FIG.  1   . The device  310  may include a radar component  301 , or may receive information based on measurements of the radar component  301 . 
     Wireless communication systems may be configured to share available system resources and provide various telecommunication services (e.g., telephony, video, data, messaging, broadcasts, etc.) based on multiple-access technologies such as CDMA systems, TDMA systems, FDMA systems, OFDMA systems, SC-FDMA systems, TD-SCDMA systems, etc. that support communication with multiple users. In many cases, common protocols that facilitate communications with wireless devices are adopted in various telecommunication standards. For example, communication methods associated with eMBB, mMTC, and ultra-reliable low latency communication (URLLC) may be incorporated in the 5G NR telecommunication standard, while other aspects may be incorporated in the 4G LTE standard. As mobile broadband technologies are part of a continuous evolution, further improvements in mobile broadband remain useful to continue the progression of such technologies. 
       FIG.  4    is a call flow diagram  400  illustrating communications between a first wireless device  402  (e.g., UE) and a second wireless device  404  (e.g., base station, RSU, UE, IAB node). The first wireless device  402  and/or the second wireless device  404  may include a radar component  301  or may receive information from a radar component. The example will be described for a base station and a UE to illustrate the concept. However, the example of a base station and a UE is merely one example of a first wireless device and a second wireless device, and the aspects presented herein may be similarly applied for a second wireless device that is an RSU, an IAB node, another UE, etc., as well as for a different type of first wireless device. In some aspects, at  405 , the base station (e.g.,  404 ) may communicate with the UE (e.g.,  402 ) via a communication link/beam, which may reflect off an object prior to a reception of the communication beam. At  406 , the base station (e.g.,  404 ) may detect a non-line-of-sight (NLoS) condition between the base station (e.g.,  404 ) and the UE (e.g.,  402 ). For example, the communication link between the base station (e.g.,  404 ) and the UE (e.g.,  402 ) may include a path that reflects off the object, such as a building, in the communication environment, such that a portion of the communication path beyond the reflection point may not be within a direct line-of-sight (LoS) of the base station (e.g.,  404 ). At  408 , the base station (e.g.,  404 ) may transmit a configuration to the UE (e.g.,  402 ) to monitor a set of beams associated with the NLoS portion of the communication link. 
     At  410   a , the UE (e.g.,  402 ) may perform radar detection of potential obstructions to the set of beams associated with the NLoS portion of the communication link. For example, and object in the communication environment, such as a vehicle, may include a trajectory that passes through the NLoS portion of the communication link and blocks/obstructs the communication link between the base station (e.g.,  404 ) and the UE (e.g.,  402 ). At  410   b , the base station (e.g.,  404 ) may perform similar radar detection of potential obstructions to the set of beams in the LoS portion of the communication link. 
     Example aspects of radar detection/radar sensing are described in connection with  FIG.  14   . A radar component  301 , which may also be referred to as a radar device, as described in connection with  FIGS.  3  and  4   ) may transmit a radar transmission (e.g., which may also be referred to as radar waves, radar waveform, radar pulses, and/or radar signals, etc.) and measure reflections of the radar transmission to detect/sense physical objects or physical surrounding.  FIG.  14    is a diagram  1400  illustrating an example of frequency modulated continuous wave (FMCW) signals generated from a radar component  301  (e.g., an FMCW radar) that may be used to measure for a beam blockage in accordance with various aspects of the present disclosure. The radar component  301  may detect/sense an object  1420  by transmitting a set of radar transmissions, which may be a set of chirp signals (or may also be referred to as a pulse signals), where each of the chirp signals may have a frequency that varies linearly (e.g., have a frequency sweeping) over a fixed period of time (e.g., over a sweep time) by a modulating signal. For example, as shown by the diagram  1400 , a transmitted chirp  1402  may have a starting frequency at  1404  of a sinusoid. Then the frequency may be gradually (e.g., linearly) increased on the sinusoid until it reaches the highest frequency at  1406  of the sinusoid, and then the frequency of the signal may return to  1408  and another chirp  1410  may be transmitted in the same way. In other words, each chirp may include an increase in the frequency (e.g., linearly) and a drop in the frequency, such that the radar component  301  may transmit chirps sweeping in frequency. 
     After one or more chirps (e.g., chirps  1402 ,  1410 ,  1412 , etc.) are transmitted by the radar component  301 , the transmitted chirps may reach the object  1420  and reflect back to the radar component  301 , such as shown by the reflected chirps  1414 ,  1416 , and  1418 , which may correspond to the transmitted chirps  1402 ,  1410 , and  1412 , respectively. As there may be a distance between the radar component  301  and the object  1420  and/or it may take time for a transmitted chirp to reach the object  1420  and reflect back to the radar component  301 , a delay may exist between a transmitted chirp and its corresponding reflected chirp. The delay may be proportional to a range between the radar component  301  and the object  1420  (e.g., the further the target, the larger the delay and vice versa). Thus, the radar component  301  may be able to measure or estimate a distance between the radar component  301  and the object  1420  based on the delay. However, in some examples, it may not be easy for some devices to measure or estimate the distance based on the delay between a transmitted chirp and a reflected chirp. 
     In other examples, as an alternative, the radar component  301  may measure a difference in frequency between the transmitted chirp and the reflected chirp, which may also be proportional to the distance between the radar component  301  and the object  1420 . In other words, as the frequency difference between the reflected chirp and the transmitted chirp increases with the delay, and the delay is linearly proportional to the range, the distance of the object  1420  from the radar component  301  may also be determined based on the difference in frequency. Thus, the reflected chirp from the object may be mixed with the transmitted chirp and down-converted to produce a beat signal (f b ) which may be linearly proportional to the range after demodulation. For example, the radar component  301  may determine a beat signal  1422  by mixing the transmitted chirp  1402  and its corresponding reflected chirp  1414 . In some examples, a radar device may also be used to detect/sense the velocity and direction of a using the FMCW. For example, an FMCW receiver may be able to identify the beat frequency/range based on a range spectrum. The FMCW receiver may also be able to identify the velocity based on a Doppler spectrum and/or the direction based on a direction of arrival (DoA) spectrum with multiple chirps. 
     At  412 , the base station (e.g.,  404 ) may transmit a CSI-RS to the UE (e.g.,  402 ). The CSI-RS may be transmitted on one or more beams associated with the configured set of beams to determine a quality of the one or more beams used for the communication link between the base station (e.g.,  404 ) and the UE (e.g.,  402 ). At  414 , the UE (e.g.,  402 ) may transmit a CSI report the base station (e.g.,  404 ) based on the CSI-RS received, at  412 . The CSI report may be indicative of the quality of the one or more beams used for the communication link between the base station (e.g.,  404 ) and the UE (e.g.,  402 ). 
     At  416 , the UE (e.g.,  402 ) may transmit an indication to the base station (e.g.,  404 ) of an expected beam blockage in the NLoS portion of the communication link based on the radar detection performed, at  410   a . For example, radar detection techniques performed, at  410   a , may be used by the UE (e.g.,  402 ) to determine that an object in the communication environment is predicted to obstruct the communication link between the base station (e.g.,  404 ) and the UE (e.g.,  402 ). At  418 , the base station (e.g.,  404 ) may switch beams for communicating with the UE (e.g.,  402 ) in response to the beam blockage indication received, at  416 , from the UE (e.g.,  402 ). At  420 , the UE (e.g.,  402 ) may proactively transmit NACK(s) to the base station (e.g.,  404 ) on the beams that are expected to experience a beam failure. The NACK(s) transmitted, at  420 , may be independent of data transmissions on at least one beam of the set of configured beams. 
     At  422 , the base station (e.g.,  404 ) may detect a LoS condition between the base station (e.g.,  404 ) and the UE (e.g.,  402 ). For example, changes in the communication environment may cause the communication link with the UE (e.g.,  402 ) to include a communication path that no longer reflects off an object within the communication environment prior to being received by the UE (e.g.,  402 ). That is, the communication path between the base station (e.g.,  404 ) and the UE (e.g.,  402 ) may correspond to a direct LoS from the base station (e.g.,  404 ). At  424 , the base station (e.g.,  404 ) may transmit an indication to the UE (e.g.,  402 ) to stop monitoring the set of beams configured, at  408 , based on the detection, at  422 , of the LoS condition between the base station (e.g.,  404 ) and the UE (e.g.,  402 ). 
       FIGS.  5 A- 5 B  illustrate diagrams  500 - 550  of a predicted future obstruction to a communication link between a first wireless device and a second wireless device, e.g., in accordance with aspects presented herein. The communication link may be comprised of a LoS portion  558   a / 558   b  and a NLoS portion  560   a / 560   b , which may be separated via a reflection point  562   a / 526   b  of a beam communicated between the first wireless device and the second wireless device. Although the examples associated with the diagrams  500 - 550  are described for a UE  502 / 552  and a base station  504 / 554 , the aspects may be similarly applied for other devices, such as an RSU and a UE, an IAB node and a UE, or a UE and a UE. In NLoS configurations, the UE  502 / 552  and/or the base station  504 / 554  may perform radar-assisted beam failure avoidance techniques to switch communication beams prior to the communication link between the UE  502 / 552  and the base station  504 / 554  becoming obstructed. For example, the base station  554  may switch from the communication link comprised of the LoS portion  558   a  and the NLoS portion  560   a  to a second communication link comprised of a second LoS portion  558   b  and a second NLoS portion  560   b.    
       FIG.  5 A  illustrates that the base station  504  may be able to detect a future obstructer  506  that is moving in a direction to block a beam (e.g., direction  508 ) used for communication with a UE  502 .  FIG.  5 B  illustrates that there may be obstructions (e.g., future obstructer  556 ) that are not detectable by the base station  554 , which may be detected by the UE  552  that will block directional communication with the UE  552 . The UE  502 / 552  and/or the base station  504 / 554  may be configured to sense that a beam of a communication link is going to become blocked/obstructed by a future obstructer  506 / 556  before the blocking/obstruction actually occurs. Equipping the base station  504 / 554  or the UE  502 / 552  (e.g., a vehicle) with a radar may provide information that can be leveraged to improve connectivity between devices. Such techniques may be referred to as joint communication-radar techniques. Radar sensing may provide information that may be used to generate a prediction about communications within the environment and may be used to improve communication performance between devices. 
     Radar information indicative of a predicted future obstruction  506 / 556  to the communication link between the UE  502 / 552  and the base station  504 / 554  may be used to allow the base station  504 / 554  to improve beam management and/or link reliability in dynamic environments, such as vehicular networks. As conditions of vehicular networks may change rapidly when vehicles are moving at high speeds, some beam management approaches, such as reactive beam management procedures, may have limited applicability. For example, some beam management procedures may not be proactive in regard to the predicted obstructions  506 / 556 , but rather may be reactive to an obstruction that has already occurred. Beam management techniques may include determining one or more beams to use for the communication link between the UE  502 / 552  and the base station  504 / 554 , beam tracking procedures, detection of beam failures, beam recovery procedures, etc. 
     Radar devices may be configured to adapt to communication environments that include sudden changes in conditions based on reactive beam management procedures that are triggered in response to determining that a beam is blocked. For example, the UE  502 / 552  and the base station  504 / 554  may communicate over a particular beam and a vehicle (e.g., obstructer  506 / 556 ) may pass through the path of a communication link between the UE  502 / 552  and the base station  504 / 554 , which may obstruct/block the communication link. In some cases, the obstructer  506 / 556  may cause a beam failure between the UE  502 / 552  and the base station  504 / 554 . The UE  502 / 552  may detect a radio link failure (RLF) and may attempt to perform a beam failure recovery (BFR). That is, the UE  502 / 552  may first detect that the beam has failed and subsequently attempt to recover from the failure caused by the obstructer  506 / 556 . 
     Configuring devices in the communication environment to sense sidelink information, such as radar communications, may improve beam management procedures in dynamic communication environment. In less-dynamic environments, objects may be moving more slowly, such that there may be enough latency for the devices to adapt to changes based on reactive beam management techniques. However, in fast changing environments where latency is low, proactive beam management techniques may be implemented to predict future obstructions and switch beams, as illustrated in the diagram  550 , before a beam becomes blocked/obstructed. In some cases, the signal quality of backup beams being (e.g., the communication link comprised of the second LoS portion  558   b  and the second NLoS portion  560   b ) tracked by the devices in the communication environment may also change. If an RLF occurs, information about the backup beams may not be reliable. Thus, a vehicle (e.g., UE  502 / 552 ) may determine that a beam failure or a backup beam failure has occurred, which may be associated with an extended reaction time to perform the BFR. Accordingly, radar information may be leveraged to assist the UE  502 / 552  and the base station  504 / 554  in avoiding predicted beam failures. 
     The base station  504 / 554  may be equipped with a radar device that may be used to determine information about the communication environment within a LoS of the radar device. Radar sensing performed at the base station  504 / 554  may be limited to LoS portions  558   a / 558   b  of the communication link from the base station  504 / 504  to the UE  502 / 552 . That is, the base station  504 / 554  may only detect/predict future obstructions, such as the obstructer  506 , that are within the LoS of the base station  504 / 554  and may not be able to detect/predict future obstructions, such as the obstructer  556 , that are not within the LoS of the base station  504 / 554 . The NLoS portion  560   a / 560   b  refers to the portion of the beam after the reflection point  562   a / 562   b  that has a changed beam direction from the LoS portion  558   a / 558   b . The base station  504 / 554  may still communicate with the UE  502 / 552  based on the beam being reflected and received by the UE  502 / 552 . However, the base station  504 / 554  may only be able to predict future obstructions up to the reflection point  562   a / 526   b  of the beam (e.g., within the LoS portion  558   a / 558   b  of the communication link). The base station  504 / 554  may not be able to sense objects in the environment beyond the reflection point  562   a / 562   b  of the beam (e.g., corresponding to the NLoS portion  560   a / 560   b  of the communication link). Thus, the radar at the base station  504 / 554  may not be able to detect changes in the environment that occur behind objects in the NLoS portion  560   a / 560   b  of the communication link. 
     Equipping both the base station  504 / 554  and the UE  502 / 552  (e.g., a vehicle) with a radar device may allow the base station  504 / 554  and the UE  502 / 552  to receive additional information about the communication environment, particularly in regions that may be associated with NLoS portions  560   a / 560   b  of the communication link for one of the devices. For example, a NLoS portion  560   a / 560   b  of the communication link for the base station  504 / 554  may correspond to a LoS perspective of the communication link for the UE  502 / 552 . Thus, even though the base station  554  may not be configured to sense the future obstructer  556  in the NLoS portion  560   a / 560   b  of the communication link, the base station  554  may receive information from the UE  552  indicative of the future obstructer  556  and may use such information to adjust one or more communication beams. The UE  552  may transmit LoS information determined from a local radar back to the base station  554 , so that the base station  554  may initiate adjustments to the communication link over a short period of time based on expected/predicted failures of the beam/communication link. 
     In the diagram  500 , a radar device located at the base station  504  may be able to detect the future obstructer  506  located in the LoS of the base station  504 . That is, the radar at the base station  504  may be able to predict a future time and location where an obstruction may occur to a current serving beam. The communication link between the base station  504  and the UE  502  also includes a NLoS portion, although the future obstructer  506  is predicted to pass through the LoS portion of the communication link. The future obstructer  506  may be another vehicle that is predicted to cross the path of the beam being used to communicate with the UE  502  and potentially block the beam. The base station  504  may detect the obstructer  506  in advance based on the obstruction occurring in the LoS of the base station  504 . If the base station  504  detects the obstructer  506  in advance, the base station  504  may proactively switch to an alternate beam for the time period that the communication link is obstructed by the obstructer  506 . 
     In the diagram  550 , the radar device located at the base station  554  may not be able to detect the future obstructer  556  in advance, as the future obstructer  556  may be located in the NLoS portion  560   a  of the communication link. However, a radar device located at the UE  552  may be configured to detect the future obstructer  556  and predict a future time and location that the obstruction is expected to occur. That is, the radar device located at the UE  552  may be able to predict that the NLoS portion  560   a  of the current serving beam for the base station  554  is going to become blocked/obstructed. If the obstruction is associated with the NLoS portion  560   a  of the communication link for the base station  554 , the base station  554  may not be able to sense/predict the obstruction in advance, as the base station  554  may not have direct sensing of the future obstructer  556 . Thus, direct sensing by the base station  554  may not be used for proactive beam management techniques in such cases. However, the base station  554  may be in communication with one or more UEs, such as the UE  552 , which may communicate NLoS information to the base station  554 . By receiving the NLoS information from the one or more UEs, the base station  554  may be able to determine/predict future obstructions that are expected to occur in the NLoS portion  560   a  of the communication link, as well as sense the LoS portion  558   a  of the communication link for predicting obstructions that may occur in the LoS portion  558   a  of the communication link. Based on the prediction, the base station  554  may switch from the beam associated with the communication link comprised of the first LoS portion  558   a  and the first NLoS portion  560   a  to a different beam associated with a second communication link comprised of a second LoS portion  558   b  and a second NLoS portion  560   b.    
       FIG.  6    illustrates a time diagram  600  associated with an obstruction that occurs within a LoS portion of a communication link of a base station. The base station may correspond to the base station  504 , and the UE may correspond to the UE  502 , and the obstructer may correspond to the obstructer  506  in  FIG.  5 A .  FIG.  6    illustrates the radar-assisted beam failure avoidance techniques based on radar detection at the base station. The base station may use NLoS beam directions to communicate with the UE.  FIG.  6    illustrates a timeline  602  from a perspective of the base station, a timeline  604  from a perspective of the UE, and a timeline  606  from a perspective of an obstructer. 
     For each object detected by the radar located at the base station, the base station may predict a location of the object for a CSI-RS period or for an SSB period, and may determine whether the object is expected to block/obstruct a beam in a set of configured beams (e.g., serving beams or alternate beams) from a LoS viewpoint of the base station (e.g., blockages that occur between the base station and the reflection point of the communication link associated with the Tx beam direction of the base station). If the object is predicted to block the serving beam, e.g., at  607 , the base station may schedule CSI-RS in the directions of the backup/alternate beams that the base station predicts to be available after the CSI-RS period. For example, at  608 , the base station may transmit CSI-RS, and at  610 , the base station may receive CSI from the UE based on measurement of the CSI-RS. If the UE reports a strong RSRP in a tested CSI-RS direction, the base station may switch to a backup/alternate link reported by the UE, which may avoid a beam failure between the UE and the base station, e.g., when the obstructer blocks the previous beam, at  612 . 
     In the diagram  600 , the base station may configure a CSI-RS 1 for a first CSI-RS period. The base station may transmit the CSI-RS 1 to the UE, which may send a report back to the base station indicative of a channel quality associated with the CSI-RS 1. While the base station may select an initial serving beam based on the report received from the UE, the base station may subsequently determine based on local sensing of the base station that a LoS portion of the communication link is expected to be blocked by an obstructer. For example, the radar device located at the base station may predict that a beam failure is expected to occur within one CSI-RS period based on a detected obstructer blocking the initial serving beam. 
     Prior to the initial serving beam becoming blocked, the base station may test a backup beam associated with a different beam direction by transmitting a CSI-RS 2 to the UE for a second CSI-RS period. The UE may send a report back to the base station indicative of a channel quality associated with the CSI-RS 2. Based on the report received from the UE, the base station may select a backup link that is predicted to avoid the beam failure caused by the obstructer blocking the initial serving beam. That is, the base station may determine whether another beam direction is expected to be free of blockages/obstructions. If the other beam direction is not expected to be blocked, the base station may switch to the alternate beam prior to the initial serving beaming becoming blocked via the predicted obstructer. Accordingly, before the obstruction to the initial serving beam occurs and potentially causes a beam failure to the initial serving beam, the base station may select a backup beam that is not predicted to fail and may use the backup beam to communicate with the UE, such that a beam failure event may be avoided. At the end of the second CSI-RS period, the base station may transmit a CSI-RS 3 to the UE, at  614 , and receive an associated report from the UE, at  616 . The report may be indicative of whether the base station may switch back to the initial serving beam or switch to another beam for communicating with the UE. 
       FIG.  7    illustrates a diagram  700  associated with an obstruction that occurs within a NLoS portion of a communication link of a base station. The base station may correspond to the base station  554 , the UE may correspond to the UE  552 , and the obstructer may correspond to the obstructer  556  in  FIG.  5 B . The UE may receive a configuration  705  from the base station for a set of SSB/CSI-RS beams to monitor for beam blockages/obstructions from a LoS viewpoint of the UE. The UE may continuously tracks the environment for blockages/obstructions in the LoS portion of the communication link, which may correspond to a NLoS portion of the communication link from a viewpoint of the base station.  FIG.  7    illustrates a timeline  702  from a perspective of the base station, a timeline  704  from a perspective of the UE, and a timeline  706  from a perspective of an obstructer. 
     For each object detected by the radar device located at the UE, the UE may predict a location of the object for a CSI-RS period or for an SSB period, and may determine whether the object is expected to block/obstruct a beam in the set of configured beams (e.g., serving beams or alternate beams) from the LoS viewpoint of the UE (e.g., blockages that occur between the UE and the reflection point of the communication link). Thus, before a beam blockage occurs in the NLoS portion of the communication link, the base station may predict which beams in the set of beams will be blocked via information received from the UE. 
     If an object is predicted to block a serving beam, e.g., at  707 , the UE may add the corresponding beam direction to a list of beam directions that are expected to fail when transmitting the report to the base station. At the time the UE receives an SSB or a CSI-RS, the UE may also report a proactive NACK in each beam direction included in the list of beam directions that are expected to fail. Such feedback may be utilized for performing proactive beam management techniques by the base station. When the CSI-RS  708  is transmitted, the UE may report a current CSI  710 , or an RSRP, to the base station in addition to transmitting an indication that a particular beam is expected to be blocked/obstructed at a future time. 
     The base station may switch to a backup link reported by the UE to avoid a potential beam failure. Combining information sensed by both the base station and the UE may allow the base station to predict and avoid beam failures that result from obstructers in the LoS of either the base station or the UE. Thus, the base station may instruct the UE to perform beam tracking for certain beams in addition to performing beam blockage predictions. The UE may utilize local sensing to perform beam blockage predictions for the set of beams the base station has instructed the UE to monitor. 
     If the UE determines that a beam is expected to be blocked, the UE may transmit an indication/report to the base station for the corresponding beam. As such, the base station may perform proactive beam management techniques based on the configuration of the UE by the base station. For certain beams, the base station may be able to perform LoS sensing, such that the UE may not have to monitor such beams. Thus, local sensing at the base station may be used to predict beam blockages in such cases. However, in NLoS portions of the communication link, the base station may rely on the UE to report expected blockages for adapting the beams that are used in association with the communication link. 
     In the diagram  700 , the base station may configure the UE to monitor for future obstructions in the NLoS portion of the communication link of the base station. The base station may configure the UE to monitor for obstructions/blockages via one or more SSB/CSI-RS beams (e.g., serving beams or alternate beams tracked by the base station). The UE may report blockage predictions to the base station for the associated beams. The base station may continuously track the environment and configure the UE with a set of SSB/CSI-RS beams to monitor for beam blockages from a LoS viewpoint of the UE (e.g., blockages that occur between the UE and a reflection point of the communication link associated with the Rx beam of the UE). 
     The base station may transmit a CSI-RS 1 to the UE for a first CSI-RS period. Based on the CSI-RS 1, the UE may transmit a report back to the base station indicative of a channel quality associated with the serving beam used for the communication link between the UE and the base station. 
     Prior to an end of the first CSI-RS period, the radar device located at the UE may predict that a beam failure is expected to occur within one CSI-RS period based on a detected obstructer blocking the initial serving beam in the NLoS portion of the communication link. The UE may add the beam direction associated with the obstruction to a list of beam failure directions reported to the base station. Before the initial serving beam becomes blocked, the base station may transmit a CSI-RS 2 to the UE for a second CSI-RS period. The UE may test the beams associated with the CSI-RS 2, such as backup/alternate beams, and indicate whether the backup/alternate beams are expected to fail. For example, if the CSI-RS direction corresponds to a beam direction associated with the list of beam failure directions, the UE may report to the base station that the beam is expected to fail. 
     The base station may utilize the information reported from the UE to change the communication beam and adapt to the conditions of the communication environment. For example, the base station may switch to a backup link to avoid a beam failure based on the report received from the UE. Thus, when the obstructer blocks the initial serving beam between the base station and the UE, the beam for the communication link between the UE and the base station may have already been proactively switched to a different beam to avoid a beam failure. At the end of the second CSI-RS period, the base station may transmit a CSI-RS 3 to the UE and receive an associated report from the UE. The report may be indicative of whether the base station may switch back to the initial serving beam or switch to another beam for communicating with the UE. 
       FIG.  8    is a flowchart  800  of a method of wireless communication. The method may be performed by a first wireless device, e.g.,  350 ,  402 ; the apparatus  1202 , which may include the memory  360 , the TX processor  368 , the RX processor  356 , and/or the controller/processor  359 . In some aspects, the first wireless device may be a UE, a component of a UE, or may implement UE functionality (e.g., the UE  104 ,  502 ,  552 , etc.). The method may enable a device to configure another device to obtain more comprehensive information about potential beam blockages by configuration another device to monitor for beam blockages from the other device&#39;s perspective and to report potential beam blockages. The method may enable more reliable wireless communication by enabling beam adjustments to account for blockages that may be detected at the first wireless device and not the second wireless device. In some aspects, the method may be performed to avoid beam failures associated with NLoS obstructions to a communication link. 
     At  802 , the first wireless device may receive, from a second wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device. In some aspects, the configuration may be for a UE in a NLOS condition with a base station, or for another wireless device in an NLOS condition with a second wireless device. The first wireless device may be a UE, and the second wireless device may be a base station, an RSU, an IAB node, or another UE. For example, referring to  FIG.  4   , the wireless device  402  may receive, at  408 , a configuration from the second wireless device  404  to monitor a set of beams based on detection, at  406 , of a NLoS condition between the second wireless device  404  and the wireless device  402 . The reception, at  802 , may be performed by the reception component  1230  of the apparatus  1202  in  FIG.  12   . 
     At  804 , the first wireless device may perform radar detection for the potential obstruction to the set of one or more beams for the wireless communication with the second wireless device. For example, referring to  FIG.  4   , the wireless device  402  may perform, at  410   a , radar detection of potential obstructions to the set of beams configured, at  408 , based on the configuration. In some aspects, the radar detection may be based on a NLoS condition between the second wireless device  404  and the wireless device  402 . The performance, at  804 , may be performed by the performance component  1240  of the apparatus  1202  in  FIG.  12   . 
       FIG.  9    is a flowchart  900  of a method of wireless communication. The method may be performed by a UE (e.g., the UE  104 ,  502 ,  552 ; device  402 ; the apparatus  1202 ; etc.), which may include the memory  360  and which may be the entire or a component of the UE, such as the TX processor  368 , the RX processor  356 , and/or the controller/processor  359 . The method may be performed to avoid beam failures associated with NLoS obstructions to a communication link. 
     At  902 , the first wireless device may receive a configuration from a second wireless device to monitor a set of beams for beam blocking with the second wireless device. For example, referring to  FIG.  4   , the first wireless device  402  may receive, at  408 , a configuration from the second wireless device  404  to monitor a set of beams based on detection, at  406 , of a NLoS condition between the second wireless device  404  and the first wireless device  402 . Each beam of the set of beams configured, at  408 , may be associated with an SSB or each beam of the set of beams configured, at  408 , may be associated with a CSI-RS. The reception, at  902 , may be performed by the reception component  1230  of the apparatus  1202  in  FIG.  12   . 
     At  904 , the first wireless device may perform radar detection of potential obstructions to the set of beams between the second wireless device and the first wireless device. For example, referring to  FIG.  4   , the first wireless device  402  may perform, at  410   a , radar detection of potential obstructions to the set of beams configured, at  408 , based on the configuration. The performance, at  904 , may be performed by the performance component  1240  of the apparatus  1202  in  FIG.  12   . 
     At  906 , the first wireless device may receive a CSI-RS on one or more beam of the set of beams. For example, referring to  FIG.  4   , the first wireless device  402  may receive, at  412 , a CSI-RS from the second wireless device  404 . The reception, at  906 , may be performed by the reception component  1230  of the apparatus  1202  in  FIG.  12   . 
     At  908 , the first wireless device may transmit a CSI report for the one or more beam of the set of beams. For example, referring to  FIG.  4   , the first wireless device  402  may transmit, at  414 , a CSI report to the second wireless device  404  based on the CSI-RS received, at  412 . The transmission, at  908 , may be performed by the transmission component  1234  of the apparatus  1202  in  FIG.  12   . 
     At  910 , the first wireless device may transmit, to the second wireless device, an indication of potential beam blockage based on the radar detection. For example, referring to  FIG.  4   , the first wireless device  402  may transmit, at  416 , a beam blockage indication to the second wireless device  404  based on the radar detection performed, at  410   a , by the first wireless device  402 . The indication transmitted, at  416 , may comprise a list of one or more beams that are expected to experience a failure. The transmission, at  910 , may be performed by the transmission component  1234  of the apparatus  1202  in  FIG.  12   . 
     At  912 , the first wireless device may transmit a NACK on each of multiple beams that are expected to experience a failure. For example, referring to  FIG.  4   , the first wireless device  402  may transmit, at  420 , NACK(s) on beams that are expected to experience a beam failure. The indication transmitted, at  420 , may comprise NACK(s) that are independent of a data transmission on at least one beam of the set of beams. The transmission, at  912 , may be performed by the transmission component  1234  of the apparatus  1202  in  FIG.  12   . 
     At  914 , the first wireless device may receive an indication from the second wireless device to stop monitoring the set of beams. For example, referring to  FIG.  4   , the first wireless device  402  may receive, at  424 , an indication from the second wireless device  404  to stop monitoring the set of beams configured, at  408 , by the second wireless device  404 . The reception, at  914 , may be performed by the reception component  1230  of the apparatus  1202  in  FIG.  12   . 
       FIG.  10    is a flowchart  1000  of a method of wireless communication. The method may be performed by a second wireless device (e.g., device  310 ; the apparatus  1302 ). In some aspects, the method may be performed by a base station (e.g., the base station  102 ,  180 ,  504 ,  554 ; device  404 , etc.). In some aspects, the method may be performed by a UE based on sidelink communication with another UE. In some aspects, the method may be performed by an RSU, an IAB node, etc. The method may be performed by the device  310 , which may include the memory  376  and which may be the entire device or a component of the device, such as the TX processor  316 , the RX processor  370 , and/or the controller/processor  375 . The method may be performed to avoid beam failures associated with NLoS obstructions to a communication link. 
     At  1002 , the second wireless device may transmit, to a first wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device. The first wireless device may be a UE, and the second wireless device may be a base station, an IAB node, an RSU, or another UE. For example, referring to  FIG.  4   , the second wireless device  404  may transmit, at  408 , a configuration to the first wireless device  402  to monitor a set of beams based on the NLoS condition detected, at  406 , between the second wireless device  404  and the first wireless device  402 . The configuration transmitted, at  408 , may be for radar detection of potential obstructions to the set of beams between the second wireless device  404  and the first wireless device  402 . The transmission, at  1004 , may be performed by the transmission component  1334  of the apparatus  1302  in  FIG.  13   . 
     At  1004 , the second wireless device may receive, from the first wireless device, information based on radar measurement associated with the set of one or more beams for the wireless communication with the second wireless device. The reception may be performed, e.g., by the reception component  1330  and/or the indication component  1346  of the apparatus  1302  in  FIG.  13   . For example, the second wireless device may receive an indication of a potential beam blockage based on radar measurements at the first wireless device. 
       FIG.  11    is a flowchart  1100  of a method of wireless communication. The method may be performed by a second wireless device (e.g., the base station  102 ,  180 ,  504 ,  554 ; the device  404 ; the apparatus  1302 ; etc.), which may include the memory  376  and which may be the entire base station or a component of the base station, such as the TX processor  316 , the RX processor  370 , and/or the controller/processor  375 . The method may be performed to avoid beam failures associated with NLoS obstructions to a communication link. 
     At  1102 , the second wireless device may detect a NLoS condition between a second wireless device and a first wireless device. For example, referring to  FIG.  4   , the second wireless device  404  may detect, at  406 , a NLoS condition between the second wireless device  404  and the first wireless device  402 . The first wireless device may be a UE, and the second wireless device may be a base station, an RSU, an IAB node, another UE, etc. The detecting, at  1102 , may be performed by the detection component  1340  of the apparatus  1302  in  FIG.  13   . The first wireless device may be a UE, and the second wireless device may be a base station, an IAB node, an RSU, or another UE. 
     At  1104 , the second wireless device may transmit a configuration to the first wireless device of a set of beams to monitor for beam blocking in response to the NLOS condition between the second wireless device and the first wireless device. For example, referring to  FIG.  4   , the second wireless device  404  may transmit, at  408 , a configuration to the first wireless device  402  to monitor a set of beams based on the NLoS condition detected, at  406 , between the second wireless device  404  and the first wireless device  402 . The configuration transmitted, at  408 , may be for radar detection of potential obstructions to the set of beams between the second wireless device  404  and the first wireless device  402 . Each beam of the set of beams configured, at  408 , may be associated with an SSB or each beam of the set of beams configured, at  408 , may be associated with a CSI-RS. The transmission, at  1104 , may be performed by the transmission component  1334  of the apparatus  1302  in  FIG.  13   . 
     At  1106 , the second wireless device may perform radar detection at the second wireless device to monitor for the beam blocking from a first perspective of the second wireless device—the configuration configures the first wireless device to monitor for the beam blocking from a second perspective of the first wireless device. For example, referring to  FIG.  4   , the second wireless device  404  may perform, at  410   b , radar detection of potential obstructions to the set of beams (e.g., within the LoS of the second wireless device  404 ). The radar detection performed, at  410   a , may be performed for potential obstructions to the set of beams at locations that are not within the LoS of the second wireless device  404 . The performance, at  1106 , may be performed by the performance component  1342  of the apparatus  1302  in  FIG.  13   . 
     At  1108 , the second wireless device may transmit a CSI-RS on one or more beam of the set of beams. For example, referring to  FIG.  4   , the second wireless device  404  may transmit, at  412 , a CSI-RS to the first wireless device  402 . The transmission, at  1108 , may be performed by the transmission component  1334  of the apparatus  1302  in  FIG.  13   . 
     At  1110 , the second wireless device may receive a CSI report for the one or more beam of the set of beams. For example, referring to  FIG.  4   , the second wireless device  404  may receive, at  414 , a CSI report from the first wireless device  402  based on the CSI-RS transmitted, at  412 , from the second wireless device  404  to the first wireless device  402 . The reception, at  1110 , may be performed by the reception component  1330  of the apparatus  1302  in  FIG.  13   . 
     At  1112 , the second wireless device may receive information from the first wireless device based on radar measurement associated with the set of beams. For example, the second wireless device may receive, from the first wireless device, an indication of a potential beam blockage. For example, referring to  FIG.  4   , the second wireless device  404  may receive, at  416 , a beam blockage indication from the first wireless device  402  based on the radar detection performed, at  410   a . The indication transmitted, at  416 , may comprise a list of one or more beams that are expected to experience a failure. The reception, at  1112 , may be performed by the reception component  1330  of the apparatus  1302  in  FIG.  13   . 
     At  1114 , the second wireless device may switch beams for communication with the first wireless device in response to the indication. For example, referring to  FIG.  4   , the second wireless device  404  may switch, at  418 , beams for communication with the first wireless device  402  in response to the beam blockage indication received, at  416 . The switching, at  1114 , may be performed by the switcher component  1344  of the apparatus  1302  in  FIG.  13   . 
     At  1116 , the second wireless device may receive a NACK on each of multiple beams that are expected to experience a failure. For example, referring to  FIG.  4   , the second wireless device  404  may receive, at  420 , NACK(s) from the first wireless device  402  on beams that are expected to experience a beam failure. The indication received, at  420 , may comprise NACK(s) that are independent of a data transmission on at least one beam of the set of beams. The reception, at  1116 , may be performed by the reception component  1330  of the apparatus  1302  in  FIG.  13   . 
     At  1118 , the second wireless device may detect a LoS condition between the second wireless device and the first wireless device. For example, referring to  FIG.  4   , the second wireless device  404  may detect, at  422 , a LoS condition between the second wireless device  404  and the first wireless device  402 . The detecting, at  1118 , may be performed by the detection component  1340  of the apparatus  1302  in  FIG.  13   . 
     At  1120 , the second wireless device may indicate to the first wireless device to stop monitoring the set of beams. For example, referring to  FIG.  4   , the second wireless device  404  may transmit, at  424 , an indication to the first wireless device  402  to stop monitoring the set of beams configured, at  408 , based on the LoS condition detected, at  422 , between the second wireless device  404  and the first wireless device  402 . The indication, at  1120 , may be performed by the indication component  1346  of the apparatus  1302  in  FIG.  13   . 
       FIG.  12    is a diagram  1200  illustrating an example of a hardware implementation for an apparatus  1202 . In some aspects, the apparatus  1202  may be a UE, a component of a UE, or may implement UE functionality. In some aspects, the apparatus  1202  may include a cellular baseband processor  1204  (also referred to as a modem) coupled to a cellular RF transceiver  1222 . In some aspects, the apparatus  1202  may further include one or more subscriber identity modules (SIM) cards  1220 , an application processor  1206  coupled to a secure digital (SD) card  1208  and a screen  1210 , a Bluetooth module  1212 , a wireless local area network (WLAN) module  1214 , a Global Positioning System (GPS) module  1216 , or a power supply  1218 . The cellular baseband processor  1204  communicates through the cellular RF transceiver  1222  with the UE  104  and/or BS  102 / 180 . The cellular baseband processor  1204  may include a computer-readable medium/memory. The computer-readable medium/memory may be non-transitory. The cellular baseband processor  1204  is responsible for general processing, including the execution of software stored on the computer-readable medium/memory. The software, when executed by the cellular baseband processor  1204 , causes the cellular baseband processor  1204  to perform the various functions described supra. The computer-readable medium/memory may also be used for storing data that is manipulated by the cellular baseband processor  1204  when executing software. The cellular baseband processor  1204  further includes a reception component  1230 , a communication manager  1232 , and a transmission component  1234 . The communication manager  1232  includes the one or more illustrated components. The components within the communication manager  1232  may be stored in the computer-readable medium/memory and/or configured as hardware within the cellular baseband processor  1204 . The cellular baseband processor  1204  may be a component of the device  350  and may include the memory  360  and/or at least one of the TX processor  368 , the RX processor  356 , and the controller/processor  359 . In one configuration, the apparatus  1202  may be a modem chip and include just the baseband processor  1204 , and in another configuration, the apparatus  1202  may be the entire device (e.g., see  350  of  FIG.  3   ) and include the additional modules of the apparatus  1202 . 
     The reception component  1230  is configured, e.g., as described in connection with  802 ,  902 ,  906 , and  914 , to receive, from a second wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device; to receive a configuration from a second wireless device to monitor a set of beams for beam blocking with the second wireless device; to receive a CSI-RS on one or more beam of the set of beams; and to receive an indication from the second wireless device to stop monitoring the set of beams. The communication manager  1232  includes a performance component  1240  that is configured, e.g., as described in connection with  804  and  904 , to perform radar detection for the potential obstruction to the set of one or more beams for the wireless communication with the second wireless device; and to perform radar detection of potential obstructions to the set of beams between the second wireless device and the first wireless device. The transmission component  1234  is configured, e.g., as described in connection with  908 ,  910 , and  912 , to transmit a CSI report for the one or more beam of the set of beams; to transmit, to the second wireless device, an indication of potential beam blockage based on the radar detection; and to transmit a NACK on each of multiple beams that are expected to experience a failure. 
     The apparatus may include additional components that perform each of the blocks of the algorithm in the flowcharts of  FIGS.  8 - 9   . As such, each block in the flowcharts of  FIGS.  8 - 9    may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof. 
     As shown, the apparatus  1202  may include a variety of components configured for various functions. In one configuration, the apparatus  1202 , and in particular the cellular baseband processor  1204 , includes means for receiving, from a second wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device; and means for performing radar detection for the potential obstruction to the set of one or more beams for the wireless communication with the second wireless device. The apparatus  1202  further includes means for receiving a configuration from a second wireless device to monitor a set of beams for beam blocking with the second wireless device; and means for performing radar detection of potential obstructions to the set of beams between the second wireless device and the first wireless device. The apparatus  1202  further includes means for transmitting, to the second wireless device, an indication of potential beam blockage based on the radar detection. The apparatus  1202  further includes means for transmitting the NACK on each of multiple beams that are expected to experience a failure. The apparatus  1202  further includes means for receiving an indication from the second wireless device to stop monitoring the set of beams. The apparatus  1202  further includes means for receiving a CSI-RS on one or more beam of the set of beams; and means for transmitting a CSI report for the one or more beam of the set of beams. 
     The means may be one or more of the components of the apparatus  1202  configured to perform the functions recited by the means. As described supra, the apparatus  1202  may include the TX Processor  368 , the RX Processor  356 , and the controller/processor  359 . As such, in one configuration, the means may be the TX Processor  368 , the RX Processor  356 , and the controller/processor  359  configured to perform the functions recited by the means. 
       FIG.  13    is a diagram  1300  illustrating an example of a hardware implementation for an apparatus  1302 . In some aspects, apparatus  1302  may be a base station, a component of a base station, or may implement base station functionality. In some aspects, the apparatus  1302  may be a UE, an RSU, an IAB node, or a component of such. In some aspects, the apparatus  1202  may include a baseband unit  1304 . The baseband unit  1304  may communicate through a cellular RF transceiver  1322  with the UE  104 . The baseband unit  1304  may include a computer-readable medium/memory. The baseband unit  1304  is responsible for general processing, including the execution of software stored on the computer-readable medium/memory. The software, when executed by the baseband unit  1304 , causes the baseband unit  1304  to perform the various functions described supra. The computer-readable medium/memory may also be used for storing data that is manipulated by the baseband unit  1304  when executing software. The baseband unit  1304  further includes a reception component  1330 , a communication manager  1332 , and a transmission component  1334 . The communication manager  1332  includes the one or more illustrated components. The components within the communication manager  1332  may be stored in the computer-readable medium/memory and/or configured as hardware within the baseband unit  1304 . The baseband unit  1304  may be a component of the device  310  and may include the memory  376  and/or at least one of the TX processor  316 , the RX processor  370 , and the controller/processor  375 . 
     The communication manager  1332  includes a detection component  1340  that is configured, e.g., as described in connection with  1102 , and  1118 , to detect a NLoS condition between a second wireless device and a UE; and to detect a LoS condition between the second wireless device and the UE. The communication manager  1332  further includes a performance component  1342  that is configured, e.g., as described in connection with  1106 , to perform radar detection at the second wireless device to monitor for the beam blocking from a first perspective of the second wireless device—the configuration configures the UE to monitor for the beam blocking from a second perspective of the UE. The communication manager  1332  further includes a switcher component  1344  that is configured, e.g., as described in connection with  1114 , to switch beams for communication with the UE in response to the indication. The communication manager  1332  further includes an indication component  1346  that is configured, e.g., as described in connection with  1120 , to indicate to the UE to stop monitoring the set of beams. 
     The reception component  1330  is configured, e.g., as described in connection with  1004 ,  1110 ,  1112 , and  1116 , to receive, from the first wireless device, information based on radar measurement associated with the set of one or more beams for the wireless communication with the second wireless device; to receive a CSI report for the one or more beam of the set of beams; to receive, from the UE, an indication of a potential beam blockage; and to receive a NACK on each of multiple beams that are expected to experience a failure. The transmission component  1334  is configured, e.g., as described in connection with  1002 ,  1104 , and  1108 , to transmit, to a first wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device; to transmit a configuration to the UE of a set of beams to monitor for beam blocking in response to the NLOS condition between the second wireless device and the UE; and to transmit a CSI-RS on one or more beam of the set of beams. 
     The apparatus may include additional components that perform each of the blocks of the algorithm in the flowcharts of  FIGS.  10 - 11   . As such, each block in the flowcharts of  FIGS.  10 - 11    may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof. 
     As shown, the apparatus  1302  may include a variety of components configured for various functions. In one configuration, the apparatus  1302 , and in particular the baseband unit  1304 , includes means for transmitting, to a first wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device; and means for receiving, from the first wireless device, information based on radar measurement associated with the set of one or more beams for the wireless communication with the second wireless device. The apparatus  1302  further includes means for detecting a NLoS condition between the second wireless device and a UE; and means for transmitting a configuration to the UE of a set of beams to monitor for beam blocking in response to the NLOS condition between the second wireless device and the UE. The apparatus  1302  further includes means for receiving, from the UE, an indication of a potential beam blockage; and means for switching beams for communication with the UE in response to the indication. The apparatus  1302  further includes means for receiving the NACK on each of multiple beams that are expected to experience a failure. The apparatus  1302  further includes means for performing radar detection at the second wireless device to monitor for the beam blocking from a first perspective of the second wireless device, wherein the configuration configures the UE to monitor for the beam blocking from a second perspective of the UE. The apparatus  1302  further includes means for detecting a LoS condition between the second wireless device and the UE; and means for indicating to the UE to stop monitoring the set of beams. The apparatus  1302  further includes means for transmitting a CSI-RS on one or more beam of the set of beams; and means for receiving a CSI report for the one or more beam of the set of beams. 
     The means may be one or more of the components of the apparatus  1302  configured to perform the functions recited by the means. As described supra, the apparatus  1302  may include the TX Processor  316 , the RX Processor  370 , and the controller/processor  375 . As such, in one configuration, the means may be the TX Processor  316 , the RX Processor  370 , and the controller/processor  375  configured to perform the functions recited by the means. 
     It is understood that the specific order or hierarchy of blocks in the processes/flowcharts disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes/flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented. 
     The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Terms such as “if,” “when,” and “while” should be interpreted to mean “under the condition that” rather than imply an immediate temporal relationship or reaction. That is, these phrases, e.g., “when,” do not imply an immediate action in response to or during the occurrence of an action, but simply imply that if a condition is met then an action will occur, but without requiring a specific or immediate time constraint for the action to occur. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module,” “mechanism,” “element,” “device,” and the like may not be a substitute for the word “means.” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for.” 
     The following aspects are illustrative only and may be combined with other aspects or teachings described herein, without limitation. 
     Aspect 1 is a method of wireless communication at a first wireless device, comprising: receiving, from a second wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device; and performing radar detection for the potential obstruction to the set of one or more beams for the wireless communication with the second wireless device. 
     Aspect 2 may be combined with aspect 1 and further includes transmitting, to the second wireless device, an indication of the potential obstruction based on the radar detection. 
     Aspect 3 may be combined with any of aspects 1-2 and includes that the indication comprises a list of one or more beams that are expected to experience a failure. 
     Aspect 4 may be combined with any of aspects 1-3 and includes that the indication comprises a NACK independent of a data transmission on at least one beam of the set of one or more beams. 
     Aspect 5 may be combined with any of aspects 1-4 and further includes transmitting the NACK on each beam of the set of one or more beams that are expected to experience a failure. 
     Aspect 6 may be combined with any of aspects 1-5 and further includes receiving an indication from the second wireless device to stop monitoring the set of one or more beams. 
     Aspect 7 may be combined with any of aspects 1-6 and includes that each beam of the set of one or more beams is associated with an SSB. 
     Aspect 8 may be combined with any of aspects 1-7 and includes that each beam of the set of one or more beams is associated with a CSI-RS. 
     Aspect 9 may be combined with any of aspects 1-8 and further includes receiving a CSI-RS on the set of one or more beams; and transmitting a CSI report for the set of one or more beams. 
     Aspect 10 is a method of wireless communication at a second wireless device, comprising: transmitting, to a first wireless device, a configuration to monitor for a potential obstruction for a set of one or more beams for wireless communication with the second wireless device; and receiving, from the first wireless device, information based on radar measurement associated with the set of one or more beams for the wireless communication with the second wireless device. 
     Aspect 11 may be combined with aspect 10 and includes that the configuration is for radar detection of the potential obstruction for the set of one or more beams for the wireless communication with the second wireless device. 
     Aspect 12 may be combined with any of aspects 10-11 and further includes receiving, from the first wireless device, an indication of the potential obstruction; and switching beams for communication with the first wireless device in response to the indication. 
     Aspect 13 may be combined with any of aspects 10-12 and includes that the indication comprises a list of beams in the set of one or more beams that are expected to experience a failure. 
     Aspect 14 may be combined with any of aspects 10-13 and includes that the indication comprises a NACK independent of a data transmission on at least one beam of the set of one or more beams. 
     Aspect 15 may be combined with any of aspects 10-14 and further includes receiving the NACK on each beam indicated in the list of beams that are expected to experience a failure. 
     Aspect 16 may be combined with any of aspects 10-15 and further includes performing radar detection at the second wireless device to monitor for the potential obstruction from a first perspective of the second wireless device, wherein the configuration configures the first wireless device to monitor for the potential obstruction from a second perspective of the first wireless device. 
     Aspect 17 may be combined with any of aspects 10-16 and further includes detecting a LOS condition between the second wireless device and the first wireless device; and indicating to the first wireless device to stop monitoring the set of one or more beams. 
     Aspect 18 may be combined with any of aspects 10-17 and includes that each beam of the set of one or more beams is associated with an SSB. 
     Aspect 19 may be combined with any of aspects 10-18 and includes that each beam of the set of one or more beams is associated with a CSI-RS. 
     Aspect 20 may be combined with any of aspects 10-19 and further includes transmitting a CSI-RS on the set of one or more beams; and receiving a CSI report for the set of one or more beams. 
     Aspect 21 is an apparatus for wireless communication including memory and at least one processor coupled to the memory, the memory and the at least one processor configured to perform the method of any of aspects 1-9. 
     Aspect 22 may be combined with any of aspects 1-9 or 21 and includes that the first wireless device is a UE and the second wireless device is a second UE, a base station, an RSU, or an IAB node. 
     Aspect 23 may be combined with any of aspects 1-9 or 21-22 and further includes at least one of an antenna or a transceiver coupled to the at least one processor. 
     Aspect 24 is an apparatus for wireless communication including means for performing the method of any of aspects 1-9. 
     Aspect 25 may be combined with any of aspects 1-9 or 24 and includes that the first wireless device is a UE and the second wireless device is a second UE, a base station, an RSU, or an IAB node. 
     Aspect 26 may be combined with any of aspects 1-9 or 24-25 and further includes at least one of an antenna or a transceiver coupled to the means for performing the method of any of aspects 1-9. 
     Aspect 27 is a non-transitory computer-readable storage medium storing computer executable code, the code when executed by at least one processor causes the at least one processor to perform the method of any of aspects 1-9. 
     Aspect 28 is an apparatus for wireless communication including memory and at least one processor coupled to the memory, the memory and the at least one processor configured to perform the method of any of aspects 10-20. 
     Aspect 29 may be combined with any of aspects 10-20 or 28 and includes that the first wireless device is a UE and the second wireless device is a second UE, a base station, an RSU, or an IAB node. 
     Aspect 30 may be combined with any of aspects 10-20 or 28-29 and further includes at least one of an antenna or a transceiver coupled to the at least one processor. 
     Aspect 31 is an apparatus for wireless communication including means for performing the method of any of aspects 10-20. 
     Aspect 32 may be combined with any of aspects 10-20 or 31 and includes that the first wireless device is a UE and the second wireless device is a second UE, a base station, an RSU, or an IAB node. 
     Aspect 33 may be combined with any of aspects 10-20 or 31-32 and further includes at least one of an antenna or a transceiver coupled to the means for performing the method of any of aspects 10-20. 
     Aspect 34 is a non-transitory computer-readable storage medium storing computer executable code, the code when executed by at least one processor causes the at least one processor to perform the method of any of aspects 10-20.