Access control for public warning system messages on non-public networks

Abstract

A user equipment (UE) comprising: receiving circuitry configured to receive, from a cell, system information comprising: one or more network identifiers, each of the one or more network identifiers identifying a public land mobile network (PLMN) or a non-public network (NPN); and cell status information. The UE further comprises processing circuitry configured to determine whether the cell status information indicates that the cell is barred or to be considered as barred for the UE. In case the cell supports a public warning system (PWS) broadcast service, the UE is allowed to camp on the cell to receive one or more PWS messages even if the cell status information indicates that the cell is barred or to be considered as barred for the UE.

Description

Technical Field

[0001] This disclosure relates in general to wireless communications, and more specifically to access control for Public Alarm System (PWS) messages on non-public networks (NPNs). Background Technology

[0002] The 3rd Generation Partnership Project (3GPP) supports Placement Messages (PWS). PWS are used to alert the public to events such as disasters. For example, during earthquakes, tsunamis, hurricanes, or wildfires, PWS can be used to notify the public to evacuate affected areas within a specified timeframe. Additionally, PWS can be used to notify people of child abduction emergencies (e.g., Amber Alerts). PWS notifications should be delivered to the public accurately and promptly to help people prepare adequately for events. Different countries may have different requirements for the transmission of alarm information. Therefore, the 3GPP network provides different alarm systems for different countries. However, the alarm systems supported by 3GPP use a common system architecture and common signaling procedures. As listed in Table 1 below, 3GPP has standardized different alarm systems in different versions according to the requirements of the respective countries. Table 1-3 shows the public alarm systems supported by GPP. ETWS Japan Version 8 CMAS USA Version 9 KPAS South Korea Version 10 EU-ALERT European countries Version 11

[0003] The 3GPP PWS (Programmable Wiresharing) was initially specified in Release 8 to allow direct alerts to mobile users from standard user equipment (PWS-UE) capable of displaying text-based and language-related alert notifications. Since then, the number of mobile devices with little or no user interface (including wristbands, sensors, and cameras) has grown, and many of these devices are unable to display alert notifications.

[0004] At the recent 3GPP TSG SA#79 meeting, as an update to Technical Specification (TS) 22.268, additional version 16 requirements for the Enhanced Public Alarm System (ePWS) have been agreed upon.

[0005] The NR Radio Access Network (RAN) connected to the 5GC provides support for the PWS using System Information Broadcast. The NR RAN is responsible for scheduling and broadcasting alarm messages. The NR RAN is also responsible for paging the UE to provide an indication that an alarm message is being broadcast. The Earthquake and Tsunami Warning System (ETWS) is a public alarm system designed to meet regulatory requirements for alarm notifications related to earthquakes and / or tsunamis. The Commercial Mobile Alarm System (CMAS) is a public alarm system designed to deliver multiple concurrent alarm notifications. Notification messages, such as short messages or paging messages sent via Downlink Control Information (DCI), are used to inform the UE of ETWS and CMAS indications, which can be received by the UE when it is in RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED states.

[0006] The notification message indicating the ETWS / CMAS notification triggers the retrieval of system information (without delay to the next modification cycle). Different SIBs are defined for ETWS primary notifications, ETWS secondary notifications, and CMAS notifications. For example, SIB6 provides ETWS primary notifications. SIB7 provides ETWS secondary notifications. SIB8 provides CMAS alarm notifications.

[0007] Currently, there are no 3GPP Service and Functional Requirements (SA1) requirements related to NPN support for PWS. However, NPN support for PWS will benefit the public.

[0008] Therefore, there is a need in this field to control access to PWS messages on NPN. Summary of the Invention

[0009] In one example, a user equipment (UE) includes: a receiving circuit configured to receive system information from a cell, the system information including: (1) one or more network identifiers, each of the one or more network identifiers identifying a Public Land Mobile Network (PLMN) or a Non-Public Network (NPN); and (2) cell status information; and a processing circuit configured to determine whether the cell status information indicates that the cell is blocked or will be considered blocked for the UE; wherein, if the cell supports a Public Alarm System (PWS) broadcast service, the UE is allowed to pre-occupy the cell to receive one or more PWS messages, even if the cell status information indicates that the cell is blocked or will be considered blocked for the UE.

[0010] In one example, a method performed by a user equipment (UE) includes: receiving system information from a cell, the system information including: (1) one or more network identifiers, each of the one or more network identifiers identifying a public land mobile network (PLMN) or a non-public network (NPN); and (2) cell status information; determining whether the cell status information indicates that the cell is blocked or will be considered blocked for the UE; wherein, if the cell supports a public alarm system (PWS) broadcast service, the UE is allowed to pre-occupy the cell to receive one or more PWS messages, even if the cell status information indicates that the cell is blocked or will be considered blocked for the UE.

[0011] In one example, a base station apparatus includes: a transmitting circuit configured to transmit system information to a user equipment (UE), the system information including: (1) one or more network identifiers, each of the one or more network identifiers identifying a public land mobile network (PLMN) or a non-public network (NPN); and (2) cell status information; wherein, if the cell supports a public alarm system (PWS) broadcast service, the UE is permitted to pre-occupy the cell to receive one or more PWS messages, even if the cell status information indicates that the cell is blocked or will be considered blocked for the UE. Attached Figure Description

[0012] Referring to the accompanying drawings, specific implementations of the invention will now be described by way of example only. [ Figure 1 ] Figure 1 This is a flowchart illustrating an exemplary embodiment of a method used by a UE to receive PWS messages on an NPN, according to the present disclosure. [ Figure 2 ] Figure 2 This is a flowchart illustrating an exemplary embodiment of a method used by a base station to transmit PWS messages on an NPN, according to the present disclosure. Detailed Implementation

[0013] This disclosure relates to a method and apparatus for access control of PWS messages on an NPN.

[0014] According to a first aspect of this disclosure, a user equipment (UE) includes a receiving circuit configured to receive system information from a cell, the system information including: (1) one or more network identifiers, each of the one or more network identifiers identifying a Public Land Mobile Network (PLMN) or a Non-Public Network (NPN); and (2) cell status information. The UE also includes processing circuitry configured to determine whether the cell status information indicates that the cell is blocked or will be considered blocked for use by the UE. If the cell supports a Public Alarm System (PWS) broadcast service, the UE is permitted to pre-occupy the cell to receive one or more PWS messages, even if the cell status information indicates that the cell is blocked or will be considered blocked for use by the UE.

[0015] In one specific implementation of the first aspect, the cell supports PWS broadcast service if at least one of the one or more network identifiers identifies the PLMN.

[0016] In another specific implementation of the first aspect, the cell supports PWS broadcast service when the system information includes PWS-Support information element (IE).

[0017] In another specific implementation of the first aspect, PWS support for IE is included in System Information Block 1 (SIB1).

[0018] In another specific implementation of the first aspect, if the system information does not contain PWS support for IE and all one or more network identifiers recognize NPN, then PWS broadcast service is not supported in the cell.

[0019] In another specific implementation of the first aspect, although PWS broadcast service is supported in the cell and the cell status information indicates that the cell is prohibited or will be regarded as prohibited for the UE, the UE is allowed to pre-occupy the cell to receive one or more PWS messages, but the UE is not allowed to initiate a random access (RACH) procedure on the cell.

[0020] According to a second aspect of this disclosure, a method performed by a user equipment (UE) includes receiving system information from a cell, the system information including: (1) one or more network identifiers, each of the one or more network identifiers identifying a Public Land Mobile Network (PLMN) or a Non-Public Network (NPN); and (2) cell status information. The method further includes determining whether the cell status information indicates that the cell is blocked or will be considered blocked for use by the UE. If the cell supports a Public Alarm System (PWS) broadcast service, the UE is permitted to pre-occupy the cell to receive one or more PWS messages, even if the cell status information indicates that the cell is blocked or will be considered blocked for use by the UE.

[0021] In one specific implementation of the second aspect, the cell supports PWS broadcast service if at least one of the one or more network identifiers identifies the PLMN.

[0022] In another specific implementation of the second aspect, the cell supports PWS broadcast service when the system information includes PWS support information elements (IE).

[0023] In another specific implementation of the second aspect, PWS support for IE is included in System Information Block 1 (SIB1).

[0024] In another specific implementation of the second aspect, if the system information does not contain PWS support for IE and all one or more network identifiers recognize NPN, then PWS broadcast service is not supported in the cell.

[0025] In another specific implementation of the second aspect, although PWS broadcast service is supported in the cell and the cell status information indicates that the cell is prohibited or will be regarded as prohibited for the UE, the UE is allowed to pre-occupy the cell to receive one or more PWS messages, but the UE is not allowed to initiate a random access (RACH) procedure on the cell.

[0026] According to a third aspect of this disclosure, a base station apparatus includes a transmitting circuit configured to transmit system information to a user equipment (UE), the system information including: (1) one or more network identifiers, each of the one or more network identifiers identifying a Public Land Mobile Network (PLMN) or a Non-Public Network (NPN); and (2) cell status information. Where the cell supports a Public Alarm System (PWS) broadcast service, the UE is permitted to pre-occupy the cell to receive one or more PWS messages, even if the cell status information indicates that the cell is disabled or will be deemed disabled for use by the UE.

[0027] In one specific implementation of the third aspect, the cell supports PWS broadcast service if at least one of the one or more network identifiers identifies the PLMN.

[0028] In another specific implementation of the third aspect, the cell supports PWS broadcast service when the system information includes PWS support information elements (IE).

[0029] In another specific implementation of the third aspect, PWS support for IE is included in System Information Block 1 (SIB1).

[0030] In another specific implementation of the third aspect, if the system information does not contain PWS support for IE and all one or more network identifiers recognize NPN, then PWS broadcast service is not supported in the cell.

[0031] In another specific implementation of the third aspect, although PWS broadcast service is supported in the cell and the cell status information indicates that the cell is prohibited or will be regarded as prohibited for the UE, the UE is allowed to pre-occupy the cell to receive one or more PWS messages, but the cell prevents the UE from initiating a random access (RACH) procedure on the cell.

[0032] According to a fourth aspect of this disclosure, a method performed by a base station apparatus includes transmitting system information to a user equipment (UE), the system information including: (1) one or more network identifiers, each of the one or more network identifiers identifying a Public Land Mobile Network (PLMN) or a Non-Public Network (NPN); and (2) cell status information. If the cell supports a Public Alarm System (PWS) broadcast service, the UE is permitted to pre-occupy the cell to receive one or more PWS messages, even if the cell status information indicates that the cell is disabled or will be deemed disabled for use by the UE.

[0033] In one specific implementation of the fourth aspect, the cell supports PWS broadcast service if at least one of the one or more network identifiers identifies the PLMN.

[0034] In another specific implementation of the fourth aspect, the cell supports PWS broadcast service when the system information includes PWS support information elements (IE).

[0035] In another specific implementation of the fourth aspect, PWS support for IE is included in System Information Block 1 (SIB1).

[0036] In another specific implementation of the fourth aspect, if the system information does not contain PWS support for IE and all one or more network identifiers recognize NPN, then PWS broadcast service is not supported in the cell.

[0037] In another specific implementation of the fourth aspect, although PWS broadcast service is supported in the cell and the cell status information indicates that the cell is prohibited or will be regarded as prohibited for the UE, the UE is allowed to pre-occupy the cell to receive one or more PWS messages, but the cell prevents the UE from initiating a random access (RACH) procedure on the cell.

[0038] 3GPP is a collaborative agreement aimed at developing globally applicable technical specifications and technical reports for third- and fourth-generation wireless communication systems. 3GPP sets specifications for next-generation mobile networks, systems, and equipment.

[0039] 3GPP LTE is the name given to projects designed to improve the Universal Mobile Telecommunications System (UMTS) mobile phone or device standard to meet future needs. In one aspect, UMTS has been modified to provide support and specifications for Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN).

[0040] At least some aspects of the systems and methods disclosed herein can be described in conjunction with 3GPP LTE, LTE-A Advanced, and other standards including New Radio (NR) (e.g., 3GPP Releases 8, 9, 10, 11, 12, 13, 14, and / or 15), also known as 5G. However, the scope of this disclosure should not be limited in this respect. At least some aspects of the systems and methods disclosed herein can be used in other types of wireless communication systems.

[0041] Wireless communication equipment can be electronic devices used to transmit voice and / or data to a base station (BS), which in turn can communicate with the network of the equipment (e.g., the Public Switched Telephone Network (PSTN), the Internet, etc.). In describing the systems and methods herein, wireless communication equipment may alternatively be referred to as a mobile station, UE, access terminal, subscriber station, mobile terminal, remote station, user terminal, terminal, subscriber unit, mobile device, etc. Examples of wireless communication equipment include cellular phones, smartphones, personal digital assistants (PDAs), laptop computers, netbooks, e-readers, wireless modems, etc.

[0042] In 3GPP specifications, wireless communication equipment is typically referred to as UE. However, since the scope of this disclosure should not be limited to 3GPP standards, the terms "UE" and "wireless communication equipment" are used interchangeably herein to refer to the more general term "wireless communication equipment." UE may also be more generally referred to as terminal equipment.

[0043] In 3GPP specifications, a BS is commonly referred to as a Node B, Evolved Node B (eNB), Home Enhanced or Evolved Node B (HeNB), Next Generation Node B (gNB), or some other similar terminology. Since the scope of this disclosure should not be limited to the 3GPP standard, the terms "base station," "Node B," "eNB," "HeNB," and "gNB" are used interchangeably herein to refer to the more general term "base station." Furthermore, the terms "base station" or "BS" can be used to refer to an access point. An access point can be an electronic device that provides access to a network (e.g., a local area network (LAN), the Internet, etc.) for wireless communication equipment. The term "communication equipment" can be used to refer to wireless communication equipment and / or a base station. eNB and gNB can also be more generally referred to as base station equipment.

[0044] It should be noted that, as used herein, a “cell” can be any communication channel that is designated by standardization or regulatory bodies for use with Advanced International Mobile Communications (IMT-Advanced) and all or subset thereof, making it a licensed frequency band (e.g., a frequency band) adopted by 3GPP for communication between the eNB and the UE. It should also be noted that, in the general descriptions of E-UTRA and E-UTRAN, as used herein, a “cell” can be defined as “a combination of downlink resources and optional uplink resources.” The link between the carrier frequencies of the downlink resources and the carrier frequencies of the uplink resources can be indicated in the system information transmitted on the downlink resources.

[0045] "Configured cells" are those cells that the UE is aware of and that the eNB has permitted to transmit or receive information. "Configured cells" can be serving cells. The UE can receive system information and perform necessary measurements on all configured cells. "Configured cells" for radio connectivity may include primary cells and / or zero, one, or more secondary cells.

[0046] "Active cells" are those cells on which the UE is currently transmitting and receiving. In other words, active cells are those cells on which the UE monitors its Physical Downlink Control Channel (PDCCH) and, in the case of downlink transmission, on which the UE decodes its Physical Downlink Shared Channel (PDSCH). "Deactivated cells" are those cells on which the UE does not monitor PDCCH transmissions. It should be noted that "cells" can be described in different dimensions. For example, a "cell" can have temporal, spatial (e.g., geographical), and frequency characteristics.

[0047] 5G communication systems, referred to as NR technology by 3GPP, envision using time / frequency / spatial resources to enable services such as eMBB transmission, URLLC transmission, and massive machine-type communication (mMTC) transmission. Furthermore, NR considers single-beam and / or multi-beam operation for downlink and / or uplink transmission.

[0048] Various examples of the systems and methods disclosed herein will now be described with reference to the accompanying drawings, wherein like reference numerals indicate elements with similar functions. The systems and methods generally described and illustrated in the accompanying drawings can be arranged and designed in a variety of different specific embodiments. Therefore, the detailed description of this disclosure as shown in the figures is not intended to limit the scope of this disclosure, but only to represent the systems and methods described.

[0049] NPNs enable the deployment of next-generation (e.g., fifth-generation (5G) New Radio (NR)) wireless communication systems for private use. NPNs can be deployed as standalone non-public networks (SNPNs) or public network integrated NPNs (PNI-NPNs). SNPNs are operated by NPN operators and do not rely on network functionality provided by public terrestrial mobile networks (PLMNs).

[0050] SNPN is identified by a combination of PLMN ID and Network Identifier (NID). SNPN-enabled UEs are configured with a Subscription Permanent Identifier (SUPI) and credentials for each subscribed SNPN, identified by the combination of PLMN ID and NID. The SNPN Radio Access Network (RAN) broadcasts the PLMN ID and NID in system broadcast, enabling network (re)selection, overload control, access control, and blocking using the PLMN ID and NID. Furthermore, 3GPP Release 16 specifies the ability for UEs to obtain PLMN services when pre-occupied with the SNPN RAN, for example, when the UE has subscriptions and credentials for services from both the PLMN and SNPN.

[0051] PNI-NPN is an NPN deployed with the support of a PLMN. In the case of PNI-NPN, the PLMN ID identifies the network, and the Closed Access Group (CAG) ID identifies one or more CAG cells. CAG cells broadcast one or more CAG identifiers for each PLMN. Network selection and reselection are based on the PLMN ID. Cell selection and reselection, as well as access control, are based on the CAG ID. CAG cell broadcast information ensures that only UEs supporting CAG can access the cell.

[0052] System Information (SI) in NR consists of a Master Information Block (MIB) and multiple System Information Blocks (SIBs), which are divided into Minimum SIs and other SIs. The Minimum SI carries the basic information required for initial access and acquisition of any other SIs. The Minimum SI consists of the MIB and SIB1. For a UE allowed to pre-occupy a cell, it must have already acquired the contents of the Minimum SI from that cell. Other SIs consist of all SIBs not broadcast in the Minimum SI. The UE does not need to receive these SIBs before accessing the cell.

[0053] The contents and scheduling of the minimum SI, consisting of MIB and SIB1, are shown below.

[0054] The MIB provides the subframe number (SFN), key information for receiving SIB1 (subcarrier spacing (SCS), subcarrier offset, demodulation reference signal (DRMS) position, physical downlink control channel (PDCCH) configuration), cell prohibition flag, and allowed intra-frequency reselection flag. The MIB is mapped onto the Broadcast Control Channel (BCCH) logical channel and carried on the Broadcast Channel (BCH) transport channel. The BCH is then mapped onto the Physical Broadcast Channel (PBCH).

[0055] The MIB is transmitted at 80ms intervals and repeats within 80ms (according to the Synchronization Signal Block (SSB) cycle). The MIB content is identical within the 80ms interval, and the same MIB is transmitted on all SSBs within the Synchronization Signal (SS) burst set. The MIB provides the UE with the parameters required to acquire SIB1 (e.g., control resource set #0 (CORESET #0) configuration), and more specifically, the information required to monitor the PDCCH for scheduling the Physical Downlink Shared Channel (PDSCH) carrying SIB1.

[0056] SIB1 provides cell selection information, PLMN list, cell ID, tracking area code, RAN area code, cell reservation marker, connection establishment failure control information, SI scheduling information, common uplink and downlink configuration of the serving cell (random access channel (RACH), paging, etc.), supplementary uplink (SUL) configuration, SSB scheduling information, cell-specific time division duplex (TDD) uplink (UL) / downlink (DL) configuration, IP Multimedia Subsystem (IMS) emergency bearer support marker (for UEs in restricted service), IMS emergency call support marker, UE timers and constants, access control information, etc.

[0057] SIB1 carries the most critical information required for the UE to access the cell (e.g., random access parameters). SIB1 includes information about the availability and scheduling of other SIBs (e.g., SIB-to-SI message mapping, periodicity, SI window size, etc.). SIB1 also indicates whether one or more SIBs are provided only on demand; in this case, it may also provide the Physical Random Access Channel (PRACH) configuration required for the UE to request the desired SI. SIB1 is transmitted on the DL-SCH (Logical Channel: BCCH) with a period of 160ms and a variable transmission repetition period within 160ms. SIB1 is a cell-specific SIB.

[0058] The UE acquires the SI when: during cell selection (e.g., upon power-on); during cell reselection; upon returning from outside coverage; after completing a synchronization reconfiguration; upon entering the network from another radio access technology (RAT); upon receiving an indication that the SI has changed; upon receiving a PWS notification; and whenever the UE does not have a valid version of the stored SIB.

[0059] When the network initiates or changes the PWS broadcast (e.g., SIB6 / SIB7 / SIB8), it notifies the UE of the change using a short message transmitted over the downlink control information (DCI) with a paging radio network temporary identifier (P-RNTI). The DCI format 1_0 is scrambled with the P-RNTI. Upon receiving this message, the UE immediately reacquires SIB1, and the UE acquires SIB6 / SIB7 / SIB8 based on scheduling information.

[0060] According to specific implementations of this disclosure, a UE subscribed to a PLMN or a non-public network may need to be able to receive CMAS / ETWS messages. If the UE cannot find any authorized (subscribed) PLMN or non-public network, it may be allowed to automatically select and pre-claim an unauthorized network that supports CMAS / ETWS. In this case, if a CMAS / ETWS message is received, the UE may process the message, but may not be allowed to connect to the unauthorized network.

[0061] There are challenges for NPN in providing PWS services.

[0062] One challenge of NPN providing PWS services is that the current 3GPP specification does not allow a UE to pre-occupy a cell when none of the PLMNs and NPNs of the NPN or SNPN cell are permitted for use by a non-NPN UE (or an unlicensed NPN UE), even if there are no other available cells of other PLMNs / NPNs to receive CMAS / ETWS messages. For example, in the current 3GPP technical specification (TS) 38.304-gl0, section 5.3.1 stipulates: 5.3.1 Community Status and Community Reserved Space The following fields are used in MIB or SIB1 messages as specified in TS 38.331[3] to indicate cell status and cell reservation: -cellBarred(IE type: "Banned" or "Not banned") This is indicated in the MIB message. If multiple PLMNs or NPNs are indicated in SIB1, this field is shared for all PLMNs and NPNs - cellReservedForOperatorUse (IE type: "Reserved" or "Not Reserved") is indicated in the SIB1 message. If multiple PLMNs or NPNs are indicated in SIB1, this field is specified for each PLMN or each SNPN. -cellReservedForOtherUse(IE type: "true") This is indicated in the SIB1 message. If multiple PLMNs are indicated in the SIB1, this field is shared by all PLMNs. -cellReservedForFutureUse(IE type: "true") This is indicated in the SIB1 message. If multiple PLMNs or NPNs are indicated in the SIB1, this field is shared for all PLMNs and NPNs. Note: As defined in TS 38.331[3], IAB-MT ignores cellBarred, cellReservedForOperatorUse, cellReservedForFutureUse, cellReservedForOtherUse, and intraFreqReselection (i.e., intraFreqReselection is considered enabled). As defined in TS 38.331[3], IAB-MT also ignores cellReservedForOtherUse for cell prohibition determination (i.e., IAB-MT supporting NPN considers cellReservedForOtherUse for determining NPN-only cells). -iab-Support(IE type: "true") Indicated in the SIB1 message. If multiple PLMNs or NPNs are indicated in the SIB1, the field is specified for each PLMN or SNPN.

[0063] As stated above, when a cell status is indicated as "not banned" and "not reserved" for operator use, and is not "true" for other uses and not "true" for future use, then "all UEs should treat the cell as a candidate during the cell selection and cell reselection process".

[0064] When a cell broadcasts any CAG ID or NID, and the cell status is indicated as "not banned" and "not reserved" for operator use, and is "true" for other uses but not "true" for future use, "all UEs supporting NPN should treat the cell as a candidate during the cell selection and cell reselection process," but "other UEs should treat the cell as if its cell status is "banned." In other words, even for the sole purpose of receiving PWS messages, UEs that do not support NPN are not allowed to reserve the cell.

[0065] When a cell state is indicated as "true" for other purposes, and neither cell is broadcasting any CAG ID or NID, or if no CAG ID is broadcast and the UE is not operating in SNPN access mode, then "the UE should treat the cell as having a 'banned' cell state."

[0066] When a cell status is indicated as "true" for future use, the UE should treat the cell as if it were "banned". When the cell status is indicated as "not banned" and "reserved" for use by any PLMN / SNPN operator, and is not "true" for other uses and not "true" for future use, - If the cellReservedForOperatorUse field of the PLMN is set to "Reserved", then the UE assigned to Access Identity 11 or 15 operating in its HPLMN / EHPLMN should treat the cell as a candidate during the cell selection and reselection process. - If the cellReservedForOperatorUse field used for selecting / registering SNPN is set to "Reserved", the UE assigned to access identity 11 or 15 should treat that cell as a candidate during the cell selection and reselection process. - If the cell is "reserved for operator use" for registering or selecting a PLMN / SNPN, then UEs assigned to access identities 0, 1, 2, and 12 through 14 should behave as if the cell status is "banned". Note 1: Access identity identifiers 11 and 15 are only valid for HPLMN / EHPLMN; Access identity identifiers 12, 13, and 14 are only valid for the country of origin, as in TS 22.261

[12] . As specified in [the document / reference]. When the indicated cell status is "banned" or the cell status will be treated as "banned": - The UE is not allowed to select / reselect the cell, or even make emergency calls to it. -The UE should select another cell according to the following rules: - If a cell cannot obtain a MIB, its cell status will be considered "banned": - The UE can exclude banned cells as candidates for cell selection / reselection within a maximum of 300 seconds. If the selection criteria are met, the UE can select another cell on the same frequency. -otherwise: - If the intraFreqReselection field in the MIB message is set to "Allow", the UE can select another cell on the same frequency if the reselection criteria are met; - The UE should exclude banned cells as candidates for cell selection / reselection within 300 seconds. - If the intraFreqReselection field in the MIB message is set to "Disallowed": - If the cell operates in a licensed spectrum, or if the cell belongs to a PLMN that is indicated to be equivalent to a registered PLMN, or if the cell belongs to a UE's registered SNPN: - The UE should not reselect a cell on the same frequency as the prohibited cell; -otherwise: If the reselection criteria are met, the UE can select another cell on the same frequency. - The UE should exclude prohibited cells if the cell is operating in a licensed spectrum, or if the cell belongs to a PLMN that is indicated to be equivalent to the registered PLMN, and should also exclude cells on the same frequency as candidates for cell selection / reselection for 300 seconds.

[0067] Another option for choosing a neighborhood may include changes to the RAT.

[0068] Another challenge for NPN to provide PWS services is that even if the behavior listed in the 3GPP specification is modified to allow non-NPN UEs to pre-occupy NPN or SNPN cells when no other cells are available, it will not instruct the UE that the SNPN or NPN cell can broadcast PWS messages when PWS messages are available.

[0069] Specific implementations of this disclosure allow non-NPN UEs (e.g., UEs that do not support NPN) to monitor PWS messages on SNPN or NPN cells that provide PWS services when no other suitable or acceptable cells are available. Furthermore, when no other suitable or acceptable cells are available, NPN-UEs that are not authorized to pre-occupy SNPN or NPN cells may pre-occupy those cells in order to receive PWS messages.

[0070] According to a specific implementation of this disclosure, a new indication is added to the SI broadcast by the cell, indicating that the cell is capable of broadcasting PWS messages. For example, this indication can be added to the MIB and / or at least one SIB (e.g., SIB1) as a new IE. This new IE may be referred to as "PWS Support". The PWS Support IE may take the enumeration value "True" to indicate that the cell is capable of broadcasting Public Alarm Messages (PWS). The cell may be an NPN cell or a non-NPN cell. The following is an exemplary implementation of PWS supporting IE to SIB1. ...For the sake of brevity, this section of text has been deleted... In the example, if PWS supports IE and is added to SIBI, the SIBI field description may include:

[0071] According to another specific embodiment of this disclosure, when no other suitable or acceptable cell is available, a non-NPN UE is allowed to monitor PWS messages on an SNPN or NPN cell that provides PWS services. Furthermore, when no other suitable or acceptable cell is available, an NPN-UE that is not authorized to pre-occupy an SNPN or NPN cell may be allowed to pre-occupy that cell in order to receive PWS messages. To achieve the above objectives, the current UE cell selection or reselection behavior in the 3GPP specification needs to be modified as follows: 5.3.1 Community Status and Community Reservations (including:) [...For the sake of brevity, the existing text in section 5.3.1 above has been deleted...] When the cell broadcasts any CAG ID or NID and the cell status is indicated as "not banned" And "not reserved" for operator use, and "true" for other uses. For future use when it is not "true": - During the cell selection and cell reselection process, all UEs that support NPN should consider the cell as a candidate. - If "PWS Support" is set to "True", then during any cell selection process, all UEs that do not support NPN should treat the cell as an "acceptable cell" and should not initiate any RACH procedure on that cell. - If "PWS support" is not present, all UEs that do not support NPN should treat the cell as "banned". [...For the sake of brevity, the existing text in section 5.3.1 below has been deleted...]. 5.2.8 Pre-occupying any cell status, including: [...For the sake of brevity, the existing text in section 5.2.8 above has been deleted...] - If the UE supports voice services and the current cell does not support IMS emergency calls, as indicated by the field ims-EmergencySupport in SIB 1 as specified in TS 38.331[3], then if no suitable cell is found, the UE should perform cell selection / reselection to an acceptable cell that supports emergency calls in any supported RAT, regardless of the priority provided in the system information from the current cell. - If "PWS Support" is set to "True", and if the NPN UE supports PWS service, and if the UE is not authorized to pre-occupy the NPN / PLMN, then the UE is allowed to pre-occupy the NPN / PLMN. However, such an NPN UE should not initiate any RACH procedure when pre-occupying the cell. [...For the sake of brevity, the existing text in section 5.2.8 below has been deleted...].

[0072] By combining the above specific implementations, UEs that cannot find any other suitable cells (non-NPN UEs or NPN UEs that have not been authorized to pre-occupy NPN / PLMN) can pre-occupy unsuitable cells (until a suitable cell is found). The unsuitable cell broadcasts PWS support IE in SIB1, indicating that the NPN can broadcast PWS messages, and if the NPN will broadcast PWS messages at some time, the UE can receive PWS messages from that cell.

[0073] Figure 1 This is a flowchart illustrating a specific implementation of this disclosure of a method 100 used by a UE to receive PWS messages on an NPN. (See flowchart for details.) Figure 1 As shown, action 102 may include receiving system information from the cell, wherein the system information includes (1) one or more network identifiers, each of which identifies a PLMN or NTN non-public network (NPN), and (2) cell status information.

[0074] In an exemplary embodiment of this disclosure, the cell may broadcast one or more CAG IDs or NIDs in the system information. In an exemplary embodiment of this disclosure, system information may include: - Cell status IE (e.g., cellBarred), which indicates whether the cell is "blocked" or... "Not prohibited"; - Reserved for use by operators in IE (e.g., cellReservedForOperatorUse). It indicates whether the cell has been reserved for use by operators; - Reserved for other uses (IE, e.g., cellReservedForOtherUse), which indicates whether a cell is reserved for other uses; - Reserved for future use (e.g., cellReservedForFutureUse) indicates whether a cell is reserved for future use.

[0075] In an exemplary embodiment of this disclosure, the system information may also include an indication of whether a cell supports PWS broadcast services. For example, a new IE (PWS Support) is added to at least one MIB and one SIB (e.g., SIBI) in the MIB. The PWS Support IE may use an enumerated value "true" to indicate that the cell is capable of broadcasting PWS messages. This cell may be an NPN cell or a non-NPN cell. If PWS Support is not present in the system information, it should be considered that the PWS broadcast service is not supported by the network in the NPN cell.

[0076] like Figure 1 As shown, action 104 may include determining whether the cell supports the PWS broadcast service. For example, if "PWS Support" is set to "True" in SIB1, the cell supports the PWS broadcast service. If "PWS Support" is not present, the cell does not support the PWS broadcast service. In one exemplary implementation, the cell may be an NPN cell.

[0077] In Action 106, if the cell does not support PWS broadcast service, and if the UE is a UE that does not support NPN (e.g., a normal UE that subscribes to PLMN but not NPN), then the UE should treat the cell as "banned".

[0078] In action 108, when the cell supports PWS broadcast service, the UE can determine whether the cell status information indicates that the cell is prohibited or will be regarded as prohibited for the UE.

[0079] In action 110, if the cell supports PWS broadcast service and the cell status information indicates that the cell is not prohibited or will be considered prohibited for the UE, the UE is allowed to pre-occupy the cell to receive one or more PWS messages and the UE is allowed to initiate a random access (RACH) procedure on the cell.

[0080] In action 112, if the cell supports PWS broadcast service, the UE is allowed to pre-occupy the cell to receive one or more PWS messages, even if the cell status information indicates that the cell is prohibited or will be regarded as prohibited for the UE.

[0081] Figure 2 This is a flowchart illustrating a method 200 used by a base station to transmit PWS messages on an NPN, according to an exemplary embodiment of this disclosure. Figure 2 As shown, action 202 may include transmitting system information to one or more UEs, wherein the system information includes (1) one or more network identifiers, each of which identifies a PLMN or NTN non-public network (NPN), and (2) cell status information.

[0082] In an exemplary embodiment of this disclosure, the cell may broadcast one or more CAG IDs or NIDs in the system information. In an exemplary embodiment of this disclosure, system information may include: - Cell status IE (e.g., cellBarred), which indicates whether the cell is "blocked" or... "Not prohibited"; - Reserved for use by operators in IE (e.g., cellReservedForOperatorUse). It indicates whether the cell has been reserved for use by operators; - Reserved for other uses (IE, e.g., cellReservedForOtherUse), which indicates whether a cell is reserved for other uses; - Reserved for future use (e.g., cellReservedForFutureUse) indicates whether a cell is reserved for future use.

[0083] In an exemplary embodiment of this disclosure, the system information may also include an indication of whether a cell supports PWS broadcast services. For example, a new IE (PWS Support) is added to at least one MIB and one SIB (e.g., SIB1) within a MIB. The PWS Support IE may use an enumerated value "true" to indicate that the cell is capable of broadcasting PWS messages. This cell may be an NPN cell or a non-NPN cell. If PWS Support is not present in the system information, it should be considered that the PWS broadcast service is not supported by the network in an NPN cell.

[0084] like Figure 2As shown, action 204 may include broadcasting one or more PWS messages, whereby non-NPN UEs and NPN-UEs (who are not normally allowed to pre-occupy the cell) may pre-occupy the cell to receive the one or more PWS messages when no other suitable or acceptable cell is available for them. It should be noted that although the UE is allowed to pre-occupy the cell to receive one or more PWS messages when PWS broadcasting service is supported in the cell and the cell status information indicates that the cell is prohibited or will be considered prohibited for use by the UE, the cell prevents the UE from initiating a random access (RACH) procedure on that cell. In other words, the UE is not allowed to initiate a RACH procedure on that cell.

[0085] As will be apparent from this disclosure, various techniques can be used to implement the concepts of this disclosure, provided that they do not depart from the scope of these concepts. Furthermore, while these concepts have been described with specific reference to certain embodiments, those skilled in the art will recognize that changes in form and detail may be made without departing from the scope of these concepts. Therefore, this disclosure is to be considered illustrative rather than restrictive in all respects. It should also be understood that this disclosure is not limited to the specific embodiments specifically described; rather, many rearrangements, modifications, and substitutions are possible without departing from the scope of this disclosure. Summary of the Invention

[0086] In one example, a user equipment (UE) includes: a receiving circuit configured to receive system information from a cell, the system information including: (1) one or more network identifiers, each of the one or more network identifiers identifying a Public Land Mobile Network (PLMN) or a Non-Public Network (NPN); and (2) cell status information; and a processing circuit configured to determine whether the cell status information indicates that the cell is blocked or will be considered blocked for the UE; wherein, if the cell supports a Public Alarm System (PWS) broadcast service, the UE is allowed to pre-occupy the cell to receive one or more PWS messages, even if the cell status information indicates that the cell is blocked or will be considered blocked for the UE.

[0087] In one example, the UE, where at least one of the one or more network identifiers identifies the PLMN, supports PWS broadcast service.

[0088] In one example, the UE, where the system information includes the PWS support information element (IE), indicates that the cell supports PWS broadcast service.

[0089] In one example, the UE, in which PWS-supported IE is included in System Information Block 1 (SIB1).

[0090] In one example, the UE, where PWS broadcast service is not supported in the cell if the system information does not contain PWS-supported IE and the one or more network identifiers all recognize NPN.

[0091] In one example, the UE, while supporting PWS broadcast service in the cell and with cell status information indicating that the cell is prohibited or will be considered prohibited for the UE, is allowed to pre-occupy the cell to receive one or more PWS messages, but is not allowed to initiate a random access (RACH) procedure on the cell.

[0092] In one example, a method performed by a user equipment (UE) includes: receiving system information from a cell, the system information including: (1) one or more network identifiers, each of the one or more network identifiers identifying a public land mobile network (PLMN) or a non-public network (NPN); and (2) cell status information; determining whether the cell status information indicates that the cell is blocked or will be considered blocked for the UE; wherein, if the cell supports a public alarm system (PWS) broadcast service, the UE is allowed to pre-occupy the cell to receive one or more PWS messages, even if the cell status information indicates that the cell is blocked or will be considered blocked for the UE.

[0093] In one example, the method wherein, if at least one of the one or more network identifiers identifies a PLMN, the cell supports PWS broadcast service.

[0094] In one example, the method is used where the cell supports PWS broadcast service if the system information includes a PWS support information element (IE).

[0095] In one example, the method, in which PWS support for IE is included in System Information Block 1 (SIB1).

[0096] In one example, the method states that if PWS broadcast service is not supported in the system information and all one or more network identifiers recognize NPN, then PWS broadcast service is not supported in the cell.

[0097] In one example, the method allows the UE to pre-occupy the cell to receive one or more PWS messages, even though PWS broadcast services are supported in the cell and the cell status information indicates that the cell is prohibited or will be considered prohibited for the UE. However, the UE is not allowed to initiate a random access (RACH) procedure on the cell.

[0098] In one example, a base station apparatus includes: a transmitting circuit configured to transmit system information to a user equipment (UE), the system information including: (1) one or more network identifiers, each of the one or more network identifiers identifying a public land mobile network (PLMN) or a non-public network (NPN); and (2) cell status information; wherein, if the cell supports a public alarm system (PWS) broadcast service, the UE is permitted to pre-occupy the cell to receive one or more PWS messages, even if the cell status information indicates that the cell is blocked or will be considered blocked for the UE.

[0099] In one example, the base station device, wherein the cell supports PWS broadcast service if at least one of the one or more network identifiers identifies the PLMN.

[0100] In one example, the base station device, wherein the cell supports PWS broadcast service when the system information includes PWS support information element (IE).

[0101] In one example, the base station device includes PWS-supported IE in System Information Block 1 (SIB1).

[0102] In one example, the base station device, wherein if the system information does not contain PWS support for IE and all one or more network identifiers recognize NPN, then PWS broadcast service is not supported in the cell.

[0103] In one example, the base station apparatus, although PWS broadcast service is supported in the cell and the cell status information indicates that the cell is prohibited or will be considered prohibited for the UE, allows the UE to pre-occupy the cell to receive one or more PWS messages, but the cell prevents the UE from initiating a random access (RACH) procedure on the cell.

[0104] In one example, a method performed by a base station device includes: transmitting system information to a user equipment (UE), the system information including: (1) one or more network identifiers, each of the one or more network identifiers identifying a public land mobile network (PLMN) or a non-public network (NPN); and (2) cell status information; wherein, if the cell supports a public alarm system (PWS) broadcast service, the UE is permitted to pre-occupy the cell to receive one or more PWS messages, even if the cell status information indicates that the cell is blocked or will be considered blocked for the UE.

[0105] In one example, the method wherein, if at least one of the one or more network identifiers identifies a PLMN, the cell supports PWS broadcast service.

[0106] In one example, the method is used where the cell supports PWS broadcast service if the system information includes a PWS support information element (IE).

[0107] In one example, the method, in which PWS support for IE is included in System Information Block 1 (SIB1).

[0108] In one example, the method states that if PWS broadcast service is not supported in the system information and all one or more network identifiers recognize NPN, then PWS broadcast service is not supported in the cell.

[0109] In one example, the method allows the UE to pre-occupy the cell to receive one or more PWS messages, even though PWS broadcast services are supported in the cell and the cell status information indicates that the cell is prohibited or will be considered prohibited for the UE. However, the cell prevents the UE from initiating a random access (RACH) procedure on the cell. <Cross-reference>

[0110] This non-provisional patent application claims priority to provisional patent application 63 / 082,559, filed on September 24, 2020, pursuant to 35 U.SC §119, the entire contents of which are incorporated herein by reference.

Claims

1. A user equipment (UE), the UE comprising: A receiving circuit configured to receive system information from a base station, the system information including: (1) One or more network identifiers, each of the one or more network identifiers identifying a Public Land Mobile Network (PLMN) or a Non-Public Network (NPN); and (2) Cell status information; and Processing circuitry, configured to determine whether cell status information indicates that the cell is blocked or will be considered blocked for use by the UE, wherein... The processing circuitry is configured to determine whether the Public Alarm System (PWS) broadcast service is supported by the cell based on whether the system information from the cell includes the PWS Support Information Element (IE). When the PWS broadcast service is supported by the cell, the UE is allowed to pre-occupy the cell to receive one or more PWS messages, even if all PLMNs and NPNs of the cell are not allowed for the UE.

2. The UE according to claim 1, wherein when the system information includes the PWS supporting IE, the cell supports the PWS broadcast service.

3. The UE according to claim 2, wherein the PWS support IE is included in system information block 1 SIB1.

4. The UE according to claim 2, wherein, If the system information does not contain information indicating that the PWS supports IE and all of the one or more network identifiers recognize NPN, then the PWS broadcast service is not supported in the cell.

5. A method performed by a user equipment (UE), the method comprising: Receive system information from the cell, the system information including: (1) One or more network identifiers, each of the one or more network identifiers identifying a Public Land Mobile Network (PLMN) or a Non-Public Network (NPN); and (2) Cell status information; Determine whether the cell status information indicates that the cell is prohibited or will be considered prohibited for use by the UE, wherein, Based on whether the system information from the cell includes the PWS support information element (IE), it is determined whether the Public Alarm System (PWS) broadcast service is supported by the cell, wherein... When the PWS broadcast service is supported by the cell, the UE is allowed to pre-occupy the cell to receive one or more PWS messages, even if all PLMNs and NPNs of the cell are not allowed for the UE.

6. A base station apparatus, the base station apparatus comprising: A transmitting circuit configured to transmit system information to a user equipment (UE), the system information including: (1) One or more network identifiers, each of the one or more network identifiers identifying a Public Land Mobile Network (PLMN) or a Non-Public Network (NPN); and (2) Cell status information; The transmission of system information via the transmitting circuit enables the UE to determine whether the cell status information indicates that the cell is blocked or will be considered blocked for use by the UE. Based on whether the system information from the cell includes the PWS support information element (IE), determine whether the Public Alarm System (PWS) broadcast service is supported by the cell, and When the PWS broadcast service is supported by the cell, the UE is allowed to pre-occupy the cell to receive one or more PWS messages, even if all PLMNs and NPNs of the cell are not allowed for the UE.

7. The base station apparatus according to claim 6, wherein when the system information includes the PWS supporting IE, the cell supports the PWS broadcast service.

8. The base station apparatus according to claim 7, wherein the PWS support IE is included in system information block 1 SIB1.

9. The base station apparatus according to claim 7, wherein, If the system information does not contain information indicating that the PWS supports IE and all of the one or more network identifiers recognize NPN, then the PWS broadcast service is not supported in the cell.

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