Managing transmission and reception of public warning messages

Abstract

To receive a public warning service (PWS) message, user equipment (UE) receives, in a cell of a non-terrestrial network (NTN), a first segment of the PWS message; after leaving the cell, and prior to receiving a second segment of the PWS, the UE retains the first segment of the PWS message; and the UE receives, from the NTN subsequently to the retaining, a second segment of the PWS message.

Description

PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PCMANAGING TRANSMISSION AND RECEPTION OF PUBLIC WARNING MESSAGESCROSS-REFENCE TO RELATED APPLICATION

[0001] This application claims priority to and the benefit of the filing date of provisional U.S. Patent Application No. 63 / 717,888 entitled “Managing Transmission and Reception of Public Warning Messages,” filed on November 7, 2025. The entire content of the provisional application is hereby expressly incorporated herein by referenceFIELD OF THE DISCLOSURE

[0002] This disclosure relates generally to wireless communication systems, and particularly to managing transmission and reception of public warning messages.BACKGROUND

[0003] This background description is provided for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

[0004] The 5G technology relies primarily on legacy terrestrial networks. However, the 3rd Generation Partnership Project (3GPP) organization has proposed to extend 5G communications to non-terrestrial networks (NTNs) with 5G new radio (NR) technologies, or with the Long- Term -Evolution (LTE) technologies tailored for the Narrowband Internet-of-Thing (NB-IoT) or the enhanced Machine Type Communication (eMTC) scenarios. In an NTN, an RF transceiver is mounted on a satellite, an unmanned aircraft systems (UAS) also referred to as drone, balloon, plane, or another suitable apparatus. For simplicity, the discussion below refers to all such apparatus as satellites. In addition to satellites, an NTN can include the sat-gateways that connect the Non-Terrestrial Network to a public data network, feeder links between sat-gateways and satellites, service links between satellites, and inter-satellite links (ISL) when satellites form constellations.

[0005] A satellite can belong to one of several types based on altitude, orbit, and beam footprint size. The types include Low-Earth Orbit (LEO) satellite, Medium-Earth Orbit (MEO)PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC satellite, Geostationary Earth Orbit (GEO) satellite, UAS platform (including High Altitude Platform Station (HAPS)), and High Elliptical Orbit (HEO) satellite. GEO satellites are also known as the Geosynchronous Orbit (GSO) satellites, and LEO / MEO satellites are also known as non-GSO (NGSO) satellites.

[0006] A GSO satellite can communicate with one or more sat-gateways deployed over a satellite targeted coverage area (e.g., a region, country, continent, etc.). A non-GSO satellite at different times can communicate with one or several serving sat-gateways. An NTN is designed to ensure service and feeder link continuity between successive serving sat-gateways, with sufficient time duration to proceed with mobility anchoring and hand-over procedures.

[0007] A satellite can support a transparent or a regenerative (with on board processing) payload, and typically generates several beams for a given service area bounded by the field of view. The footprints of the beams typically have an elliptic shape and depend on the on-board antenna configuration and the elevation angle. For a transparent payload implementation, a satellite can apply RF filtering and / or frequency conversion and amplification, and refrain from changing the waveform signal. For a regenerative payload implementation, a satellite can apply RF filtering, frequency conversion and amplification, demodulation and decoding, routing, and / or coding / modulation. This approach is effectively equivalent to implementing most of the functions of a base station, e.g., a gNB or an eNB.

[0008] NB-IoT and eMTC technologies are expected to be particularly suitable for loT devices operating in remote areas with limited or no terrestrial connectivity. Such loT devices can be used in a variety of industries including for example transportation (maritime, road, rail, air) and logistics; solar, oil, and gas harvesting; utilities; farming; environmental monitoring; and mining. However, to ensure the required loT connectivity, deployment of these technologies requires satellite connectivity to provide coverage beyond terrestrial deployments. Satellite NB- loT or eMTC is defined in a complementary manner to terrestrial deployments.

[0009] Many non-IoT UEs that fully support LTE and 5G networks have only the capability to connect to NB-IoT Non-Terrestrial Networks (NTNs) for messaging services. In some scenarios, these UEs have (only) NB-IoT NTN coverage. Currently, there are no procedures for a RAN to broadcast public warning service (PWS) messages via an NB-IoT NTN, and for a UE to receive a PWS message via an NB-IoT NTN. PWS messages contain critical information such asPATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC disaster information, emergency information or government information related to people’s safety. Further, in some cases, a UE is unable to simultaneously receive a PWS message and maintain a connection with a RAN.SUMMARY

[0010] An example embodiment of these techniques is a method for receiving a public warning service (PWS) message, the method implemented in a user equipment (UE) and comprising: receiving, in a cell of a non-terrestrial network (NTN), a first segment of the PWS message; after leaving the cell, and prior to receiving a second segment of the PWS, retaining the first segment of the PWS message; and receiving, from the NTN subsequently to the retaining, a second segment of the PWS message. Leaving the cell can include no longer camping on the cell, detecting an out-of-coverage event, or otherwise detecting a change in registration or connection in the cell.

[0011] Another example embodiment of these techniques processing hardware and a transceiver. The UE is configured to implement a method of any of the preceding claimsBRIEF DESCRIPTION OF THE DRAWINGS

[0012] Fig. l is a block diagram of an example wireless communication system in which a user device and a base station of this disclosure can implement the techniques of this disclosure for communicating a PWS message;

[0013] Fig. 2 is a block diagram of an example protocol stack according to which the UE of Fig. 1 communicates with base stations;

[0014] Fig. 3A is a block diagram of an example NTN node with transparent payload implementation, in which a base station is on the ground and connects to a satellite via a sat- gateway.

[0015] Fig. 3B is a block diagram of an example NTN node with regenerative payload implementation, in which a base station is located on a satellite.

[0016] Fig. 4A illustrates a scenario in which a UE receives a portion of a PWS message in an NTN cell, leaves the area of coverage of the NTN cell, and discards the portion of the PWS upon re-entering the area of coverage of the NTN cell;PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0017] Fig. 4B illustrates a scenario in which a UE receives a portion of a PWS message in an NTN cell, leaves the area of coverage of the NTN cell, and discards the portion of the PWS upon entering the areas of coverage of a new NTN cell;

[0018] Fig. 5 illustrates a scenario in which a UE performs a serving a cell change from a source NTN cell to a target NTN cell;

[0019] Fig. 6A illustrates an example scenario in which a UE receives one or more segments of a PWS message in an NTN cell, detects an out-of-coverage event, retains the one or more segments of the PWS message after selecting the NTN cell again, and receives the remaining segments of the PWS message in the NTN cell;

[0020] Fig. 6B illustrates an example scenario generally similar to that of Fig. 6A, but in which the UE enters a different NTN cell associated with the same satellite as the initial cell;

[0021] Fig. 6C illustrates an example scenario generally similar to that of Fig. 6A, but in which the UE enters a different NTN cell associated with a different satellite;

[0022] Fig. 6D illustrates an example scenario generally similar to that of Fig. 6A, but in which the UE establishes and then releases an RRC connection prior to selecting the NTN cell again;

[0023] Fig. 6E illustrates an example scenario generally similar to that of Fig. 6D, but in which the UE discards the already-received segments of the PWS message upon selecting the NTN cell again due to the limitations of the NTN cell, such as the NTN operating according to an NB-IoT RAT;

[0024] Fig. 6F illustrates an example scenario generally similar to that of Fig. 6A, but in which the UE establishes an RRC connection and discards the already-received segments of the PWS message due to the limitations of the UE, such as the inability to receive both broadcast and dedicated DE messages in the RRC CONNECTED state;

[0025] Fig. 6G illustrates an example scenario generally similar to that of Fig. 6F, but in which the UE retains the already -received segments of the PWS message and requests only the missing segments from the RAN via a DL dedicates message, rather than the entire PWS message as in the scenario of Fig. 6F;PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0026] Fig. 7 is a flow diagram of an example method in a RAN for broadcasting a segmented PWS message via at least one NTN cell;

[0027] Fig. 8A is a flow diagram of an example method in a RAN for broadcasting a segmented PWS message via one NTN cell and then via another NTN cell, with the same or different respective number of segments;

[0028] Fig. 8B is a flow diagram of an example method in a RAN for broadcasting a segmented PWS message via an NTN cell and then broadcasting the PWS message without segmentation via another NTN cell;

[0029] Fig. 9A is a flow diagram of an example method in a RAN for broadcasting a PWS message in accordance with the method of Fig. 8A or Fig. 8B, and then broadcasting the segmented PWS message via a terrestrial cell;

[0030] Fig. 9B is a flow diagram of an example method in a RAN for broadcasting a PWS message in accordance with the method of Fig. 8A or Fig. 8B, and then broadcasting the PWS message without segmentation via a terrestrial cell;

[0031] Fig. 10 is a flow diagram of an example method in a UE for receiving a segmented PWS message at least via two NTN cells;

[0032] Fig. 11 is a flow diagram of an example method in a UE for determining whether to retain or discard previously received segments of a PWS message, depending on whether the new cell is an NTN cell or a TN cell;

[0033] Fig. 12A is a flow diagram of an example method in a UE for determining whether to retain or discard previously received segments of a PWS message, depending on whether the prior cell and the cell belong to the same RAT;

[0034] Fig. 12B is a flow diagram of an example method in a UE for determining whether to retain or discard previously received segments of a PWS message, depending on whether the prior cell and the cell belong to the same tracking area;

[0035] Fig. 12C is a flow diagram of an example method in a UE for determining whether to retain or discard previously received segments of a PWS message, depending on whether the prior cell and the cell belong to the same RAT and the same tracking area;PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0036] Fig. 13 A is a flow diagram of an example method in a UE for determining whether to retain or discard previously received segments of a PWS message, depending on whether the RAT of the new cell is associated with NB-IoT;

[0037] Fig. 13B is a flow diagram of an example method in a UE for determining whether to retain or discard previously received segments of a PWS message, depending on whether the RAT of the new cell is associated with NB-IoT or eMTC;

[0038] Fig. 14A is a flow diagram of another example method in a UE for determining whether to retain or discard previously received segments of a PWS message, depending on whether the RAT of the new cell is associated with NB-IoT;

[0039] Fig. 14B is a flow diagram of another example method in a UE for determining whether to retain or discard previously received segments of a PWS message, depending on whether the RAT of the new cell is associated with NB-IoT or eMTC;

[0040] Fig. 14C is a flow diagram of an example method in a UE for determining whether to retain or discard previously received segments of a PWS message, depending on whether the new cell indicates support of assembling a PWS message from segments received in different cells;

[0041] Fig. 14D is a flow diagram of an example method in a UE for determining whether to retain or discard previously received segments of a PWS message, depending on whether the new cell indicates transmission of the same segments of a PWS message as another cell;

[0042] Fig. 15 is a flow diagram of an example method in a RAN for transmitting a PWS message in response to a request from a UE;

[0043] Fig. 16A is a flow diagram of an example method in a RAN for transmitting a PWS message in response to a request from a UE and a determination that the RAN has a PWS message to broadcast;

[0044] Fig. 16B is a flow diagram of another example method in a RAN for transmitting a PWS message in response to a request from a UE;PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0045] Fig. 17 is a flow diagram of an example method in a RAN for determining whether to transmit an entire PWS message or a portion of the PWS message, depending on the request from the UE;

[0046] Fig. 18 is a flow diagram of an example method in a UE for receiving a PWS message in response to a request from the UE;

[0047] Fig. 19A is a flow diagram of an example method in a UE for determining whether to request a PWS message from a RAN, depending on whether the RAN is broadcasting the PWS message;

[0048] Fig. 19B is a flow diagram of an example method in a UE for determining whether to request a PWS message from a RAN, depending on whether the UE attempted to receive the PWS message prior to establishing a radio connection with the RAN;

[0049] Fig. 19C is a flow diagram of an example method in a UE for determining whether to request a PWS message from a RAN, depending on whether the UE can receive the PWS message while maintaining a radio connection with the RAN;

[0050] Fig. 20A is a flow diagram of an example method in a RAN for determining which DE lower-layer message to transmit to the UE, depending on whether a received message is a NAS message or a PWS message;

[0051] Fig. 20B is a flow diagram of an example method in a RAN for determining in which field of a DE lower-layer message to transmit a received message to the UE, depending on whether the received message is a NAS message or a PWS message;

[0052] Fig. 21 A is a flow diagram of an example method in a UE for determining whether an upper-layer message is a NAS message or a PWS message, depending on which DE lower-layer message the UE received from the RAN;

[0053] Fig. 2 IB is a flow diagram of an example method in a UE for determining whether an upper-layer message is a NAS message or a PWS message, depending on which field of a DL lower-layer message the RAN used to transmit the upper-layer message;PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0054] Fig. 22 is a flow diagram of an example method in a RAN for determining in which field of a DL lower-layer message the RAN should transmit a message to the UE, depending on whether the message is a CMAS message or an ETWS message; and

[0055] Fig. 23 is a flow diagram of an example method in a UE for determining whether a message is a CMAS message or an ETWS message, depending in which field of a DL lower- layer message the RAN used to transmit the message to the UE.DETAILED DESCRIPTION OF THE DRAWINGS

[0056] Generally speaking, the techniques discussed below enable efficient transmission and reception of PWS messages via NB-IoT NTN cells. At least some of these techniques also can apply to other types of NTNs such as eMTC NTN, NR NTN and 6GNTN.

[0057] Referring first to Fig. 1, a wireless communication system 100 includes a UE 102, a base station (BS) 104, a base station 106, a radio access network (RAN) 105, a core network (CN) 110. The RAN 105 may include a BS 104 and / or a BS 106. The CN 110 may be an evolved packet core (EPC) 111, a fifth generation (5G) core (5GC) 160, or a sixth generation core (6GC) 170, for example. The BS 104 and / or the BS 106 in the RAN 105 communicate with UEs via one or more satellites (as suggested by the satellite icon). The RAN 105 may include one or more additional BS(s) that may communicate with other UEs via one or more satellites. The RAN 105 may include one or more additional BS(s) that may communicate with other UEs via terrestrial antennas (e.g., antennas on the ground).

[0058] The BS 104 covers a cell 124 A, and the BS 106 covers a cell 126. The BS 104 may additionally cover a cell 124B. The BS(s) 104, 106 operate these cells with the same or different radio access technologies (RATs) such as 5G NR (or simply, “NR”), Evolved Universal Terrestrial Radio access (E-UTRA), NB-IoT, 6G, and / or 6G loT. Generally, the RAN 105 can be or include one or more RANs as described below. If the BS 104 is a gNB, the cell 124 is an NR cell and the RAN 105 is or includes a NR RAN. If the BS 104 is an ng-eNB or eNB, the cell 124 is an E-UTRA cell or a NB-IoT cell and the RAN 105 is or includes an E-UTRA network (E-UTRAN). If the BS 104 is a 6G BS (e.g., 6gNB), the cell 124 is a 6G cell or a 6G loT cell and the RAN 105 is or includes a 6G RAN. Similarly, the cell 126 is an NR cell, an E-UTRA or NB-IoT cell, a 6G or 6G loT cell, depending on the BS 106 is a gNB, an ng-eNB or eNB, or aPATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC6G BS. The UE 102 can support at least one of 6G, 6G loT, NR, E-UTRA, and / or NB-IoT air interface to communicate with the BSs 104 and 106. Each of the BS 104, the BS 106, and / or the additional base station(s) can connect to the CN 110 via an interface (e.g., SI, NG, or N6G interface). The BS 104, and the BS 106, and / or the additional base station(s) also can be interconnected via an interface (e.g., X2, Xn, or X6G interface) for interconnecting RAN nodes.

[0059] Among other components, the EPC 111 may include a Serving Gateway (SGW) 112, a Mobility Management Entity (MME) 114, and a Packet Data Network Gateway (PGW) 116.The SGW 112 in general is configured to transfer user-plane packets related to audio calls, video calls, Internet traffic, etc., and the MME 114 is configured to manage authentication, registration, paging, and other related functions. The PGW 116 provides connectivity from the UE to one or more external packet data networks, e.g., an Internet network and / or an Internet Protocol (IP) Multimedia Subsystem (IMS) network. The EPC 111 may include other MME, SGW and / or PGW not shown in Fig. 1. The 5GC 160 includes a User Plane Function (UPF) 162 and an Access and Mobility Management Function (AMF) 164, and / or Session Management Function (SMF) 166. The UPF 162 is configured to transfer user-plane packets related to audio calls, video calls, Internet traffic, etc., the AMF 164 is configured to manage authentication, registration, paging, and other related functions, and the SMF 166 is configured to manage protocol data unit (PDU) sessions. The 6GC 170 includes a 6G UPF 172 and a 6G AMF 174, and / or 6G SMF 176, similar to the UPF 162, the AMF 164 and the SMF 176 with enhanced functions respectively.

[0060] The cells 124A, 124B, and 126 partially overlap, so that the UE 102 can select, reselect, or hand over from one of the cells 124 and 126 to the other. The BS 104 and BS 106 may exchange messages via the CN 110. Alternatively, the BS 104 and the BS 106 may support an X2, Xn, X6G interface to directly exchange messages. In general, the CN 110 is able to connect to any suitable number of BSs supporting, NR cells, 6G cells, 6G loT cells, NB-IoT cells, and / or EUTRA cells.

[0061] BS 104 is equipped with processing hardware 130 that includes one or more general- purpose processors (e.g., CPUs) and a non-transitory computer-readable memory (CRM) storing instructions that the one or more general -purpose processors execute. Additionally or alternatively, the processing hardware 130 may include special-purpose processing units.PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PCAccording to an embodiment illustrated in Fig. 1, the processing hardware 130 includes a processor 134 to process data that the BS 104 transmits in the downlink direction, or data that the BS 104 receives in the uplink direction. The processing hardware 130 also includes a transceiver 132 configured to transmit data in the downlink direction and to receive data in the uplink direction. The CRM (not shown) stores executable codes for the processor 134 to perform methods described below according to embodiments described in this section. The processing hardware 130 further includes a protocol controller 136 configured to perform operation and procedures of protocols for communicating with UEs, e.g., as described for Fig. 2. The processing hardware 130 further includes a public warning service (PWS) controller 138 configured to perform transmission (e.g., broadcast) of PWS messages to UEs via the NTN cell 124A and / or the NTN cell 124B. The BS 104 may receive the PWS messages from the CN 110 (e.g., the MME 114 or AMF 164 or 174). The BS 106 includes generally similar components. In particular, components 140, 142, 144, 146, and 148 of the BS 106 may be similar to the components 130, 132, 134, 136, and 138, respectively.

[0062] The UE 102 is equipped with processing hardware 150 that can include one or more general-purpose processors such as CPUs and non-transitory CRM storing machine-readable instructions executable on the one or more general-purpose processors, and / or special-purpose processing units. As schematically illustrated in Fig. 1, the processing hardware 150 includes a processor 154 to prepare data that the UE 102 transmits in the uplink direction, or to process data that the UE 102 receives in the downlink direction. The processing hardware 150 also includes a transceiver 152 configured to transmit data in the uplink direction and to receive data in the downlink direction. The process hardware 150 further includes a protocol controller 156 configured to perform communication functions of protocol layers, e.g., described in Fig. 2. The process hardware 150 further includes a PWS controller 158 configured to receive and process PWS messages or message segments as described below.

[0063] Fig. 2 illustrates, in a simplified manner, an example protocol stack 200 according to which the UE 102 can communicate with a 6G BS, eNB / ng-eNB, or a gNB (e.g., one or more of the BSs 104, 106).

[0064] In the example stack 200, a physical (PHY) layer 202 provides transport channels to a MAC sublayer 204, which in turn provides logical channels to a RLC sublayer 206. The RLCPATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC sublayer 206 in turn provides RLC channels to a PDCP sublayer 208. The PDCP sublayer 208 in turn can provide data transfer services to a radio resource control (RRC) sublayer 210, an Internet Protocol (IP) layer and / or a Service Data Adaptation Protocol (SDAP) sublayer (not shown in Fig. 2). The PDCP sublayer 208 receives packets (e.g., from the RRC sublayer 210, the SDAP sublayer, or the IP layer, layered directly or indirectly over the PDCP layer 208) that can be referred to as service data units (SDUs), and output packets (e.g., to the RLC layer 206) that can be referred to as protocol data units (PDUs). Except where the difference between SDUs and PDUs is relevant, this disclosure for simplicity refers to both SDUs and PDUs as “packets”. In some implementations, the PHY layer 202, MAC sublayer 204, RLC sublayer 206, PDCP sublayer 208, RRC sublayer 210 are EUTRA layers or sublayers. In other implementations, the PHY layer 202, MAC sublayer 204, RLC sublayer 206, PDCP sublayer 208, RRC sublayer 210 are NR layers or sublayers. In yet other implementations, the PHY layer 202, MAC sublayer 204, RLC sublayer 206, PDCP sublayer 208, RRC sublayer 210 are 6G layers or sublayers.

[0065] The RRC sublayer 210 provide data transfer services to a Non- Access-Stratum (NAS) layer 212. The NAS layer 212 includes a mobility management (MM) sublayer and / or a session management (SM) sublayer. In some implementations, the MM sublayer is an EPS MM (EMM), a 5G MM (5GMM) sublayer, or a 6G MM sublayer (6GMM). In some implementations, the SM sublayer is an EPS SM (ESM) sublayer, a 5G SM (5GSM) sublayer, or a 6G SM (6GSM) sublayer. When the BS 104 or 106 receives UL NAS PDUs from the UE 102, the BS forwards the UL NAS PDUs to the CN 110 without processing the UL NAS PDUs. When the BS receives DL NAS PDUs from the CN 110, the BS forwards the DL NAS PDUs to the UE 102 without processing the DL NAS PDUs. That is, the NAS layer 212 is transparent to the BS.

[0066] On a control plane, the PDCP sublayer 208 can provide signaling radio bearers (SRBs) to the RRC sublayer 210 to exchange RRC messages or NAS messages (e.g., MM messages and / or SM messages), for example. On a user plane, the PDCP sublayer 208 can provide Data Radio Bearers (DRBs) to support user plane data exchange. User plane data exchanged on the PDCP sublayer 208 can be SDAP PDUs, Internet Protocol (IP) packets or Ethernet packets.

[0067] Fig. 3A illustrates a certain type of NTN deployment referred to as transparent payload architecture, which involves a NTN gateway 302 and “transparent” satellites 304 and 306 for extending the range of the Uu interface. In this deployment, satellites 304 and 306 connect to thePATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PCBS 104 via the NTN gateway 302. In some implementations, the satellites 304 and 306 are covering the Earth surface using two different Physical Cell IDs (PCIs). In other implementations, the satellites 304 and 306 are covering the Earth surface using the same PCI. Each of the satellites 304 and 306 implements a frequency conversion and a Radio Frequency (RF) amplifier in both the uplink and downlink directions. With that being said, the satellite function is similar to that of an analogue RF repeater. As a result, the satellites 304 and 306 repeat the Uu radio interface from the feeder link (between the NTN gateway and the satellite) to the service link (between the satellite and the UE) in the downlink direction and vice versa in the uplink direction. The Satellite Radio Interface (SRI) on the feeder link is the Uu, and the NTN gateway 302 supports all necessary functions to forward the signal of the Uu interface. The NTN gateway 302 can be placed at the same site as the BS 104 location, or be connected to the BS 104 at a distance via a wired link. It is also possible to connect more than one NTN gateway to a BS. Different transparent satellites may be connected to the same BS on the ground, via the same NTN gateway, or via different NTN gateways.

[0068] Fig. 3B illustrates a certain type of NTN deployment 300B referred to as regenerative payload architecture, which involves the UE 102, the satellite gateway 302, a satellite 304, a satellite 306, the BS 104 on the satellite 304, and the BS 106 on the satellite 306. Each of the satellites 304 and 306 implements a RF filtering, a RF amplifier, and a frequency conversion in both the uplink and / or downlink directions. As a result, the BS 104 communicates with the UE 102 via the satellite 304 and the Uu radio interface in the downlink direction and vice versa in the uplink direction. The BS 104 communicates with the CN 110 via a feeder link (between the NTN gateway 302 and the satellite 304) and a link between the NTN gateway 302 and the CN 110. The NTN gateway 302 can be placed at the same site as the CN 114 location, or be connected to the CN 110 at a distance via a wired link or a wireless link.

[0069] Fig. 4A illustrates an example scenario 400A in which the UE 102 initially is in the coverage of the NTN cell 124A at time ti. The UE 102 registers with the 110 (not shown in Fig.4) via the cell 124A at time ti. Later at time t2, the UE 102 detects out of coverage of the cell 124A and does not camp on any cell (i.e., the UE is in a no service state). Later at time ts, the UE 102 enters coverage of the cell 124A and camps on the cell 124A again. At time t3, the UE 102 may perform a tracking area update procedure via the cell 124A with the CN 110 to indicatePATENT APPLICATION Attorney Docket No.: 31730 / 308598-00 / PC“in-coverage” to the CN 110. Alternatively, the UE 102 does not perform the tracking area update procedure upon entering coverage of the cell 124A. Before the UE 102 moves out of coverage, the UE 102 receives segment(s) 1, ..., K of a PWS message (i.e., PWS message segment(s) 1, • • , K). The PWS message consists of N segments, where K and N are positive integers and 0 < K < N. The PWS message can be an Earthquake and Tsunami Warning System (ETWS) message or a Commercial Mobile Alert Service (CMAS) message. The UE 102 has not received all the segments of the PWS messages because the UE 102 detects out of coverage at time t2. When the UE 102 enters the cell 124A at time t3, the UE 102 discards the segment(s) 1, ..., K in accordance with section 5.2.2.4 in 3GPP specification 36.331. Therefore, the UE starts over to receive segments 1 , .. ., N of the PWS message from the cell 124A. The discarding action specified in the 3GPP specification causes efficiency in reception of PWS messages.

[0070] Fig. 4B illustrates an example scenario 400B similar to the scenario 400A. Later at time t2, the UE 102 moves to the NTN cell 124B. If the cell 124B and the cell 124A belong to different tracking areas, the UE 102 at time t2 may perform a tracking area update procedure forPATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC a tracking area change via the cell 124B with the CN 110 (not shown in Fig. 4B). Otherwise, the UE 102 does not perform a tracking area update procedure for a tracking area change at time t2. Before the UE 102 moves into the cell 124B, the UE 102 receives segment(s) 1, . .. , K of a PWS message (i.e., PWS message segment(s) 1, K). The PWS message consists ofN segments, where K and N are positive integers and 0 < K < N. The PWS message can be an ETWS message or a CMAS message. The UE 102 has not received all the segments of the PWS messages because the UE 102 moves into the cell 124B at time t2. When the UE 102 enters the cell 124B at time t2, the UE 102 discards the segment(s) 1, . .. , K in accordance with section 5.2.2.4 in 3GPP specification 36.331. Therefore, the UE starts over to receive segments 1 , ..., N of the PWS message from the cell 124B. The discarding action specified in the 3GPP specification causes efficiency in reception of PWS messages.

[0071] Fig. 5 illustrates an example scenario 500 in which the UE 102 may experience a serving cell change from the NTN cell 124A to the NTN cell 126B. In the scenario 500, the UE 102 is within the cell 124A served by the satellite 304 from time ti to time t2, and within the cell 126 served by the satellite 306 from time t3 to time U. During time ti and time t2, the UE 102 initially is in the coverage of the cell 124A and registers with the CN 110 (not shown in Fig. 5). Before the UE 102 is in coverage of the cell 126, the UE 102 receives segment(s) 1, . .. , K of a PWS message (i.e., PWS message segment(s) 1, ..., K). The PWS message consists ofN segments, where K and N are positive integers and 0 < K < N. The PWS message can be an ETWS message or a CMAS message. The UE 102 has not received all the segments of the PWS messages from the cell 124A because the UE 102 moves out of coverage of the cell 124A.When the UE 102 enters the cell 126 during time ts and time L, the UE 102 discards the segment(s) 1, ..., K in accordance with section 5.2.2.4 in 3GPP specification 36.331. Therefore, the UE starts over to receive segments 1 , . . ., N of the PWS message from the cell 126. The discarding action specified in the 3GPP specification causes efficiency in reception of PWS messages.

[0072] Next, several example scenarios in which the RAN 105 (e.g., the BS 104 and / or the BS 106) operating in the system of Fig. 1 communicates with the UE 102 via the satellite 304 and / or the satellite 306. The BS 104, 106 can be either on the ground as described for Fig. 3A or located with the satellite 304 as described for Fig. 3B. Generally speaking, events in Figs. 6A-PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC14D that are similar are labeled with similar reference numbers (e.g., event 616 of Figs. 6A-6C is similar to event 716 of Fig. 7-8B, block 816 of Fig. 8 A, event 817 of Fig. 8B, event 1016 of Figs. 10-14D), with differences discussed below where appropriate. With the exception of the differences shown in the figures and discussed below, any of the alternative implementations discussed with respect to a particular event (e.g., for messaging and processing) may apply to events labeled with similar reference numbers in other figures. Note, the descriptions below may apply to communication between a UE and a base station in a terrestrial network.

[0073] Fig. 6A illustrates an example scenario 600A, in which the UE 102 initially camps on the NTN cell 124A of the BS 104 (not shown in Fig. 6A) in the RAN 105. Events 604, 606, 608, 616A, 674A, and 676A occur via the cell 124A. The UE 102 receives 602 a master information block (MIB) from the RAN 105. The UE 102 receives 606 at least one first system information block (SIB) from the RAN 105. In some implementations, the UE 102 determines to select the cell 124 A after event 604 and / or event 606 or during event 606. In such cases, event 602 occurs after event 604 and / or event 606 or during event 606.

[0074] In some implementations, the at least one first SIB (e.g., SIB1) includes initial access information for communicating with the cell 124A. For example, the initial access information includes random access configuration parameters, search space configuration parameters, a physical downlink control channel (PDCCH) configuration, a physical downlink shared channel (PDSCH) configuration, and / or a physical uplink shared channel (PUSCH) configuration. In some implementations, the at least one first SIB includes SystemlnformationBlockType 1 , a SystemInformationBlockType2, and / or a SystemInformationBlockType31 , as defined in 3GPP specification 36.331. In other implementations, the at least one first SIB includes SystemlnformationBlockType 1-NB, a SystemInformationBlockType2-NB, and / or SystemInformationBlockType31-NB as defined in 3GPP specification 36.331. In yet other implementations, the at least one first SIB includes a SIB1 and / or a SIB 19 as defined in 3GPP specification 38.331. In yet other implementations, the at least one first SIB includes one or more SIBs defined for 6G communication.

[0075] After event 606, the UE 102 receives 608 segment(s) 1, . .. , K of a PWS message in transmissions 1, . . ., K, as described for Fig. 4A. K is a positive integer. The PWS message consists of N segments, where K and N are positive integers and 0 < K < N. In somePATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC implementations, the UE 102 receives the segment(s) 1, . . ., K based on scheduling information in a SIB of the at least one first SIB. In some implementations, the SIB including scheduling information is a SIB1, a SystemlnformationBlockTypel, or a SystemlnformationBlockTypel - NB. In some implementations, the scheduling information indicates that one or more PWS messages is / are being broadcast on the cell 124A. In some implementations, the UE 102 receives the segment(s) 1, . . ., K via a broadcast control channel (BCCH).

[0076] After event 608 and before receiving all the segments of the PWS message, the UE 102 detects 610 out of coverage of the cell 124 A and does not camp on a cell. After event 610, the UE 102 enters the cell 124A and selects 612A the cell 124A. In some implementations, the UE 102 detects and / or synchronizes with the cell 124 A after event 610. The UE 102 then receives 674A a MTB and 676A at least one second SIB. Examples and implementations described for the at least one first SIB can apply to the at least one second SIB. In some implementations, the at least one second SIB and the at least one first SIB are different instances of the same SIB(s) and may have the same or different content.

[0077] After or in response to events 610, 674A, 676A, and / or 612A, the UE 102 retains (e.g., keeps, maintains, or stores) 614 the segment(s) 1, ..., K. After events 612A, 676A, 676A, and / or 614, the UE 102 receives or continues receiving 616A segment(s) K+l, . . ., N from the RAN 105. K+l < N. In some implementations, the UE 102 receives the segment(s) K+l, ..., N via a / the BCCH. In some implementations, the UE 102 receives the segment(s) K+l, . .. , N based on scheduling information in a SIB of the at least one second SIB. The scheduling information in the at least one second SIB may be the same as or different from the scheduling information in the at least one first SIB. In some implementations, the SIB including scheduling information is a SIB1, SystemlnformationBlockTypel, SystemlnformationBlockTypel -NB. The scheduling information indicates that one or more PWS messages is / are being broadcast on the cell 124A. The retention of the segment(s) 1, .. ., K avoids delaying completing reception of the PWS message. In some implantations, after events 612A, 674A, and / or 676A or during event 616A, the RAN 105 may still broadcast the segment(s) 1, ..., K on the cell 124A, and the UE 102 may skip reception of at least one of the segment(s) 1, . .. , K from the cell 124 A, which saves power ofthe UE 102.PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0078] In some implementations, if the at least one second SIB or the scheduling information indicates no PWS message is being broadcast, the UE 102 does not attempt to receive a PWS message and / or a PWS message segment on the cell 124A. This is because the RAN 105 stops broadcasting a / the PWS message on the cell 124A. In such cases, the UE 102 may discard the segment(s) 1, ... K. Alternatively, the UE 102 may still retain the segment(s) 1, . .. , K.

[0079] After completing reception of the segments 1, .. ., N, the UE 102 assembles 618 the segments 1, .. . , N into the PWS message. The retention of the segment(s) 1, . .. , K at event 614 avoids delaying completing reception of the PWS message after reentering the cell 124A. After event 618, the UE 102 may display the PWS message on a display of the UE 102 to inform a user. In some implementations, the UE 102 may retain the PWS message for a predetermined period. After the predetermined period passes, the UE 102 may discard the PWS message. In other implementations, the UE 102 discards the PWS message after displaying the PWS message and / or determining that a user has read the PWS message.

[0080] In some implementations, each of the segment 1, . . . , N is a SIB (i.e., an instance of the SIB). For example, the SIB is a SystemlnformationBlockType 11 , a SystemlnformationBlockType 12 , SystemlnformationBlockType 11-NB, a SystemlnformationBlockType 12-NB, a SIB7, or a SIB8. In another example, the SIB is a 6G SIB for ETWS and CMAS. In yet another example, the SIB is a 6G SIB for ETWS only. In yet another example, the SIB is a 6G SIB for CMAS only.

[0081] In some implementations, the segments 1, .. . , N includes a message identifier, a serial number, a segment type, a segment number and / or a portion of the PWS message. In some implementations, the RAN 105 (e.g., the BS 104) sets the message identifier in each of the segments 1, ..., N to the same value. In some implementations, the RAN 105 (e.g., the BS 104) sets the serial number in each of the segments 1, .. ., N to the same value. In some implementations, the RAN 105 (e.g., the BS 104) includes a last segment indicator in the segment N to indicate that the segment N is the last segment of the PWS message. In some implementations, the RAN 105 (e.g., the BS 104) includes a coding scheme field in the first segment (i.e., the segment 1) of the PWS message. The RAN 105 (e.g., the BS 104) may not include the coding scheme field in the segment(s) 2, .. ., N.PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0082] In some implementations, N < 64. In other implementations, 64 < N < 128. In yet other implementations, 64 < N < 192. In yet other implementations, 63 < N < 256. In yet other implementations, 64 < N < 512. In some implementations, the RAN 105 (e.g., the BS 104, the BS 106, and / or another BS) transmits the PWS message via a TN cell without segmentation. In other implementations, the RAN (e.g., the BS 104, the BS 106, and / or another BS) segments the PWS message into 1, . . .., M segments and transmits the segments 1, ..., M via a NTN cell (e g., the cell 124B, the cell 126 or another NTN cell). M is positive integer. M can be the same value as N or a different value from N. In some implementations, M can be smaller than N. For example, the cell 124A is a NB-IoT cell and the NTN cell is a NR NTN cell, a LTE (i.e., EUTRA) NTN cell, or an eMTC NTN cell. Because the NTN cell has wider bandwidth than the NT-IoT cell, the RAN 105 segments the PWS message into M segments less than N segments. In some implementations, M < 64. In other implementations, 63 < M < 128. In yet other implementations, 63 < M < 256. In yet other implementations, 63 < M < 512.

[0083] In other implementations, the RAN (e.g., the BS 104, the BS 106, and / or another BS) segments the PWS message into 1, . .. ., L segments and transmits the segments 1, . . ., L via a TN cell. L is positive integer. L can be the same value as N or M or a different value from N and / or M. In some implementations, L can be smaller than N. For example, the cell 124A is a NB-IoT cell and the TN cell is a NR cell, a LTE (i.e., EUTRA) cell, or an eMTC NTN cell. Because the TN cell has wider bandwidth than the NT-IoT cell, the RAN 105 segments the PWS message into L segments less than N segments. In some implementations, L < 64. In other implementations, 64 < L < 128. In yet other implementations, 64 < N < 192. In yet other implementations, 64 < L < 256. In yet other implementations, 64 < L < 512.

[0084] In some implementations, the events occurs while the UE 102 operates in an idle state (e.g., RRC_IDLE state) or an inactive state (e.g., RRC_INACTIVE state). The UE 102 operates in the idle state may or may not have a suspended RRC connection.

[0085] Fig. 6B illustrates an example scenario 600B similar to the scenario 600A. Events 674B, 676B, 616B occurs via the cell 124B instead of the cell 124A. The differences between Fig. 6A and Fig. 6B are described below. After event 608 and before receiving all the segments of the PWS message, the UE 102 selects or reselects 612B the cell 124B. The UE 102 then receives 674B a MIB and 676B at least one second SIB from the RAN 105.PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0086] After or in response to events 674B, 676B, and / or 612B, the UE 102 retains the segment(s) 1, ..., K. After events 612B, 674B, 676B, and / or 614, the UE 102 receives or continues receiving 616B segment(s) K+l, .. N from the RAN 105 and assembles 618 the segments 1, .. . , N into the PWS message. In some implementations, the UE 102 receives the segment(s) K+l, . .. , N based on scheduling information in a SIB of the at least one second SIB. In some implementations, the SIB including scheduling information is a SIB1, SystemlnformationBlockTypel, SystemlnformationBlockTypel -NB. The scheduling information indicates that one or more PWS messages is / are being broadcast on the cell 124B. The retention of the segment(s) 1, .. ., K avoids delaying completing reception of the PWS message. In some implantations, after events 612B, 674B, and / or 676B or during event 616B, the RAN 105 may still broadcast the segment(s) 1, . . ., K on the cell 124B, and the UE 102 may skip reception of at least one of the segment(s) 1, . .. , K from the cell 124B, which saves power ofthe UE 102.

[0087] In some implementations, if the at least one second SIB or the scheduling information indicates no PWS message is being broadcast, the UE 102 does not attempt to receive a PWS message and / or a PWS message segment on the cell 124B. This is because the RAN 105 does not broadcast or stops broadcasting a / the PWS message on the cell 124B. In such cases, the UE 102 may discard the segment(s) 1, ... K. Alternatively, the UE 102 may still retain the segment(s) 1, ..., K.

[0088] Fig. 6C illustrates an example scenario 600C similar to the scenarios 600A and 600B. Events 674C, 676C, and 616C occurs via the cell 126 instead of the cell 124A or the cell 124B. The differences among Figs. 6A, 6B and 6C are described below. After event 608 and before receiving all the segments of the PWS message, the UE 102 selects or reselects 612C the NTN cell 126. The UE 102 then receives 674C a MIB and 676C at least one second SIB from the RAN 105.

[0089] After or in response to events 674C, 676C, and / or 612C, the UE 102 retains the segment(s) 1, ..., K. After events 612C, 674C, 676C, and / or 614, the UE 102 receives or continues receiving 616C segment(s) K+l, .. ., N from the RAN 105 and assembles 618 the segments 1 , .. . , N into the PW S message. In some implementations, the UE 102 receives the segment(s) K+l, . .. , N based on scheduling information in a SIB of the at least one second SIB.PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PCIn some implementations, the SIB including scheduling information is a SIB I, SystemlnformationBlockTypel, SystemlnformationBlockTypel-NB. The scheduling information indicates that one or more PWS messages is / are being broadcast on the cell 126. The retention of the segment(s) 1, .. K avoids delaying completing reception of the PWS message. In some implantations, after events 612C, 674C, and / or 676C or during event 616C, the RAN 105 may still broadcast the segment(s) 1, ..., K on the cell 126, the UE 102 may skip reception of at least one of the segment(s) 1, .. . , K from the cell 126, which saves power of the UE 102.

[0090] In some implementations, if the at least one second SIB or the scheduling information indicates no PWS message is being broadcast, the UE 102 does not attempt to receive a PWS message and / or a PWS message segment on the cell 126. This is because the RAN 105 does not broadcast or stops broadcasting a / the PWS message on the cell 126. In such cases, the UE 102 may discard the segment(s) 1, ... K. Alternatively, the UE 102 may still retain the segment(s) 1, ..., K.

[0091] Fig. 6D illustrates an example scenario 600D similar to the scenario 600A, except that the scenario 600D includes events 662, 664 and 666 instead of event 610. Events 662 and 664 occurs via the cell 124A. The differences between Fig. 6A and Fig. 6D are described below. After event 608 and before receiving all the segments of the PWS message, the UE 102 in the idle state establishes 662 a connection with the RAN 105 via the cell 124A, e.g., to transmit data to the RAN 105 or responds to paging received from the RAN 105. In some implementations, the connection includes at least one signaling radio bearer (SRB) and / or at least one DRB. The UE 102 transitions to a connected state (e.g., RRC CONNECTED state) upon or after establishing the connection or a SRB (e.g., SRB1) of the at least one SRB. The UE 102 communicates data (e.g., control-plane messages and / or user-plane data) with the RAN via the connection. Later in time, the UE 102 releases 666 the connection with the RAN 105 and transitions to the idle state after (e.g., in response to) releasing the connection. In some implementations, the UE receives 664 a connection release message from the RAN 105 and releases 666 the connection in response to the connection release message. In some implementations, the connection release message is a RRC connection release message (e.g., RRCConnectionRelease or RRCConnectionRelease-NB message) or a RRC release messagePATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC(e.g., RRCRelease message). In other implementations, the UE 102 detects a failure on the connection and releases the connection in response to detecting the failure. After releasing the connection or transitioning to the idle state, the UE 102 selects 612A the cell 124A. After or in response to events 662, 664, 666, 674A, 676A, and / or 612A, the UE 102 retains (e.g., keeps, maintains, or stores) 614 the segment(s) 1, . . ., K. The UE then may receive or continue receiving 616A segment(s) K+l, ..., N from the RAN 105 and assemble 618 the segments 1, ..., N into the PWS message, as described for Fig. 6A.

[0092] Fig. 6E illustrates an example scenario 600E similar to the scenarios 600A and 600D, except that the scenario 600D includes events 615, 616E instead of events 610, 614, 616A, and 616D. The differences between Fig. 6E and Fig. 6D are described below. After or in response to events 662, 664, 666, 674A, 676A, and / or 612A, the UE 102 discards 615 the segment(s) 1 , ..., K. In some implementations, the UE 102 may do so because the UE 102 does not have enough memory to store the segment(s) 1, . . ., K. In some implementations, after discarding the segment(s) 1 , .. . , K, the UE 102 may receive 616E the segments 1 , . . . , N of the PW S message and assemble 618 the segments 1, .. ., N into the PWS message. In some implementations, the UE 102 receives the segment(s) 1, . . ., N based on scheduling information in a SIB of the at least one second SIB. The scheduling information in the at least one second SIB may be the same as or different from the scheduling information in the at least one first SIB.

[0093] Fig. 6F illustrates an example scenario 600F similar to the scenarios 600A, 600D, and 600E, except that the scenario 600F includes events 668 A and 616F instead of events 610, 614, 664, 666, 616A, 616D, and 616E. The differences among Figs. 6A, 6D, 6E, and Fig. 6F are described below. In this scenario, the RAN 105 transmits 616F one or more DL dedicated messages via the connection to the UE 102, including the segments 1, . . ., N. The RAN 105 may do so because the UE 102 is not capable of simultaneously receiving a (broadcast) PWS message and maintaining the connection. In some implementations, the RAN 105 transmits 616F a single DL dedicated message including the segments 1, . . ., N to the UE 102. In other implementations, the RAN 105 transmits 616F DL dedicated messages 1, .. ., N to the UE 102, including the segments 1, ..., N respectively. In yet other implementations, the RAN 105 transmits 616F E DL dedicated messages including the segments 1, . . . , N, where P is an integer and 1 < P < N.PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0094] In some implementations, the UE 102 transmits 668 A a PWS message request to the RAN 105 via the connection or during the connection establishment 662. In response to the PWS message request, the RAN 105 transmits 616F the one or more DL dedicated messages to the UE 102 via the connection. In some implementations, the RAN 105 transmits 616F the one or more DL dedicated messages via a dedicated control channel (DCCH) to the UE 102. In some implementations, the one or more DL dedicated messages is / are RRC messages. In some implantations, while transmitting 616F the dedicated messages, the RAN 105 is broadcasting the segment(s) 1, .. . , K and / or the segment(s) K+l, . .. , N via the cell 124A as described for Fig. 6A. In some implementations, each of the one or more DL dedicated messages is an existing DL RRC message. For example, the DL RRC message is a RRCConnectionReconfiguration message, a RRCReconfiguration message, a DLInformationTransfer message, a DLDedicatedMessageSegment message, RRCConnectionReconfiguration-NB message, a DLInformationTransfer-NB message, or a DLDedicatedMessageSegment-NB message. In other implementations, each of the one or more DL dedicated messages is a DL RRC message defined in a 3GPP Release 19 specification and / or one or more later releases. In some implementations, the DL dedicated message is dedicated to transmitting system information or one or more SIBs to a UE. For example, the DL dedicated message a DLDedicatedSystemlnformation message, a DLDedicatedSystemlnformationSegment message, DLDedicatedSystemlnformation-NB message or a DLDedicatedSystemlnformationSegment-NB message.

[0095] In some implementations, the UE 102 includes a message identifier and / or a serial number in the PWS message request. The RAN 105 determines which PWS message requested by the UE 102 based on the message identifier and / or the serial number. That is, the RAN 105 identifies the PWS message based on the message identifier and / or the serial number. In some implementations, the PWS message request is a UL message (e.g., a RRC message) for PWS message request. In other implementations, the PWS message request is an indicator in a UL message (e.g., a RRC message). For example, the UL message is a RRC request message, a RRC complete message, or an UE assistance information message. The RRC request message may be an RRCConnectionRequest message, an RRCConnectionResumeRequest message, an RRCConnectionRequest-NB message, or an RRCConnectionResumeRequest-NB message. The RRC complete message may be an RRCConnectionComplete message, an RRCConnectionResumeComplete message, an RRCConnectionSetupComplete-NB message, orPATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC an RRCConnectionResumeComplete-NB message. The UE assistance information message is an UEAssistancelnformation message or an UEAssistancelnformation-NB message. In yet other implementations, the PWS message request is a field or a control element in a UL MAC PDU.

[0096] Fig. 6G illustrates an example scenario 600G similar to the scenarios 600A, 600D and 600F, except that the scenario 600G includes events 668B and 616G instead of events 610, 614, 665, 666, 668A, 616A, 616D, and 616F. The differences among Figs. 6A, 6D, 6F, and Fig. 6G are described below. In this scenario, the UE 102 transmits 668B a PWS message request to the RAN 105 via the connection or during the connection establishment 662, similar to event 668A. In the PWS message request, the UE 102 indicates which segments of the PWS message are received and / or which segments of the PWS message are missing. Thus, the RAN 105 determines which segments of the PWS message to transmit in accordance with the indication. In response to the PWS message request, the RAN 105 transmits the determined segments in one or more DL dedicated message to the UE 102. For example, the UE 102 indicates the segment(s) 1, .. . , K are received in the PWS message request. In response to the PWS message request, the RAN 105 transmits 616G one or more dedicated messages to the UE 102 via the connection, including the segment(s) K+l, .. . , N. In some implantations, while transmitting 616Gthe dedicated messages, the RAN 105 is broadcasting the segment(s) 1, ..., K and / or the segments K+l, . . ., N via the cell 124A as described for Fig. 6A.

[0097] In some implementations, the UE 102 includes a message identifier and / or a serial number in the PWS message request. The RAN 105 determines which PWS message requested by the UE 102 based on the message identifier and / or the serial number. That is, the RAN 105 identifies the PWS message based on the message identifier and / or the serial number. In some implementations, the UE 102 includes a bitmap in the PWS message request to indicate which segments are received and / or which segments are missing. Each bit in the bitmap may corresponds to a received or missing segment. For example, if a bit is set to 1, the bit indicates a corresponding segment is received. Otherwise, if the bit is set to 0, the bit indicates a corresponding segment is missing. In other implementations, the UE 102 includes segment numbers of received segments in the PWS message request to indicate corresponding segments are received.PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0098] In some implementations, the RAN 105 transmits 616G a single DL dedicated message including the segments K+l, . . . , N to the UE 102. In other implementations, the RAN 105 transmits 616F DL dedicated messages K+l, .. ., N to the UE 102, including the segments K+l, . . ., N respectively. In yet other implementations, the RAN 105 transmits 616F P DL dedicated messages including the segments K+l, . .. , N, where P is a positive integer and P < (N- K).

[0099] Next, several example methods that can be implemented in a UE (e.g., the UE 102) or a RAN (e.g., a RAN node such as the base station 104, DU 174 or CU 172) are discussed with reference to Figs. 7-16. Descriptions for Figs. 6A-6G can apply to Figs. 7-16. Each of these methods can be implemented using processing hardware such as one or more processors to execute instructions stored on a non-transitory computer-readable medium such as computer memory.

[0100] Fig. 7 illustrates an example method 700, which can be implemented by a RAN. The method 700 begins at block 706, where the RAN broadcasts at least one SIB. At block 705, the RAN receives a PWS message from a network node. For example, the network node is a CN node such as a MME or an AMF. At block 707, the RAN segments the PWS message into N PWS message segments, where N is a positive integer. At block 716, the RAN transmits the N PWS message segments via at least one first satellite and at least one first NTN cell with a first RAT (e.g., events 608, 616A, 616B, 616C, and / or 616E).

[0101] Fig. 8A illustrates an example method 800A, which can be implemented by a RAN. The method 800A begins with the method 700 as described with respect to Fig. 7. At block 807, the RAN segments the PWS message into M PWS message segments, where M is a positive integer. At block 816, the RAN transmits the M PWS message segments via at least one second satellite and at least one second NTN cell with a second RAT.

[0102] In some implementations, M is smaller than N. In other implementations, M is equal to N. In some implementations, the first RAT is a NB-IoT and the first NTN cell is a NB-IoT NTN cell. In other implementations, the first RAT is a LTE eMTC and the first NTN cell is an eMTC NTN cell. In yet other implementations, the first RAT is a LTE and the first NTN cell is an LTE NTN cell. In yet other implementations, the first RAT is a NR and the first NTN cell is a NR NTN cell. In yet other implementations, the first RAT is 6G and the first NTN cell is a 6GPATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PCNTN cell. In yet other implementations, the first RAT is 6G loT and the first NTN cell is a 6G loT NTN cell.

[0103] In some implementations, the second RAT is a NB-IoT and the second NTN cell is a NB-IoT NTN cell. In other implementations, the second RAT is LTE eMTC and the second NTN cell is an eMTC NTN cell. In yet other implementations, the second RAT is a LTE and the second NTN cell is an LTE NTN cell. In yet other implementations, the second RAT is a NR and the second NTN cell is a NR NTN cell. In yet other implementations, the second RAT is 6G and the second NTN cell is a 6G NTN cell. In yet other implementations, the second RAT is 6G loT and the second NTN cell is a 6G loT NTN cell.

[0104] Fig. 8B is a flow diagram of an example method 800B similar to the method 800A, except that the method 800B includes block 817 instead of blocks 807 and 816. At block 817, the RAN transmits the PWS message without segmentation via at least one second satellite and at least one second NTN cell with a second RAT.

[0105] Fig. 9A illustrates an example method 900A, which can be implemented by a RAN. The method 900A begins with the method 800A or 800B as described with respect to Fig. 8A or 8B. At block 930, the RAN segments the PWS message into L PWS message segments, where L is a positive integer. At block 932, the RAN transmits the L PWS message segments via at least one TN cell with a third RAT.

[0106] In some implementations, L is smaller than M and / or N. In other implementations, L is equal to M or N. In some implementations, the third RAT is a NB-IoT and the one TN cell (TN cell(s) is / are one or more NB-IoT cells. In other implementations, the third RAT is a LTE eMTC and the TN cell(s) is / are eMTC cell(s). In yet other implementations, the third RAT is a LTE and the TN cell(s) is / are LTE cell(s). In yet other implementations, the third RAT is a NR and the TN cell(s) is / are NR cell(s). In yet other implementations, the third RAT is 6G and the TN cell(s) is / are 6GNTN cell(s). In yet other implementations, the third RAT is 6G loT and the TN cell(s) is / are 6G loT cell(s).

[0107] Fig. 9B is a flow diagram of an example method 900B similar to the method 900A, except that the method 900B includes block 931 instead of blocks 930 and 932. At block 931, thePATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PCRAN transmits the PWS message without segmentation via at least one TN cell with a third RAT.

[0108] Fig. 10 illustrates an example method 1000, which can be implemented by a UE. The method 1000 begins at block 1008, where the UE receives a first portion of N PWS message segments via a first NTN cell, where N is an integer and larger than one. At block 1012, the UE enters a second NTN cell before receiving all of the N PWS message segments. At block 1014, the UE retains the first portion of the N PWS message segments in response to entering the second NTN cell. At block 1016, the UE receives the rest portions of the N PWS message segments via the second NTN cell. At block 1018, the UE assembles the first portion and the rest portions of the N PWS message segments into a PWS message.

[0109] If the UE supports communication with a TN, the UE may perform blocks 1038, 3042 and 1044. At block 1038, the UE may receive a first portion of M PWS message segments via a first TN cell, where M is an integer and larger than one. At block 1042, the UE may enter a second TN cell before receiving all of the M PWS message segments. At block 1044, the UE may discard the first portion of the M PWS message segments in response to entering the second TN cell.

[0110] In some implementations, the second NTN cell and the first NTN cell are the same cell. In other implementations, second NTN cell is different from the first NTN cell. In such cases, a PCI of the second NTN cell and a PCI of the first NTN cell may be the same or different.[OHl] In some implementations, the UE enters the second NTN cell in response to performing a cell selection or a cell reselection from the first NTN cell. In other implementations, the UE enters the second NTN cell after detecting out of coverage of the first NTN cell. In yet other implementations, the UE enters the second NTN cell in response to releasing a connection with the first NTN cell (e.g., entering an idle state). In one implementation, the UE releases the connection with the first NTN cell in response to releasing a connection release message from the first NTN cell. In another implementation, the UE releases the connection with the first NTN cell in response to a failure or an expiry of a timer (e.g., T311).PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0112] Fig. 11 illustrates an example method 1100 similar to the method 1000, which can be implemented by an UE. The method 1100 begins at block 1008. At block 1112, the UE enters a second cell before receiving all of the N PWS message segments. At block 1134, the UE determines whether the second cell is a NTN cell or a TN cell. If the second cell is a NTN cell (i.e., “NTN cell” branch of block 1134), the flow proceeds to blocks 1014, 1016, and 1018. Otherwise, if the second cell is a TN cell (i.e., “TN cell” branch of block 1134), the flow proceeds to block 1144. At block 1144, the UE discards the first portion of the N PWS message segments in response to entering the TN cell. Descriptions for Fig. 10 can apply to Fig. 11.

[0113] Fig. 12A illustrates an example method 1200A similar to the method 1000, which can be implemented by an UE. The method 1200A begins with blocks 1008 and 1012. At block 1236, the UE determines whether the first NTN cell and the second NTN cell belong to the same RAT. If the first NTN cell and the second NTN cell belong to the same RAT (i.e., “Yes” branch of block 1236), the flow proceeds to blocks 1014, 1016, and 1018. Otherwise, if the first NTN cell and the second NTN cell do not belong to the same RAT (i.e., “No” branch of block 1236), the flow proceeds to block 1244. At block 1244, the UE discards the first portion of the N PWS message segments in response to entering the second NTN cell. Description for Fig. 10 can apply to Fig. 12.

[0114] Fig. 12B is a flow diagram of an example method 1200B similar to the method 1200A, except that the method 1200B includes block 1235 instead of block 1236. At block 1235, the UE determines whether the first NTN cell and the second NTN cell belong to the same tracking area. If the first NTN cell and the second NTN cell belong to the same tracking area (i.e., “Yes” branch of block 1235), the flow proceeds to block 1014, 1016 and 1018. Otherwise, if the first NTN cell and the second NTN cell do not belong to the same tracking area (i.e., “No” branch of block 1235), the flow proceeds to block 1244.

[0115] Fig. 12C is a flow diagram of an example method 1200C similar to the method 1200A, except that the method 1200C includes block 1237 instead of block 1236. At block 1237, the UE determines whether the first NTN cell and the second NTN cell belong to the same RAT and the same tracking area. If the first NTN cell and the second NTN cell belong to the same RAT and the same tracking area (i.e., “Yes” branch of block 1237), the flow proceeds to block 1014, 1016 and 1018. Otherwise, if the first NTN cell and the second NTN cell do not belong to the samePATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PCRAT and the same tracking area (i.e., “No” branch of block 1237), the flow proceeds to block 1244.

[0116] Fig. 13A illustrates an example method 1300A, which can be implemented by an UE. The method 1300A begins at block 1308. At block 1308, the UE receives a first portion of N PWS message segments via a first NTN cell of a RAT, where N is an integer and larger than one. At block 1312, the UE enters a second NTN cell of the RAT before receiving all of the N PWS message segments. At block 1350A, the UE determines whether the RAT is a NB-IoT. If the RAT is a NB-loT (e.g., “Yes” branch of block 1350A), the flow proceeds to blocks 1014, 1016, and 1018. Otherwise, if the RAT is not the NB-IoT (e.g., “No” branch of block 1350A), the flow proceeds to block 1244. For example, the RAT with “No branch” is NR cell, LTE (i.e., EUTRA), UTE eMTC, or 6G.

[0117] Fig. 13B is a flow diagram of an example method 1300B similar to the method 1300A, except that the method 1300B includes block 1350B instead of block 1350A. At block 1350B, the UE determines whether the RAT is a NB-IoT or eMTC. If the RAT is a NB-IoT or eMTC (i.e., “Yes” branch of block 135OB), the flow proceeds to blocks 1014, 1016, and 1018. Otherwise, if the RAT is neither the NB-IoT nor the eMTC (i.e., “No” branch of block 1350B), the flow proceeds to block 1244. For example, the RAT with “No branch” is NR, LTE (i.e., EUTRA), or 6G.

[0118] Fig. 14A illustrates an example method 1400A, which can be implemented by an UE. The method 1400A begins with blocks 1408, where the UE receives a first portion of N PWS message segments via a first cell of a RAT, where N is an integer and larger than one. At block 1412, the UE enters a second cell of the RAT before receiving all of the N PWS message segments. If the RAT is a NB-IoT (i.e., “Yes” branch of block 1350A), the flow proceeds to blocks 1414, 1016, and 1018. At block 1414, the UE retains the first portion of the N PWS message segments in response to entering the second cell. Otherwise, if the RAT is not the NB- loT (i.e., “No” branch of block 1350A), the flow proceeds to block 1444. At block 1444, the UE discards the first portion of the N PWS message segments in response to entering the second cell.

[0119] Fig. 14B is a flow diagram of an example method 1400B similar to the method 1400A, except that the method 1400B includes block 1350B instead of block 1350A. If the RAT is a NB-IoT or eMTC (i.e., “Yes” branch of block 1350B), the flow proceeds to blocks 1414, 1016,PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC and 1018. Otherwise, if the RAT is neither the NB-IoT nor the eMTC (i.e., “No” branch of block 135OB), the flow proceeds to block 1444.

[0120] Fig. 14C is a flow diagram of an example method 1400C similar to the method 1400A, except that the method 1400C includes block 1452 instead of block 1350A. At block 1452, the UE determines whether the second cell indicates supporting UEs to assemble PWS message segments received from different cells. If the second cell indicates supporting UEs to assemble PWS message segments received from different cells (i.e., “Yes” branch of block 1452), the flow proceeds to blocks 1414, 1016, and 1018. Otherwise, if the second cell does not indicate supporting UEs to assemble PWS message segments received from different cells (i.e., “No” branch of block 1452), the flow proceeds to block 1444. In some implementations, the “other cell(s)” can be specific cell(s) including the first cell. In other implementations, the “other cell(s)” generally refers to cells other than the second cell.

[0121] In some implementations, the UE receives a SIB transmitted on the second cell. The SIB may be a SIB1, a SIB 19, a SystemlnformationBlockType 1 , a SystemlnformationBlockType 1- NB, a SystemlnformationBlockType 31 , or a SystemlnformationBlockType 31 -NB . If the SIB includes the indication of supporting UEs to assemble PWS message segments received from different cells, the UE performs blocks 1414, 1016, and 1018. Otherwise, if the SIB does not include the indication of supporting UEs to assemble PWS message segments received from different cells, the UE performs block 1444.

[0122] Fig. 14D is a flow diagram of an example method 1400D similar to the method 1400C, except that the method OOD includes block 1453 instead of block 1452. At block 1453, the UE determines whether the second cell indicates the same segments of a PWS message are transmitted as other cell(s). If the second cell indicates the same segments of the PWS message are transmitted as other cell(s) (i.e., “Yes” branch of block 1453), the flow proceeds to blocks 1414, 1016, and 1018. Otherwise, if the second cell does not indicate the same segments of the PWS message as other cell(s) (i.e., “No” branch of block 1453), the flow proceeds to block 1444.

[0123] In some implementations, the UE receives a SIB transmitted on the second cell. The SIB may be a SIB1, a SIB 19, a SystemlnformationBlockType 1 , a SystemlnformationBlockType 1- NB, a SystemlnformationBlockType 37, or a SystemlnformationBlockType 31-NB . If the SIB includes the indication of transmitting the same segments of the PWS message as other cell(s),PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC the UE performs blocks 1414, 1016, and 1018. Otherwise, if the SIB does not include the indication of transmitting the same segments of the PWS message as other cell(s), the UE performs block 1444.

[0124] Description for Fig. 10 can apply to Figs. 12A-12C, 13A-13B and 14A-14D. Description for Figs. 13A and 13B can apply to Figs. 14A and 14B, respectively.

[0125] Fig. 15 illustrates an example method 1500, which can be implemented by a RAN.The method 1500 begins at block 1562, where the RAN establishes a connection with a UE via a cell. At block 1568, the RAN may receive a PWS message request from the UE. At block 1516, the RAN transmits the PWS message to the UE via the connection.

[0126] In some implementations, the cell is a NTN cell. In other implementations, the cell is a TN cell. In some implementations, the PWS message request indicates receipt or missing of one or more segments. In such cases, the RAN at block 1516 may transmit missing segments of the PWS message to the UE. In other implementations, the PWS message request requests transmission of the PWS message.

[0127] Fig. 16A illustrates an example method 1600A similar to the method 1500, which can be implemented by a RAN. The method begins with block 1562 and optionally with block 1568. The RAN determines whether the RAN is broadcasting a PWS message via the cell. If the RAN is broadcasting a PWS message (e.g., “Yes” branch of block 1654), the flow proceeds to block 1516. Otherwise, if the RAN is not broadcasting a PWS message (i.e., “No” branch of block 1654), the flow proceeds to block 1670 where the flow ends.

[0128] Fig. 16B illustrates an example method 1600B similar to the methods 1500 and 1600A, which can be implemented by a RAN. The method begins at block 1562 and proceeds to block 1655. At block 1655, the RAN determines whether the RAN receives a PWS message request from the UE. If the RAN receives a PWS message request from the UE (i.e., “Yes” branch of block 1655), the flow proceeds to block 1516. Otherwise, if the RAN does not receive a PWS message request from the UE, the flow proceeds to block 1670.

[0129] Fig. 17 illustrates an example method 1700, which can be implemented by a RAN. The method begins at block 1768. At block 1768, the RAN receives a PWS message request from a UE. At block 1758, the RAN determines whether the PWS message request indicatesPATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC specific segments received. If the PWS message request does not indicate receipt of one or more specific segments (i.e., “Yes” branch of block 1758), the flow proceeds to block 1516.Otherwise, if the PWS message request indicates receipt of one or more specific segments (i.e., “No” branch of block 1758), the flow proceeds to block 1716. At block 1716, the RAN transmits missing portions of the PWS message to the UE via the connection.

[0130] Fig. 18 illustrates an example method 1800, which can be implemented by an UE. The method begins at block 1862 where the UE establishes a connection with a RAN via a cell. At block 1868, the UE may transmit a PWS message request to the RAN via the connection. At block 1816, the UE receives the PWS message from the RAN via the connection.

[0131] In some implementations, the cell is aNTN cell. In other implementations, the cell is a TN cell. In some implementations, the PWS message request indicates receipt or missing of one or more segments. In such cases, the UE at block 1816 may receive missing segments of the PWS message to the UE. In other implementations, the PWS message request requests transmission of the PWS message.

[0132] Fig. 19A illustrates an example method 1900A similar to the method 1800, which can be implemented by an UE. The method begins at block 1862. At block 1954, the UE determines whether the RAN is broadcasting a PWS message via the cell. If the RAN is broadcasting a PWS message via the cell (i.e., “Yes” branch of block 1954), the flow proceeds to block 1868. Otherwise, if the RAN is not broadcasting a PWS message via the cell (i.e., “No” branch of block 1954), the flow proceeds to block 1972. At block 1972, the UE refrains from transmitting a PWS message request to the RAN.

[0133] In some implementations, before establishing the connection, the UE receives a SIB broadcast on the cell (e.g., event 606). If the SIB indicates that the RAN is broadcasting a PWS message, the UE performs block 1868. Otherwise, if the SIB indicates that the RAN is not broadcasting a PWS message, the UE performs block 1972.

[0134] Fig. 19B illustrates an example method 1900B similar to the method 1900A, except that the method 1900B includes block 1980 instead of block 1954. At block 1980, the UE determines whether the UE attempts to receive a PWS message via the cell before establishing the connection. If the UE attempts to receive a PWS message via the cell before establishing thePATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC connection (i.e., “Yes” branch of block 1980), the flow proceeds to block 1868. Otherwise, if the UE does not attempt to receive a PWS message before establishing the connection (i.e., “No” branch of block 1980), the flow proceeds to block 1972.

[0135] In some implementations, before establishing the connection, the UE receives a SIB broadcast on the cell (e.g., event 606). If the SIB indicates that the RAN is broadcasting a PWS message, the UE attempts to receive a PWS message. Otherwise, if the SIB indicates that the RAN is not broadcasting a PWS message, the UE does not attempt to receive a PWS message.

[0136] Fig. 19C illustrates an example method 1900C similar to the method 1900A, except that the method 1900C includes block 1982 instead of block 1954. At block 1982, the UE determines whether the UE supports simultaneously receiving a (broadcast) PWS message and maintaining the connection. If the UE supports simultaneously receiving a (broadcast) PWS message and maintaining the connection (i.e., “Yes” branch of block 1982), the flow proceeds to block 1868. Otherwise, if the UE does not support simultaneously receiving a (broadcast) PWS message and maintaining the connection (i.e., “No” branch of block 1982), the flow proceeds to block 1972.

[0137] Fig. 20A illustrates an example method 2000A, which can be implemented by a RAN. The method begins at block 1562. At block 2005, the RAN receives an upper message from a network node (e.g., a CN node such as a MME, AMF, or a 6G CN node). At block 2084, the RAN determines whether the upper layer message is a PWS message or a NAS message. If the upper layer message is a PWS message (i.e., “PWS message” branch of block 2084), the flow proceeds to block 2016A. At block 2016 A, the RAN transmits a first DL lower message including the PWS message to the UE via the connection. Otherwise, if the upper layer message is a NAS message (e.g., “NAS message” branch of block 2084), the flow proceeds to block 2086. At block 2086, the RAN transmits a second DL lower layer message including the NAS message to the UE via the connection.

[0138] In some implementations, the first DL lower layer message and the second DL lower layer message are RRC messages. In some implementations, the second DL lower layer message is a DL information transfer message (e.g., DLInformationTransfer message or a DLInformationTransfer-NB). In some implementations, the first DL lower layer message is aPATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC new (dedicated, special-purpose) RRC message that augments a relevant standard such as 3GPP specification 36.331 or 38.331.

[0139] Fig. 20B illustrates an example method 2000B similar to the method 2000A, except that the method 2000B includes blocks 2085, 2087, and 2016B instead of blocks 2086 and 2016A. If the upper layer message is a PWS message (i.e., “PWS message” branch of block 2084), the flow proceeds to block 2085. At block 2085, the RAN includes the PWS message in a first field in a DL lower layer message. Otherwise, if the upper layer message is a NAS message (e.g., “NAS message” branch of block 2084), the flow proceeds to block 2087. At block 2087, the RAN includes the NAS message in a second field in the DL lower layer message. The flow proceeds to block 2016B from block 2085 as well as block 2087. At block 2016B, the RAN transmits the DL lower layer message to the UE via the connection.

[0140] In some implementations, the DL lower layer message is a RRC message. For example, the RRC message is a DL information transfer message (e.g., DLInformationTransfer message or DLInformationTransfer-NB message). In some implementations, the first field is a new (dedicated, special -purpose) field that augments a relevant standard such as 3 GPP specification 36.331 or 38.331. In some implementations, the second field is dedicatedlnfoNAS or dedicatedlnfoNAS-rl3.

[0141] In some implementations, if the PWS message is an ETWS message, the RAN includes the ETWS message in a first sub-field in the first field. If the PWS message is a CMAS message, the RAN includes the CMAS message in a second sub-field in the first field.

[0142] Fig. 21A illustrates an example method 2100A, which can be implemented by an UE. The method begins at block 1862. At block 2116, the UE receives a DL lower layer message from the RAN. At block 2118, the UE retrieves an upper layer message from the DL lower layer message. At block 2190, the UE determines whether the DL lower layer message is a first DL lower layer message or a second DL lower layer message. If the DL lower layer message is the first DL lower layer message (i .e., “first DL lower layer message” branch of block 2190), the flow proceeds to block 2192. At block 2192, the UE determines that the upper layer message is a PWS message and processes the PWS message. Otherwise, if the DL lower layer message is the second DL lower layer message (i.e., “second DL lower layer message” branch of blockPATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC2190), the flow proceeds to block 2194. At block 2194, the UE determines that the upper layer message is a NAS message and processes the NAS message.

[0143] Descriptions for Fig. 20A can apply to Fig. 21A. In some implementations, the UE processes the PWS message by displaying the PWS message and / or generating a notification sound. In some implementations, the UE processes the NAS message using a NAS layer protocol.

[0144] Fig. 21B illustrates an example method 2100B similar to the method 2100A, except that the method 2000B includes block 2191 instead of block 2190. At block 2191, the UE determines whether the UE retrieves the upper layer message from a first field or a second field in the DL lower layer message. If the UE retrieves the upper layer message from the first field (i.e., “first field” branch of block 2191), the flow proceeds to block 2192. Otherwise, if the UE retrieves the upper layer message from the second field (i.e., “second field” branch of block2191), the flow proceeds to block 2194. Descriptions for Fig. 20B can apply to Fig. 21B.

[0145] Fig. 22 illustrates an example method 2200, which can be implemented by a RAN. The method begins at block 705 and proceeds to block 2296. At block 2096, the RAN determines whether the PWS message is an ETWS message or a CMAS message. If the PWS message is an ETWS message (i.e., “ETWS message” branch of block 2296), the flow proceeds to block 2285. At block 2285, the RAN includes the ETWS message in a first field in at least one DL lower layer message. Otherwise, if the PWS message is a CMAS message (i.e., “CMAS message” branch of block 2296), the flow proceeds to block 2287. At block 2287, the RAN includes the CMAS message in a second field in the at least one DL lower layer message. The flow proceeds to block 2216 from block 2285 as well as block 2287. At block 2216, the RAN transmits the at least one DL lower layer message.

[0146] In some implementations, the at least one DL lower layer message is / are at least one SIB and the RAN broadcasts the at least one SIB. In other implementations, the at least one DL lower layer message is / are at least one dedicated RRC message. For example, each of the at least one dedicated RRC message is a DL information transfer message (e.g., DLInformationTransfer message or DLInformationTransfer-NB message). In another example, each of the at least one dedicated RRC message is a new (dedicated, special-purpose) RRC message that augments a relevant standard such as 3GPP specification 36.331 or 38.331.PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0147] Fig. 23 illustrates an example method 2300, which can be implemented by an UE. The method begins at block 2316. At block 2316, the UE receives at least one DL lower layer message from the RAN. At block 2338, the UE retrieves a PWS message from the at least one DL lower layer message. At block 2391, the UE determines whether the UE retrieves the PWS message from a first field or a second field in the at least one DL lower layer message. If the UE retrieves the PWS message from the first field (i.e., “first field” branch of block 2391), the flow proceeds to block 2392. At block 2392, the UE determines that the PWS message is an ETWS message and process the ETWS message. Otherwise, if the UE retrieves the upper layer message from the second field (i.e., “second field” branch of block 2391), the flow proceeds to block 2394. At block 2394, the UE determines that the PWS message is a CMAS message and process the CMAS message. Descriptions for Fig. 23 can apply to Fig. 22.

[0148] The following list of examples reflects a variety of the embodiments explicitly contemplated by the present disclosure. The following description may be applied to the description above.

[0149]

[0150] Example 1. A method for receiving a public warning service (PWS) message, the method implemented in a user equipment (UE) and comprising: receiving, in a cell of a nonterrestrial network (NTN), a first segment of the PWS message; after leaving the cell (e.g., detecting a change in registration with the cell, detecting a change in connection with the cell), and prior to receiving a second segment of the PWS, retaining the first segment of the PWS message; and receiving, from the NTN subsequently to the retaining, a second segment of the PWS message.

[0151] Example 2. The method of example 1, wherein the leaving the cell includes: detecting that the UE is out of coverage of the cell.

[0152] Example 3. The method of example 1, wherein the leaving the cell includes: receiving, in the cell, a request to release a radio connection between the UE and the NTN.

[0153] Example 4. The method of example 3, further comprising: establishing the radio connection with the NTN after the receiving of the first segment and prior to the leaving the cell.PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0154] Example 5. The method of example 1, further comprising: establishing the radio connection with the NTN after the receiving of the first segment.

[0155] Example 6. The method of any of the preceding examples, further comprising: after the leaving the cell, selecting the cell again; wherein the second segment of the PWS message is received in the cell.

[0156] Example 7. The method of any of examples 1-3, wherein: the cell is a first cell; the method further comprising: after the leaving the cell, selecting a second cell of the NTN; and wherein the second segment of the PWS message is received in the second cell.

[0157] Example 8. The method of example 7, wherein: the first cell and the second cell are associated with a same satellite.

[0158] Example 9. The method of example 7, wherein: the first cell and the second cell are associated with different respective satellites.

[0159] Example 10. The method of any of the preceding examples, wherein: the cell operates using a low-power wide area network (LPWA) technology.

[0160] Example 11. The method of example 10, wherein the cell is a narrowband (NB) Internet-of-Things (loT) cell.

[0161] Example 12. The method of example 10, wherein the cell is an enhanced Machine Type Communication (eMTC) cell.

[0162] Example 13. The method of example 10, wherein the cell is a 5G new radio (NR) cell.

[0163] Example 14. The method of example 7, wherein the second cell is one of an NB-IoT cell or an eMTC cell.

[0164] Example 15. The method of any of the preceding examples, wherein: the first segment of the PWS message is received via a broadcast channel of the cell.

[0165] Example 16. The method of example 15, wherein the broadcast channel is a broadcast control channel (BCCH).PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0166] Example 17. The method of example 5 or 16, further comprising: receiving, in the cell, a system information block (SIB), wherein the first segment of the PWS message is scheduled according to the SIB.

[0167] Example 18. The method of example 17, wherein the SIB is one of SIB1 or SIB19.

[0168] Example 19. The method of example 15, wherein: the first segment of the PWS message is one of a plurality of segments received in the cell prior to the leaving the cell; and wherein each of the plurality of segments is received in a respective SIB transmission.

[0169] Example 20. The method example 19, wherein: each SIB transmission is one of a SIB7, SIB8, or SIBI L

[0170] Example 21. The method example 19, wherein: each SIB transmission is from a SIB dedicated to Commercial Mobile Alert Service (CMAS).

[0171] Example 22. The method of example 1, wherein: the second segment of the PWS message is received via a broadcast channel of the cell.

[0172] Example 23. The method of example 7, wherein: the first segment of the PWS message is received via a broadcast channel of the first cell; and the second segment of the PWS message is received via a broadcast channel of the second cell.

[0173] Example 24. The method of example 1, wherein: the first segment of the PWS message is received via a broadcast channel of the cell; and the second segment of the PWS message is received via a downlink (DL) dedicated message.

[0174] Example 25. The method of example 23, wherein the DL dedicated message is received via an RRC connection.

[0175] Example 26. The method of example 23 or 24, further comprising: transmitting, to the NTN, a request for a remainder of the PWS message, wherein the DL dedicated message is received in response to the request.

[0176] Example 27. The method of example 26, wherein the request for the remainder of the PWS message includes an indication that the first segment of the PMS is already received.

[0177] Example 28. The method of any of examples 23-26, wherein the second segment of the PWS message is received via the DL dedicated message when the UE does not supportPATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC concurrent reception of broadcast data and reception of communication over a dedicated radio connection.

[0178] Example 29. The method of example 7 wherein: the retaining of the first segment of the PWS message is further in response to determining that the first cell and the second cell support a same radio access technology (RAT).

[0179] Example 30. The method of example 7 wherein: the retaining of the first segment of the PWS message is further in response to determining that the first cell and the second cell belong to a same tracking area.

[0180] Example 31. The method of example 7, wherein: the retaining of the first segment of the PWS message is further in response to determining that the first cell and the second cell belong to a same tracking area and are associated with a same RAT.

[0181] Example 32. The method of any of examples 1-5, wherein: the retaining of the first segment of the PWS message is further in response to determining that the cell operates using an NB-IoT RAT.

[0182] Example 33. The method of any of examples 1-5, wherein: the retaining of the first segment of the PWS message is further in response to determining that the cell operates using an eMTC RAT.

[0183] Example 34. The method of example 7, wherein: the retaining of the first segment of the PWS message is further in response to determining that the second cell indicates support assembly of the PWS messages from segments received in different cells.

[0184] Example 35. The method of example 7, wherein: the retaining of the first segment of the PWS message is further in response to determining that the second cell indicates same segmentation of the PWS message as the first cell.

[0185] Example 36. The method of any of the preceding examples, further comprising: assembling the PWS message using the first segment of the PWS message and the second segment of the PWS message.PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0186] Example 37. The method of example 36, further comprising: determining, using a field in the PWS message, whether the PWS message is a Tsunami Warning System (ETWS) message or a Commercial Mobile Alert Service (CMAS) message.

[0187] Example 38. A method for receiving a public warning service (PWS) message, the method implemented in a user equipment (UE) and comprising: receiving, in a first cell of a radio access network (RAN), a first segment of the PWS message; after leaving the cell (e.g., detecting a change in registration in the first cell, detecting a change in connection in the first cell), selecting a second cell, wherein at least one of the first cell or the second cell is a nonterrestrial network (NTN) cell that operates using a low-power wide area network (LPWA) technology; in response to the selecting, discarding the first segment of the PWS message.

[0188] Example 39. The method of example 38, wherein the NTN cell is a narrowband (NB) Internet-of-Things (loT) NTN cell.

[0189] Example 40. The method of example 38, wherein the NTN cell is an enhanced Machine Type Communication (eMTC) NTN cell.

[0190] Example 41. The method of any of examples 38-40, further comprising: receiving, in the first cell, the first segment of the PWS message and the second segment of the PWS message.

[0191] Example 42. The method of example 41, wherein: the first segment of the PWS message and the second segment of the PWS message are received via a broadcast channel of the second cell.

[0192] Example 43. The method of example 41, wherein: the first segment of the PWS message and the second segment of the PWS message are received via a downlink (DL) dedicated message.

[0193] Example 44. The method of example 43, further comprising: transmitting, in the second cell, a request for the PWS message, wherein the DL dedicated message is responsive to the request for the PWS message.

[0194] Example 45. The method of any of examples 38-44, wherein: the first segment of the PWS message is received via a broadcast channel of the first cell.PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC

[0195] Example 46. The method of example 38-45, wherein the discarding the first segment of the PWS is further in response to: determining that the second cell is a terrestrial network (TN) cell, wherein the first cell is an NTN cell.

[0196] Example 47. The method of any of examples 38-45, wherein the discarding the first segment of the PWS is further in response to: determining that the first cell and the second cell operate according to different radio access technologies (RATs).

[0197] Example 48. The method of any of examples 38-45, wherein the discarding the first segment of the PWS is further in response to: determining that the first cell and the second cell belong to different tracking areas.

[0198] Example 49. The method of any of examples 38-45, wherein the discarding the first segment of the PWS is further in response to: determining that the second cell is not an NB-IoT NTN cell.

[0199] Example 50. The method of any of examples 38-45, wherein the discarding the first segment of the PWS is further in response to: determining that the second cell is not an eMTC NTN cell.

[0200] Example 51. The method of any of examples 38-45, wherein the discarding the first segment of the PWS is further in response to: determining that the second cell does not indicate support of assembly of the PWS messages from segments received in different cells..

[0201] Example 52. A method for transmitting a public warning service (PWS) message, the method implemented in a radio access network (RAN) and comprising: receiving, from a network node, a public warning service (PWS) message; transmitting a first segment of the PWS message via a first cell, and transmitting a second segment of the PWS message via a second cell, wherein at least one of the first cell and the second cell is a non-terrestrial network (NTN) cell that operates using a low-power wide area network (LPWA) technology.

[0202] Example 53. An apparatus comprising: processing hardware; and a transceiver; the apparatus configured to implement a method of any of the preceding examples.

[0203] Generally speaking, description for one of the above figures can apply to another of the above figures. Examples, implementations and methods described above can be combined, if there is no conflict. An event or block described above can be optional or omitted. For example,PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC an event or block with dashed lines in the figures can be optional. In some implementations, “message” is used and can be replaced by “information element (IE)”, and vice versa. In some implementations, “IE” is used and can be replaced by “field”, and vice versa. In some implementations, “configuration” can be replaced by “configurations” or “configuration parameters”, and vice versa. In some implementations, “satellite information” can be replaced by “satellite assistance information”. In some implementations, “satellite” can be replaced by “NTN” or “NTN cell” or vice versa.

[0204] A user device in which the techniques of this disclosure can be implemented (e.g., the UE 102) can be any suitable device capable of wireless communications such as a smartphone, a tablet computer, a laptop computer, a mobile gaming console, a point-of-sale (POS) terminal, a health monitoring device, a drone, a camera, a media-streaming dongle or another personal media device, a wearable device such as a smartwatch, a wireless hotspot, a femtocell, or a broadband router. Further, the user device in some cases may be embedded in an electronic system such as the head unit of a vehicle or an advanced driver assistance system (ADAS). Still further, the user device can operate as an internet-of-things (loT) device or a mobile-internet device (MID). Depending on the type, the user device can include one or more general-purpose processors, a computer-readable memory, a user interface, one or more network interfaces, one or more sensors, etc.

[0205] Certain embodiments are described in this disclosure as including logic or a number of components or modules. Modules may can be software modules (e.g., code, or machine- readable instructions stored on non-transitory machine-readable medium) or hardware modules. A hardware module is a tangible unit capable of performing certain operations and may be configured or arranged in a certain manner. A hardware module can comprise dedicated circuitry or logic that is permanently configured (e.g., as a special-purpose processor, such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC), a digital signal processor (DSP), etc.) to perform certain operations. A hardware module may also comprise programmable logic or circuitry (e.g., as encompassed within a general-purpose processor or other programmable processor) that is temporarily configured by software to perform certain operations. The decision to implement a hardware module in dedicated andPATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC permanently configured circuitry, or in temporarily configured circuitry (c.g., configured by software) may be driven by cost and time considerations.

[0206] When implemented in software, the techniques can be provided as part of the operating system, a library used by multiple applications, a particular software application, etc. The software can be executed by one or more general-purpose processors or one or more specialpurpose processors.

Claims

PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PCWhat is claimed is:

1. A method for receiving a public warning service (PWS) message, the method implemented in a user equipment (UE) and comprising: receiving, in a cell of a non-terrestrial network (NTN), a first segment of the PWS message; after leaving the cell, and prior to receiving a second segment of the PWS, retaining the first segment of the PWS message; and receiving, from the NTN subsequently to the retaining, a second segment of the PWS message.

2. The method of claim 1, wherein the leaving the cell includes at least one of: detecting that the UE is out of coverage of the cell, or detecting a change in registration in the cell.

3. The method of any of the preceding claims, further comprising: after the leaving the cell, selecting the cell again; wherein the second segment of the PWS message is received in the cell.

4. The method of any of claims 1-3, wherein: the cell is a first cell; the method further comprising: after the leaving the first cell, selecting a second cell of the NTN; and wherein the second segment of the PWS message is received in the second cell.

5. The method of claim 4, wherein: the retaining of the first segment of the PWS message is in response to determining that the first cell and the second cell support a same radio access technology (RAT).

6. The method of claim 4, wherein: the retaining of the first segment of the PWS message is further in response to determining that the first cell and the second cell belong to a same tracking area.PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC7. The method of claim 4, wherein: the first cell and the second cell are associated with different respective satellites.

8. The method of claim 4, wherein: the retaining of the first segment of the PWS message is in response to determining that the second cell indicates support assembly of the PWS messages from segments received in different cell.

9. The method of claim 4, wherein: the retaining of the first segment of the PWS message is in response to determining that the second cell indicates same segmentation of the PWS message as the first cell.

10. The method of any of claims 1-3, wherein at least one of the first segment of the PWS message and the second segment of the PWS message is received via a broadcast channel of the cell.

11. The method of any of claims 1-3, wherein: the first segment of the PWS message is received on a broadcast channel of the cell of the NTN; and the second segment of the PWS message is received via a downlink (DL) dedicated message.

12. The method of claim 11, further comprising: transmitting, to the NTN, a request for a remainder of the PWS message, wherein the DL dedicated message is received in response to the request.

13. The method of claim 12, wherein the request for a remainder of the PWS message includes an indication that the first segment of the PMS is already received.

14. The method of any of claims 1-3, wherein:PATENT APPLICATIONAttorney Docket No.: 31730 / 308598-00 / PC the retaining of the first segment of the PWS message is in response to determining that the cell operates using an NB-IoT RAT.

15. A user equipment (UE) comprising: processing hardware; and a transceiver; the UE configured to implement a method of any of the preceding claims.

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