Wireless Network Selection in International Areas

Abstract

A method of wireless communication by a user equipment (UE) includes determining whether the UE has transitioned between an international area and a national area. The method also includes triggering a public land mobile network (PLMN) selection of a network for receiving services in response to the UE having transitioned between the international area and the national area. The method of wireless communication by the UE includes performing a PLMN search for higher priority PLMNs. The method includes determining a list of candidate PLMNs based on the search. The method further includes selecting a PLMN from the list of candidate PLMNs in response to an identity of the serving PLMN not being a shared operating region code (MCC). The candidate PLMN has either the same MCC as the identity of the serving PLMN or a shared MCC. The selected PLMN has a higher priority than the serving PLMN.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 273,877, entitled "WIRELESS NETWORK SELECTION IN INTERNATIONAL AREAS," filed on October 29, 2021, which claims the benefit of U.S. Provisional Patent Application No. 17 / 582,696, entitled "WIRELESS NETWORK SELECTION IN INTERNATIONAL AREAS," filed on January 24, 2022, the disclosures of which are expressly incorporated by reference in their entireties herein.

[0002] Aspects of the present disclosure relate generally to wireless communications, and more particularly, to techniques and apparatus for network selection for satellite access in international areas. [Background technology]

[0003] Wireless communication systems have been widely deployed to provide various telecommunication services, such as telephony, video, data, messaging, and broadcast. A typical wireless communication system may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access technologies include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems, and Long Term Evolution (LTE). LTE / LTE-Advanced is a set of extensions to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the 3rd Generation Partnership Project (3GPP (registered trademark, same below)).

[0004] A wireless communication network may include a number of base stations (BSs) capable of supporting communication for a number of user equipments (UEs). The user equipments (UEs) may communicate with the base stations (BSs) via downlinks and uplinks. The downlink (or forward link) refers to the communication link from the BS to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the BS. As described in more detail, a BS may be referred to as a Node B, gNB, access point (AP), radio head, transmit / receive point (TRP), new radio (NR) BS, 5G Node B, etc.

[0005] The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that allows various user equipment to communicate at city, national, regional, or even global levels. New Radio (NR), sometimes referred to as 5G, is a set of extensions to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP). NR is designed to improve spectral efficiency, lower costs, improve services, utilize new spectrum, and better support mobile broadband Internet access by using Orthogonal Frequency Division Multiplexing (OFDM) with Cyclic Prefix (CP) (CP-OFDM) on the downlink (DL) and CP-OFDM and / or SC-FDM (e.g., also known as Discrete Fourier Transform Spread OFDM (DFT-s-OFDM)) on the uplink (UL), better integrating with other open standards, and supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. Summary of the Invention [Means for solving the problem]

[0006] In some aspects of the disclosure, a method of wireless communication by a user equipment (UE) includes determining whether the UE has transitioned between an international area and a domestic area, and further including triggering a public land mobile network (PLMN) selection of a network for receiving services in response to the UE having transitioned between the international area and the domestic area.

[0007] In another aspect of the disclosure, a method of wireless communication by a user equipment (UE) includes performing a PLMN search for a higher priority public land mobile network (PLMN). The method also includes determining a list of candidate PLMNs based on the search. The method further includes, in response to an identity of the serving PLMN not being a shared operational geographical code (MCC), selecting a PLMN from among the list of candidate PLMNs, the candidate PLMN having either the same MCC as the identity of the serving PLMN or a shared MCC. The selected PLMN has a higher priority than the serving PLMN.

[0008] Another aspect of the disclosure is directed to an apparatus for wireless communication by a user equipment (UE), the apparatus having a memory and one or more processors coupled to the memory. The processor is configured to determine whether the UE has transitioned between an international area and a domestic area. The processor is further configured to trigger a public land mobile network (PLMN) selection of a network for receiving services in response to the UE having transitioned between the international area and the domestic area.

[0009] Another aspect of the disclosure is directed to an apparatus for wireless communication by a user equipment (UE), having a memory and one or more processors coupled to the memory. The processor is configured to perform a PLMN search for a higher priority public land mobile network (PLMN). The processor is also configured to determine a list of candidate PLMNs based on the search. The processor is further configured to select a PLMN from among the list of candidate PLMNs in response to an identity of the serving PLMN not being a shared operating geographical code (MCC), the candidate PLMN having either the same MCC as the identity of the serving PLMN or a shared MCC. The selected PLMN has a higher priority than the serving PLMN.

[0010] Aspects generally include methods, apparatus, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, wireless communication devices, and processing systems, substantially as described with reference to and as illustrated by the accompanying drawings and this specification.

[0011] The foregoing has outlined rather broadly the features and technical advantages of the embodiments according to the present disclosure in order that the following Detailed Description may be better understood. Additional features and advantages are described. The concepts and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions are within the scope of the appended claims. The properties of the disclosed concepts, both their organization and method of operation, together with associated advantages, will be better understood in consideration of the following description in conjunction with the accompanying figures. Each of the figures is provided for the purpose of illustration and description, and not as a definition of the limits of the claims.

[0012] So that the features of the present disclosure can be understood in detail, a particular description may be made by reference to the embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings only illustrate certain embodiments of the present disclosure and therefore should not be considered as limiting the scope of the present disclosure, since the description may admit of other equally effective embodiments. The same reference numbers in different drawings may identify the same or similar elements. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a block diagram conceptually illustrating one embodiment of a wireless communication network, in accordance with various aspects of the present disclosure. [Diagram 2] FIG. 1 is a block diagram conceptually illustrating an example of a base station communicating with a user equipment (UE) in a wireless communication network, in accordance with various aspects of the present disclosure. [Diagram 3] FIG. 1 illustrates a deployment scenario for a non-terrestrial based network (NTN) in accordance with aspects of the present disclosure. [Figure 4] FIG. 1 illustrates a deployment scenario for a non-terrestrial based network (NTN) in accordance with aspects of the present disclosure. [Diagram 5] FIG. 1 illustrates another deployment scenario for a non-terrestrial based network (NTN) in accordance with aspects of the present disclosure. [Figure 6] FIG. 1 is a flow diagram illustrating public land mobile network (PLMN) selection when the UE is located in the international area, according to aspects of the present disclosure. [Figure 7] FIG. 1 is a flow diagram illustrating public land mobile network (PLMN) selection when a UE is served by a PLMN with a shared PLMN ID, according to aspects of the disclosure. [Figure 8] 1 is a flow diagram illustrating an example process performed, for example, by a user equipment (UE), in accordance with various aspects of the present disclosure. [Figure 9] 1 is a flow diagram illustrating another example process performed, for example, by a user equipment (UE), in accordance with various aspects of the present disclosure. [Figure 10] 1 is a flow diagram illustrating another example process performed, for example, by a user equipment (UE), in accordance with various aspects of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Various aspects of the present disclosure are described more fully below with reference to the accompanying drawings. However, the present disclosure may be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout the present disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on these teachings, those skilled in the art should understand that the scope of the present disclosure is intended to encompass all aspects of the present disclosure, whether implemented independently of or in combination with any other aspects of the present disclosure. For example, an apparatus can be implemented or a method can be practiced using any number of the aspects described. Furthermore, the scope of the present disclosure is intended to encompass such an apparatus or method that is practiced using other structures, functions, or structures and functions in addition to or other than the various aspects of the present disclosure described. It should be understood that any aspect of the present disclosure disclosed can be embodied by one or more elements of a claim.

[0015] Several aspects of a telecommunications system are now presented with reference to various devices and techniques, which are described in the Detailed Description below and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using hardware, software, or a combination thereof. Whether such elements are implemented as hardware or software depends on the particular application and design constraints imposed on the overall system.

[0016] Although aspects may be described using terminology commonly associated with 5G and beyond wireless technologies, it should be noted that aspects of the disclosure may also be applied in other generation-based communication systems, such as and including 3G and / or 4G technologies.

[0017] Aspects of the present disclosure provide techniques for performing public land mobile network (PLMN) selection for non-terrestrial based network (NTN) access, for example, via satellite. As described, the satellite coverage area may span multiple countries and international areas. The international areas include areas outside any jurisdiction of a country and may also be referred to as extraterritorial areas.

[0018] In general, a legacy PLMN selection procedure is a procedure that a user equipment (UE) uses to select a network to camp on and receive services. Aspects of the present disclosure address scenarios that the legacy procedure does not cover, such as when the UE is physically located in an international area, or when the UE is served by a PLMN with a shared PLMN identity (ID), or when radio cells are deployed to cover a geographic area located in the international area. The described techniques can be deployed, for example, by a UE, to perform PLMN selection for NTN (e.g., satellite) access. In some cases, the NTN access can be considered a separate radio access technology (RAT) from the terrestrial-based access.

[0019] According to aspects of the present disclosure for a UE located in an international area, when the UE returns to coverage, the UE can apply a first option, which includes triggering a PLMN selection when leaving or entering the international area. In a second option, the UE can also consider the Home Public Land Mobile Network (HPLMN) list or the Equivalent Home Public Land Mobile Network (EHPLMN) list as the highest priority instead of the most recently registered PLMN. This can be done in addition to or instead of the first option. Additionally or alternatively, the UE can implement a third option, which uses a separate international PLMN selector list or relies on an indication of whether the PLMN is intended for international access or not, i.e., when coverage from the PLMN extends into the international area. Additionally or alternatively, in a fourth option, the UE can delete the Equivalent PLMN list. If a periodic search for High Priority PLMNs (HP-PLMNs) is performed while the UE is roaming, the UE may apply a fifth option in which the UE does not limit the search based on the Operating Region Code (MCC).

[0020] If the UE is served by a PLMN with a shared PLMN ID (e.g., with a MCC starting with 9, such as 9xx), the UE may be in or outside the international area. In either case, it would be beneficial to have an improved PLMN selection procedure. According to aspects of the present disclosure, if the UE is served by a PLMN with a shared PLMN ID, during a PLMN search for a high-priority public land mobile network (HP-PLMN), the UE does not exclude candidate PLMNs with a different MCC than the serving PLMN. This applies to both international and national, e.g., national, PLMN selection. Additionally or alternatively, the UE may implement a third option that uses a separate international PLMN selector list or relies on an indication of whether the PLMN is intended for international access.

[0021] FIG. 1 illustrates a network 100 in which aspects of the disclosure may be practiced. The network 100 may be a 5G or NR network, or some other wireless network, such as an LTE network. The wireless network 100 may include a number of BSs 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with user equipment (UE) and may also be referred to as a base station, NR BS, Node B, gNB, 5G Node B (NB), access point, transmit / receive point (TRP), etc. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" may refer to a coverage area of ​​a BS and / or a BS subsystem serving this coverage area, depending on the context in which the term is used.

[0022] A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and / or another type of cell. A macro cell may cover a relatively large geographic area (e.g., a few kilometers in radius) and may allow unrestricted access by UEs with a service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with a service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs that have an association with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG)). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. 1, BS 110a may be a macro BS for macro cell 102a, BS 110b may be a pico BS for pico cell 102b, and BS 110c may be a femto BS for femto cell 102c. A BS may support one or multiple (e.g., three) cells. The terms "eNB," "base station," "NR BS," "gNB," "TRP," "AP," "Node B," "5G NB," and "cell" may be used interchangeably.

[0023] In some aspects, the cells may not necessarily be stationary and the geographic area of ​​the cells may move according to the location of the mobile BS. In some aspects, the BSs may be interconnected to each other and / or to one or more other BSs or network nodes (not shown) within the wireless network 100 through various types of backhaul interfaces, such as direct physical connections, virtual networks, etc., using any suitable transport network.

[0024] Wireless network 100 may also include relay stations. A relay station is an entity capable of receiving a data transmission from an upstream station (e.g., a BS or a UE) and transmitting the data transmission to a downstream station (e.g., a UE or a BS). A relay station may also be a UE capable of relaying a transmission for another UE. In the embodiment shown in FIG. 1, relay station 110d may communicate with macro BS 110a and UE 120d to facilitate communication between BS 110a and UE 120d. A relay station may also be referred to as a relay BS, a relay base station, a repeater, etc.

[0025] Wireless network 100 may be a heterogeneous network including different types of BSs, e.g., macro BSs, pico BSs, femto BSs, relay BSs, etc. These different types of BSs may have different transmit power levels, different coverage areas, and different susceptibility to interference within wireless network 100. For example, macro BSs may have high transmit power levels (e.g., 5-40 watts), while pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1-2 watts).

[0026] As an example, BSs 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and core network 130 may exchange communications via backhaul links 132 (e.g., S1, etc.). Base stations 110 may communicate with each other via other backhaul links (e.g., X2, etc.), either directly or indirectly (e.g., through core network 130).

[0027] The core network 130 may be an evolved packet core (EPC) that may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME may be a control node that handles signaling between the UE 120 and the EPC. All user IP packets may be forwarded through the S-GW, which itself may be connected to a P-GW. The P-GW may provide IP address allocation as well as other functions. The P-GW may be connected to a network operator's IP services. The operator's IP services may include the Internet, intranet, IP multimedia subsystem (IMS), and packet switched (PS) streaming services.

[0028] The core network 130 may provide user authentication, access authorization, tracking, IP connectivity, and other access, routing, or mobility functions. One or more of the base stations 110 or access node controllers (ANCs) may interface with the core network 130 through backhaul links 132 (e.g., S1, S2, etc.) and may perform radio configuration and scheduling for communication with the UEs 120. In some configurations, various functions of each access network entity or base station 110 may be distributed across various network devices (e.g., radio heads and access network controllers) or may be integrated within a single network device (e.g., base station 110).

[0029] The UEs 120 (e.g., 120a, 120b, 120c) may be dispersed throughout the wireless network 100, and each UE may be fixed or mobile. A UE may also be referred to as an access terminal, terminal, mobile station, subscriber unit, station, etc. A UE may be a cellular telephone (e.g., a smartphone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, a biometric sensor / device, a wearable device (smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., music or video device, or satellite radio), a vehicle component or sensor, a smart meter / sensor, industrial manufacturing equipment, a global positioning system device, or any other suitable device configured to communicate over a wireless or wired medium.

[0030] One or more UEs 120 may establish a protocol data unit (PDU) session for the network slice. In some cases, the UE 120 may select a network slice based on an application or subscription service. By having different network slices serving different applications or subscriptions, the UE 120 may improve its resource utilization within the wireless network 100 while also meeting the performance specifications of the UE 120's individual applications. In some cases, the network slice used by the UE 120 may be served by an AMF (not shown in FIG. 1 ) associated with one or both of the base station 110 or the core network 130. Furthermore, session management of the network slice may be performed by an access and mobility management function (AMF).

[0031] The UE 120 may include a PLMN selection module 140. For simplicity, only one UE 120d is shown as including a PLMN selection module 140. The PLMN selection module 140 may determine whether the UE has transitioned between an international area and a national area. The PLMN selection module 140 may also trigger a public land mobile network (PLMN) selection in response to the UE having transitioned between an international area and a national area. The PLMN selection module 140 may perform a PLMN search for a higher priority public land mobile network (PLMN). The PLMN selection module 140 may also determine a list of candidate PLMNs based on the search. The PLMN selection module 140 may select a PLMN from the list of candidate PLMNs in response to the serving PLMN's identity not being a shared operating geographic code (MCC).

[0032] Some UEs may be considered as machine type communication (MTC) UEs or evolved or enhanced machine type communication (eMTC) UEs. MTC UEs and eMTC UEs may include, for example, a robot, a drone, a remote device, a sensor, a meter, a monitor, a location tag, etc., capable of communicating with a base station, another device (e.g., a remote device), or some other entity. A wireless node may provide connectivity to or to a network (e.g., a wide area network such as the Internet, or a cellular network), for example, via a wired or wireless communication link. Some UEs may be considered as Internet of Things (IoT) devices and / or may be implemented as NB-IoT (narrowband Internet of Things) devices. Some UEs may be considered as customer premises equipment (CPE). The UE 120 may be included within a housing that houses components of the UE 120, such as a processor component, a memory component, etc.

[0033] In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular radio access technology (RAT) and may operate on one or more frequencies. The RAT may also be referred to as a radio technology, an air interface, etc. The frequencies may also be referred to as a carrier, a frequency channel, etc. To avoid interference between wireless networks of different RATs, each frequency may support a single RAT in a given geographic area. In some cases, NR networks or 5G RAT networks may be deployed.

[0034] In some aspects, two or more UEs 120 (e.g., those shown as UE 120a and UE 120e) may communicate directly (e.g., without using base station 110 as an intermediary to communicate with each other) using one or more sidelink channels. For example, UEs 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (e.g., which may include vehicle-to-vehicle (V2V) protocols, vehicle-to-infrastructure (V2I) protocols, etc.), mesh networks, etc. In this case, UEs 120 may perform scheduling operations, resource selection operations, and / or other operations described elsewhere as being performed by base station 110. For example, base station 110 may configure UE 120 via downlink control information (DCI), radio resource control (RRC) signaling, medium access control-control element (MAC-CE), or via system information (e.g., system information block (SIB)).

[0035] As noted above, Figure 1 is provided as one example only, and other examples may differ from those described with respect to Figure 1.

[0036] 2 shows a block diagram of a design 200 of a base station 110 and a UE 120, which may be one of the base stations and one of the UEs in FIG. 1. Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general T≧1 and R≧1.

[0037] At the base station 110, the transmit processor 220 may receive data from a data source 212 for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based at least in part on a channel quality indicator (CQI) received from that UE, process (e.g., code and modulate) the data for each UE based at least in part on the MCS selected for that UE, and provide data symbols for all UEs. Reducing the MCS reduces throughput but improves reliability of transmission. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI), etc.) and control information (e.g., CQI requests, grants, higher layer signaling, etc.) and provide overhead and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signal (PSS) or secondary synchronization signal (SSS)). A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​the data symbols, control symbols, overhead symbols, and / or reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 may process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively. According to various aspects described in more detail below, positional coding may be used to generate a synchronization signal to convey additional information.

[0038] At the UE 120, antennas 252a-252r may receive downlink signals from the base station 110 and / or other base stations and may provide received signals to demodulators (DEMODs) 254a-254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254a-254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols and provide decoded data for the UE 120 to a data sink 260 and may provide decoded control and system information to a controller / processor 280. The channel processor may determine a reference signal received power (RSRP), a received signal strength indicator (RSSI), a reference signal received quality (RSRQ), a channel quality indicator (CQI), etc. In some aspects, one or more components of the UE 120 may be included within a housing.

[0039] On the uplink, at the UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.) from the controller / processor 280. The transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266, if applicable, further processed by modulators 254a-254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to the base station 110. At the base station 110, uplink signals from the UE 120 and other UEs may be received by antennas 234, processed by demodulator 254, detected by a MIMO detector 236, if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by the UE 120. The receive processor 238 may provide the decoded data to a data sink 239 and may provide the decoded control information to the controller / processor 240. The base station 110 may include a communication unit 244 and may communicate with the core network 130 via the communication unit 244. The core network 130 may include a communication unit 294, a controller / processor 290, and a memory 292.

[0040] The controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or any other components of FIG. 2 may perform one or more techniques associated with PLMN selection, as described in more detail elsewhere. For example, the controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or any other components of FIG. 2 may perform or direct operations of, for example, the processes of FIGS. 6-10 and / or other processes as described. The memories 242 and 282 may store data and program codes for the base station 110 and the UE 120, respectively. The scheduler 246 may schedule the UE for data transmission on the downlink and / or uplink.

[0041] In some aspects, the UE 120 may include means for determining, means for switching, means for selecting, means for triggering, means for prioritizing, means for removing, means for acquiring, and / or means for receiving. Such means may include one or more components of the UE 120 described in connection with FIG.

[0042] As noted above, Figure 2 is provided as one example only, and other examples may differ from those described with respect to Figure 2.

[0043] Aspects of the present disclosure provide techniques for performing PLMN selection for non-terrestrial based network (NTN) access, e.g., via satellite. As described, the coverage area of ​​a satellite may span multiple countries and international areas. International areas include areas outside any jurisdiction of a country and may also be referred to as extraterritorial areas.

[0044] In general, a legacy PLMN selection procedure is a procedure that a UE uses to select a network to camp on and receive services (e.g., as specified in 3GPP TS 23.122). Aspects of the present disclosure address scenarios that the legacy procedure does not cover, such as when the UE is physically located in the international area or when the UE is served by a PLMN that has a shared PLMN identity (ID). A shared PLMN ID has a three-digit operating region code (MCC) starting with 9, e.g., 9xx, where x can be any number. A shared PLMN ID may also be referred to as a global PLMN ID.

[0045] According to aspects of the present disclosure, a new branch of the PLMN selection procedure is introduced. The UE first determines whether it is located in the international area. If it is, the UE follows the new PLMN selection procedure. If it is not, the UE follows the legacy PLMN selection procedure.

[0046] The legacy PLMN selection procedure can be triggered in one of two ways. The first way is that the UE recovers from a loss of coverage, such as when it powers up or loses and reacquires service. In this scenario, the PLMNs will be selected in a particular order. The UE first attempts to select the last registered PLMN, if available. If that PLMN is not available, the UE proceeds to select an ordered list of PLMNs in the following order: i) Either the Home PLMN (HPLMN) (if the Equivalent HPLMN (EHPLMN) list does not exist or is empty), or the highest priority EHPLMN that is available (if an EHPLMN list exists); ii) each PLMN and / or Radio Access Technology (RAT) combination in a “User Controlled PLMN Selector with Access Technology” data file in the Subscriber Identity Module (SIM) (e.g., in order of priority); iii) each PLMN and / or radio access technology combination in an “Operator Controlled PLMN Selector with Access Technology” data file stored in the SIM (e.g., in order of priority) or in the UE (e.g., in order of priority); iv) other PLMNs and / or radio access technologies with better received signal quality (e.g., in a random order); or v) Other PLMNs and / or radio access technologies in order of decreasing signal quality.

[0047] Another legacy PLMN selection procedure triggers periodically when the UE is currently served by a PLMN, such as when the UE is roaming. That is, a roaming UE periodically searches for higher priority PLMNs and reselects (e.g., following the same prioritization as for PLMN selection upon return from coverage loss) to a higher priority PLMN in the same country as the (current) serving PLMN. In some cases, the UE may also consider PLMNs in a list of equivalent PLMNs provided by the serving PLMN (e.g., using Non-Access Stratum (NAS) protocol signaling during the registration procedure).

[0048] In some cases, it may be beneficial to modify the legacy PLMN selection procedure to accommodate UEs in international areas or UEs served by PLMNs with shared PLMN IDs, such as non-terrestrial based network (NTN) access networks. Various deployments of NTNs, including satellite networks, are described with respect to Figures 3, 4, and 5.

[0049] 3 and 4 are diagrams illustrating deployment scenarios of a non-terrestrial network (NTN) according to aspects of the present disclosure. FIG. 3 illustrates a deployment where the NTN cell coverage covers one country (e.g., Country A) and its contiguous waters. Typically, the contiguous waters extend up to 200 miles from the coast of a given country. This is referred to as leakage into international waters. There are various scenarios for broadcasting the PLMN ID in this deployment. In a first scenario, the broadcast PLMN ID has the Operational Region Code (MCC) of Country A. In another scenario, the PLMN ID includes the MCC of Country A and a shared MCC reserved for international waters.

[0050] Figure 4 shows a deployment where the NTN cell coverage is only for international waters. In this deployment, there is leakage into the contiguous waters of country A. The PLMN ID can be broadcast according to different scenarios. In the first scenario, the operator's home MCC is included in the PLMN ID. In the second scenario, a shared MCC is included. In the third scenario, the operator's home MCC and a shared MCC reserved for international waters are included.

[0051] FIG. 5 illustrates another deployment scenario of a non-terrestrial based network (NTN) according to aspects of the present disclosure. FIG. 5 illustrates a legacy satellite-based deployment scenario for a vessel (e.g., vessel 502) and an airplane (not shown) deployment via satellite 506. In this case, the satellite link is used only as a backhaul. Furthermore, 3GPP access can be provided by an on-board radio access network (RAN) 504. This deployment would be applicable in international waters and / or international airspace (e.g., in the case of an airplane instead of a vessel 502). Furthermore, this deployment may experience little or no issues with cross-border leakage or issues with the use of PLMN IDs.

[0052] Considering the various problems presented in the above developments, it may be advantageous for the UE to perform a modified version of the PLMN selection procedure to access networks such as NTNs when the UE is served from within the international area or by a PLMN with a shared PLMN ID. As described, the UE may generate a list of available PLMNs that are allowed to be selected when the UE is served from within the international area or by a PLMN with a shared PLMN ID, and perform PLMN selection based on the new list. Other solutions are also described, such as triggering PLMN selection when transitioning between the international area and the national area.

[0053] The described techniques can be deployed, for example, by a UE, to perform PLMN selection for NTN (e.g., satellite) access. In some cases, the NTN access can be considered a separate radio access technology (RAT) from the terrestrial-based access. The NTN access may use a separate frequency band compared to the terrestrial-based access.

[0054] Furthermore, a UE performing PLMN selection for non-terrestrial (satellite) access can be assumed to be configured with a "User Controlled PLMN Selector with Access Technology" and / or "Operator Controlled PLMN Selector with Access Technology" file in the Universal SIM (USIM), each of which may contain a prioritized (e.g., ordered) list of PLMNs with the corresponding supported RATs.

[0055] In general, the PLMN selection procedure can be performed at the NAS protocol layer. As mentioned above, each PLMN can broadcast its own identity (e.g., PLMN ID) in the system information, including the MCC that uniquely defines the country of that PLMN. Therefore, the lower layer (e.g., Access Stratum (AS)) can scan available networks and provide a list of available PLMNs to the NAS layer along with the RAT. PLMN IDs with shared MCC (e.g., 9xx) are not associated with any country. These PLMN IDs are used for the international area, but not exclusively.

[0056] During a legacy periodic PLMN search for a high priority PLMN (HP-PLMN), the UE excludes candidate PLMNs that have a different MCC than the serving PLMN. The rationale is to limit the search to the same country. This should not be done if the UE knows that it is located in the international area. According to aspects of the present disclosure, during a PLMN search for a HP-PLMN, the UE does not limit its search to the same MCC as the serving PLMN. For example, if the identity of the serving PLMN is not a shared MCC, the UE selects from among the candidate PLMNs that have either the same MCC as the identity of the serving PLMN or a shared MCC. The selected PLMN has a higher priority than the serving PLMN. If the identity of the serving PLMN is a shared MCC, the UE selects a PLMN from among the candidate PLMNs that have either the shared MCC or the MCC corresponding to the country in which the UE is currently geographically located.

[0057] During the legacy periodic PLMN search for a high priority PLMN (HP-PLMN), the UE considers the equivalent PLMN list provided by the serving PLMN. This should not be done if the serving PLMN was not selected when the UE was located in the international area. For example, the UE may belong to a Canadian customer departing from the United States. In this case, the equivalent PLMN list provided by the last serving PLMN in the United States may not be valid for the Canadian customer when on international waters. According to aspects of the present disclosure, upon entering the international area, the UE deletes the equivalent PLMN list provided by the last serving PLMN before PLMN selection.

[0058] Currently, the UE always considers the last registered PLMN (RPLMN) as the highest priority for PLMN selection. This should not be the case by default when transitioning into or out of an international area. For example, the UE may belong to a Canadian customer leaving the United States. In this case, the customer may prefer Canadian PLMNs when on international waters rather than US PLMNs serving that port. According to aspects of the present disclosure, the UE does not consider the RPLMN as the highest priority PLMN when transitioning into or out of an international area. Rather, the UE considers the HPLMN list or EHPLMN list (obtained from the USIM) as the highest priority, as in the case of PLMN selection at power-on. Therefore, the UE may not select the RPLMN as the UE is transitioning into / out of an international area.

[0059] In a further aspect of the disclosure, the UE triggers PLMN selection when it finds itself in the international area. The UE also triggers PLMN selection when it moves out of the international area. These new triggers can be for PLMN selection upon recovery from loss of coverage. These new triggers can be added to the legacy triggers.

[0060] In some aspects, when moving into or out of the international area, the UE may perform PLMN selection in a manner similar to PLMN selection upon power-up or recovery from loss of coverage. For example, if the UE finds itself out of coverage of the RPLMN for a certain period of time, the UE will declare an "out of service" (OOS) condition. The UE considers itself deregistered from the RPLMN and performs PLMN selection. The UE first performs a PLMN search (also referred to as a PLMN scan) and creates a list of candidate PLMNs based on the search. According to these aspects, if the RPLMN is in the candidate list, the RPLMN is considered the highest priority PLMN candidate. If the RPLMN is not in the candidate list, the UE follows a prioritized list, for example, a list stored in the USIM.

[0061] In other aspects, when moving into or out of the international area, the UE may perform PLMN selection in a manner similar to completing a periodic search for higher priority PLMNs. For example, while registered to a serving PLMN that is not the highest priority PLMN (e.g., HPLMN or EHPLMN), the UE periodically performs a higher priority (HP) PLMN scan. The periodicity of the search is determined by the UE, and the network sets a minimum value for the periodicity (minimum periodic search timer). After each search, the UE creates a list of candidate PLMNs. According to these aspects, only PLMNs with the same MCC as the serving PLMN are kept in the candidate list, unless there is a shared MCC. The UE then selects the highest priority PLMN according to the prioritized list.

[0062] Currently, there is no scheme that specifies a different PLMN prioritization for PLMN selection when the UE is not domestic but is in the international area. According to aspects of the present disclosure, the UE has a separate PLMN selector list in the USIM designated for the international area. This separate international list may have a different priority than the legacy PLMN selector list. Alternatively, a new indication that the PLMN can be selected in the international area may be added to the legacy PLMN selector list. According to aspects of the present disclosure, for a radio cell deployed to cover a geographic area located in the international area, the broadcast channel of the radio cell of the PLMN may include an indication that the PLMN of the radio cell is intended for international access. In other aspects, the indication may be obtained from the USIM. Upon receiving the indication, the UE may consider the PLMN of the radio cell as intended for international access. These aspects may be applied, for example, to the scenario illustrated by FIG. 5. In some aspects, the new indication may be implemented as a binary flag. In other aspects, the new indication may be implemented as an MCC associated with the international area.

[0063] FIG. 6 is a flow diagram illustrating public land mobile network (PLMN) selection when the UE is located in the international area according to aspects of the disclosure. At block 610, PLMN selection begins. For example, the selection may begin based on loss of coverage (e.g., during power-up) or while roaming. At block 620, the UE determines its physical location. Based on the location, the UE determines whether the UE is located in the international area at block 630. If not, then legacy PLMN selection is made at block 640. If the UE is located in the international area, then at block 650, the logic follows a separate branch in the PLMN selection procedure and the UE initiates the international PLMN selection procedure.

[0064] For example, if the UE is out of coverage, the UE may apply a first option, which includes triggering PLMN selection when leaving or entering the international area. In a second option, the UE may also consider the HPLMN list or EHPLMN list as the highest priority instead of the most recently registered PLMN. This may be done in addition to or instead of the first option. Additionally or alternatively, the UE may implement a third option, which uses a separate international PLMN selector list or relies on an indication of whether the PLMN is for international access or not. Additionally or alternatively, in a fourth option, the UE may delete the equivalent PLMN list. If a periodic search for higher priority PLMNs is performed, the UE may apply a fifth option, in which the UE does not limit the search based on the MCC.

[0065] When a UE is served by a PLMN with a shared PLMN ID (e.g., with MCC 9xx), the UE may be in or outside the international area. In either case, it would be beneficial to have an improved PLMN selection procedure. A problem with the legacy PLMN selection procedure in this scenario is that during a periodic PLMN search for a HP-PLMN, the UE excludes candidate PLMNs with a different MCC than the serving PLMN. The rationale is to limit the search to the same country. This should not be done if the serving PLMN has a shared PLMN ID (e.g., MCC is 9xx) or if the candidate PLMN has a shared PLMN ID. According to aspects of the present disclosure, when the UE is served by a PLMN with a shared PLMN ID, during a PLMN search for a HP-PLMN, the UE does not exclude candidate PLMNs with a different MCC than the serving PLMN. The UE can select PLMNs with MCCs corresponding to the country in which the UE is located in addition to PLMNs with shared MCCs. Furthermore, if the serving PLMN identity is not a shared MCC, the UE may select a PLMN with the same MCC as the serving PLMN's MCC or may select a PLMN with a shared MCC. This applies to both international and domestic PLMN selection. Additionally or alternatively, the UE may use a separate international PLMN selector list or rely on an indication of whether a PLMN is intended for international access.

[0066] 7 is a flow diagram illustrating PLMN selection when the UE is served by a PLMN with a shared public land mobile network (PLMN) ID, according to aspects of the disclosure. At block 710, PLMN selection begins. For example, the selection may begin based on the UE being roaming. At block 720, the UE determines a physical location of the UE. Based on the location, the UE determines whether the UE is located in an international area at block 730. If not, then a PLMN selection procedure for the domestic case is performed at block 740. If the UE is located in the international area, then at block 750, the UE initiates an international PLMN selection procedure.

[0067] In both blocks 740 and 750, the UE may apply a sixth option. During a legacy periodic PLMN search for a high priority PLMN (HP-PLMN), the UE excludes candidate PLMNs that have a different MCC than the serving PLMN. According to aspects of the present disclosure, during a PLMN search for a HP-PLMN, the UE does not limit its search to the same MCC as the serving PLMN. This option applies regardless of whether the UE is in an international area. Rather, this option applies when the UE is served using a shared PLMN ID. Additionally or alternatively, the UE may implement a third option that uses a separate international PLMN selector list or relies on an indication of whether the PLMN is intended for international access.

[0068] As noted above, Figures 3-7 are provided as examples, and other embodiments may differ from those described with respect to Figures 3-7.

[0069] 8 is a flow diagram illustrating an example process 800, performed by, for example, a UE, in accordance with various aspects of the present disclosure. The example process 800 is one example of wireless network selection for satellite access in an international area.

[0070] 8, in some aspects, process 800 may include performing a PLMN search for a higher priority public land mobile network (PLMN) (block 802). For example, the UE may perform the PLMN search (e.g., using antennas 252, DEMOD / MOD 254, MIMO detector 256, TX MIMO processor 266, receive processor 258, transmit processor 264, controller / processor 280, and / or memory 282). In some aspects, performing the PLMN search is performed in response to determining that the UE is located in an international area. The PLMN may provide non-terrestrial network access.

[0071] In some aspects, process 800 may also include determining a list of candidate PLMNs based on the search (block 804). For example, the UE (e.g., using controller / processor 280 and / or memory 282) may determine the list of candidate PLMNs based on the search. In some aspects, the identity of the serving PLMN includes a shared operating region identity code (MCC). In other aspects, the identity of at least one of the candidate PLMNs includes an MCC. The shared MCC may be in the range of 900 to 999.

[0072] In some aspects, the process 800 may also include selecting a PLMN from among a list of candidate PLMNs in response to the serving PLMN's identity not being a shared MCC. The candidate PLMN has either the same MCC as the serving PLMN's identity or a shared MCC. The selected PLMN has a higher priority than the serving PLMN (block 806). At least one of the candidate PLMNs has a different MCC than the serving PLMN's identity. For example, the UE may select a PLMN (e.g., using antennas 252, DEMOD / MOD 254, MIMO detector 256, TX MIMO processor 266, receive processor 258, transmit processor 264, controller / processor 280, and / or memory 282). In some aspects, the selection of the PLMN is from a list dedicated to international area search. In other aspects, the selection of the PLMN is based on an indication that the PLMN is eligible for selection in the international area. If the serving PLMN identity includes a shared MCC, the list of candidate PLMNs may include candidate PLMNs that have either the shared MCC or an MCC corresponding to the country in which the UE is located.

[0073] 9 is a flow diagram illustrating an example process 900, performed by, for example, a UE, in accordance with various aspects of the present disclosure. The example process 900 is one example of wireless network selection for satellite access in an international area.

[0074] As shown in FIG. 9, in some aspects, process 900 may include determining whether the UE has transitioned between an international area and a domestic area (block 902). For example, the UE may determine whether the UE has transitioned between an international area and a domestic area (e.g., using antennas 252, DEMOD / MOD 254, MIMO detector 256, TX MIMO processor 266, receive processor 258, transmit processor 264, controller / processor 280, and / or memory 282). The UE may determine that the UE is located in the international area and then select a PLMN from a list dedicated to international area search. The UE may determine that the UE is located in the international area and then select a PLMN based on an indication that the PLMN is eligible for selection in the international area. In some aspects, the PLMN selection is for non-terrestrial based network (NTN) access.

[0075] In some aspects, process 900 may also include triggering a public land mobile network (PLMN) selection of a network for receiving services in response to the UE transitioning between the international area and the domestic area (block 904). For example, the UE may trigger the PLMN selection (e.g., using antenna 252, DEMOD / MOD 254, MIMO detector 256, TX MIMO processor 266, receive processor 258, transmit processor 264, controller / processor 280, and / or memory 282). In some aspects, during PLMN selection, a high priority PLMN list is prioritized over a most recently registered PLMN. The high priority PLMN list may include a home public land mobile network (HPLMN) list. The high priority PLMN list may include an equivalent home public land mobile network (EHPLMN) list. In some aspects, the UE may delete an equivalent public land mobile network list received from the last serving PLMN prior to PLMN selection.

[0076] FIG. 10 is a flow diagram illustrating an example process 1000 performed, for example, by a UE, according to various aspects of the disclosure. The example process 1000 is an example of wireless network selection for satellite access in an international area. As shown in FIG. 10, in some aspects, the process 1000 may include determining whether the UE is located in the international area (block 1002). For example, the UE may determine in which location the UE is located (e.g., using antenna 252, DEMOD / MOD 254, MIMO detector 256, TX MIMO processor 266, receive processor 258, transmit processor 264, controller / processor 280, and / or memory 282). In some aspects, the process 1000 may also include receiving an indication by the UE that a public land mobile network (PLMN) is eligible for selection in the international area (block 1004). For example, the UE may receive the indication (e.g., using antennas 252, DEMOD / MOD 254, MIMO detector 256, receive processor 258, controller / processor 280, and / or memory 282). In some aspects, process 1000 may also include selecting a PLMN based on the indication that the PLMN is eligible for selection in the international area (block 1006). For example, the UE may select a PLMN (e.g., using controller / processor 280 and / or memory 282).

[0077] Exemplary Aspects Aspect 1: A method of wireless communication by a user equipment (UE), comprising: determining whether the UE has transitioned between an international area and a domestic area; and triggering a public land mobile network (PLMN) selection of a network for receiving services in response to the UE having transitioned between the international area and the domestic area.

[0078] Aspect 2: The method of aspect 1, further comprising prioritizing the high priority PLMN list over a most recently registered PLMN (RPLMN) during PLMN selection.

[0079] Aspect 3: The method of aspect 1 or 2, wherein the high priority PLMN list includes a Home Public Land Mobile Network (HPLMN) list.

[0080] Aspect 4: The method of any of the preceding aspects 1 or 2, wherein the high priority PLMN list includes an equivalent home public land mobile network (EHPLMN) list.

[0081] Aspect 5: The method of any of the preceding aspects, further comprising, prior to PLMN selection, deleting the equivalent public land mobile network list received from the last serving PLMN.

[0082] Aspect 6: The method of any of the preceding aspects, wherein performing PLMN selection further includes assigning a most recently registered PLMN (RPLMN) to a priority level lower than the highest priority.

[0083] Aspect 7: The method of any of the preceding aspects, wherein performing the PLMN selection further includes selecting a PLMN having a higher priority than a most recently registered PLMN (RPLMN).

[0084] Aspect 8: The method of any of the preceding aspects, wherein the PLMN selection is for non-terrestrial based network (NTN) access.

[0085] Aspect 9: The method of any of the preceding aspects, wherein the PLMN selection selects a most recently registered PLMN (RPLMN) if available before selecting from the ordered list of PLMNs.

[0086] Example 10: The method of any of the preceding Examples 1-8, wherein the PLMN selection selects from a list generated during a high priority PLMN scan.

[0087] Aspect 11: The method of any of the preceding aspects, based on a PLMN selection procedure, where the PLMN selection is defined for either power-on or recovery from loss of coverage.

[0088] Example 12: The method of any of the preceding Examples 1-10, wherein the PLMN selection is based on a PLMN selection procedure, where the PLMN selection is made upon completion of a periodic search for higher priority PLMNs.

[0089] Aspect 13: A method of wireless communication by a user equipment (UE), comprising: performing a PLMN search for a higher priority public land mobile network (PLMN); determining a list of candidate PLMNs based on the search; and in response to an identity of the serving PLMN not being a shared operating region code (MCC), selecting a PLMN from the list of candidate PLMNs, wherein the candidate PLMN has either the same MCC as the identity of the serving PLMN or a shared MCC, and the selected PLMN has a higher priority than the serving PLMN.

[0090] Aspect 14: The method of aspect 13, wherein if the identity information of the serving PLMN includes a shared MCC, the list of candidate PLMNs includes candidate PLMNs that have either the shared MCC or an MCC corresponding to the country in which the UE is located.

[0091]

[0036] Example 15: The method of example 13 or 14, further comprising initiating a registration procedure with the selected PLMN.

[0092] Example 16: The method of any of Examples 13-15, wherein performing the PLMN search occurs in response to determining that the UE is located in an international area.

[0093] Example 17: The method of any of examples 13-16, wherein the identity of the serving PLMN includes a shared MCC.

[0094] Example 18: The method of any of examples 13-17, wherein the identity information of at least one of the candidate PLMNs includes a shared MCC.

[0095] Embodiment 19: The method of any of embodiments 13-18, wherein the shared MCC is in the range of 900-999.

[0096] Example 20: The method of any of examples 13-19, wherein at least one of the candidate PLMNs provides non-terrestrial based network access.

[0097]

[0031] Aspect 21: The method of any of aspects 13-20, further comprising selecting a PLMN based on an indication that the PLMN is eligible for selection in the international area.

[0098] Aspect 22: An apparatus for wireless communication by a user equipment (UE), comprising: a memory; and at least one processor coupled to the memory, wherein the at least one processor is configured to determine whether the UE has transitioned between an international area and a domestic area; and in response to the UE having transitioned between the international area and the domestic area, trigger a public land mobile network (PLMN) selection of a network for receiving services.

[0099] Aspect 23: The apparatus of aspect 22, wherein the at least one processor is further configured to perform PLMN selection by assigning a most recently registered PLMN (RPLMN) to a priority level lower than the highest priority.

[0100] Aspect 24: The apparatus of any of aspects 22 or 23, wherein the at least one processor is further configured to perform PLMN selection, further comprising selecting a PLMN having a higher priority than a most recently registered PLMN (RPLMN).

[0101] Example 25: The apparatus of any one of Examples 22-24, wherein the PLMN selection is for non-terrestrial based network (NTN) access.

[0102] Example 26: The apparatus of any of Examples 22-25, wherein the PLMN selection is based on a PLMN selection procedure, the PLMN selection being defined either on power-up or on recovery from loss of coverage.

[0103] Example 27: The apparatus of any of Examples 22-26, wherein the PLMN selection is based on a PLMN selection procedure, where the PLMN selection is made upon completion of a periodic search for higher priority PLMNs.

[0104] Aspect 28: An apparatus for wireless communication by a user equipment (UE), comprising: a memory; and at least one processor coupled to the memory, wherein the at least one processor is configured to perform a PLMN search for a higher priority public land mobile network (PLMN), determine a list of candidate PLMNs based on the search, and select a PLMN from the list of candidate PLMNs in response to an identity of the serving PLMN not being a shared operating geographical code (MCC), wherein the candidate PLMN has either the same MCC as the identity of the serving PLMN or a shared MCC, and wherein the selected PLMN has a higher priority than the serving PLMN.

[0105] Example 29: The apparatus of example 28, wherein if the identity information of the serving PLMN includes a shared MCC, the list of candidate PLMNs includes candidate PLMNs that have either a shared MCC or an MCC corresponding to a country in which the UE is located.

[0106] Example 30: The apparatus of example 28 or 29, wherein at least one of the candidate PLMNs provides non-terrestrial based network access.

[0107] The above disclosure provides illustration and description, but is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the embodiments.

[0108] When used, the term "component" is intended to be broadly interpreted as hardware, firmware, and / or a combination of hardware and software. When used, a processor is implemented in hardware, firmware, and / or a combination of hardware and software.

[0109] Some aspects are described in relation to a threshold value. When used, meeting a threshold can refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, etc., depending on the context.

[0110] It will be apparent that the described systems and / or methods can be implemented in various forms of hardware, firmware, and / or combinations of hardware and software. The actual specialized control hardware or software code used to implement these systems and / or methods is not limiting of the aspects. Thus, the operation and behavior of the present systems and / or methods will be described without reference to specific software code. It will be understood that software and hardware can be designed to implement the present systems and / or methods based at least in part on the present description.

[0111] Even if certain combinations of features are recited in the claims and / or disclosed herein, those combinations are not intended to limit the disclosure of the various aspects. Indeed, many of these features can be combined in ways not specifically recited in the claims and / or disclosed herein. Although each dependent claim listed below may depend directly on only one claim, the disclosure of the various aspects includes each dependent claim in combination with every other claim in the claim set. A phrase referring to "at least one of" a list of items refers to any combination of those items, including single members. As an example, "at least one of a, b, or c" is intended to encompass a, b, c, ab, ac, bc, and abc, as well as any combination having multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other sequence of a, b, and c).

[0112] No element, act, or instruction used should be construed as essential or required unless expressly described as such. Also, when used, the articles "a" and "an" are intended to include one or more items and may be used interchangeably with "one or more." Furthermore, when used, the terms "set" and "group" are intended to include one or more items (e.g., related items, unrelated items, combinations of related and unrelated items, etc.) and may be used interchangeably with "one or more." When only one item is intended, the phrase "only one" or similar language is used. Also, when used, terms such as "has," "have," and "having" are intended to be open-ended terms. Furthermore, the phrase "based on" is intended to mean "based at least in part on," unless otherwise specified.

Claims

1. 1. A method of wireless communication by a user equipment (UE), comprising: determining whether the UE has transitioned between an international area and a domestic area, performing a public land mobile network (PLMN) search, and creating a list of candidate PLMNs based on the PLMN search; triggering a PLMN selection of a network for receiving a service in response to the UE transitioning between the international area and the domestic area; The method, wherein the PLMN selection is based on a list of candidate PLMNs.

2. The method of claim 1 , further comprising prioritizing a high-priority PLMN list over a most recently registered PLMN (RPLMN) during PLMN selection.

3. The method of claim 2 , wherein the high priority PLMN list comprises a Home Public Land Mobile Network (HPLMN) list.

4. The method of claim 2 , wherein the high priority PLMN list comprises an equivalent home public land mobile network (EHPLMN) list.

5. The method of claim 2 , further comprising, prior to the PLMN selection, deleting an equivalent public land mobile network list received from a last serving PLMN.

6. The method of claim 1 , wherein performing the PLMN selection further comprises assigning a most recently registered PLMN (RPLMN) to a priority level lower than the highest priority.

7. The method of claim 1 , wherein performing the PLMN selection further comprises selecting a PLMN having a higher priority than a most recently registered PLMN (RPLMN).

8. The method of claim 1 , wherein the PLMN selection is for non-terrestrial based network (NTN) access.

9. The method of claim 1 , wherein the PLMN selector selects a most recently registered PLMN (RPLMN), if available, before selecting from an ordered list of PLMNs.

10. The method of claim 1 , wherein the PLMN selection is selected from a list generated during a high priority PLMN scan.

11. 2. The method of claim 1, wherein the PLMN selection is based on a PLMN selection procedure defined for either power-on or recovery from loss of coverage.

12. 2. The method of claim 1, wherein the PLMN selection is based on a PLMN selection procedure that occurs upon completion of a periodic search for higher priority PLMNs.

13. 1. An apparatus for wireless communication by a user equipment (UE), comprising: Memory and at least one processor coupled to the memory, wherein the at least one processor: determining whether the UE has transitioned between an international area and a domestic area, performing a public land mobile network (PLMN) search, and creating a list of candidate PLMNs based on the PLMN search; triggering a public land mobile network (PLMN) selection of a network for receiving services in response to the UE transitioning between the international area and the domestic area; and The PLMN selection is based on a list of candidate PLMNs.

14. 14. The apparatus of claim 13, wherein the at least one processor is further configured to perform the PLMN selection by assigning a most recently registered PLMN (RPLMN) to a priority level lower than a highest priority.

15. the at least one processor is further configured to perform the PLMN selection by selecting a PLMN having a higher priority than a most recently registered PLMN (RPLMN); or the PLMN selection is for a non-terrestrial network (NTN) access; or The PLMN selection is based on a PLMN selection procedure defined either for power-up or recovery from loss of coverage, or 14. The apparatus of claim 13, wherein the PLMN selection is based on a PLMN selection procedure that occurs upon completion of a periodic search for higher priority PLMNs.

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