Unicast air-to-everything (A2X) communication

Abstract

Methods, systems, and devices for wireless communication are described. A user equipment (UE), such as an unmanned air vehicle (UAV) (e.g., a source UAV), may initiate a unicast link setup procedure with another UAV (e.g., a target UAV), which may enable the UAV to communicate according to an air-to-everything (A2X) service type. The source UAV may send a direct communication request (DCR) message to the target UAV, the direct communication request (DCR) message including an application layer identifier (ID) unique to the target UAV. The source UAV may derive an application layer ID for the target UAV from a UE-specific ID unique to the target UAV. Alternatively, the source UAV may send a DCR message excluding the target UAV information. Instead, the DCR message may indicate one or more proximity parameters associated with the source UAV. The UAV may communicate a unicast message via a unicast link according to the A2X configuration and the communication parameters.

Description

[0001] Cross-references

[0002] This patent application claims priority to U.S. Patent Application No. 18 / 775,922, entitled “UNICAST AIR-TO-EVERYTHING (A2X) COMMUNICATIONS,” filed July 17, 2024, by Liu et al., and U.S. Patent Application No. 63 / 586,330, entitled “UNICAST AIR-TO-EVERYTHING (A2X) COMMUNICATIONS,” filed September 28, 2023, by Liu et al., each of which is assigned to the assignee of this application and each of which is expressly incorporated herein by reference. Technical Field

[0003] The following content relates to wireless communication, including unicast space-to-everything (A2X) communication. Background Technology

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, message sending and receiving, broadcasting, and so on. These systems can support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth-generation (4G) systems (such as Long Term Evolution (LTE) systems, LTE-A Advanced (LTE-A) systems, or LTE-A Pro systems) and fifth-generation (5G) systems (which may be referred to as New Radio (NR) systems). These systems may employ technologies such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal FDMA (OFDMA), or Discrete Fourier Transform Extended Orthogonal Frequency Division Multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations, each supporting wireless communication of communication devices, which may be referred to as User Equipment (UE).

[0005] Some wireless communications support communication between wireless devices (e.g., UEs), a process known as sidelink communication. For example, some wireless communication systems support vehicle-to-everything (V2X) communication, where vehicles within the system (e.g., UEs) can communicate with other wireless devices, including roadside infrastructure such as roadside units. Some wireless communication systems may also include UAVs that support unmanned aerial vehicle (UAV) services. UAVs can implement detection and avoidance (DAA) systems and technologies that support collision or conflict avoidance. Summary of the Invention

[0006] The described technology relates to improved methods, systems, devices, and apparatuses supporting unicast air-to-everything (A2X) communication. For example, the described technology allows a user equipment (UE) (such as an unmanned aerial vehicle (UAV)) to initiate a unicast link establishment process with another UAV, enabling the UAVs to communicate unicast messages to each other based on the A2X service type. Additionally, the described technology supports A2X configuration and communication parameters for communicating unicast messages via unicast links. The initiating UAV may be referred to as the source UAV, and the UAV establishing a unicast link with the source UAV may be referred to as the target UAV. In some examples, the source UAV may send a Direct Communication Request (DCR) message to the target UAV, which includes an application layer identifier (ID) unique to the target UAV. The source UAV may derive the application layer ID for the target UAV from the UE-specific ID unique to the target UAV and may indicate the application layer ID in the DCR message. In response to receiving the DCR message, the target UAV may establish security with the source UAV by sending a link establishment message to the source UAV.

[0007] In other examples, the source UAV may send a DCR message that excludes information about the target UAV. Instead, the source UAV may indicate one or more proximity parameters in the DCR message that enable the receiving UAV to determine the relative proximity of the source UAV and the receiving UAV. These proximity parameters may include the source UAV's location, speed, or heading, and the receiving UAV may determine the distance between the source and receiving UAVs to estimate the likelihood (e.g., probability, chance) of a collision with the source UAV. Additionally or alternatively, these proximity parameters may include the transmission power of the DCR message or the energy per resource element (EPRE) of a reference signal included in the DCR message, and the receiving UAV may determine the path loss associated with the source UAV. If the distance or path loss meets a threshold, the receiving UAV may continue the link establishment process with the source UAV.

[0008] A method for wireless communication by a first UE is described. The method may include: receiving a broadcast message from a second UE, the broadcast message including a UE-specific ID unique to the second UE for an unmanned aerial system (UAS) traffic management (UTM) system; sending a DCR message to the second UE in response to the broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both; and conveying a unicast message to the second UE according to the service type based on sending the DCR message to the second UE.

[0009] A first UE for wireless communication is described. The first UE may include: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories. The one or more processors may be able to operate individually or jointly to execute the code so that the first UE: receives a broadcast message from a second UE, the broadcast message including a UE-specific ID unique to the second UE for a UTM system; sends a DCR message to the second UE in response to the broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both; and conveys a unicast message to the second UE according to the service type based on sending the DCR message to the second UE.

[0010] Another first UE for wireless communication is described. The first UE may include: components for receiving a broadcast message from a second UE, the broadcast message including a UE-specific ID unique to the second UE for a UTM system; components for sending a DCR message to the second UE in response to the broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both; and components for conveying a unicast message to the second UE according to the service type based on sending the DCR message to the second UE.

[0011] A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to: receive a broadcast message from a second UE, the broadcast message including a UE-specific ID unique to the second UE for a UTM system; send a DCR message to the second UE in response to the broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific identifier included in the broadcast message, a service type associated with information for communicating with the first UE, or both; and convey a unicast message to the second UE according to the service type based on sending the DCR message to the second UE.

[0012] In some examples of the methods described herein, the first UE, and non-transitory computer-readable media, the service type includes the A2X service type.

[0013] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, the broadcast message may be a broadcast DAA message that further includes one or more positioning parameters associated with the second UE, including the positioning of the second UE, the speed of the second UE, the heading direction of the second UE, or a combination thereof.

[0014] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, the DCR message may be sent to the second UE based on a metric determined from the trajectory of the second UE and the one or more positioning parameters associated with the second UE satisfying a threshold.

[0015] In some examples of the methods described herein, the first UE, and non-transitory computer-readable media, the DCR message may be sent as part of a unicast link establishment process with the second UE.

[0016] In some examples of the methods described herein, the first UE, and the non-transitory computer-readable medium, at least one unicast message in the unicast message includes a unicast detection and avoidance (DAA) message.

[0017] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, the UE-specific ID includes a Civil Aviation Administration (CAA) level identity that identifies the second UE.

[0018] A method for wireless communication by a second UE is described. The method may include: sending a broadcast message to a first UE, the broadcast message including a UE-specific ID unique to the second UE for a UTM system; receiving a DCR message from the first UE in response to the broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both; and conveying a unicast message to the first UE according to the service type based on receiving the DCR message from the second UE.

[0019] A second UE for wireless communication is described. The second UE may include: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories. The one or more processors may be able to operate individually or jointly to execute the code to cause the second UE to: send a broadcast message to a first UE, the broadcast message including a UE-specific ID unique to the second UE for a UTM system; receive a DCR message from the first UE in response to the broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both; and, based on receiving the DCR message from the second UE, communicate a unicast message to the first UE according to the service type.

[0020] Another second UE for wireless communication is described. The second UE may include: components for sending a broadcast message to a first UE, the broadcast message including a UE-specific ID unique to the second UE for the UTM system; components for receiving a DCR message from the first UE in response to the broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both; and components for conveying a unicast message to the first UE according to the service type based on receiving the DCR message from the second UE.

[0021] A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to: send a broadcast message to a first UE, the broadcast message including a UE-specific ID unique to the second UE for a UTM system; receive a DCR message from the first UE in response to the broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both; and, based on receiving the DCR message from the second UE, convey a unicast message to the first UE according to the service type.

[0022] In some examples of the methods described herein, the second UE, and non-transitory computer-readable media, the service type includes the A2X service type.

[0023] In some examples of the methods described herein, the second UE, and the nontransitory computer-readable medium, the broadcast message may be a broadcast DAA message that further includes one or more positioning parameters associated with the second UE, including the positioning of the second UE, the speed of the second UE, the heading direction of the second UE, or a combination thereof.

[0024] In some examples of the methods described herein, the second UE, and non-transitory computer-readable media, the DCR message may be received as part of a unicast link establishment process with the first UE.

[0025] In some examples of the methods described herein, the second UE, and the non-transitory computer-readable medium, at least one of the unicast messages includes a unicast DAA message.

[0026] In some examples of the methods described herein, the second UE, and the nontransitory computer-readable medium, the UE-specific ID includes a CAA-level ID that identifies the second UE.

[0027] A method for wireless communication by a first UE is described. The method may include: sending a DCR message associated with a service type, the DCR message including one or more proximity parameters associated with the first UE; in response to the DCR message, receiving a link establishment message from the second UE based on a metric determined from a trajectory of a second UE and the one or more proximity parameters associated with the first UE satisfying a threshold; and conveying a unicast message to the second UE according to the service type based on receiving the link establishment message from the second UE.

[0028] A first UE for wireless communication is described. The first UE may include: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories. The one or more processors may be able to operate individually or jointly to execute the code to cause the first UE to: send a DCR message associated with a type of service, the DCR message including one or more proximity parameters associated with the first UE; receive a link establishment message from the second UE in response to the DCR message, based on a metric determined from a trajectory of a second UE and the one or more proximity parameters associated with the first UE satisfying a threshold; and communicate a unicast message to the second UE according to the type of service based on receiving the link establishment message from the second UE.

[0029] Another first UE for wireless communication is described. The first UE may include: components for transmitting a DCR message associated with a service type, the DCR message including one or more proximity parameters associated with the first UE; components for receiving a link establishment message from the second UE in response to the DCR message, based on a metric determined from a trajectory of the second UE and the one or more proximity parameters associated with the first UE satisfying a threshold; and components for conveying a unicast message to the second UE according to the service type based on receiving the link establishment message from the second UE.

[0030] A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to: send a DCR message associated with a type of service, the DCR message including one or more proximity parameters associated with a first UE; in response to the DCR message, receive a link establishment message from the second UE based on a metric determined from a trajectory of a second UE and the one or more proximity parameters associated with the first UE satisfying a threshold; and based on receiving the link establishment message from the second UE, convey a unicast message to the second UE according to the type of service.

[0031] In some examples of the methods described herein, the first UE, and non-transitory computer-readable media, the service type includes the A2X service type.

[0032] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, the one or more proximity parameters associated with the first UE include the location of the first UE, the speed of the first UE, the heading direction of the first UE, or a combination thereof, and the threshold includes a distance threshold.

[0033] In some examples of the methods described herein, the first UE, and the nontransient computer-readable medium, the one or more proximity parameters associated with the first UE include the transmission power of the DCR message, the energy per resource element (EPRE) of the reference signal included in the DCR message, or a combination thereof, and the threshold includes a path loss threshold.

[0034] The methods described herein, examples of the first UE, and some examples of non-transitory computer-readable media may further include operations, features, components, or instructions for sending a broadcast message that includes a set of location parameters associated with the first UE and a CAA-level ID identifying the first UE, wherein the one or more proximity parameters associated with the first UE include an application layer ID that may be unique to the first UE, the application layer ID being associated with a service type and derived from the CAA-level ID included in the broadcast message.

[0035] The methods described herein, examples of the first UE, and non-transitory computer-readable media may further include operations, features, components, or instructions for receiving one or more broadcast messages from one or more other UEs, wherein each of the one or more broadcast messages includes a UE-specific ID and a set of proximity parameters associated with the corresponding UE among the one or more other UEs, and wherein the DCR message may be sent as part of a unicast link establishment process with the second UE.

[0036] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, the UE-specific ID includes a CAA-level ID that identifies the second UE.

[0037] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, the one or more broadcast messages include one or more broadcast DAA messages.

[0038] In the methods described herein, and in some examples of the first UE and non-transitory computer-readable media, the DCR message excludes the application layer ID associated with the service type.

[0039] In some examples of the methods described herein, the first UE, and the non-transitory computer-readable medium, at least one unicast message in the unicast message includes a unicast DAA message.

[0040] A method for wireless communication by a second UE is described. The method may include: transmitting a broadcast message including a UE-specific ID unique to the second UE for a UTM system; receiving a DCR message associated with a service type from a first UE in response to the broadcast message, the DCR message including one or more proximity parameters associated with the first UE; transmitting a link establishment message to the first UE in response to the DCR message based on a metric determined from the trajectory of the second UE and the one or more proximity parameters associated with the first UE satisfying a threshold; and conveying a unicast message to the first UE according to the service type based on transmitting the link establishment message to the first UE.

[0041] A second UE for wireless communication is described. The second UE may include: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories. The one or more processors may be able to operate individually or jointly to execute the code to cause the second UE to: send a broadcast message including a UE-specific ID unique to the second UE for a UTM system; receive a DCR message associated with a service type from a first UE in response to the broadcast message, the DCR message including one or more proximity parameters associated with the first UE; send a link establishment message to the first UE in response to the DCR message based on a metric determined from the trajectory of the second UE and the one or more proximity parameters associated with the first UE satisfying a threshold; and communicate a unicast message to the first UE according to the service type based on sending the link establishment message to the first UE.

[0042] Another second UE for wireless communication is described. The second UE may include: components for transmitting a broadcast message including a UE-specific ID unique to the second UE for the UTM system; components for receiving a DCR message associated with a service type from a first UE in response to the broadcast message, the DCR message including one or more proximity parameters associated with the first UE; components for transmitting a link establishment message to the first UE in response to the DCR message, based on a metric determined from the trajectory of the second UE and the one or more proximity parameters associated with the first UE satisfying a threshold; and components for communicating a unicast message to the first UE according to the service type based on transmitting the link establishment message to the first UE.

[0043] A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to: send a broadcast message including a UE-specific ID unique to the second UE for a UTM system; receive a DCR message associated with a service type from a first UE in response to the broadcast message, the DCR message including one or more proximity parameters associated with the first UE; send a link establishment message to the first UE in response to the DCR message based on a metric determined from the trajectory of the second UE and the one or more proximity parameters associated with the first UE satisfying a threshold; and convey a unicast message to the first UE according to the service type based on sending the link establishment message to the first UE.

[0044] In some examples of the methods described herein, the second UE, and non-transitory computer-readable media, the service type includes the A2X service type.

[0045] In some examples of the methods, second UEs, and nontransitory computer-readable media described herein, the one or more proximity parameters associated with the first UE include the location of the first UE, and the methods, apparatus, and nontransitory computer-readable media may include further operations, features, components, or instructions for determining the metric including the distance between the first UE and the second UE, wherein the threshold includes a distance threshold.

[0046] In some examples of the methods, second UEs, and nontransitory computer-readable media described herein, the one or more proximity parameters associated with the first UE include the transmission power of the DCR message, and the methods, apparatus, and nontransitory computer-readable media may include further operations, features, components, or instructions for: measuring the reference signal received power (RSRP) associated with receiving the DCR message; and determining, based on the RSRP and the one or more proximity parameters, a metric including the path loss associated with the DCR message, wherein the threshold includes a path loss threshold.

[0047] The methods described herein, examples of the second UE, and some examples of nontransitory computer-readable media may further include operations, features, components, or instructions for: receiving a broadcast message from the first UE, the broadcast message including a set of location parameters associated with the first UE and a CAA-level ID identifying the first UE, wherein the one or more proximity parameters associated with the first UE include an application layer ID that may be unique to the first UE, the application layer ID being associated with a service type and derived from the CAA-level ID included in the broadcast message; and determining a metric including the distance between the first UE and the second UE based on the set of location parameters and the one or more proximity parameters, wherein the threshold includes a distance threshold.

[0048] In some examples of the methods described herein, the second UE, and the nontransitory computer-readable medium, the UE-specific ID includes a CAA-level ID that identifies the second UE.

[0049] In the methods described herein, and in some examples of the second UE and non-transitory computer-readable media, the DCR message excludes the application layer ID associated with the service type.

[0050] In some examples of the methods described herein, the second UE, and non-transitory computer-readable media, the broadcast message includes a set of proximity parameters associated with the second UE.

[0051] In some examples of the methods described herein, the second UE, and the non-transitory computer-readable medium, at least one of the unicast messages includes a unicast DAA message.

[0052] A method for wireless communication by a first UE is described. The method may include: establishing a communication link with a second UE based on a service type; communicating a sidelink message to the second UE indicating one or more parameters for the transmission of unicast DAA messages; and communicating one or more unicast DAA messages to the second UE based on the one or more parameters.

[0053] A first UE for wireless communication is described. The first UE may include: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories. The one or more processors may be able to operate individually or jointly to execute the code to enable the first UE to: establish a communication link with a second UE according to a service type; communicate with the second UE a sidelink message indicating one or more parameters for the communication of unicast DAA messages; and communicate with the second UE one or more unicast DAA messages according to the one or more parameters.

[0054] Another first UE for wireless communication is described. The first UE may include: components for establishing a communication link with a second UE according to a service type; components for communicating a sidelink message with the second UE indicating one or more parameters for the communication of unicast DAA messages; and components for communicating one or more unicast DAA messages with the second UE according to the one or more parameters.

[0055] A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to: establish a communication link with a second UE based on a service type; communicate a sidelink message to the second UE indicating one or more parameters for the transmission of unicast DAA messages; and communicate one or more unicast DAA messages to the second UE based on the one or more parameters.

[0056] In some examples of the methods described herein, the first UE, and non-transitory computer-readable media, the service type includes the A2X service type.

[0057] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, conveying the sidelink message may include operations, features, components, or instructions for: receiving the UAI sidelink message from the second UE; and determining the one or more parameters for conveying the unicast DAA message based on the one or more positioning parameters associated with the second UE.

[0058] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, conveying the sidelink message may include operations, features, components, or instructions for receiving the UAI sidelink message from the second UE.

[0059] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, conveying the one or more unicast DAA messages may include operations, features, components, or instructions for receiving the one or more unicast DAA messages from the second UE.

[0060] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, conveying the sidelink message may include operations, features, components, or instructions for sending the sidelink message to the second UE.

[0061] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, conveying the one or more unicast DAA messages may include operations, features, components, or instructions for receiving the one or more unicast DAA messages from the second UE.

[0062] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, conveying the one or more unicast DAA messages may include operations, features, components, or instructions for: sending a request to the second UE for the unicast DAA message in the one or more unicast DAA messages; and receiving the unicast DAA message from the second UE based on the request.

[0063] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, conveying the one or more unicast DAA messages may include operations, features, components, or instructions for: sending one or more location reference signals (PRS) to the second UE; and receiving the one or more unicast DAA messages from the second UE based on the one or more PRS.

[0064] The methods described herein, examples of the first UE, and some examples of nontransitory computer-readable media may further include operations, features, components, or instructions for: sending a first control message to the second UE indicating a set of configurations for the service type; and sending a second control message to the second UE indicating that a configuration from the set of configurations can be activated, the configuration including the one or more parameters.

[0065] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, the first control message includes a radio resource control (RRC) message, and the second control message includes a media access control (MAC) control element (MAC-CE) message or a sidelink control information (SCI) message.

[0066] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, conveying the sidelink message may include operations, features, components, or instructions for sending the UAI sidelink message to the second UE.

[0067] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, conveying the sidelink message may include operations, features, components, or instructions for sending the UAI sidelink message to the second UE.

[0068] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, conveying the one or more unicast DAA messages may include operations, features, components, or instructions for sending the one or more unicast DAA messages to the second UE.

[0069] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, conveying the sidelink message may include operations, features, components, or instructions for receiving the sidelink message from the second UE.

[0070] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, conveying the one or more unicast DAA messages may include operations, features, components, or instructions for sending the one or more unicast DAA messages to the second UE.

[0071] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, conveying the one or more unicast DAA messages may include operations, features, components, or instructions for: receiving a request from the second UE for a unicast DAA message in the one or more unicast DAA messages; and sending the unicast DAA message to the second UE based on the request.

[0072] In some examples of the methods described herein, the first UE, and the nontransitory computer-readable medium, conveying the one or more unicast DAA messages may include operations, features, components, or instructions for: receiving one or more location reference signals (PRS) from the second UE; and sending the one or more unicast DAA messages to the second UE, the one or more unicast DAA messages including location information associated with the first UE based on the receipt of the one or more PRS.

[0073] The methods described herein, examples of the first UE, and some examples of nontransitory computer-readable media may further include operations, features, components, or instructions for: receiving a first control message indicating a set of configurations for the service type; and receiving a second control message indicating that a configuration from the set of configurations can be activated, the configuration including the one or more parameters.

[0074] In some examples of the methods described herein, the first UE, and the non-transitory computer-readable medium, the first control message includes an RRC message, and the second control message includes a MAC-CE message or an SCI message. Attached Figure Description

[0075] Figure 1 An example of a wireless communication system supporting unicast A2X communication according to one or more aspects of this disclosure is shown.

[0076] Figure 2 An example of a wireless communication system supporting unicast A2X communication according to one or more aspects of this disclosure is shown.

[0077] Figures 3 to 5 An example of a process flow supporting unicast A2X communication according to one or more aspects of this disclosure is shown.

[0078] Figure 6 and Figure 7 A block diagram of an apparatus supporting unicast A2X communication according to one or more aspects of this disclosure is shown.

[0079] Figure 8 A block diagram of a communication manager supporting unicast A2X communication according to one or more aspects of this disclosure is shown.

[0080] Figure 9 A diagram of a system including a device supporting unicast A2X communication is shown according to one or more aspects of this disclosure.

[0081] Figures 10 to 17 A flowchart illustrating a method for supporting unicast A2X communication according to one or more aspects of this disclosure is shown. Detailed Implementation

[0082] Wireless communication systems can support communication between ground-based wireless devices (e.g., user equipment (UE), network entities) and air vehicles such as unmanned aerial vehicles (UAVs) or other unmanned aerial systems (UAS). Such UAVs can access or otherwise benefit from UAV-related services and communications (which may be referred to as air-to-everything (A2X) services and communications or UAV-to-everything (U2X) services and communications, etc.). For example, wireless communication systems can support UAV-to-UAV communication and UAV-to-ground UE communication. Some types of UAV-to-UAV communication may include broadcast messages, such as broadcast remote identifier (BRID) messages indicating information about the UAV's location and heading, flight information for remote identification, or a unique UAV identifier specific to the UAV (e.g., a Civil Aviation Administration (CAA) level identity), etc. Additionally, UAV-to-UAV communication may include broadcast and / or unicast detection and avoidance (DAA) messages designed to assist UAVs in avoiding collisions with each other. Such DAA messages may resemble safety messages used in vehicle-to-everything (V2X) communications, as UAVs can broadcast information about their location, heading, and other positional data. While V2X and A2X operations may share some similarities, some procedures and parameters used for V2X communications and services may differ from or be inapplicable to A2X services and communications, and may require defining separate A2X procedures and parameters.

[0083] Therefore, aspects of this disclosure relate to techniques enabling the establishment of unicast links for A2X communication between two UEs (e.g., UAVs). Specifically, aspects of this disclosure support signaling for initiating a unicast link establishment process between two UEs, techniques for performing the unicast link establishment process, and configurations and parameters for communicating via the unicast link according to an A2X service. For example, a first UE receiving a broadcast DAA can detect a potential collision with a second UE broadcasting the DAA. The first UE can be triggered to initiate a unicast link establishment process and can therefore send a Direct Communication Request (DCR) message to the second UE. The DCR message may include a unique identifier (ID) for the second UE to indicate that the DCR message is intended for the second UE. In some cases, the unique ID may be an application layer ID derived by the first UE from the UAV ID for the second UE included in the broadcast DAA. Based on receiving the DCR message, the second UE can respond using a link establishment message sent to the first UE, and the first and second UEs can subsequently communicate unicast messages via the established unicast link.

[0084] In some examples, the first UE and the second UE may communicate via a unicast link based on one or more communication parameters (e.g., one or more parameters for conveying unicast DAA messages). For example, the first UE may determine one or more communication parameters and may indicate such one or more communication parameters to the second UE, for example, via a sidelink message. Additionally or alternatively, the second UE may send a UE Auxiliary Information (UAI) message to the first UE indicating a preferred set of communication parameters, and the first UE may determine one or more communication parameters based on the UAI message. In some examples, the first UE, the second UE, or both may be configured (e.g., via control signaling, such as Radio Resource Control (RRC) messages) with a set of configurations for conveying unicast DAA messages and may receive control messages (e.g., Media Access Control (MAC) Control Element (MAC-CE), Sidelink Control Information (SCI)) indicating that a configuration in the set is activated. The first UE and the second UE may communicate based on one or more communication parameters associated with the activated configuration.

[0085] The various aspects of this disclosure are first described in the context of a wireless communication system. Then, the various aspects of this disclosure are discussed with reference to a processing flow. The various aspects of this disclosure are further illustrated by apparatus diagrams, system diagrams, and flowcharts relating to unicast A2X communication, and are described with reference to these apparatus diagrams, system diagrams, and flowcharts.

[0086] Figure 1 An example of a wireless communication system 100 supporting unicast A2X communication according to one or more aspects of this disclosure is shown. The wireless communication system 100 may include one or more network entities 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an Advanced LTE (LTE-A) network, an LTE-A Pro network, a New Radio (NR) network, or a network operating under other systems and radio technologies, including future systems and radio technologies not explicitly mentioned herein.

[0087] Network entity 105 may be distributed across a geographical area to form wireless communication system 100, and may include devices employing different forms or having different capabilities. In various examples, network entity 105 may be referred to as a network element, mobility element, radio access network (RAN) node, or network equipment, etc. In some examples, network entity 105 and UE 115 may wirelessly communicate via one or more communication links 125 (e.g., radio frequency (RF) access links). For example, network entity 105 may support coverage area 110 (e.g., a geographical coverage area) within which UE 115 and network entity 105 may establish one or more communication links 125. Coverage area 110 may be an example of a geographical area within which network entity 105 and UE 115 may support the transmission of signals according to one or more radio access technologies (RATs).

[0088] UE 115 can be distributed throughout the coverage area 110 of wireless communication system 100, and each UE 115 can be stationary or mobile, or stationary and mobile at different times. UE 115 can be devices in different forms or with different capabilities. Figure 1 Some example UE 115s are illustrated herein. The UE 115 described herein can be able to support various types of devices (such as, e.g., ...). Figure 1 It communicates with other UEs (115 or network entity 105) as shown.

[0089] As described herein, nodes of the wireless communication system 100 (which may be referred to as network nodes or wireless nodes) may be network entity 105 (e.g., any network entity described herein), UE 115 (e.g., any UE described herein), network controller, apparatus, device, computing system, one or more components, or another suitable processing entity configured to perform any of the techniques described herein. For example, a node may be UE 115. Alternatively, a node may be network entity 105. Furthermore, a first node may be configured to communicate with a second or third node. In one aspect of this example, the first node may be UE 115, the second node may be network entity 105, and the third node may be UE 115. In another aspect of this example, the first node may be UE 115, the second node may be network entity 105, and the third node may be network entity 105. In other aspects of this example, the first node, the second node, and the third node may be different from these examples. Similarly, references to UE 115, network entity 105, device, equipment, computing system, etc., may include disclosures of UE 115, network entity 105, device, equipment, computing system, etc., as nodes. For example, a disclosure that UE 115 is configured to receive information from network entity 105 also discloses that a first node is configured to receive information from a second node.

[0090] In some examples, network entity 105 may communicate with core network 130, communicate with each other, or both. For example, network entity 105 may communicate with core network 130 via one or more backhaul communication links 120 (e.g., according to S1, N2, N3, or other interface protocols). In some examples, network entities 105 may communicate with each other directly (e.g., directly between network entities 105) or indirectly (e.g., via core network 130) via backhaul communication links 120 (e.g., according to X2, Xn, or other interface protocols). In some examples, network entities 105 may communicate with each other via midhaul communication link 162 (e.g., according to midhaul interface protocol) or fronthaul communication link 168 (e.g., according to fronthaul interface protocol) or any combination thereof. Backhaul communication link 120, midhaul communication link 162, or fronthaul communication link 168 may be or include one or more wired links (e.g., electrical links, fiber optic links), one or more wireless links (e.g., radio links, wireless optical links), etc., or various combinations thereof. UE 115 can communicate with core network 130 via communication link 155.

[0091] One or more network entities in network entity 105 described herein may include or be referred to as base station 140 (e.g., transceiver base station, radio base station, NR base station, access point, radio transceiver, node B, eNodeB (eNB), next-generation node B or gigabit node B (any of which may be referred to as gNB), 5G NB, next-generation eNB (ng-eNB), home node B, home evolution node B, or other suitable terms). In some examples, network entity 105 (e.g., base station 140) may be implemented in an aggregated (e.g., monolithic, standalone) base station architecture that may be configured to utilize a protocol stack that is physically or logically integrated within a single network entity 105 (e.g., a single RAN node, such as base station 140).

[0092] In some examples, network entity 105 may be implemented in a decomposed architecture (e.g., a decomposed base station architecture, a decomposed RAN architecture) that can be configured to utilize protocol stacks physically or logically distributed across two or more network entities 105, such as an Integrated Access Backhaul (IAB) network, an Open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance), or a Virtualized RAN (vRAN) (e.g., a Cloud RAN (C-RAN)). For example, network entity 105 may include one or more of the following: a Central Unit (CU) 160, a Distributed Unit (DU) 165, a Radio Unit (RU) 170, a RAN Intelligent Controller (RIC) 175 (e.g., a near-real-time RIC, a non-real-time RIC), a Service Management and Orchestration (SMO) 180 system, or any combination thereof. 170 may also be referred to as a radio headend, intelligent radio headend, remote radio headend (RRH), remote radio unit (RRU), or transmit / receive point (TRP). One or more components of network entity 105 in a decomposed RAN architecture may be co-located, or one or more components of network entity 105 may be located in distributed locations (e.g., separate physical locations). In some examples, one or more network entities 105 in a decomposed RAN architecture may be implemented as virtual units (e.g., virtual CU (VCU), virtual DU (VDU), virtual RU (VRU)).

[0093] The functional splitting among CU 160, DU 165, and RU 170 is flexible and can support different functionalities depending on which functions (e.g., network layer functions, protocol layer functions, baseband functions, RF functions, and any combination thereof) are performed at CU 160, DU 165, or RU 170. For example, a protocol stack functional splitting can be used between CU 160 and DU 165, allowing CU 160 to support one or more layers of the protocol stack, and DU 165 to support one or more different layers of the protocol stack. In some examples, CU 160 can host higher protocol layer (e.g., Layer 3 (L3), Layer 2 (L2)) functionalities and signaling (e.g., Radio Resource Control (RRC), Serving Data Adaptation Protocol (SDAP), Packet Data Convergence Protocol (PDCP)). CU 160 can connect to one or more DU 165 or RU 170, and one or more DU 165 or RU 170 can host lower protocol layers, such as Layer 1 (L1) (e.g., Physical (PHY) layer) or L2 (e.g., Radio Link Control (RLC) layer, Medium Access Control (MAC) layer) functionality and signaling, and each can be at least partially controlled by CU 160. Additionally or alternatively, a protocol stack functional split can be employed between DU 165 and RU 170, such that DU 165 can support one or more layers of the protocol stack, and RU 170 can support one or more different layers of the protocol stack. DU 165 can support one or more different cells (e.g., via one or more RU 170). In some cases, functional decomposition between CU 160 and DU 165, or between DU 165 and RU 170, can be performed within the protocol layer (e.g., some functions of the protocol layer can be performed by one of CU 160, DU 165, or RU 170, while other functions of the protocol layer can be performed by different of CU 160, DU 165, or RU 170). CU 160 can be further functionally decomposed into CU control plane (CU-CP) functions and CU user plane (CU-UP) functions. CU 160 can be connected to one or more DU 165 via midhaul communication link 162 (e.g., F1, F1-c, F1-u), and DU 165 can be connected to one or more RU 170 via fronthaul communication link 168 (e.g., open fronthaul (FH) interface). In some examples, the midhaul communication link 162 or the fronthaul communication link 168 may be implemented based on the interfaces (e.g., channels) between the layers of the protocol stack, which are supported by the corresponding network entities 105 communicating via such communication links.

[0094] In a wireless communication system (e.g., wireless communication system 100), the infrastructure and spectrum resources for radio access can support wireless backhaul link capabilities to supplement wired backhaul connections, thereby providing an IAB network architecture (e.g., to core network 130). In some cases, in an IAB network, one or more network entities 105 (e.g., IAB node 104) may be partially controlled by each other. One or more IAB nodes 104 may be referred to as donor entities or IAB donors. One or more DU 165s or one or more RU 170s may be partially controlled by one or more CU 160s associated with donor network entity 105 (e.g., donor base station 140). One or more donor network entities 105 (e.g., IAB donors) may communicate with one or more additional network entities 105 (e.g., IAB node 104) via supported access and backhaul links (e.g., backhaul communication link 120). IAB node 104 may include an IAB mobile terminal (IAB-MT) controlled (e.g., scheduled) by a DU 165 of a coupled IAB donor. The IAB-MT may include a separate set of antennas for relaying communication with UE 115, or may share the same antennas (e.g., those of RU 170) for access to IAB node 104 via DU 165 of IAB node 104. (e.g., referred to as a virtual IAB-MT (vIAB-MT)). In some examples, IAB node 104 may include a DU 165 that supports communication links with additional entities (e.g., IAB node 104, UE 115) within a relay chain or configuration (e.g., downstream) of the access network. In such cases, one or more components of the decomposed RAN architecture (e.g., one or more IAB nodes 104 or components of IAB node 104) may be configured to operate according to the techniques described herein.

[0095] When the techniques described herein are applied in the context of a decomposed RAN architecture, one or more components of the decomposed RAN architecture can be configured to support unicast A2X communication as described herein. For example, some operations described as being performed by UE 115 or network entity 105 (e.g., base station 140) may additionally or alternatively be performed by one or more components of the decomposed RAN architecture (e.g., IAB node 104, DU 165, CU 160, RU 170, RIC 175, SMO 180).

[0096] UE 115 may include or be referred to as a mobile device, wireless device, remote device, handheld device, or subscriber device, or any other suitable term, wherein "device" may also be referred to as a cell, station, terminal, or client, etc. UE 115 may also include or be referred to as a personal electronic device, such as a cellular phone, personal digital assistant (PDA), tablet computer, laptop computer, or personal computer. In some examples, UE 115 may include or be referred to as a wireless local loop (WLL) station, Internet of Things (IoT) device, Internet of Everything (IoE) device, or machine-type communication (MTC) device, etc., which may be implemented in various objects such as appliances or vehicles, meters, etc.

[0097] The UE 115 described herein can communicate with various types of devices, such as other UEs 115 that sometimes act as relays, network entities 105, and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, etc. Figure 1 As shown.

[0098] UE 115 and network entity 105 can wirelessly communicate with each other via one or more communication links 125 (e.g., access links) using resources associated with one or more carriers. The term "carrier" can refer to a set of RF spectrum resources having a defined physical layer structure for supporting communication link 125. For example, a carrier for communication link 125 may include a portion of the RF spectrum band (e.g., a bandwidth portion (BWP)) operating according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling coordinating carrier operation, user data, or other signaling. Wireless communication system 100 can support communication with UE 115 using carrier aggregation or multi-carrier operation. Depending on the carrier aggregation configuration, UE 115 can be configured using multiple downlink component carriers and one or more uplink component carriers. Carrier aggregation can be used in conjunction with both frequency division duplex (FDD) component carriers and time division duplex (TDD) component carriers. Communication between network entity 105 and other devices can refer to communication between these devices and any part of network entity 105 (e.g., entity, sub-entity). For example, the terms “send,” “receive,” or “communicate” when referring to network entity 105 can refer to any part of the RAN’s network entity 105 (e.g., base station 140, CU160, DU 165, RU 170) communicating with another device (e.g., directly or via one or more other network entities 105).

[0099] In some examples, such as in carrier aggregation configurations, a carrier may also have acquisition signaling or control signaling to coordinate the operation of other carriers. A carrier may be associated with a frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute RF Channel Number (EARFCN)) and may be identified according to a channel grating used for discovery by UE 115. A carrier may operate in standalone mode, in which case initial acquisition and connection can be performed by UE 115 via that carrier, or the carrier may operate in non-standalone mode, in which case different carriers (e.g., the same or different radio access technologies) are used to anchor the connection.

[0100] The communication link 125 shown in the wireless communication system 100 may include downlink transmission (e.g., forward link transmission) from network entity 105 to UE 115, uplink transmission (e.g., return link transmission) from UE 115 to network entity 105, or both, as well as other transmission configurations. A carrier may carry downlink communication or uplink communication (e.g., in FDD mode), or may be configured to carry both downlink and uplink communication (e.g., in TDD mode).

[0101] A carrier may be associated with a specific bandwidth of the RF spectrum, and in some examples, the carrier bandwidth may be referred to as the carrier or the “system bandwidth” of the wireless communication system 100. For example, the carrier bandwidth may be one bandwidth in a set of bandwidths for a particular radio access technology (e.g., 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, 20 MHz, 40 MHz, or 80 MHz). Devices of the wireless communication system 100 (e.g., network entity 105, UE 115, or both) may have hardware configurations that support communication using a specific carrier bandwidth, or may be configured to support communication using one carrier bandwidth in a set of carrier bandwidths. In some examples, the wireless communication system 100 may include network entity 105 or UE 115 that supports concurrent communication using carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 may be configured to operate using a portion (e.g., subband, BWP) or all of the carrier bandwidth.

[0102] The signal waveform transmitted via a carrier may include multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform extended OFDM (DFT-S-OFDM)). In a system employing MCM, a resource element may refer to a resource of one symbol period (e.g., the duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing may be inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the decoding rate of the modulation scheme, or both), such that a relatively high number of resource elements (e.g., in the transmission duration) and a relatively high-order modulation scheme can correspond to a relatively high communication rate. Wireless communication resources may refer to a combination of RF spectrum resources, temporal resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial resources can increase the data rate or data integrity used for communication with UE 115.

[0103] The time interval for network entity 105 or UE 115 can be expressed as a multiple of a basic time unit, such as the sampling period. seconds, in response This can represent the supported subcarrier spacing, while The supported Discrete Fourier Transform (DFT) size can be represented. Time intervals for communication resources can be organized according to radio frames, each with a specified duration (e.g., 10 milliseconds (ms)). Each radio frame can be identified by a System Frame Number (SFN) (e.g., ranging from 0 to 1023).

[0104] Each frame may include multiple consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may (e.g., in the time domain) be divided into subframes, and each subframe may be further divided into a number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix appended to each symbol period). In some wireless communication systems 100, time slots may be further divided into multiple micro-time slots associated with one or more symbols. Excluding the cyclic prefix, each symbol period may be associated with one or more (e.g., The duration of a symbol period is associated with a (number) sampling period. The duration of a symbol period can depend on the subcarrier spacing or the operating frequency band.

[0105] A subframe, time slot, micro-time slot, or symbol can be the smallest scheduling unit of the wireless communication system 100 (e.g., in the time domain) and can be referred to as a transmission time interval (TTI). In some examples, the duration of the TTI (e.g., the number of symbol periods in the TTI) can be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 can be dynamically selected (e.g., in a burst of shortened TTIs (sTTIs)).

[0106] Depending on the technology, carriers can be used to multiplex physical channels for communication. For example, one or more of Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), or hybrid TDM-FDM techniques can be used to multiplex physical control channels and physical data channels for signaling via a downlink carrier. The control region (e.g., control resource set (CORESET)) of the physical control channel may be defined by a set of symbol periods and may extend across the system bandwidth of the carrier or a subset of that bandwidth. One or more control regions (e.g., CORESET) can be configured for a set of UEs 115. For example, one or more UEs in UE 115 may monitor or search for control regions to obtain control information based on one or more search space sets, and each search space set may include one or more control channel candidates in one or more aggregation levels arranged in a concatenated manner. The aggregation level of control channel candidates may refer to the amount of control channel resources (e.g., control channel elements (CCEs)) associated with coded information for a control information format having a given payload size. The search space set may include: a common search space set configured to transmit control information to multiple UEs 115, and a UE-specific search space set used to transmit control information to a specific UE 115.

[0107] Network entity 105 may provide communication coverage via one or more cells (e.g., macro cells, small cells, hotspots, or other types of cells, or any combination thereof). The term "cell" may refer to a logical communication entity used (e.g., using a carrier) to communicate with network entity 105 and may be associated with an identifier used to distinguish adjacent cells (e.g., Physical Cell Identifier (PCID), Virtual Cell Identifier (VCID), or other identifier). In some examples, a cell may also refer to a coverage area 110 or a portion of coverage area 110 (e.g., a sector) in which a logical communication entity operates. Depending on various factors such as the capabilities of network entity 105, the range of such cells may be from smaller areas (e.g., structures, subsets of structures) to larger areas. For example, a cell may be a building, a subset of buildings, or external space between or overlapping coverage areas 110, or may include buildings, subsets of buildings, or external space between or overlapping coverage areas.

[0108] Macro cells typically cover a relatively large geographic area (e.g., a radius of several kilometers) and allow unrestricted access to UE 115 that has a service subscription with a network provider supporting the macro cell. In contrast, small cells may be associated with a lower-power network entity 105 (e.g., a lower-power base station 140) and may operate using the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to UE 115 that has a service subscription with a network provider, or restricted access to UE 115 associated with a small cell (e.g., UE 115 in a Closed Subscriber Group (CSG), or UE 115 associated with a user in a home or office). Network entity 105 may support one or more cells and may also use one or more component carriers to support communication via one or more cells.

[0109] In some examples, a carrier can support multiple cells and can be configured with different cells based on different protocol types that provide access for different types of devices (e.g., MTC, Narrowband IoT (NB-IoT), Enhanced Mobile Broadband (eMBB)).

[0110] In some examples, network entity 105 (e.g., base station 140, RU 170) may be mobile, and thus provide communication coverage to mobile coverage areas 110. In some examples, different coverage areas 110 associated with different technologies may overlap, but the different coverage areas 110 may be supported by the same network entity 105. In some other examples, overlapping coverage areas 110 associated with different technologies may be supported by different network entities 105. The wireless communication system 100 may include, for example, a heterogeneous network in which different types of network entities 105 use the same or different radio access technologies to provide coverage for various coverage areas 110.

[0111] The wireless communication system 100 can support synchronous or asynchronous operation. For synchronous operation, network entities 105 (e.g., base station 140) can have similar frame timings, and transmissions from different network entities 105 can be approximately time-aligned. For asynchronous operation, network entities 105 can have different frame timings, and in some examples, transmissions from different network entities 105 may not be time-aligned. The techniques described herein can be used for both synchronous and asynchronous operation.

[0112] Some UE 115 devices (such as MTC or IoT devices) can be low-cost or low-complexity devices and can provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC can refer to data communication technologies that allow devices to communicate with each other or with network entity 105 (e.g., base station 140) without human intervention. In some examples, M2M communication or MTC may include communication from devices with integrated sensors or instruments to measure or acquire information and relay such information to a central server or application that uses the information or presents it to people interacting with the application. Some UE 115 devices may be designed to collect information or enable automated behavior of machines or other devices. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based billing.

[0113] Some UE 115s can be configured to operate in a power-saving mode, such as half-duplex communication (e.g., a mode that supports unidirectional communication via transmission or reception but does not involve concurrent transmission and reception). In some examples, half-duplex communication can be performed at a reduced peak rate. Other power-saving techniques for UE 115s include entering a power-saving deep sleep mode when not engaged in active communication, operating with limited bandwidth (e.g., according to narrowband communication), or a combination of these techniques. For example, some UE 115s can be configured to operate using a narrowband protocol type associated with a defined portion or range (e.g., a set of subcarriers or resource blocks (RBs)) within a carrier, within a carrier's guard band, or outside a carrier.

[0114] Wireless communication system 100 may be configured to support ultra-reliable communication or low-latency communication, or various combinations thereof. For example, wireless communication system 100 may be configured to support ultra-reliable low-latency communication (URLLC). UE 115 may be designed to support ultra-reliable or low-latency or critical functions. Ultra-reliable communication may include private or group communication and may be supported by one or more services, such as push-to-talk, video, or data. Support for ultra-reliable, low-latency functions may include prioritization of services, and such services may be used for public safety or general business applications. The terms “ultra-reliable,” “low-latency,” and “ultra-reliable low-latency” are used interchangeably herein.

[0115] In some examples, UE 115 may be configured to support direct communication with other UE 115s via device-to-device (D2D) communication link 135 (e.g., according to peer-to-peer (P2P), D2D, or sidelink protocols). In some examples, one or more UE 115s performing D2D communication in a group may be within the coverage area 110 of network entity 105 (e.g., base station 140, RU 170), which may support aspects of such D2D communication configured (e.g., scheduled by network entity 105). In some examples, one or more UE 115s in such a group may be outside the coverage area 110 of network entity 105, or may otherwise be unable or not configured to receive transmissions from network entity 105. In some examples, the group of UE 115s communicating via D2D communication may support a one-to-many (1:M) system in which each UE 115 transmits to each of the other UE 115s in the group. In some examples, network entity 105 may facilitate the scheduling of resources used for D2D communication. In other examples, D2D communication may be performed between UEs 115 without involving network entity 105.

[0116] In some systems, the D2D communication link 135 may be an example of a communication channel (such as a sidelink communication channel) between vehicles (e.g., UE 115). In some examples, vehicles may communicate using vehicle-to-vehicle (V2X) communication, vehicle-to-vehicle (V2V) communication, or a combination of these. Vehicles may signal information related to traffic conditions, signal control, weather, safety, emergencies, or any other information relevant to the V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure (such as roadside units), or communicate with the network via one or more network nodes (e.g., network entity 105, base station 140, RU 170) using vehicle-to-network (V2N) communication, or both.

[0117] Core network 130 provides user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. Core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), which may include at least one control plane entity (e.g., a mobility management entity (MME), access and mobility management function (AMF)) for managing access and mobility, and at least one user plane entity (e.g., a serving gateway (S-GW), packet data network (PDN) gateway (P-GW), or user plane function (UPF)) for routing packets or interconnecting to external networks. The control plane entity manages non-access stratum (NAS) functions, such as mobility, authentication, and bearer management of UE 115 served by network entity 105 (e.g., base station 140) associated with core network 130. User IP packets can be delivered through the user plane entity, which provides IP address allocation and other functions. The user plane entity may connect to one or more network operator IP services 150. IP services 150 may include access to the Internet, intranets, IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0118] Wireless communication system 100 can operate using one or more frequency bands in the range of 300 MHz to 300 GHz. Generally, the area from 300 MHz to 3 GHz is referred to as the Ultra High Frequency (UHF) band or decimeter band because the wavelength range is approximately one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features (which may be referred to as clusters), but these waves are sufficient to penetrate structures so that macrocells can provide service to UE 115 located indoors. Compared to communication using smaller frequencies and longer wavelengths in the lower frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz, communication using UHF waves can be associated with smaller antennas and shorter ranges (e.g., less than 100 km).

[0119] The wireless communication system 100 can also operate in the Ultra High Frequency (SHF) band (also known as the centimeter band) in the range of 3 GHz to 30 GHz or in the Extremely High Frequency (EHF) band (e.g., 30 GHz to 300 GHz) (also known as the millimeter band) using the spectrum. In some examples, the wireless communication system 100 can support millimeter-wave (mmW) communication between the UE 115 and the network entity 105 (e.g., base station 140, RU170), and the EHF antennas of the corresponding devices can be smaller and more closely spaced than UHF antennas. In some examples, such techniques facilitate the use of antenna arrays within the device. However, compared to SHF or UHF transmission, EHF transmission may experience even greater attenuation and a shorter range. The techniques disclosed herein can be adopted for transmission across one or more different frequency bands, and the frequency band usage specified across these frequency bands may vary by country or regulatory authority.

[0120] Wireless communication system 100 may utilize both licensed and unlicensed RF spectrum bands. For example, wireless communication system 100 may employ Licensed Assisted Access (LAA), LTE Unlicensed (LTE-U) radio access technology, or NR technology using unlicensed frequency bands (such as the 5 GHz Industrial, Scientific, and Medical (ISM) band). When operating using unlicensed RF spectrum bands, devices such as network entity 105 and UE 115 may employ carrier sensing for collision detection and avoidance. In some examples, operation using unlicensed frequency bands may be based on carrier aggregation configurations combined with component carriers operating using licensed frequency bands (e.g., LAA). Operation using unlicensed spectrum may include downlink transmission, uplink transmission, P2P transmission, or D2D transmission, etc.

[0121] Network entity 105 (e.g., base station 140, RU 170) or UE 115 may be equipped with multiple antennas that can be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. The antennas of network entity 105 or UE 115 may be located within one or more antenna arrays or antenna panels, which can support MIMO operation or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly (such as an antenna tower). In some examples, the antennas or antenna arrays associated with network entity 105 may be located at different geographical locations. Network entity 105 may include an antenna array having a collection of multiple rows and columns of antenna ports that network entity 105 can use to support beamforming for communication with UE 115. Similarly, UE 115 may include one or more antenna arrays that can support various MIMO or beamforming operations. Additionally or alternatively, the antenna panel may support RF beamforming for signals transmitted via the antenna ports.

[0122] Network entity 105 or UE 115 may use MIMO communication to leverage multipath signal propagation and improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers. This technique may be referred to as spatial multiplexing. The multiple signals may be transmitted, for example, by a transmitting device via different antennas or different combinations of antennas. Similarly, the multiple signals may be received by a receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry information associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include: single-user MIMO (SU-MIMO), for which multiple spatial layers are transmitted to the same receiving device; and multi-user MIMO (MU-MIMO), for which multiple spatial layers are transmitted to multiple devices.

[0123] Beamforming (also known as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting or receiving device (e.g., network entity 105, UE 115) to shape or guide an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting and receiving devices. Beamforming can be achieved by combining signals transmitted via antenna elements of an antenna array such that some signals propagating along a specific orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to the signals transmitted via the antenna elements may include applying amplitude shifts, phase shifts, or both to the signals carried via the antenna elements associated with the device. The adjustments associated with each of these antenna elements may be defined by a beamforming weight set associated with a specific orientation (e.g., relative to the antenna array of the transmitting or receiving device or relative to some other orientation).

[0124] Network entity 105 or UE 115 may use beamsweeping technology as part of beamforming operations. For example, network entity 105 (e.g., base station 140, RU 170) may use multiple antennas or antenna arrays (e.g., antenna panels) for beamforming operations to facilitate directional communication with UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times by network entity 105 along different directions. For example, network entity 105 may transmit signals according to different beamforming weight sets associated with different transmission directions. Transmission along different beam directions may be used to identify (e.g., by a transmitting device (such as network entity 105) or by a receiving device (such as UE 115)) the beam direction for later transmission or reception by network entity 105.

[0125] Some signals (such as data signals associated with a specific receiving device) may be transmitted by a transmitting device (e.g., transmitting network entity 105, transmitting UE 115) along a single beam direction (e.g., the direction associated with the receiving device (such as receiving network entity 105 or receiving UE 115). In some examples, the beam direction associated with transmission along a single beam direction may be determined based on the signals transmitted along one or more beam directions. For example, UE 115 may receive one or more signals transmitted by network entity 105 along different directions and may report to network entity 105 an indication of signals received by UE 115 with the highest signal quality or other acceptable signal quality.

[0126] In some examples, transmissions performed by a device (e.g., network entity 105 or UE 115) may be performed using multiple beam directions, and the device may use a combination of digital pre-decoding or beamforming to generate a combined beam for transmission (e.g., from network entity 105 to UE 115). UE 115 may report feedback indicating pre-decoding weights for one or more beam directions, and this feedback may correspond to a set of beams configured across the system bandwidth or one or more sub-bands. Network entity 105 may transmit reference signals (e.g., cell-specific reference signals (CRS), channel state information reference signals (CSI-RS)) that may or may not be pre-decoded. UE 115 may provide feedback for beam selection, which may be a pre-decoding matrix indicator (PMI) or codebook-based feedback (e.g., multi-panel codebook, linear combination codebook, port selection codebook). Although these techniques are described with reference to signals transmitted by network entity 105 (e.g., base station 140, RU 170) along one or more directions, UE 115 may use similar techniques to transmit signals multiple times along different directions (e.g., to identify the beam direction used by UE 115 for subsequent transmission or reception), or to transmit signals along a single direction (e.g., to transmit data to a receiving device).

[0127] A receiving device (e.g., UE 115) may perform reception operations according to multiple reception configurations (e.g., directional listening) when receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from a transmitting device (e.g., network entity 105). For example, the receiving device may perform reception according to multiple reception directions by: receiving via different antenna subarrays; processing the received signal according to different antenna subarrays; receiving according to different sets of reception beamforming weights (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of the antenna array; or processing the received signal according to different sets of reception beamforming weights applied to signals received at multiple antenna elements of the antenna array. Any of these operations may be referred to as “listening” according to different reception configurations or reception directions. In some examples, the receiving device may use a single reception configuration to receive along a single beam direction (e.g., when a data signal is received). A single receiver configuration can be aligned along a beam direction determined based on listening according to different receiver configuration directions (e.g., a beam direction determined to have the highest signal strength, highest signal-to-noise ratio (SNR), or other acceptable signal quality based on listening according to multiple beam directions).

[0128] The wireless communication system 100 can be a packet-based network operating according to a layered protocol stack. In the user plane, communication at the bearer or PDCP layer can be IP-based. The RLC layer can perform packet segmentation and reassembly for transmission via logical channels. The MAC layer can perform priority handling and multiplexing of logical channels to transport channels. The MAC layer can also use error detection, error correction, or both to support retransmission to improve link efficiency. In the control plane, the RRC layer can provide the establishment, configuration, and maintenance of RRC connections between the UE 115 and network entity 105 or core network 130 that support user plane data radio bearers. The PHY layer can map transport channels to physical channels.

[0129] UE 115 and network entity 105 can support data retransmission to increase the likelihood of successful data reception. Hybrid Automatic Repeat Request (HARQ) feedback is a technique used to increase the likelihood of correctly receiving data via communication links (e.g., communication link 125, D2D communication link 135). HARQ may include a combination of error detection (e.g., using Cyclic Redundancy Check (CRC)), forward error correction (FEC), and retransmission (e.g., Automatic Repeat Request (ARQ)). HARQ can improve throughput at the MAC layer under poor radio conditions (e.g., low signal-to-noise ratio conditions). In some examples, the device may support same-slot HARQ feedback, in which case the device can provide HARQ feedback in a specific time slot for data received via a previous symbol in that time slot. In some other examples, the device may provide HARQ feedback in subsequent time slots or according to a different time interval.

[0130] Wireless communication system 100 can support communication between ground-based wireless devices (e.g., UE 115, network entity 105) and air vehicles such as UAV UE 115 or other unmanned aerial systems. For example, the wireless communication system can support UAV-to-UAV communication (between UAV UE 115 via communication link 125) and UAV-to-ground UE or network entity communication. Some types of UAV-to-UAV communication may be referred to as A2X services and communications, such as DAA messages designed to assist UAV UE 115 in avoiding collisions with each other. Such DAA messages may broadcast information about the UAV's location, heading, and other positional information. UAV UE 115 can broadcast DAA messages, and any UAV UE 115 may be able to receive DAA messages and determine, based on the positional information in the DAA messages, whether there is a risk of collision with the broadcasting UAV UE 115. Additionally, A2X services may include broadcasting BRID messages, which may include a unique UE-specific ID associated with the sending UAV UE 115. In some cases, BRID messages can also indicate information about the location and heading of the UAV UE 115, as well as flight information for remote identification. In some examples, the ground UE 115 may be associated with a user on the ground.

[0131] Additionally, the wireless communication system 100 may support unicast link establishment for A2X communication between two UAV UEs 115 according to the techniques described herein. The first UE 115 (e.g., a UAV UE) may broadcast a DAA message indicating its location information and, in some cases, a UE-specific ID (such as a CAA-level ID) unique to the first UE 115. The second UE 115 (e.g., a UAV UE) may receive the broadcast DAA message and determine, based on the location information, whether a collision with the first UE 115 is possible or imminent. For example, the application layer of the second UE 115 may compare its trajectory (e.g., the trajectory of the second UE 115) with the location information of the first UE 115. If the application layer of the second UE 115 detects a possible collision, it may initiate a collision avoidance or conflict resolution process with the first UE 115. In some examples, the second UE 115 may notify the Unmanned Aerial Vehicle Service Provider (USS) of the detected potential collision.

[0132] As part of the collision avoidance or conflict resolution process, the second UE 115 may select a communication mode (e.g., broadcast or unicast) for DAA conflict resolution, for example, based on any associated A2X policy and input received from the application layer. If the second UE 115 selects the broadcast communication mode, it may broadcast a DAA message including a request to exchange information for conflict resolution. The first UE 115 may receive the DAA message and respond by broadcasting a second DAA message including a conflict resolution response. In other scenarios, the second UE 115 may optionally select the unicast communication mode and may trigger (e.g., initiate) a UE-oriented Layer 2 link establishment process for unicast communication with the first UE 115.

[0133] For example, as described herein, triggering a Layer 2 link establishment process may include a second UE 115 sending a DCR message to a first UE 115, wherein the DCR message includes a request to exchange information for conflict resolution, a request to establish a unicast link with the first UE 115, or a combination thereof. Additionally, the DCR message may include target user information associated with the target of the DCR message (e.g., the first UE 115), such as a unique UE-specific ID associated with the first UE 115, to indicate that the DCR message is intended for the first UE 115. In some cases, the unique ID may be an application layer ID associated with the first UE 115 derived by the second UE 115 from a CAA-level ID associated with the first UE 115 (e.g., as indicated in a broadcast DAA). For example, the second UE 115 may derive the application layer ID associated with the first UE 115 based on a one-to-one mapping between the CAA-level ID and the application layer ID indicated in the DCR message.

[0134] Alternatively, the DCR message may exclude target user information and may optionally include location information associated with the second UE 115. In the absence of explicit target user information, a DCR message sent from the second UE 115 may be responded to by one or more other UEs 115. In some cases, the DCR message may explicitly indicate location information associated with the second UE 115, such as location, speed, and direction (e.g., heading). The first UE 115 may use the location information to determine whether to respond to the DCR message and, in doing so, continue the unicast link establishment process.

[0135] In other cases, the DCR message may include information to assist the first UE 115 in determining location information associated with the second UE 115. For example, the DCR message may include an indication of the transmit power of the DCR message (e.g., a reference signal such as a demodulation reference signal (DMRS) in the DCR message) or the energy per resource element (EPRE) of the DCR message (e.g., the energy per resource element of the reference signal such as the DMRS in the DCR message). Here, the first UE 115 may measure the received reference signal received power (RSRP) of the received DCR message and may use the RSRP and transmit power or EPRE to calculate the path loss associated with the DCR message. Based on the path loss, the first UE 115 may determine whether to respond to the DCR message and continue the unicast link establishment process.

[0136] In another example, when the DCR message excludes target user information, the second UE 115 may optionally include a unique UE-specific ID (e.g., an application layer ID associated with the A2X service type) corresponding to the second UE 115 in the DCR message. The second UE 115 may periodically send broadcast DAA messages, which include location information and a CAA-level ID unique to the second UE 115. The second UE 115 may derive the UE-specific ID from the CAA-level ID used for broadcasting the DAA message to indicate this in the DCR message. The first UE 115 may receive both the broadcast DAA message and the DCR message from the second UE 115. The first UE 115 may use the UE-specific ID of the second UE 115 from the DCR message and the location information of the second UE 115 from the broadcast DAA message to determine the proximity of the second UE 115 to the first UE 115. Based on the proximity (e.g., based on the distance between the second UE 115 and the first UE 115), the first UE 115 may determine whether to respond to the DCR message.

[0137] If the first UE 115 determines that it has responded to the DCR, the first UE 115 may send a link establishment message to the second UE 115, and the first UE 115 and the second UE 115 may subsequently communicate unicast messages via the established unicast link. In some examples, the first UE 115 and the second UE 115 may communicate via the unicast link based on one or more communication parameters (e.g., one or more parameters for communicating unicast DAA messages). For example, the first UE 115 may determine one or more communication parameters and may indicate such one or more communication parameters to the second UE 115, for example, via a sidelink message. Additionally or alternatively, the second UE 115 may send a UAI message indicating a preferred set of communication parameters to the first UE 115, and the first UE 115 may determine one or more communication parameters based on the UAI message. In some examples, the first UE 115, the second UE 115, or both may be configured (e.g., via control signaling, such as RRC messages) with a set of configurations for conveying unicast DAA messages, and may receive control messages (e.g., MAC-CE, SCI) indicating that a configuration in the set of configurations is activated. The first UE 115 and the second UE 115 may communicate via a unicast link according to one or more communication parameters associated with the activated configuration.

[0138] Figure 2 An example of a wireless communication system 200 supporting unicast A2X communication according to one or more aspects of this disclosure is shown. The wireless communication system 200 includes UAV 205-a, UAV 205-b, UAV 205-c, and network entity 105-a. Network entity 105-a may be a terrestrial wireless device operating on the ground. UAV 205 may be an example of an airborne UE (e.g., a UAV UE) operating in autonomous flight mode. For example, UAV 205 may be an aircraft, a drone, a remotely operated manned aircraft, or a manned aircraft, etc.

[0139] The wireless communication system 200 can support communication between network entity 105-a and UAV 205 via a corresponding communication link, which can be referred to herein. Figure 1 An example of the described communication link 125. For example, UAV 205 and network entity 105-a can perform uplink and downlink communication via a Uu link (e.g., a bidirectional link capable of both uplink and downlink communication), and UAV 205 can communicate with each other via one or more PC5 links (e.g., sidelink communication links). In this way, wireless communication system 200 can support UAV-to-UAV communication and UAV-to-ground UE communication.

[0140] UAV 205 can operate as part of an Unmanned Aerial Vehicle System (UAS) traffic management (UTM) system and can support A2X services and communications. A2X applications can include any application that uses one or more A2X services. Generally, the term "A2X communication" can refer to communication that supports A2X services utilizing Uu and / or PC5 reference points. An A2X service belongs to an A2X service type and may include message or other data delivery. An A2X service may be associated with one or more A2X applications, and an A2X application may be associated with one or more A2X services. An example of an A2X service may include DAA, where UAV 205 can monitor traffic and maintain a safe distance from nearby aircraft (e.g., cooperative and non-cooperative aircraft) to avoid collision hazards.

[0141] For example, UAV 205 can send and receive A2X services (e.g., BRID, DAA, UAV-to-UAV communication, UAV-to-ground communication) via a PC5 link. Some types of A2X communication may include DAA messages designed to assist UAV 205 in avoiding collisions with each other. Such DAA messages may broadcast information about the UAV's location, heading, and other positional information. DAA messages can provide situational awareness, alerts, and avoidance to maintain safe beyond-line-of-sight (BVLOS) operation of UAV 205. Additionally, different variations or types of DAA messages may correspond to different requirements of UAV 205. For example, broadcast DAA may include an application-layer DAA payload indicating the CAA-level UAV ID, location, heading, time, and other information (e.g., position and orientation information) associated with the transmitting UAV 205, and may be broadcast periodically by UAV 205. DAA collision avoidance messages may be broadcast or unicast and may indicate data that differs from (or is other than) the information indicated in the broadcast DAA message.

[0142] To support DAA signaling, UAV 205 can utilize a DAA system (or Sensing and Avoidance (SAA) system), which allows UAV 205 to integrate into civilian airspace by avoiding collisions with other aircraft or UAVs, buildings, power lines, birds, and other obstacles. Such systems are configured to observe the environment surrounding UAV 205, determine if a collision is imminent, and generate a new flight path to avoid it. UAV DAA / SAA systems can combine data from multiple sensors, using sensor fusion algorithms, image recognition, and artificial intelligence to support collision avoidance. The data can be fed back to the UAV's onboard computer and / or flight controller, which can then determine evasive maneuvers or flight path corrections to avoid a collision.

[0143] Some DAA solutions can be active or passive solutions that utilize sensor data. Passive solutions can use optoelectronic data (e.g., cameras), passive radar, and / or acoustic data. Active solutions can use sonar, lidar, and / or active radar. Some solutions can also be communication-based. For example, UAV 205 can use systems designed for manned aviation, such as Traffic Collision and Avoidance Systems (TCAS) and / or Automatic Dependent Surveillance-Broadcast (ADS-B) systems that periodically broadcast and receive identification data, location data, and other information. Some standards define DAA requirements based on Airborne Collision Avoidance Systems (ACAS).

[0144] Some types of A2X services may include BRID messages, which may indicate the UAS ID, UA type, UAS ID type, UAV 205 location and heading information, and flight information for remote identification. BRID messages may indicate the identifier of the sending UAV 205 (e.g., CAA-level UAV ID or UAS ID), UAS ID type, or unmanned aerial vehicle (UA) type. For example, a UAS ID may indicate a serial number (e.g., expressed in CTA-2063-A serial number format), a registration ID such as a CAA-level ID (e.g., provided by the CAA or an authorized representative if the Civil Aviation Administration (CAA) provides a method for registering the UAS), and a UTM ID (e.g., a Universally Unique ID (UUID)), which may be a unique ID provided by the UTM that can be traced back to a registration ID that can act as a dialogue ID to protect the exposure of operationally sensitive information. A UAS ID type may indicate a serial number, registration ID, or UTM UUID. UA type can help infer the performance, speed, and duration of UAV flight (e.g., a fixed-wing aircraft can generally fly forward compared to a multi-rotor aircraft), distinguish aircraft types without sharing operationally sensitive information, and correlate visual observations with received data.

[0145] In order to support such Figure 2 The example illustrates PC5-based A2X communication. UAV 205 can be configured with policies and parameters (e.g., RAT type, RF parameters, QoS requirements, service PLMN) to perform PC5 communication with other devices (e.g., other UAVs, other UEs). Some A2X services and procedures may depend on or be associated with V2X services and procedures. However, in some cases, due to differences in service type, application, policy and QoS requirements, and radio parameter requirements, some parameters and procedures for V2X may not be applicable to A2X services. In this respect, conventional V2X technologies may not be suitable for A2X policies and parameters for UAV 205.

[0146] For example, a V2X procedure for establishing a unicast communication link between UEs (e.g., a Layer 2 link establishment procedure) may not directly translate into A2X services and communications. As an example, a UE operating according to a V2X service type may initiate a unicast link establishment procedure with a target UE by sending a DCR that includes an indication of the V2X service type and the target UE's application layer ID, but the A2X service may have a defined A2X service type that differs from the V2X service type. In V2X, the application layer ID may be an ID for vehicles, pedestrians, or RSUs (e.g., in the context of a V2X application), which may not be usable for UEs supporting A2X services (e.g., BRID, DAA). For example, the application layer ID associated with an A2X service may be directly derived from the A2X service's payload. In another example, an A2X service may be associated with an A2X-specific PC5 QoS identifier (PQI) that is not interchangeable with a V2X PQI. Additionally or alternatively, some A2X services and procedures may not have adequately defined parameters or configurations to achieve optimal performance. Therefore, the technology described in this article supports A2X services and communications based on conventional V2X technology, but has been adapted to suit A2X devices and scenarios.

[0147] UAV 205-a can send broadcast DAA messages 215 to other UAVs 205 according to a broadcast communication mode. In some cases, UAV 205-a can broadcast DAA messages periodically, for example, based on a periodicity. The broadcast DAA message 215 may indicate A2X service information that identifies the A2X service associated with the broadcast DAA message 215, such as the A2X service type or A2X service ID. The broadcast DAA message 215 may further include an application layer DAA payload that may indicate a unique UE-specific ID for UAV 205-a, such as the CAA-level UAV ID of UAV 205-a. The application layer DAA payload may further indicate the location information of UAV 205-a, such as speed, location, or heading. The UE receiving the broadcast DAA message 215 may determine whether to decode or respond to the broadcast DAA message 215 based on the indicated A2X service type. For example, a terrestrial UE may avoid responding to broadcast DAA message 215 because a terrestrial UE may not wish to participate in the indicated A2X service.

[0148] However, UAV 205 (such as UAV 205-b, UAV 205-c, or both) may receive broadcast DAA messages 215 (e.g., based on an indicated A2X service) and may pass application-layer DAA payloads to upper layers of UAV 205, such as the application layer. The application layer of UAV 205 may perform collision detection to determine whether a potential collision with UAV 205-a is possible. In some examples, collision detection may include comparing the positioning information of UAV 205-a with the trajectory, position, location, or some combination thereof of UAV 205. For example, UAV 205 may determine a metric (e.g., a collision detection metric) based on the trajectory and location of UAV 205-a, and the trajectory and location of UAV 205, where a collision or potential collision scenario can be detected if the metric meets a threshold.

[0149] exist Figure 2 In the example, UAV 205-c may be far enough away from UAV 205-a that UAV 205-c cannot detect a potential collision with UAV 205-a. UAV 205-b may be relatively closer to UAV 205-a or may have a trajectory or location that conflicts with UAV 205-a's trajectory or location, and thus, UAV 205-b can detect a potential collision scenario with UAV 205-a. Therefore, UAV 205-b can initiate a collision avoidance or conflict resolution process with UAV 205-a. As part of the collision avoidance or conflict resolution process, UAV 205-b can, for example, select a unicast communication mode for DAA collision elimination based on any associated A2X strategy and input received from the application layer. UAV 205-b can trigger (e.g., initiate) a unicast (e.g., Layer 2) link establishment process for unicast communication with UAV 205-a, where UAV 205-b can be understood or referred to as a source device (e.g., a source UE), and UAV 205-a can be understood or referred to as a target device (e.g., a target UE). During the unicast link establishment process, UAV 205-b can determine the destination Layer 2 ID for signaling reception used for PC5 unicast link establishment, where the destination Layer 2 ID can be understood as the ID of the target device (e.g., UAV 205-a), with which UAV 205-b wishes to establish a unicast link.

[0150] The application layer of UAV 205-b can provide application information for PC5 unicast communication. This application information may include the A2X service type and, in some cases, the UE-specific ID associated with UAV 205-a. In some examples, the application layer may additionally provide any A2X application requirements for unicast communication, and UAV 205-b may determine the associated PC5 QoS parameters and PC5 QoS Flow ID (PFI). UAV 205-b may send a DCR message 220 to UAV 205-a as part of the unicast link establishment process. The DCR message 220 may include an indication requesting the establishment of a unicast link with UAV 205-a. In some cases, DCR message 220 may further include information about the source device (e.g., UAV 205-b), such as a unique UE-specific ID associated with UAV 205-b (e.g., CAA-level ID, application layer ID), and may include information related to the A2X service type for establishing the requested link, security information for establishing security with UAV 205-a, or any combination thereof.

[0151] The techniques described herein support schemes for establishing A2X unicast links, such as those for transmitting DAA messages between UAVs based on collision detection. In the first scheme, and as referenced... Figure 3 As described, DCR message 220 may further include information about the target device (e.g., UAV 205-a), such as the application layer ID for A2X unicast communication associated with UAV 205-a. Here, the source device (e.g., UAV 205-b) may derive or otherwise obtain the application layer ID for UAV 205-a based on a unique UE-specific ID associated with UAV 205-a (e.g., as indicated in the DAA payload of broadcast DAA message 215). For example, UAV 205-b may derive the application layer ID for UAV 205-a using a one-to-one mapping from the UE-specific ID of UAV 205-a to the application layer ID of UAV 205-a. In some cases, the application layer ID of UAV 205-b may be derived or otherwise obtained from the application layer ID of UAV 205-a, and the application layer ID may be provided to UAV 205-b. DCR message 220 may include an implicit or explicit indication of the application layer ID of UAV 205-a.

[0152] In some examples, UAV 205-b may derive the UE-specific ID of UAV 205-a based on the CAA-level ID of UAV 205-a (e.g., when broadcast DAA message 215 indicates the CAA-level ID of UAV 205-a). Here, UAV 205-b may then determine the application layer ID of UAV 205-a based on the mapping between the UE-specific ID and the application layer ID. Alternatively, the UE-specific ID may include the CAA-level ID of UAV 205-a or an example thereof, such that UAV 205-b derives the application layer ID from the CAA-level ID of UAV 205-a. In some examples, the CAA-level ID of UAV 205-a may be used directly (e.g., and indicated) as the application layer ID of UAV 205-a. Alternatively, the application layer ID for UAV 205-a may be derived from the UE-specific ID of UAV 205-a according to a function (e.g., hash function, truncation, padding).

[0153] Due to the nature of A2X communication and devices, the A2X communication channel can be a LOS channel, allowing A2X signals (e.g., broadcast DAA message 215, DCR message 220) to reach UAVs relatively far from the sending UAV. However, unicast DAA messages (e.g., unicast DAA message 225) and collision detection procedures may only be useful for UAVs that are relatively close to each other and at risk of collision. Therefore, the source device, the target device, or both can choose whether to respond to A2X messages (e.g., broadcast DAA message 215, DCR message 220) based on proximity.

[0154] In the first approach, the source device (e.g., the device sending DCR message 220, such as UAV 205-b) can determine whether to respond to the A2X message. For example, UAV 205-b may receive multiple broadcast DAA messages 215 from multiple UAVs 205 (such as UAV 205-a and UAV 205-c). Each broadcast DAA message 215 may include a corresponding UE-specific ID and one or more corresponding positioning parameters associated with the corresponding UAV 205. The one or more positioning parameters may indicate the location and trajectory of the corresponding UAV 205, such as positioning, speed, and heading. UAV 205-b may select or otherwise determine the broadcast DAA message 215 based on one or more positioning parameters, wherein the broadcast DAA message is responded to with DCR message 220. For example, UAV 205-b can select a target device (e.g., UAV 205) based on the distance between UAV 205-b and the target device, and establish an A2X unicast communication link with the target device to avoid collisions (e.g., for communication of unicast DAA messages 225).

[0155] UAV 205-b can determine its distance from UAV 205-a using one or more positioning parameters indicated in broadcast DAA message 215 received from UAV 205-a, and can determine its distance from UAV 205-c using one or more positioning parameters indicated in broadcast DAA message 215 received from UAV 205-c. UAV 205-b can determine that UAV 205-a is closer than UAV 205-c, and if so, can select UAV 205-a as the target device and send DCR message 220. In some cases, UAV 205-b can compare this distance to a threshold distance, wherein if the distance meets (e.g., is less than) the threshold distance, UAV 205-b sends DCR message 220 to the target device. Alternatively or additionally, the UAV205-b may determine a metric based on the distance and the trajectory of the UAV 205-b, and if the metric meets a threshold (e.g., a distance threshold), a DCR message 220 may be sent to the target device.

[0156] In any case, UAV 205-b may include the UE-specific ID of the selected target device (such as UAV 205-a) in DCR message 220. UAV 205-a may respond to DCR message 220 by establishing security with UAV 205-b based on the information included in DCR message 220 (such as the UE-specific ID). UAV 205-a and UAV 205-b may subsequently transmit one or more unicast DAA messages 225 via the established unicast communication link.

[0157] In the second option, and as referenced Figure 4 As described, UAV 205-b can exclude target device information from DCR message 220. Here, DCR message 220 may include an indication of an A2X service type (e.g., a DAA message), and any device interested in using the indicated A2X service type via a unicast link (e.g., any UAV 205) can respond to DCR message 220 and establish a unicast link with UAV 205-b. To prevent responses from UAV 205 relatively far from UAV 205-b, UAV 205-b may include an indication of one or more proximity parameters in DCR message 220 (e.g., one or more parameters that can be used to derive proximity to UAV 205-b). Therefore, in the second scenario, the target device (e.g., the device receiving DCR message 220, such as UAV 205-a) can determine whether to respond to DCR message 220 based on one or more proximity parameters.

[0158] For example, UAV 205-a may determine whether UAV 205-b is relatively adjacent to UAV 205-a based on one or more proximity parameters. In some cases, one or more proximity parameters may include information indicating the location or position of UAV 205-b, such as location, speed, and heading, and UAV 205-a may determine whether the distance between UAV 205-a and UAV 205-b meets (e.g., is less than) a distance threshold. UAV 205-a may, for example, use one or more proximity parameters and the trajectory of UAV 205-a to determine a metric, and may compare the metric with the distance threshold. If the metric meets the distance threshold, UAV 205-a may respond to DCR message 220 by establishing security with UAV 205-b and subsequently transmitting a unicast message (e.g., unicast DAA message 225) via the established unicast link.

[0159] In other cases, one or more proximity parameters may include information that enables UAV 205-a to identify the path loss associated with DCR message 220, such as the transmit power of DCR message 220, the EPRE of the reference signal included in DCR message 220 (e.g., DMRS, such as Physical Side Link Shared Channel (PSSCH) DMRS), or combinations thereof. UAV 205-a may measure the RSRP of DCR message 220 and may calculate the path loss associated with DCR message 220 based on one or more proximity parameters and RSRP. In this example, the threshold may be a path loss threshold, and UAV 205-a may compare the calculated path loss with the path loss threshold. Additionally or alternatively, UAV 205-a may use the path loss and the trajectory of UAV 205-a to determine a metric, and may compare that metric with the path loss threshold. In either case, if the path loss threshold is met, UAV 205-a can respond to DCR message 220 by establishing security with UAV 205-b and subsequently transmitting unicast messages (e.g., unicast DAA message 225) via the established unicast link.

[0160] In another example, one or more proximity parameters may include a unique UE-specific ID associated with UE 115-b, such as an application layer ID associated with an A2X service type. UE 115-b may send one or more broadcast DAA messages 215, which include location information associated with UE 115-b and a unique CAA-level ID for UE 115-b. UE 115-b may derive the application layer ID from the CAA-level ID used for broadcasting DAA messages 215. UE 115-a may receive broadcast DAA messages 215 and DCR messages 220 from the second UE 115-b. UE 115-a may determine the location or position of UE 115-b based on the application layer ID of UE 115-b and the location information from the broadcast DAA messages. For example, UE 115-a can identify (e.g., based on mapping) that the application layer ID of UE 115-b indicated in DCR message 220 corresponds to the CAA-level ID indicated in broadcast DAA message 215 sent by UE 115-b. Therefore, UE 115-a can use the location information in the corresponding broadcast DAA message 215 to determine the location or position of UE 115-b. For example, UE 115-a can determine the distance between UE 115-a and UE 115-b, or the proximity of UE 115-b to UE 115-a. UE 115-a can determine a metric based on the proximity or distance and trajectory of UE 115-a. If the metric meets the corresponding distance threshold (e.g., proximity threshold, distance threshold), UE 115-a can respond to DCR message 220 by establishing security with UAV 205-b and subsequently transmitting a unicast message (e.g., unicast DAA message 225) via the established unicast link.

[0161] After establishing an A2X unicast link between UAV 205-a and UAV 205-b, and as referenced... Figure 5As discussed, UAV 205 can communicate unicast DAA message 225 according to a unicast DAA message configuration including one or more parameters. The one or more parameters may include periodic or power control information (e.g., transmit power for transmitting unicast DAA message 225) for communicating unicast DAA message 225. In some examples, a source device (e.g., UAV 205-b) can configure a target device (e.g., UAV 205-a) using one or more parameters for communicating unicast DAA messages via a unicast link. For example, UAV 205-b may send a first control message, such as an RRC message (e.g., a sidelink RRC message), indicating a set of configurations to UAV 205-a, each configuration associated with one or more corresponding parameters. UAV 205-b may additionally send a second control message (e.g., a sidelink control message, such as MAC-CE or SCI) to UAV 205-a, wherein the second control message indicates that one of the configurations in the set is activated. Therefore, UAV 205-a and UAV 205-b can convey unicast DAA messages 225 according to one or more parameters corresponding to the activated configuration.

[0162] In another example, the source device (e.g., UAV 205-b) may configure the target device (e.g., UAV 205-a) using one or more parameters based on sidelink UE Auxiliary Information (UAI) provided by the target device. UAV 205-a may send a sidelink UAI message to UAV 205-b indicating a preferred configuration for conveying the unicast DAA message (e.g., a preferred value for each of the one or more parameters). Additionally or alternatively, UAV 205-a may indicate its location information (e.g., location, speed, heading) in the sidelink UAI message. Based on the sidelink UAI message, UAV 205-b may select or otherwise determine one or more parameters for conveying the unicast DAA message 225. UAV 205-b may indicate one or more parameters to UAV 205-a, for example, via a sidelink message.

[0163] Additionally or alternatively, UAV 205-b may be configured to UAV 205-a to measure and report location information associated with UAV 205-a, for example, as part of a unicast DAA message 225 or via a separate sidelink message. UAV 205-b may indicate to UAV 205-a one or more parameters for reporting, such as the triggering event for UAV 205-a to send the report, transmission power, periodicity for sending the report, location information to be included in the report (such as timing advance (TA)), or a combination thereof. In some cases, the location information included in the report may be based on a Global Navigation Satellite System (GNSS) or on one or more Positioning Reference Signals (PRS). In the latter example, network entity 105-a or UAV 205-b may send one or more PRS to UAV 205-a, and UAV 205-a may determine the location information based on those one or more PRS. In some examples, UAV 205-b may request a report from UAV 205-a, for example, by sending a sidelink message indicating the request. UAV 205-a may then send a report to UAV 205-b in response to the request.

[0164] Figure 3 An example of a process flow 300 supporting unicast A2X communication according to one or more aspects of this disclosure is shown. Process flow 300 may be implemented, or can be implemented, by aspects of wireless communication systems 100 and 200. For example, process flow 300 illustrates operation between UAVs 305, which may be examples of corresponding devices (e.g., UE, UAV UE) described herein. Process flow 300 illustrates an example A2X unicast link establishment process based on a collision detection process for a UTM system.

[0165] In the following description of process flow 300, operations between UAVs 305 may be sent in a different order than the example order shown, or operations performed by UAVs 305 may be performed in a different order or at different times. Some operations may also be omitted from process flow 300, and other operations may be added to process flow 300. Additionally, although process flow 300 illustrates UAVs 305, it should be understood that any device or combination of devices may perform the operations shown.

[0166] At 320, UAV 305-c can send and UAV 305-a can receive a first broadcast DAA message including a first application layer DAA payload. The application layer DAA payload may include a UE-specific ID unique to UAV 305-c for the UTM system. In some examples, the UE-specific ID may include a CAA-level ID identifying UAV 305-c or an example thereof. In some cases, the application layer DAA payload may further include an indication of the service type and one or more positioning parameters associated with UAV 305-c, such as the location of UAV 305-c, the speed of UAV 305-c, the heading of UAV 305-c, or a combination thereof. The service type may be an A2X service type.

[0167] At 325, UAV 305-b can send and UAV 305-a can receive a second broadcast DAA message including a second application layer DAA payload. The application layer DAA payload may include a UE-specific ID unique to UAV 305-b for the UTM system. In some examples, the UE-specific ID may include a CAA-level ID identifying UAV 305-b or an example thereof. In some cases, the application layer DAA payload may further include an indication of the service type and one or more positioning parameters associated with UAV 305-b, such as the location of UAV 305-b, the speed of UAV 305-b, the heading of UAV 305-b, or a combination thereof. The service type may be an A2X service type.

[0168] At 330, UAV 305-a can determine whether a potential collision scenario exists with UAV 305-c, UAV 305-b, or both, based on the broadcast DAA received at 320 and 325. For example, UAV 305-a can pass a first application-layer DAA payload to its application layer. The application layer can compare the information included in the first application-layer DAA payload with the trajectory and location of UAV 305-a to detect a collision with UAV 305-c (e.g., a potential collision scenario). Figure 3 In the example, the application layer can detect that there is no conflict with UAV 305-c.

[0169] UAV 305-a can transfer the second application layer DAA payload to the application layer of UAV 305-a. The application layer can compare the information included in the second application layer DAA payload with the trajectory and positioning of UAV 305-a to detect collisions with UAV 305-b. Figure 3In the example, the application layer can detect a collision with UAV 305-b (e.g., a potential collision scenario). Based on the detected collision, the application layer of UAV 305-a can initiate a collision avoidance or conflict resolution (e.g., DAA collision elimination) process with UAV 305-b.

[0170] At 335, UAV 305-a can select a unicast communication mode (e.g., based on input received from the application layer at 330 and the associated A2X policy) for collision avoidance or conflict resolution procedures with UAV 305-b. Based on the selected unicast communication mode, UAV 305-a can initiate (e.g., trigger) a unicast link establishment procedure for unicast communication with UAV 305-b.

[0171] At 340, UAV 305-a can derive the application layer ID for UAV 305-b based on the UE-specific ID (e.g., CAA-level ID) indicated in the broadcast DAA message at 325. The application layer ID can be associated with an A2X service type. In some examples, UAV 305-a can derive the application layer ID for UAV 305-b using a mapping between UE-specific IDs and application layer IDs (e.g., a one-to-one mapping). In some cases, the UE-specific ID (e.g., CAA-level ID) can be used as the application layer ID.

[0172] At 345, UAV 305-a can send, and UAV 305-b can receive, a DCR message that includes a request to establish an A2X unicast link. The DCR message may additionally indicate the application layer ID derived at 340. The DCR message may be sent at 345 as part of the unicast link establishment process with UAV 305-b. In some cases, UAV 305-a may send the DCR message at 345 based on a metric that meets a threshold, where this metric is determined according to the trajectory of UAV 305-a and one or more positioning parameters included in a broadcast DAA message at 325.

[0173] At position 350, in response to receiving a DCR message at position 345, UAV 305-b can send and UAV 305-a can receive a link establishment message. UAV 305-a and UAV 305-b can establish a unicast link based on the link establishment message.

[0174] At 355, UAV 305-a and UAV 305-b can communicate A2X unicast messages to each other via the established unicast link, depending on the A2X service type. A2X unicast messages may include at least one DAA message, and in some examples, one or more BRID messages.

[0175] Figure 4An example of a process flow 400 supporting unicast A2X communication according to one or more aspects of this disclosure is shown. Process flow 400 may implement aspects of wireless communication systems 100 and 200, or may be implemented by aspects of wireless communication systems 100 and 200. For example, process flow 400 may exemplify operation between UAVs 405, which may be examples of the corresponding devices described herein. Process flow 400 exemplifies an example A2X unicast link establishment process based on a collision detection process for a UTM system.

[0176] In the following description of process flow 400, operations between UAVs 405 may be sent in a different order than the example order shown, or operations performed by UAVs 405 may be performed in a different order or at different times. Some operations may also be omitted from process flow 400, and other operations may be added to process flow 400. Additionally, although process flow 400 illustrates UAVs 405, it should be understood that any device or combination of devices may perform the operations shown.

[0177] At 425, UAV 405-b can send and UAV 405-a can receive broadcast DAA messages including an application-layer DAA payload. The application-layer DAA payload may include a UE-specific ID unique to UAV 405-b for the UTM system. In some examples, the UE-specific ID may include a CAA-level ID identifying UAV 405-b or an example thereof. In some cases, the application-layer DAA payload may further include an indication of the service type and one or more positioning parameters associated with UAV 405-b, such as the location of UAV 405-b, the speed of UAV 405-b, the heading of UAV 405-b, or a combination thereof. The service type may be an A2X service type.

[0178] At 430, UAV 405-a can determine whether a potential collision scenario exists with UAV 405-b based on the broadcast DAA received at 425. For example, UAV 405-a can pass a first application-layer DAA payload to its application layer. The application layer can compare the information included in the first application-layer DAA payload with the trajectory and location of UAV 405-a to detect a conflict with UAV 405-c (e.g., a potential collision scenario). Figure 4 In the example, the application layer can detect a collision with UAV 405-b (e.g., a potential collision scenario). Based on the detected collision, the application layer of UAV 405-a can initiate a collision avoidance or conflict resolution (e.g., DAA collision elimination) process with UAV 405-b.

[0179] At 435, UAV 405-a can select a unicast communication mode (e.g., based on input received from the application layer at 430 and the associated A2X policy) for collision avoidance or conflict resolution procedures with UAV 405-b. Based on the selected unicast communication mode, UAV 405-a can initiate (e.g., trigger) a unicast link establishment procedure for unicast communication with UAV 405-b.

[0180] At 440, UAV 405-a can send, and UAV 405-b can receive, a DCR message that includes a request to establish an A2X unicast link with UAV 405-b. UAV 405-a can send the DCR message as part of the unicast link establishment process with UAV 405-b. For example, the DCR message can be sent via PSSCH and may include one or more reference signals (e.g., DMRS). The DCR message may exclude the application layer ID of UAV 405-b associated with its service type.

[0181] The DCR message may indicate one or more proximity parameters associated with UAV 405-a. In some examples, the one or more proximity parameters may include the location of UAV 405-a, the speed of UAV 405-a, the heading of UAV 405-a, or a combination thereof. In some cases, the one or more proximity parameters may include the transmit power of the DCR message, the EPRE of the DMRS included in the DCR message, or a combination thereof. In some examples, the one or more proximity parameters may include an application layer ID that is unique to UAV 405-a and derived from the CAA-level ID associated with UAV 405-a.

[0182] At 445, UAV 405-b can determine whether a metric (e.g., a proximity metric) meets a threshold. UAV 405-b can determine the metric, for example, based on its trajectory and one or more proximity parameters indicated in the DCR message, and can compare the metric to a threshold. If one or more proximity parameters include the location of UAV 405-a, the speed of UAV 405-a, the heading of UAV 405-a, or a combination thereof, the metric can correspond to the distance between UAV 405-a and UAV 405-b, and the threshold can be a distance threshold. If one or more proximity parameters include the transmit power of the DCR message, the EPRE of the DMRS included in the DCR message, or a combination thereof, the metric can correspond to the path loss associated with the DCR message, and the threshold can be a path loss threshold. In this example, UAV 405-b can measure the RSRP associated with receiving the DCR message and can determine the metric (e.g., path loss) based on one or more proximity parameters and the RSRP.

[0183] At position 450, if the metric satisfies the threshold at position 445, then UAV 405-b can send and UAV 405-a can receive the link establishment message. For example, if the metric corresponds to the distance between UAV 405-a and UAV 405-b and the metric satisfies (e.g., less than) the distance threshold, then UAV 405-a can determine that UAV 405-a and UAV 405-b are relatively close and can continue the unicast link establishment process by sending a link establishment message. If the metric corresponds to the path loss of the DCR message and the metric satisfies (e.g., less than) the path loss threshold, then UAV 405-a can determine that the path loss of the DCR message is small; therefore, UAV 405-a can assume that UAV 405-b is relatively close to UAV 405-a and can continue the unicast link establishment process by sending a link establishment message. UAV 405-a and UAV 405-b can establish a unicast link based on the link establishment message.

[0184] At 455, UAV 405-a and UAV 405-b can communicate A2X unicast messages to each other via the established unicast link, depending on the A2X service type. A2X unicast messages may include at least one DAA message, and in some examples, one or more BRID messages.

[0185] Figure 5 An example of a process flow 500 supporting unicast A2X communication according to one or more aspects of this disclosure is shown. Process flow 500 may implement aspects of wireless communication systems 100 and 200, or may be implemented by aspects of wireless communication systems 100 and 200. For example, process flow 500 may exemplify operation between UAVs 505, which may be examples of the corresponding devices described herein. Process flow 500 exemplifies an example of UAVs 505 communicating via a unicast communication link based on one or more parameters used to convey unicast DAA messages.

[0186] In the following description of process flow 500, operations between UAVs 505 may be sent in a different order than the example order shown, or operations performed by UAVs 505 may be performed in a different order or at different times. Some operations may also be omitted from process flow 500, and other operations may be added to process flow 500. Additionally, although process flow 500 illustrates UAVs 505, it should be understood that any device or combination of devices may perform the operations shown.

[0187] At point 525, UAV 505-a and UAV 505-b can establish unicast communication links with each other based on their service type. The service type can be A2X service type. The unicast communication links can be used to transmit unicast DAA messages.

[0188] At 530, UAV 505-a and UAV 505-b can transmit at least one side link message via a unicast communication link.

[0189] In some examples, UAV 505-b may send and UAV 505-a may receive a first sidelink message in at least one sidelink message. Here, the first sidelink message may include a UAI sidelink message (e.g., a UEAssistanceInformationSidelink message) or examples thereof. In some cases, the UAI sidelink message may indicate one or more positioning parameters associated with UAV 505-b, such as the positioning of UAV 505-b, the speed of UAV 505-b, the heading of UAV 505-b, or a combination thereof. In such cases, UAV 505-a may determine one or more parameters for conveying unicast DAA messages based on one or more positioning parameters. Additionally, in some examples, UAV 505-a may send and UAV 505-b may receive a second sidelink message indicating one or more of the determined parameters.

[0190] In other cases, the UAI sidelink message may indicate one or more parameters used to transmit unicast DAA messages. These parameters may include, but are not limited to, the periodicity of the transmission of unicast DAA messages, the transmission power used to transmit unicast DAA messages, or a combination thereof.

[0191] Alternatively, UAV 505-a can send and UAV 505-b can receive a first sidelink message in at least one sidelink message. Here, the first sidelink message may indicate one or more parameters, including periodicity for conveying unicast DAA messages, location information associated with UAV 505-b to be included in one or more unicast DAA messages, a triggering event for conveying one or more unicast DAA messages, or a combination thereof.

[0192] In some cases, at least one sidelink message may include a first control message (e.g., a sidelink RRC message) indicating a set of configurations for conveying unicast DAA messages, wherein each configuration in the set may be associated with one or more parameters. UAV 505-a may send and UAV 505-b may receive the first control message. Additionally, at least one sidelink message may include a second control message (e.g., MAC-CE, SCI) indicating a configuration from the set and indicating that the configuration is activated. UAV 505-a may send and UAV 505-b may receive the second control message.

[0193] In some examples, at 535, UAV 505-a can send and UAV 505-b can receive a message indicating a request for a DAA message (e.g., a request for UAV 505-b to send a DAA message to UAV 505-b via a unicast link).

[0194] In some examples, at 540, UAV 505-a can transmit and UAV 505-b can receive one or more PRS.

[0195] At 545, UAV 505-a and UAV 505-b may convey one or more unicast DAA messages based on one or more parameters. For example, via a unicast link, UAV 505-a may send and UAV 505-b may receive one or more unicast DAA messages. Additionally or alternatively, via a unicast link, UAV 505-b may send and UAV 505-a may receive one or more unicast DAA messages. In some examples, in response to a request for a DAA message at 535, UAV 505-b may send and UAV 505-a may receive one or more unicast DAA messages. In some cases, UAV 505-b may send and UAV 505-a may receive one or more unicast DAA messages including location information associated with UAV 505-b, wherein the location information is determined by UAV 505-b based on the PRS received at 540.

[0196] Figure 6A block diagram 600 of a device 605 supporting unicast A2X communication according to one or more aspects of this disclosure is shown. Device 605 may be an example of various aspects of UE 115 as described herein. Device 605 may include a receiver 610, a transmitter 615, and a communication manager 620. Device 605, or one or more components of device 605 (e.g., receiver 610, transmitter 615, and communication manager 620), may include at least one processor that may be coupled to at least one memory to individually or jointly support or implement the described technologies. Each of these components may communicate with each other (e.g., via one or more buses).

[0197] Receiver 610 may provide components for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to unicast A2X communication). The information may be transmitted to other components of device 605. Receiver 610 may utilize a single antenna or a collection of antennas.

[0198] Transmitter 615 may provide components for transmitting signals generated by other components of device 605. For example, transmitter 615 may transmit information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to unicast A2X communication). In some examples, transmitter 615 may be co-located with receiver 610 in a transceiver module. Transmitter 615 may utilize a single antenna or a collection of multiple antennas.

[0199] The communication manager 620, receiver 610, transmitter 615, or various combinations thereof, or various components thereof, may be examples of components used to perform various aspects of unicast A2X communication as described herein. For example, the communication manager 620, receiver 610, transmitter 615, or various combinations thereof, or components thereof, may be able to perform one or more of the functions described herein.

[0200] In some examples, the communication manager 620, receiver 610, transmitter 615, or various combinations or components thereof may be implemented in hardware (e.g., in communication management circuitry). The hardware may include at least one of the following: a processor, digital signal processor (DSP), central processing unit (CPU), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, microcontroller, discrete gate or transistor logic device, discrete hardware component, or any combination thereof, configured as or otherwise individually or collectively to support components for performing the functions described herein. In some examples, at least one processor and at least one memory coupled to said at least one processor may be configured to perform one or more of the functions described herein (e.g., instructions stored in at least one memory are executed individually or collectively by one or more processors).

[0201] Additionally or alternatively, the communication manager 620, receiver 610, transmitter 615, or various combinations or components thereof may be implemented in code executed by at least one processor (e.g., as communication management software or firmware). If implemented in code executed by at least one processor, the functionality of the communication manager 620, receiver 610, transmitter 615, or various combinations or components thereof may be performed by any combination of a general-purpose processor, DSP, CPU, ASIC, FPGA, microcontroller, or these or other programmable logic devices (e.g., configured as or otherwise individually or jointly to support components for performing the functions described in this disclosure).

[0202] In some examples, the communication manager 620 may be configured to use or otherwise cooperate with the receiver 610, the transmitter 615, or both to perform various operations (e.g., receiving, acquiring, monitoring, outputting, transmitting). For example, the communication manager 620 may receive information from the receiver 610, transmit information to the transmitter 615, or be integrated with the receiver 610, the transmitter 615, or both to acquire information, output information, or perform various other operations as described herein.

[0203] Communication manager 620 can support wireless communications according to examples disclosed herein. For example, communication manager 620 is capable of, configured to, or operable to support components for receiving broadcast messages from a second UE, the broadcast messages including a UE-specific ID unique to the second UE for the UTM system. Communication manager 620 is capable of, configured to, or operable to support components for sending DCR messages to the second UE in response to broadcast messages, wherein the DCR messages include an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both. Communication manager 620 is capable of, configured to, or operable to support components for conveying unicast messages to the second UE based on the service type, based on sending DCR messages to the second UE.

[0204] Additionally or alternatively, the communication manager 620 may support wireless communications according to the examples disclosed herein. For example, the communication manager 620 may be capable of, configured to, or operable to support components for sending a broadcast message to a second UE, the broadcast message including a UE-specific ID unique to the first UE for the UTM system. The communication manager 620 may be capable of, configured to, or operable to support components for receiving a DCR message from the second UE in response to the broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both. The communication manager 620 may be capable of, configured to, or operable to support components for conveying a unicast message to the second UE based on the service type upon receiving the DCR message from the second UE.

[0205] Additionally or alternatively, the communication manager 620 may support wireless communications according to the examples disclosed herein. For example, the communication manager 620 may be capable of, configured to, or operable to support components for transmitting a DCR message associated with a service type, the DCR message including one or more proximity parameters associated with a first UE. The communication manager 620 may be capable of, configured to, or operable to support components for receiving a link establishment message from a second UE in response to a DCR message, based on a metric determined from a trajectory of a second UE and the satisfaction of a threshold value for one or more proximity parameters associated with the first UE. The communication manager 620 may be capable of, configured to, or operable to support components for communicating unicast messages with the second UE according to a service type based on receiving a link establishment message from the second UE.

[0206] Additionally or alternatively, the communication manager 620 may support wireless communications according to the examples disclosed herein. For example, the communication manager 620 may be capable of, configured to, or operable to support components for sending a broadcast message including a UE-specific ID unique to the first UE for the UTM system. The communication manager 620 may be capable of, configured to, or operable to support components for receiving a DCR message associated with a service type from a second UE in response to a broadcast message, the DCR message including one or more proximity parameters associated with the second UE. The communication manager 620 may be capable of, configured to, or operable to support components for sending a link establishment message to a second UE in response to a DCR message, based on a metric determined from the trajectory of the first UE and one or more proximity parameters associated with the second UE satisfying a threshold. The communication manager 620 may be capable of, configured to, or operable to support components for communicating a unicast message to the second UE based on a service type, based on sending a link establishment message to the second UE.

[0207] Additionally or alternatively, the communication manager 620 may support wireless communications according to the examples disclosed herein. For example, the communication manager 620 may be capable of, configured to, or operable to support components for establishing a communication link with a second UE based on a service type. The communication manager 620 may be capable of, configured to, or operable to support components for conveying sidelink messages with the second UE, indicating one or more parameters for conveying unicast DAA messages. The communication manager 620 may be capable of, configured to, or operable to support components for conveying one or more unicast DAA messages with the second UE based on one or more parameters.

[0208] By including or configuring a communication manager 620 according to an example as described herein, device 605 (e.g., at least one processor that controls or is otherwise coupled to receiver 610, transmitter 615, communication manager 620, or a combination thereof) can support technologies for improving A2X services and communications. For example, device 605 can establish an A2X unicast link with another device and communicate via the A2X unicast link according to a configuration for A2X unicast communication, thereby reducing processing at device 605, reducing power consumption, and improving communication efficiency.

[0209] Figure 7A block diagram 700 of a device 705 supporting unicast A2X communication according to one or more aspects of this disclosure is shown. Device 705 may be an example of aspects of device 605 or UE 115 as described herein. Device 705 may include a receiver 710, a transmitter 715, and a communication manager 720. Device 705, or one or more components of device 705 (e.g., receiver 710, transmitter 715, and communication manager 720), may include at least one processor that can be coupled to at least one memory to support the described technology. Each of these components may communicate with each other (e.g., via one or more buses).

[0210] Receiver 710 may provide components for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to unicast A2X communication). The information may be transmitted to other components of device 705. Receiver 710 may utilize a single antenna or a collection of antennas.

[0211] Transmitter 715 may provide components for transmitting signals generated by other components of device 705. For example, transmitter 715 may transmit information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to unicast A2X communication). In some examples, transmitter 715 may be co-located with receiver 710 in a transceiver module. Transmitter 715 may utilize a single antenna or a collection of multiple antennas.

[0212] Device 705 or its various components may be examples of parts for performing various aspects of unicast A2X communication as described herein. For example, communication manager 720 may include broadcast message component 725, DCR message component 730, unicast communication component 735, link establishment component 740, sidelink message component 745, or any combination thereof. Communication manager 720 may be examples of aspects of communication manager 620 as described herein. In some examples, communication manager 720 or its various components may be configured to use or otherwise cooperate with receiver 710, transmitter 715, or both to perform various operations (e.g., receiving, acquiring, monitoring, outputting, transmitting). For example, communication manager 720 may receive information from receiver 710, transmit information to transmitter 715, or be integrated with receiver 710, transmitter 715, or both to acquire information, output information, or perform various other operations as described herein.

[0213] Communication manager 720 can support wireless communication according to the examples disclosed herein. Broadcast message component 725 is capable of, configured to, or operable to support components for receiving broadcast messages from a second UE, the broadcast message including a UE-specific ID unique to the second UE for the UTM system. DCR message component 730 is capable of, configured to, or operable to support components for sending DCR messages to the second UE in response to the broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both. Unicast communication component 735 is capable of, configured to, or operable to support components for conveying unicast messages to the second UE based on the service type when sending DCR messages to the second UE.

[0214] Additionally or alternatively, the communication manager 720 may support wireless communication according to the examples disclosed herein. The broadcast message component 725 is capable of, configured to, or operable to support components for sending a broadcast message to a second UE, the broadcast message including a UE-specific ID unique to the first UE for the UTM system. The DCR message component 730 is capable of, configured to, or operable to support components for receiving a DCR message from the second UE in response to a broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both. The unicast communication component 735 is capable of, configured to, or operable to support components for conveying a unicast message to the second UE based on the service type received from the DCR message received from the second UE.

[0215] Additionally or alternatively, the communication manager 720 may support wireless communication according to the examples disclosed herein. The DCR message component 730 is capable of, configured to, or operable to support components for sending a DCR message associated with a service type, the DCR message including one or more proximity parameters associated with the first UE. The link establishment component 740 is capable of, configured to, or operable to support components for receiving a link establishment message from the second UE in response to a DCR message, based on a metric determined from the trajectory of the second UE and one or more proximity parameters associated with the first UE satisfying a threshold. The unicast communication component 735 is capable of, configured to, or operable to support components for communicating a unicast message to the second UE based on the service type upon receiving the link establishment message from the second UE.

[0216] Additionally or alternatively, the communication manager 720 may support wireless communication according to the examples disclosed herein. The broadcast message component 725 is capable of, configured to, or operable to support components for sending a broadcast message including a UE-specific ID unique to the first UE for the UTM system. The DCR message component 730 is capable of, configured to, or operable to support components for receiving a DCR message associated with a service type from a second UE in response to a broadcast message, the DCR message including one or more proximity parameters associated with the second UE. The link establishment component 740 is capable of, configured to, or operable to support components for sending a link establishment message to a second UE in response to a DCR message, based on a metric determined from the trajectory of the first UE and one or more proximity parameters associated with the second UE satisfying a threshold. The unicast communication component 735 is capable of, configured to, or operable to support components for communicating a unicast message to the second UE based on a service type, based on sending a link establishment message to the second UE.

[0217] Additionally or alternatively, the communication manager 720 may support wireless communications according to the examples disclosed herein. The link establishment component 740 is capable of, configured to, or operable to support components for establishing a communication link with the second UE based on the service type. The sidelink messaging component 745 is capable of, configured to, or operable to support components for conveying sidelink messages to the second UE, indicating one or more parameters for conveying unicast DAA messages. The unicast communication component 735 is capable of, configured to, or operable to support components for conveying one or more unicast DAA messages to the second UE based on one or more parameters.

[0218] Figure 8 A block diagram 800 of a communication manager 820 supporting unicast A2X communication according to one or more aspects of this disclosure is shown. The communication manager 820 may be an example of a communication manager 620, a communication manager 720, or aspects thereof as described herein. The communication manager 820 or its various components may be examples of parts for performing various aspects of unicast A2X communication as described herein. For example, the communication manager 820 may include a broadcast message component 825, a DCR message component 830, a unicast communication component 835, a link establishment component 840, a sidelink message component 845, a positioning component 850, or any combination thereof. Each of these components, or its components or sub-components (e.g., one or more processors, one or more memories), may communicate directly or indirectly with each other (e.g., via one or more buses).

[0219] Communication manager 820 can support wireless communication according to the examples disclosed herein. Broadcast message component 825 is capable of, configured to, or operable to support components for receiving broadcast messages from a second UE, the broadcast message including a UE-specific ID unique to the second UE for the UTM system. DCR message component 830 is capable of, configured to, or operable to support components for sending DCR messages to the second UE in response to the broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both. Unicast communication component 835 is capable of, configured to, or operable to support components for conveying unicast messages to the second UE based on the service type, based on the sending of DCR messages to the second UE.

[0220] In some examples, the service type includes the A2X service type.

[0221] In some examples, the broadcast message is a broadcast DAA message, which further includes one or more positioning parameters associated with the second UE, including the second UE's location, speed, heading, or a combination thereof. In some examples, a DCR message is sent to the second UE based on a metric determined from the second UE's trajectory and one or more positioning parameters associated with the second UE meeting a threshold.

[0222] In some examples, the DCR message is sent as part of the unicast link establishment process with the second UE. In some examples, at least one unicast message in the unicast message includes a unicast DAA message. In some examples, the UE-specific ID includes a CAA-level ID that identifies the second UE.

[0223] Additionally or alternatively, the communication manager 820 may support wireless communications according to examples disclosed herein. In some examples, the broadcast message component 825 is capable of, configured to, or operable to support components for sending a broadcast message to a second UE, the broadcast message including a UE-specific ID unique to the first UE for the UTM system. In some examples, the DCR message component 830 is capable of, configured to, or operable to support components for receiving a DCR message from the second UE in response to a broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both. In some examples, the unicast communication component 835 is capable of, configured to, or operable to support components for conveying a unicast message to the second UE based on the service type received from the DCR message received from the second UE.

[0224] In some examples, the service type includes the A2X service type.

[0225] In some examples, the broadcast message is a broadcast DAA message, which further includes one or more positioning parameters associated with the first UE, including the first UE's location, speed, heading, or a combination thereof. In some examples, the DCR message is received as part of a unicast link establishment process with the second UE. In some examples, at least one unicast message in the unicast message includes a unicast DAA message. In some examples, the UE-specific ID includes a CAA-level ID identifying the first UE.

[0226] Additionally or alternatively, the communication manager 820 may support wireless communications according to examples disclosed herein. In some examples, the DCR message component 830 is capable of, configured to, or operable to support components for sending a DCR message associated with a service type, the DCR message including one or more proximity parameters associated with the first UE. The link establishment component 840 is capable of, configured to, or operable to support components for receiving a link establishment message from the second UE in response to a DCR message, based on a metric determined from the trajectory of the second UE and the satisfaction of a threshold for one or more proximity parameters associated with the first UE. In some examples, the unicast communication component 835 is capable of, configured to, or operable to support components for communicating a unicast message to the second UE based on a service type upon receiving a link establishment message from the second UE.

[0227] In some examples, the service type includes the A2X service type.

[0228] In some examples, one or more proximity parameters associated with the first UE include the location of the first UE, the speed of the first UE, the heading direction of the first UE, or a combination thereof. In some examples, the threshold includes a distance threshold.

[0229] In some examples, one or more proximity parameters associated with the first UE include the transmit power of the DCR message, the EPRE of the reference signal included in the DCR message, or a combination thereof. In some examples, the threshold includes a path loss threshold.

[0230] In some examples, the broadcast message component 825 is capable of, configured to, or able to operate to support components for sending broadcast messages that include a set of location parameters associated with a first UE and a CAA-level ID identifying the first UE, wherein one or more proximity parameters associated with the first UE include an application layer ID unique to the first UE, which is associated with a service type and derived from the CAA-level ID included in the broadcast message.

[0231] In some examples, the broadcast message component 825 is capable of, configured to, or able to operate to support components for receiving one or more broadcast messages from one or more other UEs, wherein each of the one or more broadcast messages includes a UE-specific ID and a set of proximity parameters associated with the corresponding UE among the one or more other UEs, and wherein the DCR message is sent as part of a unicast link establishment process with a second UE.

[0232] In some examples, the UE-specific ID includes a CAA-level ID that identifies a second UE. In some examples, one or more broadcast messages include one or more broadcast DAA messages. In some examples, the DCR message excludes the application layer ID associated with the service type. In some examples, at least one unicast message in the unicast message includes a unicast DAA message.

[0233] Additionally or alternatively, the communication manager 820 may support wireless communications according to examples disclosed herein. In some examples, the broadcast message component 825 is capable of, configured to, or operable to support components for sending a broadcast message including a UE-specific ID unique to the first UE for the UTM system. In some examples, the DCR message component 830 is capable of, configured to, or operable to support components for receiving a DCR message associated with a service type from a second UE in response to a broadcast message, the DCR message including one or more proximity parameters associated with the second UE. In some examples, the link establishment component 840 is capable of, configured to, or operable to support components for sending a link establishment message to a second UE in response to a DCR message, based on a metric determined from the trajectory of the first UE and one or more proximity parameters associated with the second UE satisfying a threshold. In some examples, the unicast communication component 835 is capable of, configured to, or operable to support components for communicating a unicast message to the second UE based on a service type upon sending a link establishment message to the second UE.

[0234] In some examples, the service type includes the A2X service type.

[0235] In some examples, one or more proximity parameters associated with the second UE include the location of the second UE, and the location component 850 is capable of, configured to, or operable to support components for determining a metric including the distance between the second UE and the first UE, wherein the threshold includes a distance threshold.

[0236] In some examples, one or more proximity parameters associated with the second UE include the transmission power of the DCR message, and the positioning component 850 is capable of, configured to, or operable to support components for measuring the RSRP associated with receiving the DCR message. In some examples, one or more proximity parameters associated with the second UE include the transmission power of the DCR message, and the positioning component 850 is capable of, configured to, or operable to support components for determining a metric including path loss associated with the DCR message based on the RSRP and the one or more proximity parameters, wherein the threshold includes a path loss threshold.

[0237] In some examples, broadcast message component 825 is capable of, configured to, or operable to support components for receiving a broadcast message from a second UE, the broadcast message including a set of location parameters associated with the second UE and a CAA-level ID identifying the second UE, wherein one or more proximity parameters associated with the second UE include an application layer ID unique to the first UE, the application layer ID being associated with a service type and derived from the CAA-level ID included in the broadcast message. In some examples, location component 850 is capable of, configured to, or operable to support components for determining a metric including the distance between the first UE and the second UE based on the set of location parameters and one or more proximity parameters, wherein the metric includes a distance threshold.

[0238] In some examples, the UE-specific ID includes a CAA-level ID that identifies the first UE.

[0239] In some examples, the DCR message excludes the application layer ID associated with the service type. In some examples, the broadcast message includes a set of proximity parameters associated with the first UE. In some examples, at least one unicast message in the unicast message includes a unicast DAA message.

[0240] Additionally or alternatively, the communication manager 820 may support wireless communications according to examples disclosed herein. In some examples, the link establishment component 840 is capable of, configured to, or operable to support components for establishing a communication link with the second UE based on a service type. The sidelink messaging component 845 is capable of, configured to, or operable to support components for conveying sidelink messages to the second UE, indicating one or more parameters for conveying unicast DAA messages. In some examples, the unicast communication component 835 is capable of, configured to, or operable to support components for conveying one or more unicast DAA messages to the second UE based on one or more parameters.

[0241] In some examples, the service type includes the A2X service type.

[0242] In some examples, to support the delivery of sidelink messages, the sidelink message component 845 is capable of, configured to, or operable to support components for receiving UAI sidelink messages from the second UE. In some examples, to support the delivery of sidelink messages, the unicast communication component 835 is capable of, configured to, or operable to support components for determining one or more parameters for the delivery of unicast DAA messages based on one or more positioning parameters associated with the second UE.

[0243] In some examples, to support the delivery of sidelink messages, the sidelink message component 845 is capable of, configured to, or operable to support components for receiving UAI sidelink messages from the second UE. In some examples, to support the delivery of one or more unicast DAA messages, the unicast communication component 835 is capable of, configured to, or operable to support components for receiving one or more unicast DAA messages from the second UE.

[0244] In some examples, to support the delivery of sidelink messages, the sidelink message component 845 is capable of, configured to, or operable to support components for sending sidelink messages to the second UE. In some examples, to support the delivery of one or more unicast DAA messages, the unicast communication component 835 is capable of, configured to, or operable to support components for receiving one or more unicast DAA messages from the second UE.

[0245] In some examples, to support the delivery of one or more unicast DAA messages, the unicast communication component 835 is capable of, configured to, or operable to support components for sending a request to a second UE for one or more unicast DAA messages. In some examples, to support the delivery of one or more unicast DAA messages, the unicast communication component 835 is capable of, configured to, or operable to support components for receiving unicast DAA messages from a second UE based on a request.

[0246] In some examples, to support the delivery of one or more unicast DAA messages, the positioning component 850 is capable, configured, or operable to support components for sending one or more positioning reference signals (PRS) to the second UE. In some examples, to support the delivery of one or more unicast DAA messages, the unicast communication component 835 is capable, configured, or operable to support components for receiving one or more unicast DAA messages from the second UE based on one or more PRS.

[0247] In some examples, the unicast communication component 835 is capable of, configured to, or operable to support components for sending a first control message to a second UE indicating a set of configurations for a service type. In some examples, the unicast communication component 835 is capable of, configured to, or operable to support components for sending a second control message to a second UE indicating that a configuration from the configuration set is activated, the configuration including one or more parameters.

[0248] In some examples, the first control message includes an RRC message, and the second control message includes a MAC-CE message or an SCI message.

[0249] In some examples, in order to support the delivery of sidelink messages, the sidelink message component 845 can be, configured, or operated to support components for sending UAI sidelink messages to a second UE.

[0250] In some examples, in order to support the delivery of one or more unicast DAA messages, the unicast communication component 835 is capable of, configured to, or able to operate to support components for sending one or more unicast DAA messages to a second UE.

[0251] In some examples, in order to support the delivery of sidelink messages, the sidelink message component 845 can be, configured, or operated to support components for receiving sidelink messages from a second UE.

[0252] In some examples, in order to support the delivery of one or more unicast DAA messages, the unicast communication component 835 is capable of, configured to, or able to operate to support components for sending one or more unicast DAA messages to a second UE.

[0253] In some examples, to support the delivery of one or more unicast DAA messages, the unicast communication component 835 is capable of, configured to, or operable to support components for receiving requests for unicast DAA messages from a second UE. In some examples, to support the delivery of one or more unicast DAA messages, the unicast communication component 835 is capable of, configured to, or operable to support components for sending unicast DAA messages to a second UE based on a request.

[0254] In some examples, to support the delivery of one or more unicast DAA messages, the positioning component 850 is capable, configured, or operable to support components for receiving one or more Positioning Reference Signals (PRS) from the second UE. In some examples, to support the delivery of one or more unicast DAA messages, the sidelink messaging component 845 is capable, configured, or operable to support components for sending one or more unicast DAA messages to the second UE, the one or more unicast DAA messages including positioning information associated with the first UE based on the receipt of one or more PRS.

[0255] In some examples, the unicast communication component 835 is capable of, configured to, or operable to support a component for receiving a first control message indicating a set of configurations for a service type. In some examples, the unicast communication component 835 is capable of, configured to, or operable to support a component for receiving a second control message indicating that a configuration from the configuration set is activated, the configuration including one or more parameters.

[0256] In some examples, the first control message includes an RRC message, and the second control message includes a MAC-CE message or an SCI message.

[0257] Figure 9 A diagram of a system 900 including a device 905 supporting unicast A2X communication according to one or more aspects of this disclosure is shown. Device 905 may be an example of device 605, device 705, or UE 115 as described herein, or may include components thereof. Device 905 may communicate with one or more network entities 105, one or more UEs 115, or any combination thereof (e.g., wirelessly). Device 905 may include components for bidirectional voice and data communication, including components for transmitting and receiving communications, such as a communication manager 920, an input / output (I / O) controller 910, a transceiver 915, an antenna 925, at least one memory 930, code 935, and at least one processor 940. These components may communicate electronically or be coupled in other ways (e.g., operational ground, communication ground, functional ground, electronic ground, electrical ground) via one or more buses (e.g., bus 945).

[0258] I / O controller 910 manages the input and output signals of device 905. I / O controller 910 can also manage peripheral devices not integrated into device 905. In some cases, I / O controller 910 may represent a physical connection or port to an external peripheral device. In some cases, I / O controller 910 may utilize an operating system such as iOS. ® ANDROID ® MS-DOS ® MS-WINDOWS® OS / 2 ® UNIX ® LINUX ® Alternatively, it may be another known operating system. Additionally or alternatively, the I / O controller 910 may represent, or interact with, a modem, keyboard, mouse, touchscreen, or similar device. In some cases, the I / O controller 910 may be implemented as part of one or more processors, such as at least one processor 940. In some cases, a user may interact with the device 905 via the I / O controller 910 or via hardware components controlled by the I / O controller 910.

[0259] In some cases, device 905 may include a single antenna 925. However, in other cases, device 905 may have more than one antenna 925, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. Transceiver 915 may communicate bidirectionally via one or more antennas 925, a wired link, or a wireless link as described herein. For example, transceiver 915 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. Transceiver 915 may also include a modem for: modulating packets; providing the modulated packets to one or more antennas 925 for transmission; and demodulating packets received from one or more antennas 925. Transceiver 915, or transceiver 915 and one or more antennas 925, may be an example of transmitter 615, transmitter 715, receiver 610, receiver 710, or any combination thereof or components thereof as described herein.

[0260] At least one memory 930 may include random access memory (RAM) and read-only memory (ROM). At least one memory 930 may store computer-readable, computer-executable code 935, including instructions that, when executed by at least one processor 940, cause device 905 to perform the various functions described herein. Code 935 may be stored in a non-transitory computer-readable medium, such as system memory or another type of memory. In some cases, code 935 may not be directly executable by at least one processor 940, but may enable a computer (e.g., when compiled and executed) to perform the functions described herein. In some cases, among other things, at least one memory 930 may also include a basic I / O system (BIOS) that controls basic hardware or software operations, such as interaction with peripheral components or devices.

[0261] At least one processor 940 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, at least one processor 940 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into at least one processor 940. At least one processor 940 may be configured to execute computer-readable instructions stored in memory (e.g., at least one memory 930) to cause device 905 to perform various functions (e.g., functions or tasks supporting unicast A2X communication). For example, device 905 or components of device 905 may include at least one processor 940 and at least one memory 930 coupled to or coupled to at least one processor 940, wherein at least one processor 940 and at least one memory 930 are configured to perform the various functions described herein. In some examples, at least one processor 940 may include multiple processors, and at least one memory 930 may include multiple memories. One or more of a plurality of processors may be coupled to one or more of a plurality of memories, which may be configured individually or collectively to perform the various functions described herein. In some examples, at least one processor 940 may be a component of a processing system, which may refer to a system of machines (such as a series of machines), circuitry (including, for example, one or both of processor circuitry (which may include at least one processor 940) and memory circuitry (which may include at least one memory 930)) or components that receive or receive input and process the input to produce, generate or obtain a set of outputs. The processing system may be configured to perform one or more of the functions described herein. Thus, at least one processor 940 or a processing system including at least one processor 940 may be configured, configurable, or operable to cause device 905 to perform one or more of the functions described herein. Furthermore, as described herein, “configured to,” “capable of being configured to,” and “capable of being operable to” are used interchangeably and may be associated with the ability to perform one or more of the functions described herein when executing code stored in at least one memory 930 or otherwise.

[0262] The communication manager 920 can support wireless communications according to examples disclosed herein. For example, the communication manager 920 is capable of, configured to, or operable to support components for receiving broadcast messages from a second UE, the broadcast messages including a UE-specific ID unique to the second UE for the UTM system. The communication manager 920 is capable of, configured to, or operable to support components for sending DCR messages to the second UE in response to the broadcast messages, wherein the DCR messages include an application layer ID derived from the UE-specific ID included in the broadcast messages, a service type associated with information for communicating with the first UE, or both. The communication manager 920 is capable of, configured to, or operable to support components for conveying unicast messages to the second UE based on the service type, based on sending DCR messages to the second UE.

[0263] Additionally or alternatively, the communication manager 920 may support wireless communications according to the examples disclosed herein. For example, the communication manager 920 may be capable of, configured to, or operable to support components for sending a broadcast message to a second UE, the broadcast message including a UE-specific ID unique to the first UE for the UTM system. The communication manager 920 may be capable of, configured to, or operable to support components for receiving a DCR message from the second UE in response to the broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both. The communication manager 920 may be capable of, configured to, or operable to support components for conveying a unicast message to the second UE based on the service type upon receiving the DCR message from the second UE.

[0264] Additionally or alternatively, the communication manager 920 may support wireless communications according to the examples disclosed herein. For example, the communication manager 920 may be capable of, configured to, or operable to support components for transmitting a DCR message associated with a type of service, the DCR message including one or more proximity parameters associated with a first UE. The communication manager 920 may be capable of, configured to, or operable to support components for receiving a link establishment message from a second UE in response to a DCR message, based on a metric determined from a trajectory of a second UE and the satisfaction of a threshold value for one or more proximity parameters associated with the first UE. The communication manager 920 may be capable of, configured to, or operable to support components for communicating a unicast message to the second UE based on the type of service upon receiving a link establishment message from the second UE.

[0265] Additionally or alternatively, the communication manager 920 may support wireless communications according to the examples disclosed herein. For example, the communication manager 920 may be capable of, configured to, or operable to support components for sending a broadcast message including a UE-specific ID unique to the first UE for the UTM system. The communication manager 920 may be capable of, configured to, or operable to support components for receiving a DCR message associated with a service type from a second UE in response to a broadcast message, the DCR message including one or more proximity parameters associated with the second UE. The communication manager 920 may be capable of, configured to, or operable to support components for sending a link establishment message to a second UE in response to a DCR message, based on a metric determined from the trajectory of the first UE and one or more proximity parameters associated with the second UE satisfying a threshold. The communication manager 920 may be capable of, configured to, or operable to support components for communicating a unicast message to the second UE based on a service type, based on sending a link establishment message to the second UE.

[0266] Additionally or alternatively, the communication manager 920 may support wireless communications according to the examples disclosed herein. For example, the communication manager 920 may be capable of, configured to, or operable to support components for establishing a communication link with a second UE based on a service type. The communication manager 920 may be capable of, configured to, or operable to support components for conveying sidelink messages with the second UE, indicating one or more parameters for conveying unicast DAA messages. The communication manager 920 may be capable of, configured to, or operable to support components for conveying one or more unicast DAA messages with the second UE based on one or more parameters.

[0267] By including or configuring a communication manager 920 according to an example as described herein, device 905 can support technologies for improving A2X services and communications. For example, the technologies described herein support an efficient A2X unicast link establishment process between devices such as device 905, which improves coordination between devices and reduces latency. Additionally, the technologies described herein support optimal parameters and configurations for communication via A2X unicast links, which enables the delivery of DAA messages with increased reliability and efficiency.

[0268] In some examples, the communication manager 920 may be configured to use or otherwise cooperate with transceiver 915, one or more antennas 925, or any combination thereof to perform various operations (e.g., receiving, monitoring, transmitting). Although the communication manager 920 is illustrated as a separate component, in some examples, one or more functions described with reference to the communication manager 920 may be supported by or performed by at least one processor 940, at least one memory 930, code 935, or any combination thereof. For example, code 935 may include instructions that can be executed by at least one processor 940 to cause device 905 to perform various aspects of unicast A2X communication as described herein, or at least one processor 940 and at least one memory 930 may be otherwise configured to perform or support such operations individually or jointly.

[0269] Figure 10 A flowchart illustrating a method 1000 supporting unicast A2X communication according to various aspects of this disclosure is shown. The operation of method 1000 can be implemented by a UE or its components as described herein. For example, the operation of method 1000 can be implemented by, as referenced... Figures 1 to 9 The UE 115 described herein performs the following: In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described functions.

[0270] At 1005, the method may include: receiving a broadcast message from a second UE, the broadcast message including a UE-specific ID unique to the second UE for the UTM system. The operation of block 1005 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1005 may be derived from references... Figure 8 The described broadcast message component 825 is executed.

[0271] At 1010, the method may include: sending a DCR message to a second UE in response to a broadcast message, wherein the DCR message includes an application layer ID derived from a UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both. Operation of block 1010 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1010 may be derived from references... Figure 8 The described DCR message component 830 is executed.

[0272] At 1015, the method may include: conveying a unicast message to the second UE based on the service type, according to the DCR message sent to the second UE. The operation of block 1015 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1015 may be as described in the references... Figure 8 The unicast communication component 835 described is executed.

[0273] Figure 11 A flowchart illustrating a method 1100 for supporting unicast A2X communication according to various aspects of this disclosure is shown. Operation of method 1100 may be implemented by a UE or its components as described herein. For example, operation of method 1100 may be implemented by, as referenced... Figures 1 to 9 The UE 115 described herein performs the following: In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described functions.

[0274] At 1105, the method may include: sending a broadcast message to a second UE, the broadcast message including a UE-specific ID unique to the first UE for the UTM system. The operation of block 1105 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1105 may be derived from references... Figure 8 The described broadcast message component 825 is executed.

[0275] At 1110, the method may include: receiving a DCR message from a second UE in response to a broadcast message, wherein the DCR message includes an application layer ID derived from a UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both. Operation of block 1110 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 1110 may be derived from references... Figure 8 The described DCR message component 830 is executed.

[0276] At 1115, the method may include: conveying a unicast message to the second UE based on the service type, according to the DCR message received from the second UE. The operation of block 1115 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1115 may be as described in the references... Figure 8 The unicast communication component 835 described is executed.

[0277] Figure 12 A flowchart illustrating a method 1200 supporting unicast A2X communication according to various aspects of this disclosure is shown. Operation of method 1200 can be implemented by a UE or its components as described herein. For example, operation of method 1200 can be implemented by, as referenced... Figures 1 to 9 The UE 115 described herein performs the following: In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described functions.

[0278] At 1205, the method may include: sending a DCR message associated with a service type, the DCR message including one or more proximity parameters associated with a first UE. The operation of block 1205 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1205 may be provided by reference to [reference needed]. Figure 8 The described DCR message component 830 is executed.

[0279] At 1210, the method may include: in response to a DCR message, receiving a link establishment message from the second UE based on a metric determined from the trajectory of the second UE and one or more proximity parameters associated with the first UE satisfying a threshold. The operation of block 1210 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1210 may be provided by reference to [reference needed]. Figure 8 The described link establishment component 840 is executed.

[0280] At 1215, the method may include: conveying a unicast message to the second UE based on a service type, at least in part, based on receiving a link establishment message from the second UE. The operation of block 1215 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1215 may be as described in the references... Figure 8 The unicast communication component 835 described is executed.

[0281] Figure 13 A flowchart illustrating a method 1300 for supporting unicast A2X communication according to various aspects of this disclosure is shown. Operation of method 1300 may be implemented by a UE or its components as described herein. For example, operation of method 1300 may be implemented by, as referenced... Figures 1 to 9 The UE 115 described herein performs the following: In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described functions.

[0282] At 1305, the method may include: sending a broadcast message including a UE-specific ID unique to the first UE for the UTM system. The operation of block 1305 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1305 may be derived from references... Figure 8 The described broadcast message component 825 is executed.

[0283] At 1310, the method may include: receiving a DCR message associated with a type of service from a second UE in response to a broadcast message, the DCR message including one or more proximity parameters associated with the second UE. Operation of block 1310 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 1310 may be provided by reference to [reference needed]. Figure 8The described DCR message component 830 is executed.

[0284] At 1315, the method may include: in response to a DCR message, sending a link establishment message to a second UE based on a metric determined from the trajectory of the first UE and one or more proximity parameters associated with the second UE satisfying a threshold. The operation of block 1315 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1315 may be provided by reference to [reference needed]. Figure 8 The described link establishment component 840 is executed.

[0285] At 1320, the method may include: conveying a unicast message to the second UE based at least in part on the service type, according to the link establishment message sent to the second UE. The operation of block 1320 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1320 may be as described in the references... Figure 8 The unicast communication component 835 described is executed.

[0286] Figure 14 A flowchart illustrating a method 1400 supporting unicast A2X communication according to various aspects of this disclosure is shown. Operation of method 1400 can be implemented by a UE or its components as described herein. For example, operation of method 1400 can be achieved by, as referenced... Figures 1 to 9 The UE 115 described herein performs the following: In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described functions.

[0287] At 1405, the method may include: sending a broadcast message including a UE-specific ID unique to the first UE for the UTM system. The operation of block 1405 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1405 may be derived from references... Figure 8 The described broadcast message component 825 is executed.

[0288] At 1410, the method may include: receiving a DCR message associated with a type of service from a second UE in response to a broadcast message, the DCR message including one or more proximity parameters associated with the second UE. Operation of block 1410 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 1410 may be provided by reference to [reference needed]. Figure 8 The described DCR message component 830 is executed.

[0289] At 1415, the method may include: measuring the RSRP associated with receiving the DCR message. The operation of block 1415 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1415 may be derived from references... Figure 8 The described positioning component 850 is executed.

[0290] At 1420, the method may include: determining a metric, including path loss associated with the DCR message, based on the RSRP, the trajectory of the first UE, and one or more proximity parameters. The operation of block 1420 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1420 may be derived from references... Figure 8 The described positioning component 850 is executed.

[0291] At 1425, the method may include: in response to a DCR message, sending a link establishment message to a second UE based on a metric satisfying a threshold, wherein the threshold includes a path loss threshold. The operation of block 1425 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1425 may be derived from references... Figure 8 The described link establishment component 840 is executed.

[0292] At 1430, the method may include: conveying a unicast message to the second UE based at least in part on the service type, according to the link establishment message sent to the second UE. The operation of block 1430 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1430 may be as described in the references... Figure 8 The unicast communication component 835 described is executed.

[0293] Figure 15 A flowchart illustrating a method 1500 for supporting unicast A2X communication according to various aspects of this disclosure is shown. Operation of method 1500 can be implemented by a UE or its components as described herein. For example, operation of method 1500 can be achieved by, as referenced... Figures 1 to 9 The UE 115 described herein performs the following: In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described functions.

[0294] At 1505, the method may include: establishing a communication link with the second UE based on the service type. The operation of block 1505 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1505 may be provided by reference to... Figure 8 The described link establishment component 840 is executed.

[0295] At 1510, the method may include: conveying a sidelink message to the second UE, indicating one or more parameters for the delivery of the unicast DAA message. Operation of block 1510 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1510 may be provided by reference to... Figure 8The described side-link messaging component 845 is executed.

[0296] At 1515, the method may include: communicating one or more unicast DAA messages to the second UE based on one or more parameters. The operation of block 1515 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1515 may be as described in references... Figure 8 The unicast communication component 835 described is executed.

[0297] Figure 16 A flowchart illustrating a method 1600 for supporting unicast A2X communication according to various aspects of this disclosure is shown. Operation of method 1600 may be implemented by a UE or its components as described herein. For example, operation of method 1600 may be implemented by, as referenced... Figures 1 to 9 The UE 115 described herein performs the following: In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described functions.

[0298] At 1605, the method may include: establishing a communication link with the second UE based on the service type. The operation of block 1605 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1605 may be provided by reference to... Figure 8 The described link establishment component 840 is executed.

[0299] At 1610, the method may include: sending a sidelink message to a second UE indicating one or more parameters for the communication of a unicast DAA message, wherein the one or more parameters include periodicity for communicating the one or more unicast DAA messages, location information associated with the second UE to be included in the one or more unicast DAA messages, a triggering event for communicating the one or more unicast DAA messages, or a combination thereof. Operation of block 1610 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 1610 may be provided by reference to [reference needed]. Figure 8 The described side-link messaging component 845 is executed.

[0300] At 1615, the method may include: sending a request to a second UE for a unicast DAA message in one or more unicast DAA messages. The operation of block 1615 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1615 may be as described in references... Figure 8 The unicast communication component 835 described is executed.

[0301] At 1620, the method may include: sending one or more PRS to the second UE. The operation of block 1620 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1620 may be derived from references... Figure 8 The described positioning component 850 is executed.

[0302] At 1625, the method may include: receiving a unicast DAA message from a second UE based on a request and one or more PRS. The operation of block 1625 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1625 may be provided by reference to... Figure 8 The unicast communication component 835 described is executed.

[0303] At 1630, the method may include: communicating one or more unicast DAA messages, including unicast DAA messages, to the second UE based on one or more parameters. The operation of block 1630 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1630 may be as described in references... Figure 8 The unicast communication component 835 described is executed.

[0304] Figure 17 A flowchart illustrating a method 1700 supporting unicast A2X communication according to various aspects of this disclosure is shown. Operation of method 1700 can be implemented by a UE or its components as described herein. For example, operation of method 1700 can be implemented by, as referenced... Figures 1 to 9 The UE 115 described herein performs the following: In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described functions.

[0305] At 1705, the method may include: establishing a communication link with the second UE based on the service type. The operation of block 1705 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1705 may be provided by reference to... Figure 8 The described link establishment component 840 is executed.

[0306] At 1710, the method may include: sending a UAI sidelink message to a second UE, the UAI sidelink message indicating one or more parameters for the transmission of a unicast DAA message, the one or more parameters including one or more positioning parameters associated with the first UE, wherein the one or more positioning parameters include the location of the first UE, the speed of the first UE, the heading direction of the first UE, or a combination thereof. The operation of block 1710 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1710 may be provided by reference to [reference needed]. Figure 8 The described side-link messaging component 845 is executed.

[0307] At 1715, the method may include: sending one or more unicast DAA messages to a second UE based on one or more parameters. The operation of block 1715 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1715 may be provided by reference to... Figure 8 The unicast communication component 835 described is executed.

[0308] The following provides an overview of the various aspects of this disclosure: Aspect 1: A method for wireless communication by a first UE, the method comprising: receiving a broadcast message from a second UE, the broadcast message including a UE-specific ID unique to the second UE for a UTM system; sending a DCR message to the second UE in response to the broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both; and conveying a unicast message to the second UE based on the service type, at least in part, based on sending the DCR message to the second UE.

[0309] Aspect 2: According to the method of aspect 1, the service type includes the A2X service type.

[0310] Aspect 3: The method according to any one of Aspects 1 to 2, wherein the broadcast message is a broadcast DAA message, the broadcast DAA message further including one or more positioning parameters associated with the second UE, the one or more positioning parameters including the location of the second UE, the speed of the second UE, the heading direction of the second UE, or a combination thereof.

[0311] Aspect 4: According to the method of aspect 3, the DCR message is sent to the second UE based at least in part on a metric determined from the trajectory of the second UE and the one or more positioning parameters associated with the second UE satisfying a threshold.

[0312] Aspect 5: The method according to any one of Aspects 1 to 4, wherein the DCR message is sent as part of the unicast link establishment process with the second UE.

[0313] Aspect 6: The method according to any one of Aspects 1 to 5, wherein at least one of the unicast messages includes a unicast DAA message.

[0314] Aspect 7: The method according to any one of Aspects 1 to 6, wherein the UE-specific ID includes a CAA-level ID that identifies the second UE.

[0315] Aspect 8: A method for wireless communication by a second UE, the method comprising: sending a broadcast message to a first UE, the broadcast message including a UE-specific ID unique to the second UE for a UTM system; receiving a DCR message from the first UE in response to the broadcast message, wherein the DCR message includes an application layer ID derived from the UE-specific ID included in the broadcast message, a service type associated with information for communicating with the first UE, or both; and conveying a unicast message to the first UE based at least in part on the service type based on receiving the DCR message from the second UE.

[0316] Aspect 9: The method according to aspect 8, wherein the service type includes the A2X service type.

[0317] Aspect 10: The method according to any one of Aspects 8 to 9, wherein the broadcast message is a broadcast DAA message, the broadcast DAA message further including one or more positioning parameters associated with the second UE, the one or more positioning parameters including the location of the second UE, the speed of the second UE, the heading direction of the second UE, or a combination thereof.

[0318] Aspect 11: According to the method of aspect 10, wherein the DCR message is received as part of the unicast link establishment process with the first UE.

[0319] Aspect 12: The method according to any one of Aspects 8 to 11, wherein at least one of the unicast messages comprises a unicast DAA message.

[0320] Aspect 13: The method according to any one of Aspects 8 to 12, wherein the UE-specific ID includes a CAA-level ID that identifies the second UE.

[0321] Aspect 14: A method for wireless communication by a first UE, the method comprising: transmitting a DCR message associated with a service type, the DCR message including one or more proximity parameters associated with the first UE; receiving a link establishment message from the second UE in response to the DCR message based at least in part on a metric determined from a trajectory of the second UE and the one or more proximity parameters associated with the first UE satisfying a threshold; and conveying a unicast message to the second UE according to the service type based at least in part on receiving the link establishment message from the second UE.

[0322] Aspect 15: The method according to aspect 14, wherein the service type includes the A2X service type.

[0323] Aspect 16: The method according to any one of Aspects 14 to 15, wherein the one or more proximity parameters associated with the first UE include the location of the first UE, the speed of the first UE, the heading direction of the first UE, or a combination thereof, and the threshold includes a distance threshold.

[0324] Aspect 17: The method according to any one of Aspects 14 to 16, wherein the one or more proximity parameters associated with the first UE include the transmission power of the DCR message, the EPRE of the reference signal included in the DCR message, or a combination thereof, and the threshold includes a path loss threshold.

[0325] Aspect 18: The method according to any one of Aspects 14 to 17, the method further comprising: sending a broadcast message including a set of location parameters associated with the first UE and a CAA-level ID identifying the first UE, wherein the one or more proximity parameters associated with the first UE include an application layer ID unique to the first UE, the application layer ID being associated with a service type and derived from the CAA-level ID included in the broadcast message.

[0326] Aspect 19: The method according to any one of Aspects 14 to 18, the method further comprising: receiving one or more broadcast messages from one or more other UEs, wherein each of the one or more broadcast messages includes a UE-specific ID and a set of proximity parameters associated with a corresponding UE among the one or more other UEs, and wherein the DCR message is sent as part of a unicast link establishment process with the second UE.

[0327] Aspect 20: The method according to aspect 19, wherein the UE-specific ID includes a CAA-level ID that identifies the second UE.

[0328] Aspect 21: The method according to any one of Aspects 19 to 20, wherein the one or more broadcast messages include one or more broadcast DAA messages.

[0329] Aspect 22: The method according to any one of Aspects 14 to 21, wherein the DCR message excludes the application layer ID associated with the service type.

[0330] Aspect 23: The method according to any one of Aspects 14 to 22, wherein at least one of the unicast messages comprises a unicast DAA message.

[0331] Aspect 24: A method for wireless communication by a second UE, the method comprising: transmitting a broadcast message including a UE-specific ID unique to the second UE for a UTM system; receiving a DCR message associated with a service type from a first UE in response to the broadcast message, the DCR message including one or more proximity parameters associated with the first UE; transmitting a link establishment message to the first UE in response to the DCR message based at least in part on a metric determined from a trajectory of the second UE and the one or more proximity parameters associated with the first UE satisfying a threshold; and conveying a unicast message to the first UE according to the service type based at least in part on transmitting the link establishment message to the first UE.

[0332] Aspect 25: The method according to aspect 24, wherein the service type includes the A2X service type.

[0333] Aspect 26: The method according to any one of Aspects 24 to 25, wherein the one or more proximity parameters associated with the first UE include the location of the first UE, the speed of the first UE, the heading direction of the first UE, or a combination thereof, the method further comprising: determining the metric including the distance between the first UE and the second UE, wherein the threshold includes a distance threshold.

[0334] Aspect 27: A method according to any one of Aspects 24 to 26, wherein the one or more proximity parameters associated with the first UE include the transmit power of the DCR message, the EPRE of a reference signal included in the DCR message, or a combination thereof, the method further comprising: measuring the reference signal received power (RSRP) associated with receiving the DCR message; and determining, at least in part, a metric including path loss associated with the DCR message based on the RSRP and the one or more proximity parameters, wherein the threshold includes a path loss threshold.

[0335] Aspect 28: The method according to any one of Aspects 24 to 27, the method further comprising: receiving a broadcast message from the first UE, the broadcast message including a set of location parameters associated with the first UE and a CAA-level ID identifying the first UE, wherein the one or more proximity parameters associated with the first UE include an application layer ID unique to the first UE, the application layer ID being associated with a service type and derived from the CAA-level ID included in the broadcast message; and determining, at least in part, a metric including a distance between the first UE and the second UE based on the set of location parameters and the one or more proximity parameters, wherein the metric includes a distance threshold.

[0336] Aspect 29: The method according to any one of Aspects 24 to 28, wherein the UE-specific ID includes a CAA-level ID that identifies the second UE.

[0337] Aspect 30: The method according to any one of Aspects 24 to 29, wherein the DCR message excludes the application layer ID associated with the service type.

[0338] Aspect 31: The method according to any one of Aspects 24 to 30, wherein the broadcast message includes a set of proximity parameters associated with the second UE.

[0339] Aspect 32: The method according to any one of Aspects 24 to 31, wherein at least one of the unicast messages comprises a unicast DAA message.

[0340] Aspect 33: A method for wireless communication by a first UE, the method comprising: establishing a communication link with a second UE based on a service type; communicating with the second UE a sidelink message indicating one or more parameters for the communication of unicast DAA messages; and communicating one or more unicast DAA messages with the second UE based on the one or more parameters.

[0341] Aspect 34: The method according to aspect 33, wherein the service type includes the A2X service type.

[0342] Aspect 35: The method according to any one of Aspects 33 to 34, wherein the sidelink message includes a UAI sidelink message indicating one or more positioning parameters associated with the second UE, the one or more positioning parameters including the location of the second UE, the speed of the second UE, the heading direction of the second UE, or a combination thereof, and wherein conveying the sidelink message includes: receiving the UAI sidelink message from the second UE; and determining the one or more parameters for conveying the unicast DAA message based at least in part on the one or more positioning parameters associated with the second UE.

[0343] Aspect 36: The method according to any one of Aspects 33 to 35, wherein the sidelink message includes a UAI sidelink message indicating the one or more parameters for the communication of the unicast DAA message, and wherein communicating the sidelink message includes: receiving the UAI sidelink message from the second UE.

[0344] Aspect 37: The method according to aspect 36, wherein the one or more parameters include periodicity of the transmission of the unicast DAA message, transmission power of the transmission of the unicast DAA message, or a combination thereof, and wherein transmitting the one or more unicast DAA messages includes: receiving the one or more unicast DAA messages from the second UE.

[0345] Aspect 38: The method according to any one of aspects 33 to 37, wherein conveying the side link message comprises: sending the side link message to the second UE.

[0346] Aspect 39: According to the method of aspect 38, wherein the one or more parameters include periodicity for conveying the one or more unicast DAA messages, location information associated with the second UE to be included in the one or more unicast DAA messages, a triggering event for conveying the one or more unicast DAA messages, or a combination thereof, and wherein conveying the one or more unicast DAA messages includes: receiving the one or more unicast DAA messages from the second UE.

[0347] Aspect 40: The method according to any one of Aspects 38 to 39, wherein conveying the one or more unicast DAA messages comprises: sending a request to the second UE for a unicast DAA message among the one or more unicast DAA messages; and receiving the unicast DAA message from the second UE at least in part based on the request.

[0348] Aspect 41: The method according to any one of Aspects 38 to 40, wherein conveying the one or more unicast DAA messages comprises: sending one or more PRS to the second UE; and receiving the one or more unicast DAA messages from the second UE based at least in part on the one or more PRS.

[0349] Aspect 42: The method according to any one of Aspects 33 to 41, the method further comprising: sending a first control message to the second UE indicating a configuration set for the service type; and sending a second control message to the second UE, the second control message indicating that a configuration from the configuration set is activated, the configuration including the one or more parameters.

[0350] Aspect 43: According to the method of aspect 42, wherein the first control message includes an RRC message, and the second control message includes a MAC-CE message or an SCI message.

[0351] Aspect 44: The method according to any one of Aspects 33 to 43, wherein the sidelink message includes a UAI sidelink message indicating one or more positioning parameters associated with the first UE, the one or more positioning parameters including the location of the first UE, the speed of the first UE, the heading direction of the first UE, or a combination thereof, and wherein conveying the sidelink message includes: sending the UAI sidelink message to the second UE.

[0352] Aspect 45: The method according to any one of Aspects 33 to 44, wherein the sidelink message includes a UAI sidelink message indicating the one or more parameters of the communication for a unicast DAA message, and wherein communicating the sidelink message includes: sending the UAI sidelink message to the second UE.

[0353] Aspect 46: The method according to aspect 45, wherein the one or more parameters include periodicity of the transmission of the unicast DAA message, transmission power of the transmission of the unicast DAA message, or a combination thereof, and wherein transmitting the one or more unicast DAA messages includes: sending the one or more unicast DAA messages to the second UE.

[0354] Aspect 47: The method according to any one of Aspects 33 to 46, wherein conveying the side link message includes: receiving the side link message from the second UE.

[0355] Aspect 48: The method according to aspect 47, wherein the one or more parameters include periodicity for conveying the one or more unicast DAA messages, location information associated with the first UE to be included in the one or more unicast DAA messages, a triggering event for conveying the one or more unicast DAA messages, or a combination thereof, and wherein conveying the one or more unicast DAA messages includes: sending the one or more unicast DAA messages to the second UE.

[0356] Aspect 49: The method according to any one of Aspects 47 to 48, wherein conveying the one or more unicast DAA messages comprises: receiving from the second UE a request for a unicast DAA message in the one or more unicast DAA messages; and sending the unicast DAA message to the second UE at least in part based on the request.

[0357] Aspect 50: The method according to any one of Aspects 47 to 49, wherein conveying the one or more unicast DAA messages comprises: receiving one or more PRS from the second UE; and sending the one or more unicast DAA messages to the second UE, the one or more unicast DAA messages comprising at least in part location information associated with the first UE based on receiving the one or more PRS.

[0358] Aspect 51: The method according to any one of Aspects 33 to 50, the method further comprising: receiving a first control message indicating a set of configurations for the service type; and receiving a second control message indicating that a configuration from the set of configurations is activated, the configuration including the one or more parameters.

[0359] Aspect 52: According to the method of aspect 51, wherein the first control message includes an RRC message, and the second control message includes a MAC-CE message or an SCI message.

[0360] Aspect 53: A first UE for wireless communication, the first UE comprising: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories and capable of operating individually or jointly to execute the code to cause the first UE to perform a method according to any one of aspects 1 to 7.

[0361] Aspect 54: A first UE for wireless communication, the first UE comprising at least one component for performing the method according to any one of aspects 1 to 7.

[0362] Aspect 55: A non-transitory computer-readable medium storing code for wireless communication, the code including instructions executable by a processor to perform the method according to any one of aspects 1 to 7.

[0363] Aspect 56: A second UE for wireless communication, the second UE comprising: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories and capable of operating individually or jointly to execute the code to cause the second UE to perform a method according to any one of aspects 8 to 13.

[0364] Aspect 57: A second UE for wireless communication, the second UE including at least one component for performing the method according to any one of aspects 8 to 13.

[0365] Aspect 58: A non-transitory computer-readable medium storing code for wireless communication, the code including instructions executable by a processor to perform the method according to any one of aspects 8 to 13.

[0366] Aspect 59: A first UE for wireless communication, the first UE comprising: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories and capable of operating individually or jointly to execute the code to cause the first UE to perform a method according to any one of aspects 14 to 23.

[0367] Aspect 60: A first UE for wireless communication, the first UE including at least one component for performing the method according to any one of aspects 14 to 23.

[0368] Aspect 61: A non-transitory computer-readable medium storing code for wireless communication, the code including instructions executable by a processor to perform the method according to any one of aspects 14 to 23.

[0369] Aspect 62: A second UE for wireless communication, the second UE comprising: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories and capable of operating individually or jointly to execute the code to cause the second UE to perform a method according to any one of aspects 24 to 32.

[0370] Aspect 63: A second UE for wireless communication, the second UE including at least one component for performing the method according to any one of aspects 24 to 32.

[0371] Aspect 64: A non-transitory computer-readable medium storing code for wireless communication, the code including instructions executable by a processor to perform the method according to any one of aspects 24 to 32.

[0372] Aspect 65: A first UE for wireless communication, the first UE comprising: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories and capable of operating individually or jointly to execute the code to cause the first UE to perform a method according to any one of aspects 33 to 52.

[0373] Aspect 66: A first UE for wireless communication, the first UE including at least one component for performing the method according to any one of aspects 33 to 52.

[0374] Aspect 67: A non-transitory computer-readable medium storing code for wireless communication, the code including instructions executable by a processor to perform the method according to any one of aspects 33 to 52.

[0375] It should be noted that the methods described herein describe possible specific implementations, and the operations and steps can be rearranged or otherwise modified, and other specific implementations are also possible. Furthermore, aspects from two or more of these methods can be combined.

[0376] While aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for illustrative purposes, and the terms LTE, LTE-A, LTE-A Pro, or NR may be used in most of the description, the techniques described herein are also applicable to networks other than LTE, LTE-A, LTE-A Pro, or NR networks. For example, the techniques described are applicable to a variety of other wireless communication systems, such as Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0377] The information and signals described herein can be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or optical particles, or any combination thereof.

[0378] The various exemplary blocks and components described herein can be implemented or performed using a general-purpose processor, DSP, ASIC, CPU, FPGA or other programmable logic device, discrete gate or transistor logic unit, discrete hardware component, or any combination thereof, designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in alternative embodiments, a processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration). Any function or operation described herein that can be performed by a processor may be performed by multiple processors capable of performing the described functions or operations individually or jointly.

[0379] The functions described herein can be implemented using hardware, software executed by a processor, firmware, or any combination thereof. When implemented using software executed by a processor, the functions can be stored as one or more instructions or code on a computer-readable medium or transmitted using one or more instructions or code on a computer-readable medium. Other examples and specific implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein can be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination of these. Features implementing the functions can also be physically located in various locations, including various portions distributed such that the functions are implemented in different physical locations.

[0380] Computer-readable media includes both non-transitory computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. Non-transitory storage media can be any available medium accessible by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compressed optical disc (CD) ROM or other optical disc storage devices, magnetic disk storage devices or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code components in the form of instructions or data structures, and accessible by a general-purpose or special-purpose computer or a general-purpose or special-purpose processor. Furthermore, any connection is appropriately referred to as computer-readable media. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included within the definition of computer-readable media. As used herein, disks and optical discs include CDs, laser discs, optical discs, digital multifunction discs (DVDs), floppy disks, and Blu-ray discs. Disks can magnetically reproduce data, and optical discs can optically reproduce data using lasers. Combinations of the above are also included within the scope of computer-readable media. Any function or operation described herein that can be performed by memory can be performed by multiple memories capable of performing the described function or operation individually or jointly.

[0381] As used herein, the word "or" in a list of items (e.g., a list of items accompanied by phrases such as "at least one of" or "one or more of") in the claims indicates an inclusive list, such that a list of at least one of, for example, A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Furthermore, as used herein, the phrase "based on" should not be construed as a reference to a closed set of conditions. For example, an example step described as "based on condition A" could be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "at least partially based on".

[0382] As used herein, including in claims, the article “a” preceding a noun is open-ended and is understood to refer to “at least one” or “one or more” of those nouns. Therefore, the terms “a,” “at least one,” “one or more,” and “at least one of one or more” are interchangeable. For example, where a claim enumerates “components” performing one or more functions, each of the individual functions may be performed by a single component or by any combination of multiple components. Thus, the term “component” having a characteristic or performing a function may refer to “at least one of one or more components” having a particular characteristic or performing a particular function. Subsequent references to a component introduced with the article “a” using the terms “the” or “the” can refer to any or all of the one or more components. For example, a component introduced with the article “a” can be understood to mean “one or more components,” and subsequent reference to “the component” in a claim can be understood as equivalent to referring to “at least one of the one or more components.” Similarly, subsequent references to a component introduced with the terms “the” or “the” as “one or more components” can refer to any or all of the one or more components. For example, reference to "the one or more components" in the subsequent claims can be understood as equivalent to reference to "at least one of the one or more components".

[0383] The term "determine" encompasses a variety of actions, and therefore, "determine" can include calculation, computation, processing, derivation, investigation, lookup (such as by searching in a table, database, or other data structure), identification, and similar actions. Furthermore, "determine" can include receiving (e.g., receiving information), accessing (e.g., accessing data stored in memory), etc. Moreover, "determine" can include parsing, obtaining, selecting, choosing, building, and other similar actions.

[0384] In the accompanying drawings, similar components or features may have the same reference numerals. Furthermore, various components of the same type can be distinguished by adding a dash after the reference numerals and a second reference numeral for differentiation between similar components. If only the first reference numeral is used in the description, the description applies to any of the similar components having the same first reference numeral, regardless of the second or other subsequent reference numerals.

[0385] The description herein, illustrated with reference to the accompanying drawings, describes an example configuration and does not represent all achievable examples or those within the scope of the claims. The term "example" as used herein means "serving as an example, instance, or illustration," not "preferred" or "advantageous over other examples." The detailed description includes specific details used to provide an understanding of the described techniques. However, these techniques can be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form to avoid obscuring the concept of the described examples.

[0386] The description herein is provided to enable those skilled in the art to implement or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A first user equipment (UE), the first user equipment (UE) comprising: One or more memories, wherein the one or more memories store processor-executable code; and One or more processors, said one or more processors coupled to said one or more memories and capable of operating individually or jointly to execute said code to enable the first UE: Receive a broadcast message from the second UE, the broadcast message including a UE-specific identifier unique to the second UE for the Unmanned Aircraft System (UAS) Traffic Management (UTM) system; In response to the broadcast message, a Direct Communication Request (DCR) message is sent to the second UE, wherein the DCR message includes an application layer identifier derived from the UE-specific identifier included in the broadcast message, a service type associated with information for communicating with the first UE, or both; and Unicast messages are communicated with the second UE based on the service type, at least in part, by sending the DCR message to the second UE.

2. The first UE according to claim 1, wherein the service type includes the air-to-everything (A2X) service type.

3. The first UE according to claim 1, wherein the broadcast message is a broadcast detection and avoidance (DAA) message, and the broadcast detection and avoidance (DAA) message further includes one or more positioning parameters associated with the second UE, the one or more positioning parameters including the location of the second UE, the speed of the second UE, the heading direction of the second UE, or a combination thereof.

4. The first UE of claim 3, wherein the DCR message is sent to the second UE based at least in part on a metric determined from the trajectory of the second UE and the one or more positioning parameters associated with the second UE satisfying a threshold.

5. The first UE according to claim 1, wherein the DCR message is sent as part of the unicast link establishment process with the second UE.

6. The first UE according to claim 1, wherein at least one of the unicast messages includes a unicast detection and avoidance (DAA) message.

7. The first UE according to claim 1, wherein the UE-specific identifier includes a Civil Aviation Administration (CAA) level identity identifying the second UE.

8. A first user equipment (UE), the first user equipment (UE) comprising: One or more memories, wherein the one or more memories store processor-executable code; and One or more processors, said one or more processors coupled to said one or more memories and capable of operating individually or jointly to execute said code to enable the first UE: Send a broadcast message to the second UE, the broadcast message including a UE-specific identifier unique to the first UE for the Unmanned Aircraft System (UAS) Traffic Management (UTM) system; In response to the broadcast message, a Direct Communication Request (DCR) message is received from the second UE, wherein the DCR message includes an application layer identifier derived from the UE-specific identifier included in the broadcast message, a service type associated with information for communicating with the first UE, or both; and Unicast messages are communicated with the second UE based on the service type, at least in part, based on the DCR message received from the second UE.

9. The first UE according to claim 8, wherein the service type includes an air-to-everything (A2X) service type.

10. The first UE of claim 8, wherein the broadcast message is a broadcast detection and avoidance (DAA) message, the broadcast detection and avoidance (DAA) message further comprising one or more positioning parameters associated with the first UE, the one or more positioning parameters including the location of the first UE, the speed of the first UE, the heading direction of the first UE, or a combination thereof.

11. The first UE of claim 10, wherein the DCR message is received as part of a unicast link establishment process with the second UE.

12. The first UE according to claim 8, wherein at least one of the unicast messages includes a unicast detection and avoidance (DAA) message.

13. The first UE of claim 8, wherein the UE-specific identifier includes a Civil Aviation Administration (CAA) level identity identifying the first UE.

14. A method for wireless communication by a first user equipment (UE), the method comprising: Receive a broadcast message from the second UE, the broadcast message including a UE-specific identifier unique to the second UE for the Unmanned Aircraft System (UAS) Traffic Management (UTM) system; In response to the broadcast message, a Direct Communication Request (DCR) message is sent to the second UE, wherein the DCR message includes an application layer identifier derived from the UE-specific identifier included in the broadcast message, a service type associated with information for communicating with the first UE, or both; and Unicast messages are communicated with the second UE based on the service type, at least in part, by sending the DCR message to the second UE.

15. The method of claim 14, wherein the service type includes an air-to-everything (A2X) service type.

16. The method of claim 14, wherein the broadcast message is a broadcast detection and avoidance (DAA) message, the broadcast detection and avoidance (DAA) message further comprising one or more positioning parameters associated with the second UE, the one or more positioning parameters including the location of the second UE, the speed of the second UE, the heading direction of the second UE, or a combination thereof.

17. The method of claim 16, wherein the DCR message is sent to the second UE based at least in part on a metric determined from the trajectory of the second UE and the one or more positioning parameters associated with the second UE satisfying a threshold.

18. The method of claim 14, wherein the DCR message is sent as part of a unicast link establishment process with the second UE.

19. The method of claim 14, wherein at least one of the unicast messages comprises a unicast detection and avoidance (DAA) message.

20. The method of claim 14, wherein the UE-specific identifier includes a Civil Aviation Authority (CAA) level identity identifying the second UE.

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