System information for supporting emergency service in non-terrestrial networks

Abstract

Wireless communication devices, systems, methods, protocols, and signaling related to system information for supporting emergency service in non-terrestrial networks are provided. For example, a method of wireless communication performed by a user equipment (UE) may include receiving, from a network unit, a message indicating one or more non-terrestrial network units support an emergency service; and connecting, based at least in part on the message indicating the one or more non-terrestrial network units support the emergency service, to a first non-terrestrial network unit of the one or more non-terrestrial network units. In some instances, the UE may select the first non-terrestrial network unit from the one or more non-terrestrial network units based at least in part on the message indicating the first non-terrestrial network unit supports the emergency service.

Description

SYSTEM INFORMATION FOR SUPPORTING EMERGENCY SERVICE IN NON-TERRESTRIAL NETWORKSINTRODUCTION

[0001] This application relates to wireless communication systems, and more particularly to supporting emergency services in non-terrestrial networks, including associated methods, devices, systems, protocols, and signaling.

[0002] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, or the like). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDM A) systems, single-carrier frequency division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE). LTE / LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP).

[0003] A wireless network may include one or more network nodes that support communication for wireless communication devices, such as a user equipment (UE) or multiple UEs. A UE may communicate with a network node via downlink communications and uplink communications. “Downlink” (or “DL”) refers to a communication link from the network node to the UE, and “uplink” (or “UL”) refers to a communication link from the UE to the network node. Some wireless networks may support device-to-device communication, such as via a local link (e.g., a sidelink (SL), a wireless local area network (WLAN) link, and / or a wireless personal area network (WPAN) link, among other examples).

[0004] The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different UEs to communicate on a municipal, national, regional, and / or global level. New Radio (NR), which may be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the 3GPP. NR is designed to better support mobile broadband internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM)on the downlink, using CP-OFDM and / or single-carrier frequency division multiplexing (SC-FDM) (also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink, as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

[0005] Some wireless communications systems support non-terrestrial networks, which may provide broad coverage areas by using high-altitude vehicles (e.g., satellites or other non-terrestrial- based high-altitude equipment) between base stations and UEs and / or by having base stations on board of the high-altitude vehicles (e.g., satellites). The use of non-terrestrial network nodes provides benefits and challenges for different aspects of wireless communications.BRIEF SUMMARY OF SOME EXAMPLES

[0006] The following summarizes some aspects of the present disclosure to provide a basic understanding of the discussed technology. This summary is not an extensive overview of all contemplated features of the disclosure and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in summary form as a prelude to the more detailed description that is presented later.

[0007] In an aspect of the disclosure, a method of wireless communication performed at a user equipment (UE) may include: receiving, from a network unit, a message indicating one or more non-terrestrial network units support an emergency service; and connecting, based at least in part on the message indicating the one or more non-terrestrial network units support the emergency service, to a first non-terrestrial network unit of the one or more non-terrestrial network units. Associated devices, systems, means, and / or non-transitory computer readable media having one or more instructions executable by one or more processors (individually, collectively, or in any combination) to cause an apparatus to perform the associated functions are also provided.

[0008] In an additional aspect of the disclosure, a method of wireless communication performed at a network unit may include: receiving information indicating one or more non-terrestrial network units support an emergency service; and transmitting a message indicating the one or more non- terrestrial network units support the emergency service. Associated devices, systems, means, and / or non-transitory computer readable media having one or more instructions executable by one or more processors (individually, collectively, or in any combination) to cause an apparatus to perform the associated functions are also provided.

[0009] In an additional aspect of the disclosure, an apparatus for wireless communications at a user equipment (UE) may comprise: one or more memories; and one or more processors coupled to theone or more memories, the one or more memories storing instructions that are executable by the one or more processors, individually or in any combination, to cause the UE to: receive, from a network unit, a message indicating one or more non-terrestrial network units support an emergency service; and connect, based at least in part on the message indicating the one or more non-terrestrial network units support the emergency service, to a first non-terrestrial network unit of the one or more nonterrestrial network units.

[0010] In an additional aspect of the disclosure, an apparatus for wireless communications at a network unit, may comprise: one or more memories; and one or more processors coupled to the one or more memories, the one or more memories storing instructions that are executable by the one or more processors, individually or in any combination, to cause the network unit to: receive information indicating one or more non-terrestrial network units support an emergency service; and transmit a message indicating the one or more non-terrestrial network units support the emergency service.

[0011] In an aspect of the disclosure, a user equipment (UE) may include means for receiving, from a network unit, a message indicating one or more non-terrestrial network units support an emergency service; and means for connecting, based at least in part on the message indicating the one or more non-terrestrial network units support the emergency service, to a first non-terrestrial network unit of the one or more non-terrestrial network units.

[0012] In an additional aspect of the disclosure, a network unit may include means for receiving information indicating one or more non-terrestrial network units support an emergency service; and means for transmitting a message indicating the one or more non-terrestrial network units support the emergency service.

[0013] In an additional aspect of the disclosure, a non-transitory computer-readable medium stores one or more instructions for wireless communication that, when executed by one or more processors, individually or in any combination, cause a user equipment (UE) to receive, from a network unit, a message indicating one or more non-terrestrial network units support an emergency service; and connect, based at least in part on the message indicating the one or more non-terrestrial network units support the emergency service, to a first non-terrestrial network unit of the one or more non-terrestrial network units.

[0014] In an additional aspect of the disclosure, a non-transitory computer-readable medium stores one or more instructions for wireless communication that, when executed by one or more processors, individually or in any combination, cause a network unit to receive information indicating one or more non-terrestrial network units support an emergency service; and transmit a message indicating the one or more non-terrestrial network units support the emergency service.

[0015] Other aspects and features will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary aspects in conjunction with the accompanying figures. While features may be discussed relative to certain aspects and figures below, all aspects can include one or more of the advantageous features discussed herein. In other words, while one or more aspects may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various aspects discussed herein. In similar fashion, while exemplary aspects may be discussed below as device, system, or method aspects, it should be understood that such exemplary aspects can be implemented in various devices, systems, and methods.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 illustrates a wireless communication network according to one or more aspects of the present disclosure.

[0017] FIG. 2 illustrates a diagram of an example disaggregated base station architecture according to one or more aspects of the present disclosure.

[0018] FIG. 3 A illustrates an example of a regenerative satellite deployment and an example of a transparent satellite deployment in a non-terrestrial network according to one or more aspects of the present disclosure.

[0019] FIG. 3B illustrates a wireless communication network with one or more non-terrestrial network units according to some aspects of the present disclosure.

[0020] FIG. 4 illustrates a signaling diagram for providing system information including one or more non-terrestrial network emergency service indicators according to some aspects of the present disclosure.

[0021] FIG. 5 illustrates a diagram of a system information block according to one or more aspects of the present disclosure.

[0022] FIG. 6 illustrates a diagram of a system information block according to one or more aspects of the present disclosure.

[0023] FIG. 7 illustrates a block diagram of a user equipment (UE) according to one or more aspects of the present disclosure.

[0024] FIG. 8 illustrates a block diagram of a network unit according to one or more aspects of the present disclosure.

[0025] FIG. 9 illustrates a flow diagram of a wireless communication method according to some aspects of the present disclosure.

[0026] FIG. 10 illustrates a flow diagram of a wireless communication method according to some aspects of the present disclosure.DETAILED DESCRIPTION

[0027] Various aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. One skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

[0028] Several aspects of telecommunication systems will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, or the like (collectively referred to as “elements”). These elements may be implemented using hardware, software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

[0029] While aspects may be described herein using terminology commonly associated with a 5G or New Radio (NR) radio access technology (RAT), aspects of the present disclosure can be applied to other RATs, such as a 3G RAT, a 4G RAT, and / or a RAT subsequent to 5G (e.g., 6G).

[0030] As wireless communication networks expand the use of non-terrestrial network units, a UE may camp on a non-terrestrial network cell. For example, the UE may camp on the non-terrestrial network cell when terrestrial network connectivity is not available, of poor quality, and / or intermittent. Camping on a non-terrestrial network cell may be particularly useful for automotive UEs, loT UEs, and / or mobile UEs. For example, a UE located in and / or traveling through a hilly area, a forest, and / or other areas where terrestrial network connectivity may be limited may determine to camp on a non-terrestrial network cell. In this regard, the UE may want to ensure that aneighboring non-terrestrial network cell the UE decides to camp on will support the service(s) the UE may need to access, such as emergency services. A UE may have no way of knowing which of the neighboring non-terrestrial network cells support one or more emergency services. As a result, a UE may camp on a neighboring non-terrestri l network cell that does not support the emergency service(s), which can result in poor user experiences (e.g., dropped emergency call, radio link failure, handover failure, etc.).

[0031] The present disclosure provides methods, devices, systems, protocols, and signaling that allow a UE to determine which neighboring non-terrestrial network cells support the emergency service(s). As a result, the UE may elect to camp on a neighboring non- terrestrial network cell that supports the emergency service(s). This can lead to an improved user experience (e.g., maintaining emergency call, no radio link failure, successful handover, faster recovery if call is dropped and / or radio link failure occurs, etc.) while also facilitating a more efficient use of network resources, UE power source(s), and / or non-terrestrial network unit power source(s) (e.g., by avoiding the UE connecting to non-terrestrial network cell(s) that do not support the emergency service(s)).

[0032] For example, in some instances the UE may maintain a list of non-terrestrial network cell(s) that support the emergency service(s) and / or a list of non-terrestrial network cell(s) that do not support the emergency service(s). Accordingly, when the UE is selecting a new non-terrestrial network cell to camp on, the UE may take into account whether the candidate non-terrestrial network cell(s) support the emergency service(s) and prioritize the candidate non-terrestrial network cell(s) that support the emergency service(s) over those that do not. In this manner, the UE may avoid unknowingly connecting to a non-terrestrial network cell that does not support the emergency service(s).

[0033] FIG. 1 illustrates a wireless communication network 100 according to one or more aspects of the present disclosure. The network 100 may be a 5G network. The network 100 includes a number of BSs 105 (individually labeled as 105a, 105b, 105c, 105d, 105e, and 105f) and other network entities. A BS 105 may be a station that communicates with UEs 115 (individually labeled as 115a, 115b, 115c, 115d, 115e, 115f, 115g, 115h, and 115k) and may also be referred to as an evolved node B (eNB), a next generation eNB (gNB), an access point, and the like. Each BS 105 may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to this particular geographic coverage area of a BS 105 and / or a BS subsystem serving the coverage area, depending on the context in which the term is used.

[0034] This disclosure relates generally to wireless communications systems, also referred to as wireless communication networks. In various aspects, the techniques and apparatus may be used for wireless communication networks such as code division multiple access (CDMA) networks, timedivision multiple access (TDM A) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks, Global System for Mobile Communications (GSM) networks, 5thGeneration (5G) or new radio (NR) networks, as well as other communications networks. As described herein, the terms “networks” and “systems” may be used interchangeably.

[0035] An OFDMA network may implement a radio technology such as evolved UTRA (E- UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM and the like. UTRA, E-UTRA, and GSM are part of universal mobile telecommunication system (UMTS). In particular, long term evolution (LTE) is a release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided from an organization named “3rd Generation Partnership Project” (3GPP), and cdma2000 is described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). These various radio technologies and standards are known or are being developed. For instance, the 3rd Generation Partnership Project (3 GPP) is a collaboration between groups of telecommunications associations that aims to define a globally applicable third generation (3G) mobile phone specification. 3GPP long term evolution (LTE) is a 3GPP project which was aimed at improving the UMTS mobile phone standard. The 3GPP may define specifications for the next generation of mobile networks, mobile systems, and mobile devices. The present disclosure is concerned with the evolution of wireless technologies from LTE, 4G, 5G, NR, and beyond with shared access to wireless spectrum between networks using a collection of new and different radio access technologies or radio air interfaces.

[0036] In particular, 5G networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. To achieve these goals, further enhancements to LTE and LTE-A are considered in addition to development of the new radio technology for 5G NR networks. The 5G NR will be capable of scaling to provide coverage (1) to a massive Internet of things (loTs) with an Ultra-high density (e.g., ~1M nodes / km2), ultra-low complexity (e.g., ~10s of bits / sec), ultra-low energy (e.g., -10+ years of battery life), and deep coverage with the capability to reach challenging locations; (2) including mission-critical control with strong security to safeguard sensitive personal, financial, or classified information, ultra-high reliability (e.g., -99.9999% reliability), ultra-low latency (e.g., - 1 ms), and users with wide ranges of mobility or lack thereof; and (3) with enhanced mobile broadband including extreme high capacity (e.g., - 10 Tbps / km2), extreme data rates (e.g., multi- Gbps rate, 100+ Mbps user experienced rates), and deep awareness with advanced discovery and optimizations.

[0037] The 5G NR may be implemented to use optimized OFDM-based waveforms with scalable numerology and transmission time interval (TTI); having a common, flexible framework to efficiently multiplex services and features with a dynamic, low-latency time division duplex (TDD) / frequency division duplex (FDD) design; and with advanced wireless technologies, such as massive multiple input, multiple output (MIMO), robust millimeter wave (mmWave) transmissions, advanced channel coding, and device-centric mobility. Scalability of the numerology in 5G NR, with scaling of subcarrier spacing, may efficiently address operating diverse services across diverse spectrum and diverse deployments. For instance, in various outdoor and macro coverage deployments of less than 3GHz FDD / TDD implementations, subcarrier spacing may occur with 15 kHz, for instance over 5, 10, 20 MHz, and the like bandwidth (BW). For other various outdoor and small cell coverage deployments of TDD greater than 3 GHz, subcarrier spacing may occur with 30 kHz over 80 / 100 MHz BW. For other various indoor wideband implementations, using a TDD over the unlicensed portion of the 5 GHz band, the subcarrier spacing may occur with 60 kHz over a 160 MHz BW. Finally, for various deployments transmitting with mmWave components at a TDD of 28 GHz, subcarrier spacing may occur with 120 kHz over a 500 MHz BW.

[0038] The scalable numerology of the 5G NR facilitates scalable TTI for diverse latency and quality of service (QoS) requirements. For instance, shorter TTI may be used for low latency and high reliability, while longer TTI may be used for higher spectral efficiency. The efficient multiplexing of long and short TTIs to allow transmissions to start on symbol boundaries. 5G NR also contemplates a self-contained integrated subframe design with uplink (UL)Zdownlink (DL) scheduling information, data, and acknowledgement in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive UL / DL that may be flexibly configured on a per-cell basis to dynamically switch between UL and DL to meet the current traffic needs.

[0039] A BS 105 may provide communication coverage for a macro cell or a small cell, such as a pico cell or a femto cell, and / or other types of cell. A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a pico cell, would generally cover a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a femto cell, would also generally cover a relatively small geographic area (e.g., a home) and, in addition to unrestricted access, may also provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in the home, and the like). A BS for a macro cell may be referred to as a macro BS. A BS for a small cell may be referred to as a small cell BS, a pico BS,a femto BS or a home BS. In FIG. 1, the BSs 105d and 105e may be regular macro BSs, while the BSs 105a-105c may be macro BSs enabled with one of three dimension (3D), full dimension (FD), or massive MIMO. The BSs 105a- 105c may take advantage of their higher dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth heamforming to increase coverage and capacity. The BS 105f may be a small cell BS which may be a home node or portable access point. A BS 105 may support one or multiple (e.g., two, three, four, and the like) cells.

[0040] In some aspects, the term “base station” (e.g., the BS 105) or “network entity” may refer to an aggregated base station, a disaggregated base station, an integrated access and backhaul (IAB) node, a relay node, and / or one or more components thereof. For example, in some aspects, “base station” or “network entity” may refer to a central unit (CU), a distributed unit (DU), a radio unit (RU), a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC), or a Non-Real Time (Non- RT) RIC, or a combination thereof. In some aspects, the term “base station” or “network entity” may refer to one device configured to perform one or more functions, such as those described herein in connection with the BSs 105. In some aspects, the term “base station” or “network entity” may refer to a plurality of devices configured to perform the one or more functions. For example, in some distributed systems, each of a number of different devices (which may be located in the same geographic location or in different geographic locations) may be configured to perform at least a portion of a function, or to duplicate performance of at least a portion of the function, and the term “base station” or “network entity” may refer to any one or more of those different devices. In some aspects, the term “base station” or “network entity” may refer to one or more virtual base stations and / or one or more virtual base station functions. For example, in some aspects, two or more base station functions may be instantiated on a single device. In some aspects, the term “base station” or “network entity” may refer to one of the base station functions and not another. In this way, a single device may include more than one base station.

[0041] The network 100 may support synchronous or asynchronous operation. For synchronous operation, the BSs may have similar frame timing, and transmissions from different BSs may be approximately aligned in time. For asynchronous operation, the BSs may have different frame timing, and transmissions from different BSs may not be aligned in time.

[0042] The UEs 115 are dispersed throughout the wireless network 100, and each UE 115 may be stationary or mobile. A UE 115 may also be referred to as a terminal, a mobile station, a subscriber unit, a station, or the like. A UE 115 may be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, or the like. In one aspect, a UE 115 may be a device that includes a Universal Integrated Circuit Card (UICC). In another aspect, aUE may be a device that does not include a UICC. In some aspects, the UEs 115 that do not include UICCs may also be referred to as loT devices or internet of everything (loE) devices. The UEs 115a- 115d are instances of mobile smart phone-type devices accessing network 100. A UE 115 may also be a machine specifically configured for connected communication, including machine type communication (MTC), enhanced MTC (eMTC), narrowband loT (NB-IoT) and the like. The UEs 115e-l 15h are instances of various machines configured for communication that access the network 100. The UEs 115i- 115k are instances of vehicles equipped with wireless communication devices configured for communication that access the network 100. A UE 115 may be able to communicate with any type of the BSs, whether macro BS, small cell, or the like. In FIG. 1, a lightning bolt (e.g., communication links) indicates wireless transmissions between a UE 115 and a serving BS 105, which is a BS designated to serve the UE 115 on the DL and / or UL, desired transmission between BSs 105, backhaul transmissions between BSs, or sidelink transmissions between UEs 115.

[0043] In operation, the BSs 105a-105c may serve the UEs 115a and 115b using 3D beamforming and coordinated spatial techniques, such as coordinated multipoint (CoMP) or multi-connectivity. The macro BS 105d may perform backhaul communications with the BSs 105a- 105c, as well as small cell, the BS 105f. The macro BS 105d may also transmits multicast services which are subscribed to and received by the UEs 115c and 115d. Such multicast services may include mobile television or stream video, or may include other services for providing community information, such as weather emergencies or alerts, such as Amber alerts or gray alerts.

[0044] The BSs 105 may also communicate with a core network. The core network may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some of the BSs 105 (e.g., which may be an instance of a gNB or an access node controller (ANC)) may interface with the core network through backhaul links (e.g., NG-C, NG-U, etc.) and may perform radio configuration and scheduling for communication with the UEs 115. In various cases, the BSs 105 may communicate, either directly or indirectly (e.g., through core network), with each other over backhaul links (e.g., XI, X2, etc.), which may be wired or wireless communication links.

[0045] The network 100 may also support communications with ultra-reliable and redundant links for some devices, such as the UE 115e. Redundant communication links with the UE 115e may include links from the macro BSs 105d and 105e, as well as links from the small cell BS 105f. Other machine type devices, such as the UE 115f (e.g., a thermometer), the UE 115g (e.g., smart meter), and UE 115h (e.g., wearable device) may communicate through the network 100 either directly with BSs, such as the small cell BS 105f, and the macro BS 105e, or in multi-action-size configurations by communicating with another user device which relays its information to thenetwork, such as the UE 115f communicating temperature measurement information to the smart meter, the UE 115g, which is then reported to the network through the small cell BS 105f. The network 100 may also provide additional network efficiency through dynamic, low-latency TDD / FDD communications, such asV2V, V2X, C-V2X communications between a UE 1 E5i, 1 15j, or 115k and other UEs 115, and / or vehicle-to-infrastructure (V2I) communications between a UE 115i, 115j, or 115k and a BS 105.

[0046] In some implementations, the network 100 utilizes OFDM-based waveforms for communications. An OFDM-based system may partition the system BW into multiple (K) orthogonal subcarriers, which are also commonly referred to as subcarriers, tones, bins, or the like. Each subcarrier may be modulated with data. In some aspects, the subcarrier spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may be dependent on the system BW. The system BW may also be partitioned into subbands. In other aspects, the subcarrier spacing and / or the duration of TTIs may be scalable.

[0047] In some aspects, the BSs 105 can assign or schedule transmission resources (e.g., in the form of time-frequency resource blocks (RB)) for DL and UL transmissions in the network 100. DL refers to the transmission direction from a BS 105 to a UE 115, whereas UL refers to the transmission direction from a UE 115 to a BS 105. The communication can be in the form of radio frames. A radio frame may be divided into a plurality of subframes or slots, for instance, about 10. Each slot may be further divided into mini-slots. In a FDD mode, simultaneous UL and DL transmissions may occur in different frequency bands. For instance, each subframe includes a UL subframe in a UL frequency band and a DL subframe in a DL frequency band. In a TDD mode, UL and DL transmissions occur at different time periods using the same frequency band. For instance, a subset of the subframes (e.g., DL subframes) in a radio frame may be used for DL transmissions and another subset of the subframes (e.g., UL subframes) in the radio frame may be used for UL transmissions.

[0048] The DL subframes and the UL subframes can be further divided into several regions. For instance, each DL or UL subframe may have pre-defined regions for transmissions of reference signals, control information, and data. Reference signals are predetermined signals that facilitate the communications between the BSs 105 and the UEs 115. For instance, a reference signal can have a particular pilot pattern or structure, where pilot tones may span across an operational BW or frequency band, each positioned at a pre-defined time and a pre-defined frequency. For instance, a BS 105 may transmit cell specific reference signals (CRSs) and / or channel state information - reference signals (CSLRSs) to enable a UE 115 to estimate a DL channel. Similarly, a UE 115 may transmit sounding reference signals (SRSs) to enable a BS 105 to estimate a UL channel. Controlinformation may include resource assignments and protocol controls. Data may include protocol data and / or operational data. In some aspects, the BSs 105 and the UEs 115 may communicate using self-contained subframes. A self-contained subframe may include a portion for DL communication and a portion for UL communication. A self-contained subframe can be DL-centric or UL-centric. A DL-centric subframe may include a longer duration for DL communication than for UL communication. A UL-centric subframe may include a longer duration for UL communication than for DL communication.

[0049] In some aspects, the network 100 may be an NR network deployed over a licensed spectrum. The BSs 105 can transmit synchronization signals (e.g., including a primary synchronization signal (PSS) and a secondary synchronization signal (SSS)) in the network 100 to facilitate synchronization. The BSs 105 can broadcast system information associated with the network 100 (e.g., including a master information block (MIB), remaining system information (RMSI), and other system information (OSI)) to facilitate initial network access. In some aspects, the BSs 105 may broadcast the PSS, the SSS, and / or the MIB in the form of synchronization signal block (SSBs) and may broadcast the RMSI and / or the OSI over a physical downlink shared channel (PDSCH). The MIB may be transmitted over a physical broadcast channel (PBCH).

[0050] In some aspects, a UE 115 attempting to access the network 100 may perform an initial cell search by detecting a PSS from a BS 105. The PSS may enable synchronization of period timing and may indicate a physical layer identity value. The UE 115 may then receive an SSS. The SSS may enable radio frame synchronization, and may provide a cell identity value, which may be combined with the physical layer identity value to identify the cell. The PSS and the SSS may be located in a central portion of a carrier or any suitable frequencies within the carrier.

[0051] After receiving the PSS and SSS, the UE 115 may receive a MIB. The MIB may include system information for initial network access and scheduling information for RMSI and / or OSI. After decoding the MIB, the UE 115 may receive RMSI and / or OSI. The RMSI and / or OSI may include radio resource control (RRC) information related to random access channel (RACH) procedures, paging, control resource set (CORESET) for physical downlink control channel (PDCCH) monitoring, physical UL control channel (PUCCH), physical UL shared channel (PUSCH), power control, and SRS.

[0052] After obtaining the MIB, the RMSI and / or the OSI, the UE 115 can perform a random access procedure to establish a connection with the BS 105. In some instances, the random access procedure may be a four-step random access procedure. For instance, the UE 115 may transmit a random access preamble and the BS 105 may respond with a random access response. The random access response (RAR) may include a detected random access preamble identifier (ID)corresponding to the random access preamble, timing advance (TA) information, an UL grant, a temporary cell-radio network temporary identifier (C-RNTI), and / or a backoff indicator. Upon receiving the random access response, the UE 115 may transmit a connection request to the BS 105 and the BS 105 may respond with a connection response. The connection response may indicate a contention resolution. In some instances, the random access preamble, the RAR, the connection request, and the connection response can be referred to as message 1 (MSG1), message 2 (MSG2), message 3 (MSG3), and message 4 (MSG4), respectively. In some instances, the random access procedure may be a two-step random access procedure, where the UE 115 may transmit a random access preamble and a connection request in a single transmission and the BS 105 may respond by transmitting a random access response and a connection response in a single transmission.

[0053] After establishing a connection, the UE 115 and the BS 105 can enter a normal operation stage, where operational data may be exchanged. For instance, the BS 105 may schedule the UE 115 for UL and / or DL communications. The BS 105 may transmit UL and / or DL scheduling grants to the UE 115 via a PDCCH. The scheduling grants may be transmitted in the form of DL control information (DCI). The BS 105 may transmit a DL communication signal (e.g., carrying data) to the UE 115 via a PDSCH according to a DL scheduling grant. The UE 115 may transmit a UL communication signal to the BS 105 via a PUSCH and / or PUCCH according to a UL scheduling grant. The connection may be referred to as an RRC connection. When the UE 115 is actively exchanging data with the BS 105, the UE 115 is in an RRC connected state.

[0054] In some aspects, after establishing a connection with the BS 105, the UE 115 may initiate an initial network attachment procedure with the network 100. The BS 105 may coordinate with various network entities or fifth generation core (5GC) entities, such as an access and mobility function (AMF), a serving gateway (SGW), and / or a packet data network gateway (PGW), to complete the network attachment procedure. For instance, the BS 105 may coordinate with the network entities in the 5GC to identify the UE, authenticate the UE, and / or authorize the UE for sending and / or receiving data in the network 100. In addition, the AMF may assign the UE with a group of tracking areas (TAs). Once the network attach procedure succeeds, a context is established for the UE 115 in the AMF. After a successful attach to the network, the UE 115 can move around the current TA. For tracking area update (TAU), the BS 105 may request the UE 115 to update the network 100 with the UE 115’ s location periodically. Alternatively, the UE 115 may only report the UE 115’s location to the network 100 when entering a new TA. The TAU allows the network 100 to quickly locate the UE 115 and page the UE 115 upon receiving an incoming data packet or call for the UE 115.

[0055] In some aspects, the BS 105 may communicate with a UE 115 using HARQ techniques to improve communication reliability, for instance, to provide a URLLC service. The BS 105 may schedule a UE 115 for a PDSCH communication by transmitting a DL grant in a PDCCH. The BS 105 may transmit a DL data packet to the UE 1 15 according to the schedule in the PDSCH. The DL data packet may be transmitted in the form of a transport block (TB). After receiving the DL data packet, the UE 115 may transmit a feedback message for the DL data packet to the BS 105. In some instances, the UE 115 may transmit the feedback on an acknowledgment resource. The feedback may be an acknowledgement (ACK) indicating that reception of the DL data packet by the UE 115 is successful (e.g., received the DL data without error) or may be a negative-acknowledgement (NACK) indicating that reception of the DL data packet by the UE 115 is unsuccessful (e.g., including an error or failing an error correction). In some aspects, if the UE 115 receives the DL data packet successfully, the UE 115 may transmit a HARQ ACK to the BS 105. Conversely, if the UE 115 fails to receive the DL transmission successfully, the UE 115 may transmit a HARQ NACK to the BS 105. Upon receiving a HARQ NACK from the UE 115, the BS 105 may retransmit the DL data packet to the UE 115. The retransmission may include the same coded version of DL data as the initial transmission. Alternatively, the retransmission may include a different coded version of the DL data than the initial transmission. The UE 115 may apply soft combining to combine the encoded data received from the initial transmission and the retransmission for decoding. The BS 105 and the UE 115 may also apply HARQ for UL communications using substantially similar mechanisms as the DL HARQ.

[0056] In some aspects, the network 100 may operate over a system BW or a component carrier (CC) BW. The network 100 may partition the system BW into multiple BWPs (e.g., portions). A BS 105 may dynamically assign a UE 115 to operate over a certain BWP (e.g., a certain portion of the system BW). The assigned BWP may be referred to as the active BWP. The UE 115 may monitor the active BWP for signaling information from the BS 105. The BS 105 may schedule the UE 115 for UL or DL communications in the active BWP. In some aspects, a BS 105 may assign a pair of BWPs within the CC to a UE 115 for UL and DL communications. For instance, the BWP pair may include one BWP for UL communications and one BWP for DL communications.

[0057] In some aspects, the network 100 may also include one or more non-terrestrial network units 155 (e.g., non-terrestrial network units 155a, 155b, and 155c, as shown). The non-terrestrial network units 155 may include a satellite or other high altitude vehicle operating in a non-terrestrial network (NTN) configuration. The non-terrestrial network units 155 may communicate with BSs 105 or the core network via gateways (e.g., ground-based terminals, NTN gateways). The non- terrestrial network units 155 may also communicate with UEs 115, which may include other highaltitude or terrestrial communications devices. In various examples, a non-terrestrial network unit 155 itself may be an example of a BS 105 (e.g., supporting a gNB processed payload). In some aspects, a BS 105 aboard a satellite or other high-altitude vehicle and / or a satellite performing one or more base station functionalities may be referred to as a non-terrestrial network unit 155. In some aspects, a non-terrestrial network unit 155 may provide a relay of signals between a BS 105 and UEs 115 (e.g., in a transparent satellite configuration, where a non-terrestrial network unit 155 and a gateway may be configured together as a remote radio unit). In some aspects, a non-terrestrial network unit 155 may be any suitable type of communication satellite configured to relay or otherwise support communications between different devices in the wireless communications network 100. The non-terrestrial network units 155 may include a space satellite, a balloon, a dirigible, or other vehicle which may support communications from a generally non-terrestrial, overhead, or elevated position. In some examples, A non-terrestrial network unit 155 may be in a geosynchronous or geostationary earth orbit, a low earth orbit, or a medium earth orbit. A non- terrestrial network unit 155 may be a multi-beam unit configured to provide service for multiple service beam coverage areas in a configured geographical service area. The non-terrestrial network units 155 may be any suitable distance away from the surface of the earth or other reference surface. In some aspects, the network 100 may also include one or more terrestrial network units (e.g., ground-based BSs 105 (e.g., tower-based, building-based, lower aerial aircraft-based, and / or other structure-based BSs), ground-based relays, ground-based terminals, ground-based NTN gateways, etc.).

[0058] Before establishing a connection with a UE 115, a BS 105 (including a non-terrestrial network unit 155) may determine the approximate location of the UE 115 (e.g. , so that the base station can select the appropriate core network to access on behalf of the UE 115). For example, to comply with various regulations or for other purposes, the base station may determine the country of the UE 115 so that the base station can select the core network of that country to access. To determine the approximate location of the UE 115 (and thus the country of the UE 1 15), a BS 105 may determine the approximate location of a UE 115 by using the propagation delay between the UE 115 and the BS 105 to determine a path along which the UE 115 is located. The BS 105 may leverage additional techniques to approximately locate the UE 115 on the path. For example, in some instances a BS 105 may determine the approximate location of a UE 115 by using a directional antenna to scan for an uplink reference signal from the UE 115. In some aspects, the BS 105 may configure communications between the UE 115 and the BS 105 based on geographic coordinates (e.g., Global Navigation Satellite System (GNSS) coordinates) reported by the UE.

[0059] A network controller 130 may couple to or communicate with one or more network nodes (e.g., the BSs 105, the non-terrestrial network units 155, ground-based terminals, NTN gateways, and / or other network nodes) and may provide coordination and control for these network nodes. The network controller 130 may communicate with the network nodes via a backhaul communication link, a midhaul communication link, or other suitable communication link. The network controller 130 may communicate with the network nodes directly and / or indirectly via one or more communication units. The network nodes may communicate with one another directly or indirectly via a wireless or wireline backhaul communication link. In some aspects, the network controller 130 may be a CU or a core network device, or may include a CU or a core network device. In this regard, the network controller 130 may include, for example, one or more devices in a core network.

[0060] Deployment of communication systems, such as 5G new radio (NR) systems, may be arranged in multiple manners with various components or constituent parts. In a 5G NR system, or network, a network node, a network entity, a mobility element of a network, a radio access network (RAN) node, a core network node, a network element, or a network equipment, such as a base station (BS), or one or more units (or one or more components) performing base station functionality, may be implemented in an aggregated or disaggregated architecture. For example, a BS (such as a Node B (NB), evolved NB (eNB), NR BS, 5G NB, access point (AP), a transmit receive point (TRP), or a cell, etc.) may be implemented as an aggregated base station (also known as a standalone BS or a monolithic BS) or a disaggregated base station.

[0061] An aggregated base station may be configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node. A disaggregated base station may be configured to utilize a protocol stack that is physically or logically distributed among two or more units (such as one or more central or centralized units (CUs), one or more distributed units (DUs), or one or more radio units (RUs)). In some aspects, a CU may be implemented within a RAN node, and one or more DUs may be co-located with the CU, or alternatively, may be geographically or virtually distributed throughout one or multiple other RAN nodes. The DUs may be implemented to communicate with one or more RUs. Each of the CU, DU and RU also can be implemented as virtual units, i.e., a virtual central unit (VCU), a virtual distributed unit (VDU), or a virtual radio unit (VRU).

[0062] Base station-type operation or network design may consider aggregation characteristics of base station functionality. For example, disaggregated base stations may be utilized in an integrated access backhaul (IAB) network, an open radio access network (O-RAN (such as the network configuration sponsored by the O-RAN Alliance)), or a virtualized radio access network (vRAN,also known as a cloud radio access network (C-RAN)). Disaggregation may include distributing functionality across two or more units at various physical locations, as well as distributing functionality for at least one unit virtually, which can enable flexibility in network design. The various units of the disaggregated base station, or disaggregated RAN architecture, can be configured for wired or wireless communication with at least one other unit.

[0063] Figure 2 shows a diagram illustrating an example disaggregated base station 200 architecture. The disaggregated base station 200 architecture may include one or more central units (CUs) 210 that can communicate directly with a core network 220 via a backhaul link, or indirectly with the core network 220 through one or more disaggregated base station units (such as a NearReal Time (Near-RT) RAN Intelligent Controller (RIC) 225 via an E2 link, or a Non-Real Time (Non-RT) RIC 215 associated with a Service Management and Orchestration (SMO) Framework 205, or both). A CU 210 may communicate with one or more distributed units (DUs) 230 via respective midhaul links, such as an Fl interface. The DUs 230 may communicate with one or more radio units (RUs) 240 via respective fronthaul links. The RUs 240 may communicate with respective UEs 115 via one or more radio frequency (RF) access links. In some implementations, the UE 115 may be simultaneously served by multiple RUs 240.

[0064] Each of the units, i.e., the CUs 210, the DUs 230, the RUs 240, as well as the Near-RT RICs 225, the Non-RT RICs 215, and the SMO Framework 205, may include one or more interfaces or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units, or an associated processor or controller providing instructions to the communication interfaces of the units, can be configured to communicate with one or more of the other units via the transmission medium. For example, the units can include a wired interface configured to receive or transmit signals over a wired transmission medium to one or more of the other units. Additionally, the units can include a wireless interface, which may include a receiver, a transmitter or transceiver (such as a radio frequency (RF) transceiver), configured to receive or transmit signals, or both, over a wireless transmission medium to one or more of the other units.

[0065] In some aspects, the CU 210 may host one or more higher layer control functions. Such control functions can include radio resource control (RRC), packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), or the like. Each control function can be implemented with an interface configured to communicate signals with other control functions hosted by the CU 210. The CU 210 may be configured to handle user plane functionality (i.e., Central Unit - User Plane (CU-UP)), control plane functionality (i.e., Central Unit - Control Plane (CU-CP)), or a combination thereof. In some implementations, the CU 210 can be logically splitinto one or more CU-UP units and one or more CU-CP units. The CU-UP unit can communicate bidirectionally with the CU-CP unit via an interface, such as the El interface when implemented in an O-RAN configuration. The CU 210 can be implemented to communicate with the DU 230, as necessary, for network control and signaling.

[0066] The DU 230 may correspond to a logical unit that includes one or more base station functions to control the operation of one or more RUs 240. In some aspects, the DU 230 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, or the like) depending, at least in part, on a functional split, such as those defined by the 3rdGeneration Partnership Project (3GPP). In some aspects, the DU 230 may further host one or more low PHY layers. Each layer (or module) can be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU 230, or with the control functions hosted by the CU 210.

[0067] Lower-layer functionality can be implemented by one or more RUs 240. In some deployments, an RU 240, controlled by a DU 230, may correspond to a logical node that hosts RF processing functions, or low-PHY layer functions (such as performing fast Fourier transform (FFT), inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, or the like), or both, based at least in part on the functional split, such as a lower layer functional split. In such an architecture, the RU(s) 240 can be implemented to handle over the air (OTA) communication with one or more UEs 115. In some implementations, real-time and non- real-time aspects of control and user plane communication with the RU(s) 240 can be controlled by the corresponding DU 230. In some scenarios, this configuration can enable the DU(s) 230 and the CU 210 to be implemented in a cloud -based RAN architecture, such as a vRAN architecture.

[0068] The SMO Framework 205 may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non- virtualized network elements, the SMO Framework 205 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements which may be managed via an operations and maintenance interface (such as an 01 interface). For virtualized network elements, the SMO Framework 205 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 290) to perform network element life cycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an 02 interface). Such virtualized network elements can include, but are not limited to, CUs 210, DUs 230, RUs 240 and Near-RT RICs 225. In some implementations, the SMO Framework 205 can communicate with a hardware aspect of a 4G RAN, such as an open eNB (O-eNB) 211, via an 01 interface. Additionally, in someimplementations, the SMO Framework 205 can communicate directly with one or more RUs 240 via an 01 interface. The SMO Framework 205 also may include a Non-RT RIC 215 configured to support functionality of the SMO Framework 205.

[0069] The Non-RT RIC 215 may he configured to include a logical function that enables non-real- time control and optimization of RAN elements and resources, Artificial Intelligence / Machine Learning (AI / ML) workflows including model training and updates, or policy-based guidance of applications / features in the Near-RT RIC 225. The Non-RT RIC 215 may be coupled to or communicate with (such as via an Al interface) the Near-RT RIC 225. The Near-RT RIC 225 may be configured to include a logical function that enables near-real-time control and optimization of RAN elements and resources via data collection and actions over an interface (such as via an E2 interface) connecting one or more CUs 210, one or more DUs 230, or both, as well as an O-eNB, with the Near-RT RIC 225.

[0070] In some implementations, to generate AI / ML models to be deployed in the Near-RT RIC 225, the Non-RT RIC 215 may receive parameters or external enrichment information from external servers. Such information may be utilized by the Near-RT RIC 225 and may be received at the SMO Framework 205 or the Non-RT RIC 215 from non-network data sources or from network functions. In some examples, the Non-RT RIC 215 or the Near-RT RIC 225 may be configured to tune RAN behavior or performance. For example, the Non-RT RIC 215 may monitor long-term trends and patterns for performance and employ AI / ML models to perform corrective actions through the SMO Framework 205 (such as reconfiguration via 01) or via creation of RAN management policies (such as Al policies).

[0071] FIG. 3A illustrates an example 300 of a regenerative satellite deployment and an example 302 of a transparent satellite deployment in a non-terrestrial network according to one or more aspects of the present disclosure. Fig. 3A is provided as an example. Other examples may differ from what is described with regard to Fig. 3A.

[0072] Example 300 shows a regenerative satellite deployment. In example 300, a UE 115 is served by a satellite 155a via a service link 304. For example, the satellite 155a may include a network node 105 (e.g., a DU, an RU, and / or a base station). In some aspects, the satellite 155a may be referred to as a non-terrestrial network node, a regenerative repeater, or an on-board processing repeater. In some aspects, the satellite 155a may demodulate an uplink radio frequency signal, and may modulate a baseband signal derived from the uplink radio signal to produce a downlink radio frequency transmission. The satellite 155a may transmit the downlink radio frequency signal on the service link 304. The satellite 155a may provide a cell that covers the UE 115.

[0073] Example 302 shows a transparent satellite deployment, which may also be referred to as a bent- pipe satellite deployment. In example 302, a UE 115 is served by a satellite 155b via the service link 304. The satellite 155b may be a transparent satellite. The satellite 155b may relay a signal received from gateway 315 via a feeder link 308. For example, the satellite 155b may receive an uplink radio frequency transmission, and may transmit a downlink radio frequency transmission without demodulating the uplink radio frequency transmission. In some aspects, the satellite 155b may frequency convert the uplink radio frequency transmission received on the service link 304 to a frequency of the uplink radio frequency transmission on the feeder link 308, and may amplify and / or filter the uplink radio frequency transmission. In some aspects, the UEs 115 shown in example 300 and example 302 may be associated with a Global Navigation Satellite System (GNSS) capability or a Global Positioning System (GPS) capability, though not all UEs have such capabilities. The satellite 155b may provide a cell that covers the UE 115.

[0074] The service link 304 may include a link between the satellite 155b and the UE 115, and may include one or more of an uplink or a downlink. The feeder link 308 may include a link between the satellite 155b and the gateway 315, and may include one or more of an uplink (e.g., from the UE 115 to the gateway 315) or a downlink (e.g., from the gateway 315 to the UE 115).

[0075] The feeder link 308 and the service link 304 may each experience Doppler effects due to the movement of the satellites 155a and 155b and / or the movement of the UE 115. These Doppler effects may be significantly larger than in a terrestrial network. The Doppler effect on the feeder link 308 may be compensated for to some degree, but may still be associated with some amount of uncompensated frequency error. Furthermore, the gateway 315 may be associated with a residual frequency error, and / or the satellites 155a and 155b may be associated with an on-board frequency error. These sources of frequency error may cause a received downlink frequency at the UE 115 to drift from a target downlink frequency.

[0076] Based at least in part on communicating via the satellite 155a or 155b, communications may have a relatively high round-trip-time (RTT) between the UE 115 and the satellite 155a or 155b and / or the gateway 315. The relatively high RTT may affect some types of communications, such as retransmissions and / or RA procedure messages.

[0077] FIG. 3B illustrates a wireless communication network 300 with one or more non-terrestrial network units according to some aspects of the present disclosure. As shown, the network 300 includes a core network 305 having a communication manager 310. The communication manager 310 may be configured to perform (or cause to be performed) one or more actions associated with the techniques of the present disclosure. The core network 305 may be in communication with a non-terrestrial network gateway 315 directly (e.g., via a backhaul communication link, a midhaulcommunication link, or other suitable communication link) or indirectly (e.g., via one or more other nodes). The non- terrestrial network gateway 315 may transmit and / or relay information from the core network to one or more non-terrestrial network units 155a, 155b, 155c, 155n. In accordance with the present disclosure, the non-terrestrial network gateway 315 may transmit and / or relay information regarding the emergency service capabilities of neighboring non-terrestrial network units to the non-terrestrial network units 155a, 155b, 155c, 155n. Each of the non-terrestrial network units 155a, 155b, 155c, 155n may include an associated communication manager 320a, 320b, 320c, 320n. The communication managers 320a, 320b, 320c, 320n may be configured to perform (or cause to be performed) one or more actions associated with the techniques of the present disclosure.

[0078] The non-terrestrial network units 155a, 155b, 155c, 155n may connect and / or communicate with one or more UEs (e.g., the UE 115) and / or one or more terrestrial network units (e.g., network unit 105). The UE 1 15 may include an associated communication manager 330 configured to perform (or cause to be performed) one or more actions associated with the techniques of the present disclosure. Similarly, the network unit 105 may include an associated communication manager 340 configured to perform (or cause to be performed) one or more actions associated with the techniques of the present disclosure. The core network 305 may also be in communication with the terrestrial network unit 105 directly (e.g., via a backhaul communication link, a midhaul communication link, or other suitable communication link) or indirectly (e.g., via one or more other nodes).

[0079] FIG. 4 illustrates a signaling diagram 400 for providing system information including one or more non-terrestrial network emergency service indicators according to some aspects of the present disclosure. The signaling diagram 400 illustrates aspects of indicating the emergency service(s) supported by one or more non-terrestrial network units in accordance with the present disclosure. In this regard, aspects of the signaling diagram 400 may be utilized in the context of the wireless communication networks 100 and 300 as well as with other aspects of the present disclosure, including aspects of FIGS. 5-10.

[0080] At action 405, the core network 305 (e.g., a network controller 130 associated with the core network 305) transmits non-terrestrial network neighbor cell information to a terrestrial network unit 105. The non-terrestrial network neighbor cell information may include information indicating one or more non-terrestrial network units support one or more emergency service(s). The non- terrestrial network neighbor cell information may also include parameters for the UE to access a RAT (e.g., NR, LTE, 3G, etc.) via non-terrestrial network access (e.g., NTN-Config information). The core network 305 may transmit the information to the terrestrial network unit 105 directly (e.g.,via a backhaul communication link, a midhaul communication link, or other suitable communication link) or indirectly (e.g., via one or more other nodes). The core network 305 may transmit the information to the terrestrial network unit 105 in any suitable format or message. In some aspects, the core network 305 and / or an associated network controller 1 0 includes an Access and Mobility Management Function (AMF). In some aspects, the information transmitted by the core network 305 to the terrestrial network unit 105 is carried in an NG application protocol (NGAP) message, for example, an AMF configuration update message. In some aspects, action 405 does not occur.

[0081] At action 410, the core network 305 (e.g., a network controller 130 associated with the core network 305) transmits non-terrestrial network neighbor cell information to a non-terrestrial network unit 155a. In some instances, the non-terrestrial network unit 155a may operate in a regenerative deployment (e.g., similar to example 300 of FIG. 3A) or a transparent deployment (e.g., similar to example 302 of FIG. 3 A). For regenerative deployments of the non-terrestrial network unit 155a, the core network 305 (e.g., a network controller 130 associated with the core network 305) may transmit the non-terrestrial network neighbor cell information to a base station, a DU, and / or an RU located in the sky and / or space associated with (e.g., coupled to and / or in communication with) the non-terrestrial network unit 155a. For transparent deployments of the non- terrestrial network unit 155a, the core network 305 (e.g., a network controller 130 associated with the core network 305) may transmit the non-terrestrial network neighbor cell information to a gateway, a base station, a DU, and / or an RU located on the ground (e.g., a terrestrial node) associated with the non-terrestrial network unit 155a.

[0082] As discussed above, the non-terrestrial network neighbor cell information may include information indicating one or more non-terrestrial network units support one or more emergency service(s) and / or include parameters for the UE to access a RAT (e.g., NR, LTE, 3G, etc.) via non- terrestrial network access (e.g., NTN-Config information). The core network 305 may transmit the information to the non-terrestrial network unit 155a directly or indirectly (e.g., via a NTN gateway). The core network 305 may transmit the information to the non-terrestrial network unit 155a in any suitable format or message. In some aspects, the core network 305 and / or an associated network controller 130 includes an Access and Mobility Management Function (AMF). In some aspects, the information transmitted by the core network 305 to the non-terrestrial network unit 155a is carried in an NG application protocol (NGAP) message, for example, an AMF configuration update message. In some aspects, action 410 does not occur.

[0083] In some aspects, the information provided to the terrestrial network unit 105 and / or the information provided to the non-terrestrial network unit 155a indicates whether each of the one or 1more non- terrestrial network units supports one or more emergency services. The one or more nonterrestrial network units may be associated with neighboring non-terrestrial network cells of the terrestrial network unit 105 and / or the non-terrestrial network 155a. In this regard, in some aspects the core network may provide the terrestrial network unit 105 with information for neighboring non-terrestrial network units that a UE may be likely to connect with in the area near the terrestrial network unit 105. Similarly, the core network may provide the non-terrestrial network unit 155a with information for neighboring non-terrestrial network units that a UE may be likely to connect with in the area near the non-terrestrial network unit 155a. The information received from the core network may include an indication of whether each of the one or more neighboring non-terrestrial network units supports the emergency service(s) (e.g., IMS emergency bearer service for a UE in a limited service mode, eCall over IMS, or otherwise).

[0084] At action 415, the terrestrial network unit 105 transmits, to one or more user equipments (UEs) including UE 115, a message indicating the one or more non-terrestrial network units support the emergency service(s). The message may be in any suitable format, including without limitation a system information block (SIB) (e.g., SIB 19, SIB 31, SIB 32, or other SIB). In some instances, the message utilizes one of the formats shown in Fig. 5 or Fig. 6. The terrestrial network unit 105 may broadcast the message. For example, the terrestrial network unit 105 may transmit a SIB 19 indicating the emergency service capabilities of neighboring non-terrestrial network units. In some instances, the terrestrial network unit 105 may transmit the message (e.g., RRC message or other suitable message) as a direct communication intended for a particular UE or a particular group of UEs. In some aspects, action 415 does not occur.

[0085] At action 420, the non-terrestrial network unit 155a transmits, to one or more user equipments (UEs) including UE 115, a message indicating the one or more non-terrestrial network units support the emergency service(s). The message may be in any suitable format, including without limitation a system information block (SIB) (e.g., SIB 19, SIB 31, SIB 32, or other SIB). In some instances, the message utilizes one of the formats shown in Fig. 5 or Fig. 6. The non- terrestrial network unit 155a may broadcast the message. For example, the non-terrestrial network unit 155a may transmit a SIB 19 indicating the emergency service capabilities of neighboring non- terrestrial network units. In some instances, the non-terrestrial network unit 155a may transmit the message (e.g., RRC message or other suitable message) as a direct communication intended for a particular UE or a particular group of UEs. In some aspects, action 420 does not occur.

[0086] In some aspects, the message (e.g., SIB 19 or otherwise) transmitted by the terrestrial network unit 105 and / or the message transmitted by the non-terrestrial network unit 155a includes at least one information element for each of the one or more non-terrestrial network units. The oneor more non-terrestrial network units may be associated with neighboring non-terrestrial network cells of the terrestrial network unit 105. The information element(s) may include an indication of whether each of the one or more non-terrestrial network units supports one or more emergency services. For example, the message may include one or more emergency service indicators for each non-terrestrial network unit (see, e.g., Figs. 5 and 6). Each emergency service indicator may indicate whether the non-terrestrial network unit supports an associated emergency service (e.g., IMS emergency bearer service for a UE in a limited service mode, eCall over IMS, or otherwise). In this regard, the emergency service indicator may provide a binary indication that the emergency service is supported (e.g., value of 1) or not supported (e.g., value of 0). In some instances, the emergency service indicator may provide an indication of one or more operating parameters and / or values associated with the non-terrestrial network unit’s support of the emergency service. In some aspects, the information element! s) included in the message may include for each of the one or more non-terrestrial network units a first information element indicating whether the non-terrestrial network unit supports a first emergency service (e.g., IP multimedia subsystem (IMS) emergency bearer service for a UE in a limited service mode), a second information element indicating whether the non-terrestrial network unit supports a second emergency service (e.g., emergency calls over IMS services), a third information element indicating whether the non-terrestrial network unit supports a third emergency service, etc.

[0087] At action 425, the UE selects a first non-terrestrial network unit (e.g., non-terrestrial network unit 155b) to connect to. In this regard, the UE may select the first non-terrestrial network unit from among the one or more non-terrestrial network units included in the message(s) from the terrestrial network unit 105 (action 415) and / or from the non-terrestrial network unit 155a (action 420) based at least in part on the message(s) indicating the first non-terrestrial network unit supports the emergency service(s). The UE may select the first non-terrestrial network unit from among the one or more non-terrestrial network units as part of a cell reselection process, a handover, an initial cell selection, and / or otherwise. In determining which non-terrestrial network unit(s) to connect to, the UE may prioritize non-terrestrial network units that support the emergency service(s), while also taking into account other factors (e.g., channel conditions, reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), CQI, etc.). In some instances, the UE may categorize and / or rank the one or more non-terrestrial network units based at least in part on what emergency service(s) each non-terrestrial network unit supports. Further, the categorization and / or ranking may be at least partially dependent upon a current status or situation of the UE. For example, if the UE has an active eCall in progress and needs to perform a cell reselection and / or handover, then the UE may give priority to neighboring non-terrestrialnetwork units that support eCall over those that do not support eCall in an effort to avoid the eCall being dropped. The UE may maintain one or more tables, lists, or other records (e.g., in an RRC database) with the categorization(s) and / or ranking(s) of the neighboring non-terrestrial network units, which may he updated from time to time as the UE receives messages from network units indicating the emergency service capabilities of non-terrestrial network units.

[0088] At action 430, the UE 115 connects with the selected non-terrestrial network unit (e.g., non- terrestrial network unit 155b). In this regard, the UE 115 may connect with the selected non- terrestrial network unit as part of a cell reselection process, a handover, an initial cell selection, and / or otherwise. For example, the UE 115 may utilize a random access channel (RACH) procedure to connect with the selected non-terrestrial network unit.

[0089] At action 435, the UE 115 communicates with the selected non-terrestrial network unit (e.g., non-terrestrial network unit 155b). In this regard, the UE may communicate with the selected non- terrestrial network unit by transmitting uplink data, transmitting uplink control information, receiving downlink data, receiving downlink control information, or otherwise.

[0090] FIG. 5 illustrates a diagram of a system information block (SIB) 500 according to one or more aspects of the present disclosure. The SIB 500 may be utilized in the context of the wireless communication networks 100 and 300 as well as with other aspects of the present disclosure, including aspects of FIGS. 4 and 6-10.

[0091] As shown, the SIB 500 includes non-terrestrial neighbor cell configuration information 505. The non-terrestrial neighbor cell configuration information 505 may include parameters for the UE to access a RAT (e.g., NR, LTE, 3G, etc.) via non-terrestrial network access (e.g., NTN-Config information). The SIB 500 also includes at least one information element for each of one or more non-terrestrial network neighbor cells 510a, 510b, ..., 510n. The information element(s) may include an indication of whether each of the one or more non-terrestrial network neighbor cells 510a, 510b, ..., 510n supports one or more emergency services. For example, the message may include one or more emergency service indicators for each non-terrestrial network neighbor cell 510a, 510b, ..., 510n. In the illustrated example of Fig. 5, each non-terrestrial network neighbor cell 510a, 510b, . .., 510n includes a plurality of emergency service indicators, namely Emergency Service 1 Indicator(s), Emergency Service 2 Indicator(s), ..., Emergency Service i Indicator(s). In this manner, the SIB 500 may indicate whether each non-terrestrial network unit supports a first emergency service (e.g., IP multimedia subsystem (IMS) emergency bearer service for a UE in a limited service mode) via the Emergency Service 1 Indicator(s), a second emergency service (e.g., emergency calls over IMS services) via the Emergency Service 2 Indicator(s), and so on.

[0092] Each emergency service indicator (or group of indicators) may indicate whether the nonterrestrial network unit supports the associated emergency service (e.g., IMS emergency bearer service for a UE in a limited service mode, eCall over IMS, or otherwise). In this regard, the emergency service indicator may provide a binary indication that the emergency service is supported (e.g., value of 1) or not supported (e.g., value of 0). In some instances, the emergency service indicator (or group of indicators) may provide an indication of one or more operating parameters and / or values associated with the non-terrestrial network unit’s support of the emergency service.

[0093] FIG. 6 illustrates a diagram of a system information block (SIB) 600 according to one or more aspects of the present disclosure. The SIB 600 may be utilized in the context of the wireless communication networks 100 and 300 as well as with other aspects of the present disclosure, including aspects of FIGS. 4, 5, and 7-10.

[0094] As shown, the SIB 600 is an example of a SIB 19 incorporating some aspects of the SIB 500 described above. In particular, the SIB 600 includes a first information element, Emergency Service Indicator 605, to indicate whether each of the one or more neighboring non-terrestrial network units supports IP multimedia subsystem (IMS) emergency bearer service for a UE in a limited service mode. In some instances, the Emergency Service Indicator 605 may include an ims- EmergencySupport information element. The SIB 600 also includes a second information element, Emergency Service Indicator 610 of Fig. 6), to indicate whether each of the one or more neighboring non-terrestrial network units supports emergency calls over IMS services (eCall). In some instances, the Emergency Service Indicator 610 may include an eCallOverlMS-Support information element. While Fig. 6 illustrates a SIB 19, a similar approach may be used in the context of SIB 31, SIB 32, and / or other SIBs.

[0095] FIG. 7 is a block diagram of a UE 700 according to one or more aspects of the present disclosure. The UE 700 may be, for instance, a UE 115 as discussed in FIGS. 1-4. As shown, the UE 700 may include a processor (or processing circuitry) 702, a memory (or memory circuitry) 704 with instructions 706, a non-terrestrial network (NTN) communication manager module 708, a transceiver 710 including a modem subsystem 712 and an RF unit 714, and one or more antennas 716. These elements may be coupled with one another. The term “coupled” may refer to directly or indirectly coupled or connected to one or more intervening elements. For instance, these elements may be in direct or indirect communication with each other, for instance via one or more buses.

[0096] The processor (or processing circuitry) 702 may include one or more processors (or processing circuitry) that may operate individually, collectively, and / or in any combination. Each processor (or processing circuitry) 702 may include a CPU, a DSP, an ASIC, a controller, a FPGAdevice, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor (or processing circuitry) 702 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0097] The memory (or memory circuitry) 704 may include one or more memories (or memory circuitry) that may operate individually, collectively, and / or in any combination. Each memory (or memory circuitry) 704 may include a cache memory (e.g., a cache memory of the processor (or processor circuitry) 702), RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, solid state memory device, hard disk drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some aspects, the memory (or memory circuitry) 704 may include a non-transitory computer-readable medium. The memory (or memory circuitry) 704 may store, or have recorded thereon, instructions 706. The instructions 706 may include instructions that, when executed by the processor 702, cause the UE 700 to perform the operations described herein with reference to a UE 115 in connection with aspects of the present disclosure, for instance, aspects of FIGS. 3A-6 and 9. Instructions 706 may also be referred to as program code. The program code may be for causing an apparatus at a wireless communication device, such as UE 700, to perform these operations, for instance by causing one or more processors (such as processor 702) to control or command the apparatus and / or the UE 700 to do so. The terms “instructions” and “code” should be interpreted broadly to include any type of computer-readable statement(s). For instance, the terms “instructions” and “code” may refer to one or more programs, routines, subroutines, functions, procedures, etc. “Instructions” and “code” may include a single computer- readable statement or many computer-readable statements.

[0098] The NTN communication manager module 708 may be implemented via hardware, software, or combinations thereof. For instance, the NTN communication manager module 708 may be implemented as a processor, circuitry, and / or instructions 706 stored in the memory 704 and executed by the processor 702. In some aspects, the NTN communication manager module 708 may be integrated within the modem subsystem 712. For instance, the NTN communication manager module 708 may be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the modem subsystem 712. The NTN communication manager module 708 may communicate with one or more components of the UE 700 to implement various aspects of the present disclosure, for instance, aspects of FIGS. 3A-6 and 9. In this regard, the NTN communication manager module 708 may include, be, and / or be part of the communication manager 330 of Fig. 3B.

[0099] In some aspects, the NTN communication manager module 708 may be configured, along with other components of the UE 700, to receive, from a network unit, a message indicating one or more non- terrestrial network units support one or more emergency services. In some aspects, the NTN communication manager module 708 may be configured, along with other components of the UE 700, to select a first non-terrestrial network unit of the one or more non-terrestrial network units based at least in part on the message indicating the first non-terrestrial network unit supports the emergency service(s). In some aspects, the NTN communication manager module 708 may be configured, along with other components of the UE 700, to connect to a first non-terrestrial network unit of the one or more non-terrestrial network units based at least in part on the message indicating the first non-terrestrial network unit supports the emergency service(s).

[0100] As shown, the transceiver 710 may include the modem subsystem 712 and the RF unit 714. The transceiver 710 can be configured to communicate bi-directionally with other devices, such as the BSs 105, NTN units 155, and / or other network units. The modem subsystem 712 may be configured to modulate and / or encode the data from the memory 704 and / or the NTN communication manager module 708 according to a MCS, e.g., a LDPC coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. The RF unit 714 may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc.) modulated / encoded data (e.g., communication signals, data signals, control signals, etc.) from the modem subsystem 712 (on outbound transmissions). The RF unit 714 may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver 710, the modem subsystem 712 and the RF unit 714 may be separate devices that are coupled together at the UE 700 to enable the UE 700 to communicate with other devices.

[0101] The RF unit 714 may provide the modulated and / or processed data, e.g., data packets (or, more generally, data messages that may contain one or more data packets and other information), to the antennas 716 for transmission to one or more other devices. The antennas 716 may further receive data messages transmitted from other devices. The antennas 716 may provide the received data messages for processing and / or demodulation at the transceiver 710. The transceiver 710 may provide the demodulated and decoded data (e.g., communication signals, data signals, control signals, messages (including SIBs) with non-terrestrial network unit emergency service indicators, etc.) to the NTN communication manager module 708 for processing. The antennas 716 may include multiple antennas of similar or different designs in order to sustain multiple transmission links.

[0102] FIG. 8 is a block diagram of a network unit 800 according to one or more aspects of the present disclosure. The network unit 800 may be a BS 105, NTN unit 155, CU 210, DU 230, and / or RU 240 as discussed in FIGS. 1-4. Accordingly, the network unit 800 may include a BS. The network unit 800 may be a terrestrial network unit or non-terrestrial network unit. The BS may be an aggregated BS or a disaggregated BS, as described above. As shown, the network unit 800 may include a processor (or processing circuitry) 802, a memory (or memory circuitry) 804, a GNSS module 808, a transceiver 810 including a modem subsystem 812 and a radio frequency (RF) unit 814, and one or more antennas 816. These elements may be coupled with one another. The term “coupled” may refer to directly or indirectly coupled or connected to one or more intervening elements. For instance, these elements may be in direct or indirect communication with each other, for instance via one or more buses.

[0103] The processor (or processing circuitry) 802 may include one or more processors (or processing circuitry) that may operate individually, collectively, and / or in any combination. Each processor (or processing circuitry) 802 may include a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor (or processing circuitry) 802 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0104] The memory (or memory circuitry) 704 may include one or more memories (or memory circuitry) that may operate individually, collectively, and / or in any combination. Each memory (or memory circuitry) 804 may include a cache memory (e.g., a cache memory of the processor 802), random access memory (RAM), magnetoresistive RAM (MRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), flash memory, a solid state memory device, one or more hard disk drives, memristor-based arrays, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some aspects, the memory (or memory circuitry) 804 may include a non-transitory computer-readable medium. The memory (or memory circuitry) 804 may store instructions 806. The instructions 806 may include instructions that, when executed by the processor 802, cause the network unit 800 to perform the operations described herein with reference to a network unit 105 or non-terrestrial network unit 155 in connection with aspects of the present disclosure, for instance, aspects of FIGS. 3A-6 and 10. Instructions 806 may also be referred to as program code. The program code may be for causing anapparatus at a wireless communication device, such as network unit 800, to perform these operations, for instance by causing one or more processors (such as processor 802) to control or command the apparatus and / or the network unit 800 to do so. The terms “instructions” and “code” should be interpreted broadly to include any type of computer-readable statement(s). For instance, the terms “instructions” and “code” may refer to one or more programs, routines, sub-routines, functions, procedures, etc. “Instructions” and “code” may include a single computer-readable statement or many computer-readable statements.

[0105] The communication manager module 808 may be implemented via hardware, software, or combinations thereof. For instance, the communication manager module 808 may be implemented as a processor, circuitry, and / or instructions 806 stored in the memory 804 and executed by the processor 802. In some instances, the communication manager module 808 may be integrated within the modem subsystem 812. For instance, the communication manager module 808 may be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the modem subsystem 812. The communication manager module 808 may communicate with one or more components of the network unit 800 to implement various aspects of the present disclosure, for instance, aspects of FIGS. 3A-6 and 10. In this regard, the communication manager module 808 may include, be, and / or be part of the communication managers 320a, 320b, 320c, 320n, 340 of Fig. 3B.

[0106] In some aspects, the communication manager module 808 may be configured, along with other components of the network unit 800, to receive (e.g., from a core network) information indicating one or more non-terrestrial network units support an emergency service. In some aspects, the communication manager module 808 may be configured, along with other components of the network unit 800, to transmit (e.g., to one or more user equipments (UEs)) a message indicating the one or more non-terrestrial network units support the emergency service. In some aspects, the communication manager module 808 may be configured, along with other components of the network unit 800, to connect to a first UE based at least in part on the network unit supporting the emergency service.

[0107] As shown, the transceiver 810 may include the modem subsystem 812 and the RF unit 814. The transceiver 810 can be configured to communicate bi-directionally with other devices, such as the UE 115, UE 700, and / or another network unit. The modem subsystem 812 may be configured to modulate and / or encode data according to a modulation and coding scheme (MCS), e.g., a low- density parity check (LDPC) coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. The RF unit 814 may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc.) modulated / encoded data(e.g., communication signals, data signals, control signals, messages (including SIBs) with nonterrestrial network unit emergency service indicators, etc.) from the modem subsystem 812 (on outbound transmissions). The RF unit 814 may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver 810, the modem subsystem 812, and / or the RF unit 814 may be separate devices that are coupled together at the network unit 800 to enable the network unit 800 to communicate with other devices.

[0108] The RF unit 814 may provide the modulated and / or processed data, e.g., data packets (or, more generally, data messages that may contain one or more data packets and other information), to the antennas 816 for transmission to one or more other devices. The antennas 816 may further receive data messages transmitted from other devices and provide the received data messages for processing and / or demodulation at the transceiver 810. The transceiver 810 may provide the demodulated and decoded data (e.g., communication signals, data signals, control signals, nonterrestrial network unit emergency service capability reports and / or information, etc.) to the communication manager module 808 for processing. The antennas 816 may include multiple antennas of similar or different designs in order to sustain multiple transmission links.

[0109] FIG. 9 is a flow diagram illustrating a wireless communication method 900 according to one or more aspects of the present disclosure. Aspects of the method 900 can be executed by a computing device (e.g., one or more processors, processing circuitry, and / or other suitable component(s)) of a wireless communication device or other suitable means for performing the blocks. For instance, the wireless communication device may be a UE (e.g., UE 115 or UE 700). The UE may utilize one or more components, such as the processor (or processing circuitry) 702, the memory (or memory circuitry) 704, the NTN communication manager module 708, the transceiver 710, the modem subsystem 712, the RF unit 714, and / or the one or more antennas 716, to execute the blocks of method 900. The method 900 may employ similar mechanisms as described in FIGS. 3A-6. As illustrated, the method 900 includes a number of enumerated blocks, but aspects of the method 900 may include additional blocks before, after, and in between the enumerated blocks. In some aspects, one or more of the enumerated blocks may be omitted or performed in a different order.

[0110] At block 910, the UE (e.g., UE 115 and / or UE 700) receives, from a network unit, a message indicating one or more non-terrestrial network units support one or more emergency services. In some instances, the UE may receive the message from a non-terrestrial network unit (see, e.g., action 420 of Fig. 4). In some instances, the UE may receive the message from a terrestrial network unit (e.g., a ground-based BS 105) (see, e.g., action 415 of Fig. 4). The messagemay be in any suitable format, including without limitation a system information block (SIB) (e.g., SIB 19, SIB 31, SIB 32, or other SIB). In some instances, the message may be a message broadcast by the network unit. For example, the UE may receive a SIB 19 broadcast by the network unit. In some instances, the message may be a direct communication intended for the UE (or a group of UEs including the UE), including without limitation an RRC message or other suitable message. In some aspects, the UE may receive the message indicating the emergency service capabilities of the one or more non-terrestrial network units regardless of whether the UE is currently camped on nonterrestrial network unit or a terrestrial network unit.

[0111] In some aspects, the message (e.g., SIB 19 or otherwise) includes at least one information element for each of the one or more non-terrestrial network units. The one or more non-terrestrial network units may be associated with neighboring non-terrestrial network cells of the network unit. The information element(s) may include an indication of whether each of the one or more non- terrestrial network units supports one or more emergency services. For example, the message may include one or more emergency service indicators for each non-terrestrial network unit (see, e.g., Figs. 5 and 6). Each emergency service indicator may indicate whether the non-terrestrial network unit supports an associated emergency service (e.g., IMS emergency bearer service for a UE in a limited service mode, eCall over IMS, or otherwise). In this regard, the emergency service indicator may provide a binary indication that the emergency service is supported (e.g., value of 1) or not supported (e.g., value of 0). In some instances, the emergency service indicator may provide an indication of one or more operating parameters and / or values associated with the non-terrestrial network unit’s support of the emergency service. In some aspects, the information element(s) included in the message may include at least one of a first information element (see, e.g., Emergency Service 1 Indicator(s) of Fig. 5 or Emergency Service Indicator 605 of Fig. 6) indicating whether each of the one or more non-terrestrial network units supports IP multimedia subsystem (IMS) emergency bearer service for a UE in a limited service mode or a second information element (see, e.g., Emergency Service 1 Indicator(s) of Fig. 5 or Emergency Service Indicator 610 of Fig. 6) indicating whether each of the one or more non-terrestrial network units supports emergency calls over IMS services.

[0112] In some aspects, the UE selects a first non-terrestrial network unit of the one or more non- terrestrial network units based at least in part on the message indicating the first non-terrestrial network unit supports the emergency service(s). In this regard, the UE may select the first non- terrestrial network unit from among the one or more non-terrestrial network units as part of a cell reselection process, a handover, an initial cell selection, and / or otherwise. In determining which non-terrestrial network unit(s) to connect to, the UE may prioritize non-terrestrial network units thatsupport the emergency service(s), while also taking into account other factors (e.g., channel conditions, reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), CQI, etc.). In some instances, the UE may categorize and / or rank the one or more non-terrestrial network units based at least in part on what emergency service(s) each non-terrestrial network unit supports. Further, the categorization and / or ranking may be at least partially dependent upon a current status or situation of the UE. For example, if the UE has an active eCall in progress and needs to perform a cell reselection and / or handover, then the UE may give priority to neighboring non-terrestrial network units that support eCall over those that do not support eCall in an effort to avoid the eCall being dropped. The UE may maintain one or more tables, lists, or other records (e.g., in an RRC database) with the categorization(s) and / or ranking(s) of the neighboring non-terrestrial network units, which may be updated from time to time as the UE receives messages from network units indicating the emergency service capabilities of non- terrestrial network units.

[0113] At block 920, the UE connects to a first non-terrestrial network unit of the one or more non- terrestrial network units based at least in part on the message received at block 910 indicating the one or more non-terrestrial network units support the emergency service(s). In this regard, as noted above the UE may connect to the first non-terrestrial network unit based at least in part on the first non-terrestrial network unit supporting one or more emergency service(s), as indicated in the message received by the UE at block 910. In some instances, the UE connects to the first non- terrestrial network unit by performing a handover from a serving network unit to the first non- terrestrial network unit. In this regard, the serving network unit may be a second non-terrestrial network unit and / or a terrestrial network unit. In some aspects, the UE connects to the first non- terrestrial unit by camping on a cell associated with the first non-terrestrial network unit. In some instances, the UE 115 may utilize a random access channel (RACH) procedure to connect with the first non-terrestrial network unit.

[0114] FIG. 10 is a flow diagram illustrating a wireless communication method 1000 according to one or more aspects of the present disclosure. Aspects of the method 1000 can be executed by a computing device (e.g., one or more processors, processing circuitry, and / or other suitable component(s)) of a wireless communication device or other suitable means for performing the blocks. For instance, the wireless communication device may include a network unit (e.g., network unit 800, BS 105, non-terrestrial network unit 155, CU 210, DU 230, and / or RU 240). The network unit 800 may utilize one or more components, such as the processor 802, the memory 804, the communication manager module 808, the transceiver 810, the modem subsystem 812, the RF unit 814, and / or the one or more antennas 816, to execute the blocks of method 1000. The method 1000may employ similar mechanisms as described in FIGS. 3A-6. As illustrated, the method 1000 includes a number of enumerated blocks, but aspects of the method 1000 may include additional blocks before, after, and in between the enumerated blocks. In some aspects, one or more of the enumerated blocks may be omitted or performed in a different order.

[0115] At block 1010, the network unit (network unit 800, BS 105, non-terrestrial network unit 155, CU 210, DU 230, and / or RU 240) receives information indicating one or more non-terrestrial network units support an emergency service. The network unit may be a non-terrestrial network unit and / or a terrestrial network unit. The network unit may receive the information from a core network and / or another network unit (e.g., network unit 800, BS 105, non-terrestrial network unit 155, CU 210, DU 230, and / or RU 240). The network unit may receive the information from the core network directly (e.g., via a backhaul communication link, a midhaul communication link, or other suitable communication link) or indirectly (e.g., via one or more other nodes). For example, in some instances the core network (e.g., core network 305 of Figs. 3B and 4 and / or network controller 130 of Fig. 1) may provide information directly to a terrestrial network unit (e.g., network unit 105 of Figs. 3A, 3B, and 4). As another example, the core network (e.g., core network 305 of Figs. 3B and 4 and / or network controller 130 of Fig. 1) may provide information directly and / or indirectly to a non-terrestrial network unit. For example, for regenerative deployments of a non-terrestrial network unit, the core network (e.g., a network controller associated with the core network) may transmit the information to a base station, a DU, and / or an RU located in the sky and / or space associated with (e.g., coupled to and / or in communication with) the non-terrestrial network unit. For transparent deployments of the non-terrestrial network unit, the core network may transmit the information to a gateway, a base station, a DU, and / or an RU located on the ground (e.g., a terrestrial node) associated with the non-terrestrial network unit, which may relay the information to the non- terrestrial unit. The network unit may receive the information from the core network in any suitable format or message. In some aspects, the core network and / or an associated network controller includes an Access and Mobility Management Function (AMF). In some aspects, the information transmitted by the core network to the network unit is carried in an NG application protocol (NGAP) message, for example, an AMF configuration update message.

[0116] In some aspects, the information indicates whether each of the one or more non-terrestrial network units supports one or more emergency services. The one or more non-terrestrial network units may be associated with neighboring non-terrestrial network cells of the network unit. In this regard, in some aspects the core network may provide the network unit with information for neighboring non-terrestrial network units that a UE may be likely to connect with in the area near the network unit. The information received from the core network may include an indication ofwhether each of the one or more neighboring non-terrestrial network units supports the emergency service(s) (e.g., IMS emergency bearer service for a UE in a limited service mode, eCall over IMS, or otherwise). In this regard, the information may provide a binary indication that the emergency service is supported (e.g., value of 1) or not supported (e.g., value of 0) by a non-terrestrial network unit. In some instances, the information may provide an indication of one or more operating parameters and / or values associated with the non-terrestrial network unit’s support of the emergency service. As discussed below, the network unit may utilize the information from the core network to generate and transmit a message indicating the emergency service capabilities of the neighboring non-terrestrial network units.

[0117] At block 1020, the network unit transmits a message indicating the one or more non- terrestrial network units support the emergency service. In some instances, the network unit transmitting the message is a non-terrestrial network unit (see, e.g., action 420 of Fig. 4). In some instances, the network unit transmitting the message is a terrestrial network unit (e.g., a ground- based BS 105) (see, e.g., action 415 of Fig. 4). The network unit may transmit the message to one or more UEs and / or to one or more other devices, including another network unit (e.g., network unit 800, BS 105, non-terrestrial network unit 155, CU 210, DU 230, and / or RU 240) that may serve as an intermediate node between the network unit and the one or more UEs. The message may be in any suitable format, including without limitation a system information block (SIB) (e.g., SIB 19, SIB 31, SIB 32, or other SIB). In some instances, the message may be a message broadcast by the network unit. For example, the network unit may transmit a SIB 19 indicating the emergency service capabilities of neighboring non-terrestrial network units. In some instances, the network unit may transmit the message (e.g., RRC message or other suitable message) as a direct communication intended for a particular UE or a particular group of UEs.

[0118] In some aspects, the message (e.g., SIB 19 or otherwise) transmitted by the network unit includes at least one information element for each of the one or more non-terrestrial network units. The one or more non-terrestrial network units may be associated with neighboring non-terrestrial network cells of the network unit. The information element(s) may include an indication of whether each of the one or more non-terrestrial network units supports one or more emergency services. For example, the message may include one or more emergency service indicators for each non- terrestrial network unit (see, e.g., Fig. 5). Each emergency service indicator may indicate whether the non-terrestrial network unit supports an associated emergency service (e.g., IMS emergency bearer service for a UE in a limited service mode, eCall over IMS, or otherwise). In this regard, the emergency service indicator may provide a binary indication that the emergency service is supported (e.g., value of 1) or not supported (e.g., value of 0). In some instances, the emergencyservice indicator may provide an indication of one or more operating parameters and / or values associated with the non-terrestrial network unit’s support of the emergency service. In some aspects, the information element(s) included in the message may include at least one of a first information element (see, e.g., Emergency Service 1 Indicator(s) of Fig. 5 or Emergency Service Indicator 605 of Fig. 6) indicating whether each of the one or more non-terrestrial network units supports IP multimedia subsystem (IMS) emergency bearer service for a UE in a limited service mode or a second information element (see, e.g., Emergency Service 2 Indicator(s) of Fig. 5 or Emergency Service Indicator 610 of Fig. 6) indicating whether each of the one or more nonterrestrial network units supports emergency calls over IMS services.

[0119] In some aspects, the network unit is a non-terrestrial network unit that supports the emergency service(s) and the method 1000 includes the non-terrestrial network unit connecting to a first UE based at least in part on the network unit supporting the emergency service. The non- terrestrial network unit may connect to the first UE as part of a cell reselection process, a handover, an initial cell selection, and / or otherwise. In some aspects, the non-terrestrial network unit connects to the first UE as part of a handover from a serving network unit. In this regard, the serving network unit may be second non-terrestrial network unit and / or a terrestrial network unit. In some instances, the non-terrestrial network unit may utilize a random access channel (RACH) procedure to connect with the first UE.

[0120] Other aspects of the present disclosure include:

[0121] Clause 1. An apparatus for wireless communications at a user equipment (UE), comprising: one or more memories; and one or more processors coupled to the one or more memories, the one or more memories storing instructions that are executable by the one or more processors, individually or in any combination, to cause the UE to: receive, from a network unit, a message indicating one or more non-terrestrial network units support an emergency service; and connect, based at least in part on the message indicating the one or more non-terrestrial network units support the emergency service, to a first non-terrestrial network unit of the one or more non-terrestrial network units.

[0122] Clause 2. The apparatus of clause 1 , wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the UE to receive the message from a non-terrestrial network unit.

[0123] Clause 3. The apparatus of any of clauses 1-2, wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the UE to receive the message from a terrestrial network unit.

[0124] Clause 4. The apparatus of any of clauses 1 -3, wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the UE to receive the message as a system information block 19 (SIB 19) broadcast by the network unit.

[0125] Clause 5. The apparatus of clause 4, wherein the SIB 19 includes at least one information element for each of the one or more non-terrestrial network units, the at least one information element including an indication of whether each of the one or more non-terrestrial network units supports the emergency service.

[0126] Clause 6. The apparatus of clause 5, wherein the at least one information element includes at least one of: a first information element indicating whether each of the one or more non-terrestrial network units supports IP multimedia subsystem (IMS) emergency bearer service for a UE in a limited service mode; or a second information element indicating whether each of the one or more non-terrestrial network units supports emergency calls over IMS services.

[0127] Clause 7. The apparatus of any of clauses 1-6, wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the UE to: select the first non-terrestrial network unit of the one or more non-terrestrial network units based at least in part on the message indicating the first non-terrestrial network unit supports the emergency service.

[0128] Clause 8. The apparatus of clause 7, wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the UE to select the first non-terrestrial network unit as part of a cell reselection process.

[0129] Clause 9. The apparatus of any of clauses 1-8, wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the UE to connect to the first non-terrestrial network unit by: performing a handover from a serving network unit to the first non-terrestrial network unit.

[0130] Clause 10. The apparatus of clause 9, wherein the serving network unit is a second nonterrestrial network unit.

[0131] Clause 11. The apparatus of clause 9, wherein the serving network unit is a terrestrial network unit.

[0132] Clause 12. An apparatus for wireless communications at a network unit, comprising: one or more memories; and one or more processors coupled to the one or more memories, the one or more memories storing instructions that are executable by the one or more processors, individually or in any combination, to cause the network unit to: receive information indicating one or more non-terrestrial network units support an emergency service; and transmit a message indicating the one or more non-terrestrial network units support the emergency service.

[0133] Clause 13. The apparatus of clause 12, wherein: the network unit is a non-terrestrial network unit; and the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the non-terrestrial network unit to: receive the information from a core network; and transmit the message to one or more user equipments (UEs).

[0134] Clause 14. The apparatus of clause 12, wherein: the network unit is a terrestrial network unit; and the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the terrestrial network unit to: receive the information from a core network; and transmit the message to one or more user equipments (UEs).

[0135] Clause 15. The apparatus of any of clauses 12-14, wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the network unit to transmit the message as a system information block 19 (SIB 19).

[0136] Clause 16. The apparatus of clause 15, wherein the SIB 19 includes at least one information element for each of the one or more non-terrestrial network units, the at least one information element including an indication of whether each of the one or more non-terrestrial network units supports the emergency service.

[0137] Clause 17. The apparatus of clause 16, wherein the at least one information element includes at least one of: a first information element indicating whether each of the one or more non-terrestrial networkunits supports IP multimedia subsystem (IMS) emergency bearer service for a UE in a limited service mode; or a second information element indicating whether each of the one or more non-terrestrial network units supports emergency calls over IMS services.

[0138] Clause 18. The apparatus of any of clauses 12-17, wherein the one or more nonterrestrial network units are neighboring network units to the network unit.

[0139] Clause 19. The apparatus of any of clauses 12, 13, and 15-18, wherein: the network unit is a non-terrestrial network unit that supports the emergency service; and the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the network unit to connect to a first UE based at least in part on the network unit supporting the emergency service.

[0140] Clause 20. The apparatus of clause 19, wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the network unit to connect to the first UE as a handover from a serving network unit.

[0141] Clause 21. The apparatus of clause 20, wherein the serving network unit is a second nonterrestrial network unit.

[0142] Clause 22. The apparatus of clause 20, wherein the serving network unit is a terrestrial network unit.

[0143] Clause 23. A method of wireless communication performed at a user equipment (UE), the method comprising: receiving, from a network unit, a message indicating one or more non-terrestrial network units support an emergency service; and connecting, based at least in part on the message indicating the one or more non-terrestrial network units support the emergency service, to a first non-terrestrial network unit of the one or more non-terrestrial network units.

[0144] Clause 24. The method of clause 23, wherein the receiving the message comprises receiving the message from a non-terrestrial network unit.

[0145] Clause 25. The method of any of clauses 23-24, wherein the receiving the message comprises receiving the message from a terrestrial network unit.

[0146] Clause 26. The method of any one or more of clauses 23-25, wherein the receiving the message comprises receiving a system information block 19 (SIB 19) broadcast by the network unit.

[0147] Clause 27. The method of clause 26, wherein the SIB 19 includes at least one information element for each of the one or more non-terrestrial network units, the at least oneinformation element including an indication of whether each of the one or more non-terrestrial network units supports the emergency service.

[0148] Clause 28. The method of clause 27, wherein the at least one information element includes at least one of: a first information element indicating whether each of the one or more non-terrestrial network units supports IP multimedia subsystem (IMS) emergency bearer service for a UE in a limited service mode; or a second information element indicating whether each of the one or more non-terrestrial network units supports emergency calls over IMS services.

[0149] Clause 29. The method of any one or more of clauses 23-28, further comprising: select the first non-terrestrial network unit of the one or more non-terrestrial network units based at least in part on the message indicating the first non-terrestrial network unit supports the emergency service.

[0150] Clause 30. The method of clause 29, wherein the selecting the first non-terrestrial network unit comprises selecting the first non-terrestrial network unit as part of a cell reselection process.

[0151] Clause 31. The method of any one or more of clauses 23-29, wherein the connecting to the first non-terrestrial network unit comprises performing a handover from a serving network unit to the first non-terrestrial network unit.

[0152] Clause 32. The method of clause 31 , wherein the serving network unit is a second non- terrestrial network unit.

[0153] Clause 33. The method of clause 31 , wherein the serving network unit is a terrestrial network unit.

[0154] Clause 34. A method of wireless communication performed at a network unit, the method comprising: receiving information indicating one or more non-terrestrial network units support an emergency service; and transmitting a message indicating the one or more non-terrestrial network units support the emergency service.

[0155] Clause 35. The method of clause 34, wherein the network unit is a non-terrestrial network unit.

[0156] Clause 36. The method of clause 34, wherein the network unit is a terrestrial network unit.

[0157] Clause 37. The method of any one or more of clauses 34-36, wherein the transmitting the message comprises transmitting a system information block 19 (SIB 19).

[0158] Clause 38. The method of clause 37, wherein the SIB 19 includes at least one information element for each of the one or more non-terrestrial network units, the at least one information element including an indication of whether each of the one or more non-terrestrial network units supports the emergency service.

[0159] Clause 39. The method of clause 38, wherein the at least one information element includes at least one of: a first information element indicating whether each of the one or more non-terrestrial network units supports IP multimedia subsystem (IMS) emergency bearer service for a UE in a limited service mode; or a second information element indicating whether each of the one or more non-terrestrial network units supports emergency calls over IMS services.

[0160] Clause 40. The method of any one or more of clauses 34-39, wherein the one or more non-terrestrial network units are neighboring network units to the network unit.

[0161] Clause 41. The method of any one or more of clauses 34-35 or 37-39, wherein the network unit is a non-terrestrial network unit that supports the emergency service; and further comprising: connecting to a first UE based at least in part on the network unit supporting the emergency service.

[0162] Clause 42. The method of clause 41 , wherein the connecting to the first UE comprises connecting to the first UE as part of a handover from a serving network unit.

[0163] Clause 43. The method of clause 42, wherein the serving network unit is a second non- terrestrial network unit.

[0164] Clause 44. The method of clause 42, wherein the serving network unit is a terrestrial network unit.

[0165] Clause 45. An apparatus for wireless communications at a user equipment (UE), comprising: a processing system that includes processor circuitry and memory circuitry that stores code and is coupled with the processor circuitry, the processing system configured to cause the UE to perform any one or more aspects, including combinations thereof, of Clauses 23-33.

[0166] Clause 46. An apparatus for wireless communications at a user equipment (UE), comprising: one or more memories;one or more transceivers; and one or more processors coupled to the one or more memories and the one or more transceivers, wherein the UE is configured to: receive, from a network unit, a message indicating one or more non-terrestrial network units support an emergency service; and connect, based at least in part on the message indicating the one or more non-terrestrial network units support the emergency service, to a first non-terrestrial network unit of the one or more non-terrestrial network units.

[0167] Clause 47. An apparatus for wireless communications at a user equipment (UE), comprising: one or more transceivers; and one or more processors coupled to the one or more transceivers, wherein the UE is configured to: receive, from a network unit, a message indicating one or more non-terrestrial network units support an emergency service; and connect, based at least in part on the message indicating the one or more non-terrestrial network units support the emergency service, to a first non-terrestrial network unit of the one or more non-terrestrial network units.

[0168] Clause 48. An apparatus for wireless communications at a network unit, comprising: a processing system that includes processor circuitry and memory circuitry that stores code and is coupled with the processor circuitry, the processing system configured to cause the network unit to perform any one or more aspects, including combinations thereof, of Clauses 34-44.

[0169] Clause 49. An apparatus for wireless communications at a network unit, comprising: one or more memories; one or more transceivers; and one or more processors coupled to the one or more memories and the one or more transceivers, wherein the network unit is configured to: receive information indicating one or more non-terrestrial network units support an emergency service; and transmit a message indicating the one or more non-terrestrial network units support the emergency service.

[0170] Clause 50. An apparatus for wireless communications at a network unit, comprising: one or more transceivers; and one or more processors coupled to the one or more transceivers, wherein the network unit isconfigured to: receive information indicating one or more non-terrestrial network units support an emergency service; and transmit a message indicating the one or more non-terrestrial network units support the emergency service.

[0171] Clause 51. A user equipment (UE) comprising one or more means to perform any one or more aspects, including combinations thereof, of clauses 1-11, 23-33, or 45-47.

[0172] Clause 52. A network unit comprising one or more means to perform any one or more aspects, including combinations thereof, of clauses 12-22, 34-44, or 48-50.

[0173] Clause 53. A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising one or more instructions that, when executed by one or more processors, individually or in any combination, of a user equipment (UE) cause the UE to perform any one or more aspects, including combinations thereof, of clauses 1-11, 23-33, or 45-47.

[0174] Clause 54. A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising one or more instructions that, when executed by one or more processors, individually or in any combination, of a network unit cause the network unit to perform any one or more aspects, including combinations thereof, of clauses 12-22, 34-44, or 48-50.The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0175] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other aspects and implementations are within the scope of the disclosure and appended claims. For instance, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring,or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as used herein, including in the claims, “or” as used in a list of items (for instance, a list of items prefaced by a phrase such as “at least one of’ or “one or more of’) indicates an inclusive list such that, for instance, a list of [at least one of A, B, or C] means A or B or C or AB or AC or BC or ABC (e.g., A and B and C).

[0176] As those of some skill in this art will by now appreciate and depending on the particular application at hand, many modifications, substitutions and variations can be made in and to the materials, apparatus, configurations and methods of use of the devices of the present disclosure without departing from the spirit and scope thereof. In light of this, the scope of the present disclosure should not be limited to that of the particular aspects illustrated and described herein, as they are merely by way of some aspects thereof, but rather, should be fully commensurate with that of the claims appended hereafter and their functional equivalents.

Claims

WHAT IS CLAIMED IS:

1. An apparatus for wireless communications at a user equipment (UE), comprising: one or more memories; and one or more processors coupled to the one or more memories, the one or more memories storing instructions that are executable by the one or more processors, individually or in any combination, to cause the UE to: receive, from a network unit, a message indicating one or more non-terrestrial network units support an emergency service; and connect, based at least in part on the message indicating the one or more non-terrestrial network units support the emergency service, to a first non-terrestrial network unit of the one or more non-terrestrial network units.

2. The apparatus of claim 1, wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the UE to receive the message from a non-terrestrial network unit.

3. The apparatus of claim 1, wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the UE to receive the message from a terrestrial network unit.

4. The apparatus of claim 1, wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the UE to receive the message as a system information block 19 (SIB 19) broadcast by the network unit.

5. The apparatus of claim 4, wherein the SIB 19 includes at least one information element for each of the one or more non-terrestrial network units, the at least one information element including an indication of whether each of the one or more non-terrestrial network units supports the emergency service.

6. The apparatus of claim 5, wherein the at least one information element includes at least one of: a first information element indicating whether each of the one or more non-terrestrial network units supports IP multimedia subsystem (IMS) emergency bearer sendee for a UE in a limited servicemode; or a second information element indicating whether each of the one or more non-terrestrial network units supports emergency calls over IMS services.

7. The apparatus of claim 1, wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the UE to: select the first non-terrestrial network unit of the one or more non-terrestrial network units based at least in part on the message indicating the first non-terrestrial network unit supports the emergency service.

8. The apparatus of claim 7, wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the UE to select the first non-terrestrial network unit as part of a cell reselection process.

9. The apparatus of claim 1, wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the UE to connect to the first non-terrestrial network unit by: performing a handover from a serving network unit to the first non-terrestrial network unit.

10. The apparatus of claim 9, wherein the serving network unit is a second non-terrestrial network unit.

11. The apparatus of claim 9, wherein the serving network unit is a terrestrial network unit.

12. An apparatus for wireless communications at a network unit, comprising: one or more memories; and one or more processors coupled to the one or more memories, the one or more memories storing instructions that are executable by the one or more processors, individually or in any combination, to cause the network unit to: receive information indicating one or more non-terrestrial network units support an emergency service; and transmit a message indicating the one or more non-terrestrial network units support the emergency service.

13. The apparatus of claim 12, wherein: the network unit is a non-terrestrial network unit; and the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the non-terrestrial network unit to: receive the information from a core network; and transmit the message to one or more user equipments (UEs).

14. The apparatus of claim 12, wherein: the network unit is a terrestrial network unit; and the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the terrestrial network unit to: receive the information from a core network; and transmit the message to one or more user equipments (UEs).

15. The apparatus of claim 12, wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the network unit to transmit the message as a system information block 19 (SIB 19).

16. The apparatus of claim 15, wherein the SIB 19 includes at least one information element for each of the one or more non-terrestrial network units, the at least one information element including an indication of whether each of the one or more non-terrestrial network units supports the emergency service.

17. The apparatus of claim 16, wherein the at least one information element includes at least one of: a first information element indicating whether each of the one or more non-terrestrial network units supports IP multimedia subsystem (IMS) emergency bearer service for a UE in a limited service mode; or a second information element indicating whether each of the one or more non-terrestrial network units supports emergency calls over IMS services.

18. The apparatus of claim 12, wherein the one or more non-terrestrial network units are neighboring network units to the network unit.

19. The apparatus of claim 12, wherein: the network unit is a non-terrestrial network unit that supports the emergency service; and the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the network unit to connect to a first UE based at least in part on the network unit supporting the emergency service.

20. The apparatus of claim 19, wherein the one or more memories store instructions that are executable by the one or more processors, individually or in any combination, to cause the network unit to connect to the first UE as a handover from a serving network unit.

21. The apparatus of claim 20, wherein the serving network unit is a second non-terrestrial network unit.

22. The apparatus of claim 20, wherein the serving network unit is a terrestrial network unit.

23. A method of wireless communication performed at a user equipment (UE), the method comprising: receiving, from a network unit, a message indicating one or more non-terrestrial network units support an emergency service; and connecting, based at least in part on the message indicating the one or more non-terrestrial network units support the emergency service, to a first non-terrestrial network unit of the one or more non-terrestrial network units.

24. The method of claim 23, wherein the receiving the message comprises receiving the message as a system information block 19 (SIB 19) from a non-terrestrial network unit.

25. The method of claim 23, wherein the receiving the message comprises receiving the message as a system information block 19 (SIB 19) from a terrestrial network unit.

26. The method of claim 23, wherein the message includes at least one information element for each of the one or more non-terrestrial network units, the at least one information element including at least one of: a first information element indicating whether each of the one or more non-terrestrial network units supports IP multimedia subsystem (IMS) emergency bearer sendee for a UE in a limited servicemode; or a second information element indicating whether each of the one or more non-terrestrial network units supports emergency calls over IMS services.

27. The method of claim 23, further comprising: selecting the first non-terrestrial network unit of the one or more non-terrestrial network units based at least in part on the message indicating the first non-terrestrial network unit supports the emergency service.

28. A method of wireless communication performed at a network unit, the method comprising: receiving information indicating one or more non-terrestrial network units support an emergency service; and transmitting a message indicating the one or more non-terrestrial network units support the emergency service.

29. The method of claim 28, wherein: the network unit is a non-terrestrial network unit; the receiving the information comprises receiving the information from a core network; and the transmitting the message comprises transmitting the message to one or more user equipments (UEs).

30. The method of claim 28, wherein: the network unit is a terrestrial network unit; the receiving the information comprises receiving the information from a core network; and the transmitting the message comprises transmitting the message to one or more user equipments (UEs).

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