Methods and apparatus related to timing synchronization status reporting

Abstract

In one embodiment, a method includes receiving a message identifying at least one user equipment for which an action will be taken to increase the certainty of a user equipment reading of a timing synchronization status report; and determining an action for increasing the certainty of the user equipment to read the timing synchronization status report based at least in part on the information about the user equipment.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to UK patent application number 2211611.5 filed on August 9, 2022, the contents of which are incorporated herein by reference as if reproduced in full. Technical Field

[0003] Example embodiments relate to apparatus, methods, and computer programs, and in particular, but not limited to, apparatus, methods, and computer programs relating to timing synchronization status reporting. Background Art

[0004] When a radio access network node detects the presence of a reportable event related to a time source used by the radio access network node as a time reference, the radio access network node may broadcast a timing synchronization status report. Summary of the invention

[0005] According to one aspect, a method is provided, the method comprising: receiving a message identifying at least one user device for which action will be taken to increase certainty of the user device's reading of a timing synchronization status report; and determining an action for increasing the certainty of the user device's reading of a timing synchronization status report based at least in part on information about the user device.

[0006] The message may include: an indication of an urgency level for increasing certainty of the user equipment's reading of the timing synchronization status report; and the determining action may be based in part on the indication of the urgency level.

[0007] A timing synchronization status report may be broadcast as part of system information, and the information about the user equipment may include: information about the periodicity of reading the broadcast system information by the user equipment; and the method may include: determining at least one parameter for broadcasting the timing synchronization status report as part of the system information based on the information about the periodicity of reading the broadcast system information at the user equipment.

[0008] The at least one parameter may include a duration for which the timing synchronization status report is included in the system information.

[0009] The method may include determining whether to page the user equipment to report reading of the timing synchronization status report, wherein the determination is based at least in part on one or more of: information derived from a user equipment message, or information regarding when a user equipment message is expected.

[0010] Determining whether to page the user equipment to report the reading of the timing synchronization status report can be based at least in part on one or more of the following: information derived from one or more messages from the user equipment that include a field for indicating the reading of the timing synchronization status report, or information about when the user equipment next expects to send a message that includes a field for indicating the reading of the timing synchronization status report.

[0011] The information about the user equipment may include a radio resource control state of the user equipment, and the method may include, in response to determining that the user equipment is in a radio resource control idle mode, broadcasting a paging timing synchronization state report to the user equipment.

[0012] According to another aspect, a method is provided, comprising: receiving a message identifying at least one user equipment for which action will be taken to increase certainty of the user equipment's reading of a timing synchronization status report; paging the user equipment for a broadcast of a timing synchronization status report; and thereafter broadcasting the timing synchronization report.

[0013] According to another aspect, a method is provided, the method comprising: sending, from a user equipment, information about a periodicity of reading of a system information block at the user equipment.

[0014] According to another aspect, a method is provided, the method comprising sending, from a user equipment, an indication that an action is to be taken to increase certainty of a user equipment's reading of a timing synchronization status report.

[0015] According to another aspect, a method is provided, the method comprising: receiving a paging message indicating a broadcast of system information including a timing synchronization status report; and reading the system information indicated by the paging message.

[0016] According to another aspect, a method is provided, the method comprising sending a request identifying at least one user equipment for which an action is to be taken to increase certainty of a user equipment's reading of a timing synchronization status report.

[0017] The request may include an indication of an urgency level for increasing certainty of the user equipment's reading of the timing synchronization status report.

[0018] According to another aspect, an apparatus is provided, comprising: a component for receiving a message identifying at least one user device for which an action will be taken to increase certainty of the user device's reading of a timing synchronization status report; and a component for determining an action for increasing certainty of the user device's reading of a timing synchronization status report based at least in part on information about the user device.

[0019] The message may include: an indication of an urgency level for increasing certainty of the user equipment's reading of the timing synchronization status report; and the determining action may be based in part on the indication of the urgency level.

[0020] A timing synchronization status report may be broadcast as part of system information, and the information about the user equipment may include: information about the periodicity of reading the broadcast system information by the user equipment; and the apparatus may include: a component for determining at least one parameter for broadcasting the timing synchronization status report as part of the system information based on the information about the periodicity of reading the broadcast system information at the user equipment.

[0021] The at least one parameter may include a duration for which the timing synchronization status report is included in the system information.

[0022] The apparatus may include means for determining whether to page the user equipment to report reading of the timing synchronization status report based at least in part on one or more of: information derived from a user equipment message, or information regarding when a user equipment message is expected.

[0023] Determining whether to page the user equipment to report the reading of the timing synchronization status report can be based at least in part on one or more of the following: information derived from one or more messages from the user equipment that include a field for indicating the reading of the timing synchronization status report, or information about when the user equipment next expects to send a message that includes a field for indicating the reading of the timing synchronization status report.

[0024] The information about the user equipment may include a radio resource control state of the user equipment, and the apparatus may include means for broadcasting a paging timing synchronization state report to the user equipment in response to determining that the user equipment is in a radio resource control idle mode.

[0025] According to another aspect, an apparatus is provided, comprising: a component for receiving a message identifying at least one user equipment for which action will be taken to increase certainty of the user equipment's reading of a timing synchronization status report; a component for broadcasting a paging timing synchronization status report to the user equipment; and a component for thereafter broadcasting the timing synchronization report.

[0026] According to another aspect, a user equipment is provided, the user equipment comprising means for sending information about the periodicity of reading of system information blocks at the user equipment.

[0027] According to another aspect, there is provided a user equipment comprising means for sending an indication that an action is to be taken to increase certainty of the user equipment's reading of a timing synchronization status report.

[0028] According to another aspect, a user equipment is provided, the user equipment comprising: means for receiving a paging message indicating a broadcast of system information including a timing synchronization status report; and means for reading the system information indicated by the paging message.

[0029] According to another aspect, an apparatus is provided that includes means for sending a request identifying at least one user equipment for which actions are to be taken to increase certainty of the user equipment's reading of a timing synchronization status report.

[0030] The request may include an indication of an urgency level for increasing certainty of the user equipment's reading of the timing synchronization status report.

[0031] According to another aspect, a device is provided, comprising: at least one processor; and at least one memory comprising computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to perform: receiving a message identifying at least one user device for which an action will be taken to increase certainty of the user device's reading of a timing synchronization status report; and determining an action for increasing certainty of the user device's reading of a timing synchronization status report based at least in part on information about the user device.

[0032] The message may include: an indication of an urgency level for increasing certainty of the user equipment's reading of the timing synchronization status report; and the determining action may be based in part on the indication of the urgency level.

[0033] A timing synchronization status report may be broadcast as part of system information, and the information about the user equipment may include: information about the periodicity of reading the broadcast system information by the user equipment; and the at least one memory and the computer program code may be configured, together with the at least one processor, to cause the apparatus to: determine at least one parameter for broadcasting a timing synchronization status report as part of the system information based on the information about the periodicity of reading the broadcast system information at the user equipment.

[0034] The at least one parameter may include a duration for which the timing synchronization status report is included in the system information.

[0035] The at least one memory and the computer program code may be configured, together with the at least one processor, to cause the apparatus to: determine whether to page a user equipment to report a reading of a timing synchronization status report based at least in part on one or more of: information derived from a user equipment message, or information regarding when a user equipment message is expected.

[0036] The at least one memory and the computer program code may be configured, together with the at least one processor, to cause the apparatus to: determine whether to page the user equipment to report the reading of a timing synchronization status report based at least in part on one or more of: information derived from one or more messages from the user equipment including a field for indicating the reading of a timing synchronization status report, or information about when the user equipment next expects to send a message including a field for indicating the reading of a timing synchronization status report.

[0037] The information about the user equipment may include: a radio resource control state of the user equipment, and the at least one memory and the computer program code may be configured, together with the at least one processor, to cause the apparatus to: in response to determining that the user equipment is in a radio resource control idle mode, broadcast a paging timing synchronization status report to the user equipment.

[0038] According to another aspect, a device is provided, comprising: at least one processor; and at least one memory comprising computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to perform: receiving a message identifying at least one user equipment for which actions will be taken to increase certainty of the user equipment's reading of a timing synchronization status report; broadcasting a paging timing synchronization status report to the user equipment; and thereafter broadcasting the timing synchronization report.

[0039] According to another aspect, a user equipment is provided, comprising: at least one processor; and at least one memory comprising computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the user equipment to execute: sending information about the periodicity of reading of system information blocks at the user equipment.

[0040] According to another aspect, a user equipment is provided, comprising: at least one processor; and at least one memory comprising computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the user equipment to execute: sending an indication of an action to be taken to increase certainty of the user equipment's reading of a timing synchronization status report.

[0041] According to another aspect, a user equipment is provided, comprising: at least one processor; and at least one memory comprising computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the user equipment to execute: receiving a paging message indicating a broadcast of system information including a timing synchronization status report; and reading the system information indicated by the paging message.

[0042] According to another aspect, a device is provided, comprising: at least one processor; and at least one memory comprising computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to execute: sending a request to identify at least one user equipment, for which action will be taken to increase certainty of the user equipment's reading of a timing synchronization status report.

[0043] The request may include an indication of an urgency level for increasing certainty of the user equipment's reading of the timing synchronization status report.

[0044] According to another aspect, an apparatus is provided, comprising: a receiving circuit system for receiving a message identifying at least one user device for which an action will be taken to increase certainty of the user device's reading of a timing synchronization status report; and a determining circuit system for determining an action for increasing certainty of the user device's reading of a timing synchronization status report based at least in part on information about the user device.

[0045] According to another aspect, an apparatus is provided, comprising: a receiving circuit system for receiving a message identifying at least one user device for which action will be taken to increase certainty of the user device's reading of a timing synchronization status report; a paging circuit system for broadcasting a timing synchronization status report to the user device; and a broadcast circuit system for thereafter broadcasting the timing synchronization report.

[0046] According to another aspect, there is provided a user equipment comprising: transmitting circuitry for transmitting information regarding a periodicity of reading of system information blocks at the user equipment.

[0047] According to another aspect, there is provided a user equipment comprising transmitting circuitry for transmitting an indication that an action is to be taken to increase certainty of a user equipment reading of a timing synchronization status report.

[0048] According to another aspect, a user equipment is provided, the user equipment comprising: receiving circuitry for receiving a paging message indicating a broadcast of system information including a timing synchronization status report; and reading circuitry for reading the system information indicated by the paging message.

[0049] According to another aspect, an apparatus is provided that includes transmitting circuitry for transmitting a request identifying at least one user equipment for which actions are to be taken to increase certainty of a user equipment's reading of a timing synchronization status report.

[0050] According to another aspect, a computer-readable medium is provided that includes program instructions stored thereon, the program instructions being used to perform: receiving a message identifying at least one user device for which actions will be taken to increase certainty of the user device's reading of a timing synchronization status report; and determining, based at least in part on information about the user device, an action for increasing certainty of the user device's reading of a timing synchronization status report.

[0051] According to another aspect, a computer-readable medium is provided that includes program instructions stored thereon, the program instructions being used to execute: receiving a message identifying at least one user device for which action will be taken to increase certainty of the user device's reading of a timing synchronization status report; broadcasting a paging timing synchronization status report to the user devices; and thereafter broadcasting the timing synchronization report.

[0052] According to another aspect, a computer readable medium comprising program instructions stored thereon for executing: sending, from a user equipment, information regarding a periodicity of reading of system information blocks at the user equipment.

[0053] According to another aspect, a computer readable medium is provided comprising program instructions stored thereon for executing: sending an indication from a user equipment that an action is to be taken to increase certainty of a user equipment reading of a timing synchronization status report.

[0054] According to another aspect, a computer readable medium including program instructions stored thereon for executing: receiving a paging message indicating a broadcast of system information including a timing synchronization status report; and reading the system information indicated by the paging message.

[0055] According to another aspect, a computer readable medium is provided including program instructions stored thereon for executing: sending a request identifying at least one user equipment for which actions are to be taken to increase certainty of user equipment reading of a timing synchronization status report.

[0056] According to another aspect, a non-transitory computer-readable medium is provided, comprising program instructions stored thereon, the program instructions being used to perform: receiving a message identifying at least one user device for which actions will be taken to increase certainty of the user device's reading of a timing synchronization status report; and determining, based at least in part on information about the user device, an action for increasing certainty of the user device's reading of a timing synchronization status report.

[0057] According to another aspect, a non-transitory computer-readable medium is provided that includes program instructions stored thereon, the program instructions being used to execute: receiving a message identifying at least one user device for which action will be taken to increase certainty of the user device's reading of a timing synchronization status report; broadcasting a paging timing synchronization status report to the user devices; and thereafter broadcasting the timing synchronization report.

[0058] According to another aspect, a non-transitory computer readable medium including program instructions stored thereon for executing: sending, from a user equipment, information regarding a periodicity of reading of a system information block at the user equipment.

[0059] According to another aspect, a non-transitory computer readable medium comprising program instructions stored thereon for executing: sending an indication from a user equipment that an action is to be taken to increase certainty of a user equipment reading of a timing synchronization status report.

[0060] According to another aspect, a non-transitory computer readable medium including program instructions stored thereon for executing: receiving a paging message indicating a broadcast of system information including a timing synchronization status report; and reading the system information indicated by the paging message.

[0061] A non-transitory computer readable medium including program instructions stored thereon for executing: sending a request identifying at least one user equipment for which actions are to be taken to increase certainty of the user equipment's reading of a timing synchronization status report.

[0062] According to another aspect, a computer program comprising computer executable code is provided, which, when executed on at least one processor, is configured to cause an apparatus to at least: receive a message identifying at least one user device for which action will be taken to increase certainty of the user device's reading of a timing synchronization status report; and determine, based at least in part on information about the user device, an action for increasing certainty of the user device's reading of a timing synchronization status report.

[0063] According to another aspect, there is provided a computer program comprising computer executable code, which, when executed on at least one processor, is configured to cause an apparatus to at least: receive a message identifying at least one user equipment for which action is to be taken to increase certainty of the user equipment's reading of a timing synchronization status report; broadcast a paging timing synchronization status report to the user equipment; and thereafter broadcast the timing synchronization report.

[0064] According to another aspect, there is provided a computer program comprising computer executable code which, when executed on at least one processor, is configured to cause a user equipment to at least: send information about a periodicity of reading of system information blocks at the user equipment.

[0065] According to another aspect, there is provided a computer program comprising computer executable code which, when executed on at least one processor, is configured to cause a user equipment to at least: send an indication that an action is to be taken to increase certainty of a user equipment reading of a timing synchronization status report.

[0066] According to another aspect, there is provided a computer program comprising computer executable code, which, when executed on at least one processor, is configured to cause a user equipment to at least: receive a paging message indicating a broadcast of system information including a timing synchronization status report; and read the system information indicated by the paging message.

[0067] According to another aspect, there is provided a computer program comprising computer executable code, which, when executed on at least one processor, is configured to cause an apparatus to at least: send a request to identify at least one user equipment for which action is to be taken to increase certainty of the user equipment's reading of a timing synchronization status report.

[0068] In the above, many different aspects have been described. It should be understood that other aspects can be provided by combining any two or more of the above aspects.

[0069] Various other aspects are also described in the following detailed description and appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Some example embodiments will now be described in more detail, by way of example only, with reference to the following examples and accompanying drawings, in which:

[0071] Figure 1 An example mobile communication system is shown in which some example embodiments may be applied;

[0072] Figure 2 According to some example embodiments Figure 1 representation of examples of operations on some elements of;

[0073] Figure 3 According to some example embodiments Figure 1 representation of examples of operations on some elements of;

[0074] Figure 4 According to some example embodiments Figure 1representation of examples of operations on some elements of;

[0075] Figure 5 According to some example embodiments Figure 1 representation of examples of operations on some elements of;

[0076] Figure 6 According to some example embodiments Figure 1 representation of examples of operations on some elements of;

[0077] Figure 7 A representation showing an example of an apparatus for implementing user equipment functionality or access node functionality according to some example embodiments is shown;

[0078] Figure 8 A representation showing an example of an apparatus for implementing a network function according to some example embodiments; and

[0079] Fig. 9 A representation of an example of a non-volatile storage medium is shown. DETAILED DESCRIPTION

[0080] As an example, the following description focuses on an example of a mobile communication system operating according to 3GPP 5G technology, but the underlying technology may also be applicable to systems operating according to other technologies (such as more evolved 3GPP technologies).

[0081] Figure 1 A simple representation of one example of a 3GPP 5G system architecture is shown. Figure 1 All cells shown are logic cells. Figure 1 The connections shown are logical connections; the actual physical connections may be different. 5G systems may include Figure 1 Other functions and structures than those shown.

[0082] The core network can provide connectivity between devices implementing user equipment functions (UE) and one or more data networks (DN) via a new generation radio access network (NG-RAN), which includes a network of devices implementing instances of gNB (gNodeB) functions.

[0083] The gNB (i) is connected to the User Plane Function (UPF) of the Core Network (CN) to route and forward user data packets and provide the device with connectivity to one or more external packet data networks (DNs), and (ii) is connected to the Access Mobility Management Function (AMF) of the Core Network (CN) to control the UE's access and change of serving cells.

[0084] The term "user equipment" (UE) may refer to any device, apparatus, or component that implements at least 3GPP user equipment (UE) functionality.

[0085] A UE may be a mobile or static device (e.g., a portable or non-portable computing device), including but not limited to the following types of devices: mobile phones, smartphones, personal digital assistants (PDAs), handheld devices, devices using wireless modems (alarm or measurement devices, etc.), laptops and / or touch screen computers, tablets, game consoles, notebook computers, and multimedia devices. It should be understood that a UE device may also be almost exclusively an uplink-only device, an example of which is a camera or video camera that loads images or video clips to a network. A UE device may also be a device capable of operating in an Internet of Things (IoT) network, in which case objects are able to transmit data over a network without human-to-human or human-to-computer interaction, such as for smart grids and connected vehicles. The device may also use the cloud. In some applications, a UE device may include a user-portable device with a radio component (such as a watch, headphones, or glasses), and the computation is performed in the cloud.

[0086] 5G enables the use of multiple-input multiple-output (MIMO) antennas and may involve a large number of base stations (gNBs), including macro sites that operate in cooperation with smaller base stations and employ various radio technologies depending on service requirements, use cases and / or available spectrum. 5G mobile communications support a wide range of use cases and related applications, including video streaming, augmented reality, different data sharing methods, and various forms of machine-type applications (such as (massive) machine-type communications (mMTC), including vehicle safety, different sensors, and real-time control). 5G can use multiple frequency bands, such as cmWave and mmWave below 6GHz or above 24GHz, and can also be integrated with existing traditional radio access technologies (such as LTE). Integration with LTE can be implemented as a system in which macro coverage is provided by LTE and 5G radio interface access comes from small cells by aggregation to LTE. In other words, 5G can support inter-RAT operability (such as LTE-5G) and inter-RI operability (inter-radio interface operability, such as below 6GHz-cmWave, 6 or above 24GHz-cmWave and mmWave). 5G networks can adopt network slicing, in which multiple independent and dedicated virtual subnets (network instances) can be created within the same infrastructure to run services with different requirements for latency, reliability, throughput, and mobility.

[0087] Low-latency applications and services can be facilitated by bringing content close to 5G systems, enabling local breakout and multi-access edge computing (MEC). 5G enables analysis and knowledge generation at the data source. This approach can involve leveraging resources that may not be continuously connected to the network, such as laptops, smartphones, tablets, and sensors. MEC provides a distributed computing environment for application and service hosting. It also enables storage and processing of content near cellular subscribers for faster response times. Edge computing covers a wide range of technologies, such as wireless sensor networks, mobile data acquisition, mobile signature analysis, collaborative distributed peer-to-peer networking and processing, and can also be categorized as local cloud / fog computing and mesh / grid computing, dew computing, mobile edge computing, cloudlet, distributed data storage and retrieval, autonomous self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (massive connectivity and / or latency critical), critical communications (autonomous vehicles, traffic safety, real-time analysis, time-critical control, healthcare applications).

[0088] 5G can also make use of satellite communications to enhance or complement the coverage of 5G services, for example by providing backhaul services. Possible use cases are to provide service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices or for passengers on board vehicles, mobile broadband (MBB), or to ensure service availability for critical communications and future railway / maritime / aeronautical communications. Satellite communications can make use of geostationary orbit (GEO) satellite systems, but also low earth orbit (LEO) satellite systems, in particular mega-constellations (systems in which hundreds of (nano) satellites are deployed). Each satellite in a mega-constellation can cover the network entities of several satellite-enabled satellites creating a terrestrial cell. A terrestrial cell can be created by a terrestrial relay node or by a gNB located on the ground or in a satellite.

[0089] 5GC adopts a service-based architecture (SBA), according to which communication between network functions uses a service-based interface (SBI). An application programming interface (API) is used for SBI.

[0090] Example embodiments are described below for the example of a 3GPP ASTI (Access Stratum Time Information) service, through which an Application Function (AF) can request time synchronization as a service for a UE or UE group. The Time Sensitive Communication and Time Synchronization Function (TSCTSF) is a network function that is responsible for receiving time synchronization requests from the AF and configuring the service within the 5GS.

[0091] For example, delivering 5G clock (e.g., UTC) information to the UE may involve the gNB providing the 5G timing information to the UE via the Uu interface using, for example, system information block SIB9. The 5G timing information may be included in a reference time information (RTI) information element in the system information block SIB9.

[0092] Figure 2 Representations of examples of operations according to some example embodiments are shown.

[0093] An application function (AF) external to the 5G core network (5GC) sends an Nnef_ASTISubscribeRequest message to the network exposure function (NEF) of the 5GC. The message includes the identifier of one or more target UEs and includes a guaranteed TSS RX flag set to "ON", which indicates that the network will take action to ensure that the target UE receives TSS reports. The message may also indicate the urgency level.

[0094] In response to receiving the Nnef_ASTISubscribeRequest message, the NEF sends an Ntsctsf_ASTISubscribeRequest message to the TSCTSF of the 5GC. The Ntsctsf_ASTISubscribeRequest message also identifies one or more target UEs and includes a guaranteed timing synchronization state (TSS) reception (RX) flag set to "ON", which indicates that the network will take action to ensure that the target UE receives the TSS report. If the Nnef_ASTISubscribeRequest message from the AF includes an emergency level indicator, the Ntsctsf_ASTISubscribeRequest to the TSCTSF also includes an emergency level indicator.

[0095] The TSCTSF issues one or more discovery requests to the Network Repository Function (NRF) of the 5GC, which is used to discover the addresses of one or more AMF instances currently associated with the target UE identified in the Ntsctsf_ASTISubscribeRequest message.

[0096] TSCTSF sends one or more Namf_NonUeN2MsgTransfer messages to one or more AMF instances discovered via NRF. The Namf_NonUeN2MsgTransfer message to each AMF instance indicates the target UE and includes a guaranteed TSS RX flag set to "ON", which indicates that the network will take action to ensure that the target UE receives the TSS report. If the Ntsctsf_ASTISubscribeRequest message includes an urgency level indicator, the Namf_NonUeN2MsgTransfer message also includes an urgency level indicator.

[0097] The AMF sends a Next Generation Application Protocol (NGAP):TSS Report Control message to one or more NG-RAN gNBs. The NGAP:TSS Report Control message to each AMF instance indicates the target UE and includes a Guaranteed TSS RX flag set to "ON", which indicates that the network will take actions to ensure that the target UE receives TSS reports. If the Namf_NonUeN2MsgTransfer message from the TSC TSF includes an urgency level indicator, the NGAP:TSS Report Control message to the gNB also includes an urgency level indicator.

[0098] In the above example, the TSC TSF's request for RAN TSS reports to the AMF and forwarding of these requests to the gNB is done via node level signalling, but this can also be achieved via, for example, UE associated signalling.

[0099] An example of an alternative to the AF requesting (via the Expose Framework) guaranteed reception of the RAN TSS at one or more UEs is to have one or more UEs make a direct request to the gNB. The gNB then forwards an indication of the request to the TSCTSF (via the AMF) to make the TSCTSF aware of the request. Such a direct request by the UE may be made directly via RRC signaling. For example, in addition to the information element UEAssistanceInformation IE that the UE may use to indicate a preference for RTI provisioning, a new information element (IE) may be included as part of the RRC signaling.

[0100] Figure 3 Representations of further operations at a gNB are shown that have received an NGAP:TSS REPORTING CONTROL message identifying one or more UEs with an RRC INACTIVE state, in accordance with some example embodiments.

[0101] A primary source event (e.g., detection of network timing synchronization degradation / failure / improvement / recovery at the gNB) triggers the gNB to generate a TSS report, include the TSS report in system information (e.g., System Information Block (SIB9)) broadcast by the gNB, and send the TSS report to the AMF instance associated with the gNB. The SIB9 broadcast by the gNB includes a field including Reference Time Information (RTI) and a field including the TSS report.

[0102] For each RRC INACTIVE UE identified in the NGAP:TSS REPORTING CONTROL message received from the AMF instance, the gNB has information about the periodicity with which the UE reads the SIBs. For example, when the UE has RRC CONNECTED state (e.g. Figure 3 ), the gNB may have received this information directly from the UE, or the gNB may have received this information from the AF via the TCSTF and AMF. For a duration based on the information about the periodicity of the UE reading SIB9, the gNB continues to include the TSS report in the SIB9 broadcast, thereby increasing the certainty that the UE reads the TSS report. Including the TSS report in more than one SIB9 broadcast is used to confirm that the UE reads the TSS report. For example, the gNB continues to include the RAN TSS report in the SIB9 broadcast for a period of time that is longer than the UE's SIB9 reading periodicity.

[0103] Figure 4 Representations of gNB operations according to some other example embodiments are shown.

[0104] A primary source event (e.g., detection of network timing synchronization degradation / failure / improvement / recovery at the gNB) triggers the gNB to generate a TSS report, include the TSS report in system information (e.g., System Information Block (SIB9)) broadcast by the gNB, and send the TSS report to the AMF instance associated with the gNB. The SIB9 broadcast by the gNB includes: a field including Reference Time Information (RTI), and a field including the TSS report.

[0105] A UE in RRC INACTIVE state may have one or more internal triggers to re-establish a connection with the gNB (and switch to RRC_CONNECTED state) for a primary purpose other than reporting the reading of a TSS report. RRC signalling messages subsequently sent by the UE may be adapted to have an additional (secondary purpose) field for indicating that the UE has read a TSS report. The information the gNB has about the UE may include information derived from these RRC signalling messages from the UE and / or (in the case where the RRC signalling has a time-based trigger) information about when the UE next expects to send such RRC signalling. The gNB shall refrain from paging the UE to switch to RRC CONNECTED state for the primary purpose of reporting the reading of a TSS report if the information provided by these RRC signalling messages satisfies the urgency level specified in the NGAP:TSS REPORTING CONTROL message from the AMF or (if no urgency level was specified in the NGAP:TSS REPORTING CONTROL message from the AMF) a default urgency level stored at the gNB. On the other hand, if the information provided by these RRC signaling messages does not conform to or cannot satisfy the urgency level specified in the NGAP:TSS Reporting Control message from the AMF, or (if no urgency level was specified in the NGAP:TSS Reporting Control message from the AMF) the default urgency level stored at the gNB, the gNB will continue to page the UE to trigger the UE to switch to the RRC CONNECTED state for the primary purpose of confirming the reading of the TSS report. In either case, the gNB receives an explicit confirmation that the UE has read the TSS report, thereby increasing the certainty at the gNB that the UE has read the TSS report.

[0106] For example, the gNB may start a timer when broadcasting a TSS report (as part of SIB9). The timer may have a value determined by the urgency level indicated in the NGAP:TSS Reporting Control message from the AMF, or if the urgency level is not indicated in the NGAP:TSS Reporting Control message from the AMM, the timer may have a default value. If, at the time of expiration of the timer, the gNB has not received any RRC signaling from the UE indicating the reading of the TSS report, the gNB may, for example, determine to page the UE itself (under the control of the gNB) to check whether the UE has read the TSS report via SIB9. In the case where there is more than one such UE, the gNB may control the paging of multiple UEs to ensure that random access by multiple UEs is randomized. An example of an alternative action upon expiration of the timer is for the gNB to notify the TSCTSF of one or more UEs for which the gNB has not received RRC signaling indicating the reading of the TSS report. The TSCTSF will then control the paging of these UEs to the TSCTSF, thereby centralizing the management of the UEs at the TSCTSF.

[0107] A periodic control procedure that may be adapted for an additional secondary purpose of providing information to the gNB regarding the reading of a TSS report may involve RRC signaling that is, for example, time-triggered, mobility-triggered, or event-triggered. For example, a mobility registration update message (RRC signaling with a mobility-based trigger) may include an additional (e.g., 1-bit) field for the UE to indicate the reading of a TSS report; and the TSC TSF may influence the AMF to configure a smaller registration area for the UE with the goal of increasing the probability that the gNB receives an indication of the reading of a TSS report via a mobility registration update message in a timely manner to avoid paging the UE to switch to an RRC connected state for the primary purpose of reporting the reading of a TSS report. As another example, a periodic registration update message (controlled by a periodic registration update timer 3512) or an RNA update message (controlled by a timer T380) may include an additional (e.g., 1-bit) field for the UE to indicate the reading of a TSS report. The gNB may have information about when the UE next expects to send these time-triggered RRC signaling messages, and the gNB may determine in time whether such a message is expected from the UE to avoid paging the UE to switch to the RRC CONNECTED state for the primary purpose of reporting the reading of the TSS report.

[0108] Figure 5 Representations of example operations at a gNB and TSCTSF are shown according to some example embodiments.

[0109] A primary source event (e.g., detection of network timing synchronization degradation / failure / improvement / recovery at the gNB) triggers the gNB to generate a TSS report, include the TSS report in system information (e.g., System Information Block (SIB9)) broadcast by the gNB, and send the TSS report to the AMF instance associated with the gNB. The SIB9 broadcast by the gNB includes: a field including Reference Time Information (RTI), and a field including the TSS report.

[0110] For each target UE (target UE identified in the NGAP:TSS Reporting Control message received from the AMF instance) for which information at the gNB indicates that the UE does not have RRC INACTIVE state (or RRC CONNECTED state), the gNB takes no action to increase the certainty that the UE has read the TSS report. In response to receiving a TSS report from the gNB via the AMF, the TSCTSF determines which target UEs (among the target UEs identified in the Ntsctsf_SubscribeRequest message sent from the AF via the NEF) have RRC IDLE state and have had some recent association with the gNB from which the TSS report was received. For this subset of target UEs, the TSCTSF initiates message paging to instruct the gNB on the broadcast of the TSS report. This action increases the certainty that RRC IDLE state UEs residing on a cell operated by the gNB will read the TSS report broadcast by the gNB.

[0111] Figure 6 Representations of examples of operations at a gNB according to some example embodiments are shown.

[0112] A primary source event (e.g., detection of network timing synchronization degradation / failure / improvement / recovery at the gNB) triggers the gNB to generate a TSS report, include the TSS report in system information (e.g., System Information Block (SIB9)) broadcast by the gNB, and send the TSS report to the AMF instance associated with the gNB. The SIB9 broadcast by the gNB includes a field indicating reference time information (RTI) and a field including the TSS report.

[0113] For each target UE (target UE identified in the NGAP:TSS Reporting Control message received from the AMF instance) for which the gNB has information indicating that the UE is camped in RRC INACTIVE state on a cell operated by the gNB, the gNB pages the UE to inform the UE of the upcoming broadcast of SIB9 including the TSS report. The UE is thus aware that the next broadcast of SIB9 includes the TSS report and reads the next broadcast of SIB9. This action of the gNB increases the certainty that the target UE reads the TSS.

[0114] The above example involving the gNB using information about the periodicity of SIB9 readings of the UE, and the above example involving the gNB sending a paging message indicating that the upcoming SIB9 broadcast will include a RAN TSS report, are examples of implicit confirmation techniques that may better avoid RAN congestion that may result from a large number of UEs reconnecting in response to the same event.

[0115] Some features of some example embodiments are as follows:

[0116] The AF may request guaranteed / confirmed receipt of a 5G network timing synchronization status report for a UE or (multiple) UE groups. For example, an additional flag is added to the exposure API between the AF and the TSCTSF. The AF may indicate how urgent a confirmation is required to influence how to react in the event that the UE does not receive a 5G RAN timing synchronization status report from the RAN.

[0117] The 5GS (gNB or TSCTSF) ensures that the UE reads the 5G RAN timing synchronization status report. Multiple options include:

[0118] (a) The RAN timing synchronization status report within the SIB is reported for a long time (or always) within the cell. It is up to the gNB to decide how often (or whether it is always provided) the RAN timing synchronization status report should be provided. To assist in this decision, the UE can indicate to the gNB the periodicity with which the UE reads SIB9 before the UE releases or suspends the RRC connection. This indication from the UE can have two purposes at the gNB: i) enable the gNB to determine the minimum period with which it should repeat the RAN timing synchronization status report to ensure that the UE will read the timing synchronization status report, and ii) let the gNB know that the UE requires this guaranteed reception of the report (i.e. as an alternative to the AF requesting guaranteed reception of the 5G network timing synchronization status report).

[0119] (b) The gNB or TSCTSF may rely on a periodic control procedure performed by the UE with the network based on an event trigger (e.g., time-based, mobility-based, or other event-based) to expect the UE to confirm the receipt of the RAN timing synchronization status report. For this confirmation, the UE may add a bit in the signaling message sent by the UE to the network.

[0120] (c) The gNB may page the UE to indicate that the upcoming SIB9 will include a RAN timing synchronization status report. If the UE is in RRC_IDLE / INACTIVE state,

[0121] There is no need to reconnect to the network, and the UE reads the subsequent SIB9 after paging.

[0122] (d) The gNB or TSCTSF may rely on paging the UE. The paging message may again include a RAN timing synchronization status report broadcast in the cell, and when the UE reconnects to the network due to paging, it may add a bit to acknowledge receipt of the report.

[0123] This may avoid multiple UEs attempting to reconnect within a short period of time (i.e., allowing the gNB or TSCTSF to control access to the network so that reconnections are not associated with new reporting events).

[0124] If guaranteed / confirmed reception of the UE's 5G RAN timing synchronization status report is required, the AF may include a flag to indicate the need for guaranteed / confirmed reception and may also include a value indicating the urgency level at which confirmation is required.

[0125] If guaranteed / confirmed reception of the UE's 5G RAN timing synchronization status report is required, the UE is in RRC_INACTIVE / IDLE state, and the gNB decides to broadcast the report in the cell using SIB9, the gNB may repeat the report for a longer period of time within the SIB9 in the cell to ensure that the UE will read the report. To determine how long the gNB should repeat the report, the gNB may use additional information provided by the AF and forwarded via the TSCTSF / AMF (i.e., the target UE requiring such guaranteed mode) or by the UE (e.g., the UE indicates how often the SIB9 will be read before changing to RRC_INACTIVE / IDLE). The gNB or TSCTSF is responsible for determining how guaranteed / confirmed reception of the UE's RAN timing synchronization status report is achieved (e.g., relying on upcoming control procedures that the UE may perform with the gNB due to time / mobility / event-based triggers; or using a paging message to indicate to the UE that the upcoming SIB9 will include a RAN timing synchronization status report for the UE to read; or RAN / CN initiated paging, etc.).

[0126] If guaranteed / confirmed reception of the UE's 5G RAN Timing Synchronization Status Report is required and the gNB decides to send this report to the UE via SIB9, the gNB may use different methods to allow the UE to read the RAN Timing Synchronization Status Report.

[0127] If guaranteed / confirmed reception of the UE’s 5G RAN timing synchronization status report is supported, the UE may indicate the frequency on which it will read SIB9 to the gNB.

[0128] Figure 7 The diagram shows the Figure 1An example of an apparatus implementing UE or RAN access node functionality in an architecture of . The apparatus may include at least one processor 802 coupled to one or more interfaces 808. For a UE, the one or more interfaces 808 may include, for example, one or more interfaces to (multiple) other devices / components for which the UE functionality provides radio communications. For a RAN access node, the one or more interfaces 808 may include, for example, an interface to a core network node that implements core network functions (such as AMF, UPF, etc.). At least one processor 802 is also coupled to a radio unit 804 including one or more antennas, etc., to perform and receive radio transmissions. At least one processor 802 may also be coupled to at least one memory 806. At least one processor 802 may be configured to execute appropriate software code to perform the above operations. The software code may be stored in the memory 806.

[0129] Figure 8 The diagram shows the Figure 1 The apparatus may include at least one processor 902 coupled to one or more interfaces 908 for communication with other core network functions or NG-RAN (new generation radio access network) nodes. The at least one processor 902 may also be coupled to at least one memory 906. The at least one processor 902 may be configured to execute appropriate software code to perform the above operations. The software code may be stored in the memory 906.

[0130] Fig. 9 Schematic diagrams of non-volatile storage media 1100a (e.g., a computer compact disc (CD) or digital versatile disc (DVD)) and 1100b (e.g., a universal serial bus (USB) memory stick) storing instructions and / or parameters 1102 that, when executed by a processor, enable the processor to perform one or more steps of the method described above.

[0131] It should be noted that the example embodiments may be implemented as circuitry in software, hardware, application logic, or a combination of software, hardware, and application logic. In the example embodiments, the application logic, software, or instruction set is maintained on any computer-readable medium. In the context of this document, a "computer-readable medium" may be any medium or component that can contain, store, communicate, propagate, or transmit instructions for use by or in conjunction with an instruction execution system, apparatus, or device, such as a base station or user equipment of the above-described example embodiments.

[0132] As used in this application, the term "circuitry" refers to all of the following: (a) hardware circuit implementations only (such as implementations in analog and / or digital circuitry only); and (b) combinations of circuits and software (and / or firmware), such as (as applicable): (i) a combination of (multiple) processors, or (ii) portions of (multiple) processors / software (including (multiple) digital signal processors), software, and (multiple) memories, which work together to enable an apparatus (such as the user equipment or base station of the above-mentioned embodiments) to perform various functions); and (c) circuits, such as (multiple) microprocessors or portions of (multiple) microprocessors, which require software or firmware to operate, even if the software or firmware is not physically present. This definition of "circuitry" applies to all uses of the word "component" in this application, including in any claims. As another example, as used in this application, the term "circuitry" would also cover implementations of hardware circuits or processors (or multiple processors) or portions of hardware circuits or processes and their accompanying software and / or firmware. For example, the term "circuitry" would also cover, if applicable to the particular claim element, a baseband integrated circuit or an application processor integrated circuit for a mobile phone, or a similar integrated circuit in a server, cellular network equipment, or other network equipment.

[0133] The features, advantages and characteristics described herein may be combined in any suitable manner in one or more example embodiments. Those skilled in the relevant art will recognize that such example embodiments may be practiced without one or more specific features or advantages of a particular embodiment. In other cases, additional features and advantages that may not be present in all example embodiments may be recognized in certain embodiments. It will be readily appreciated by those of ordinary skill in the art that the example embodiments described above may be practiced with steps in different orders and / or with hardware elements of configurations different from the disclosed configurations. Therefore, although some embodiments have been described based on these example embodiments, it will be appreciated by those skilled in the art that certain modifications, variations and alternative constructions will be clear while still within the spirit and scope of the example embodiments.

Claims

1. A method comprising: receiving a message identifying at least one user equipment for which actions are to be taken to increase certainty of reading of a timing synchronization status report by the user equipment; as well as Based at least in part on the information about the user equipment, an action is determined for increasing certainty of reading of the timing synchronization status report by the user equipment.

2. The method according to claim 1, wherein the message comprises: an indication of an urgency level for increasing certainty of reading of the timing synchronization status report by the user equipment; and wherein the determining action is based in part on the indication of the urgency level.

3. The method of claim 1 , wherein the timing synchronization status report is broadcast as part of system information, wherein the information about the user equipment comprises: Information about the periodicity of reading broadcast system information by the user equipment; and Therein the method comprises determining at least one parameter for the broadcasting of the timing synchronization status report as part of system information based on the information about the periodicity of reading of broadcast system information at the user equipment.

4. The method of claim 3, wherein the at least one parameter comprises: The duration for which the timing synchronization status report is included in the system information.

5. The method according to claim 1 or 2, comprising: Determining whether to page the user equipment to report reading of the timing synchronization status report, wherein the determination is based at least in part on one or more of: information derived from a user equipment message, or information regarding when a user equipment message is expected.

6. A method according to claim 5, wherein determining whether to page the user equipment to report the reading of the timing synchronization status report is based at least in part on one or more of the following items: information derived from one or more messages from the user equipment that include a field for indicating the reading of the timing synchronization status report, or information about when the user equipment next expects to send a message that includes a field for indicating the reading of the timing synchronization status report.

7. The method according to claim 1, wherein the information about the user equipment comprises: the radio resource control state of the user equipment, and wherein the method comprises, in response to determining that the user equipment is in a radio resource control idle mode, paging the broadcast of the timing synchronization status report to the user equipment.

8. A method comprising: receiving a message identifying at least one user equipment for which actions are to be taken to increase certainty of reading of a timing synchronization status report by the user equipment; broadcasting a paging timing synchronization status report to the user equipment; as well as The timing synchronization report is thereafter broadcast.

9. A method comprising: Information is sent from a user equipment regarding the periodicity of the reading of system information blocks at said user equipment.

10. A method comprising: An indication is sent from a user equipment that an action is to be taken to increase certainty of a reading of a timing synchronization status report by the user equipment.

11. A method comprising: receiving a paging message indicating a broadcast of system information including a timing synchronization status report; as well as The system information indicated by the paging message is read.

12. A method comprising: A request is sent identifying at least one user equipment for which actions are to be taken to increase certainty of reading of a timing synchronization status report by the user equipment.

13. The method of claim 12, wherein the request comprises: An indication of an urgency level for increasing certainty of reading of the timing synchronization status report by the user equipment.

14. An apparatus comprising: means for receiving a message identifying at least one user equipment for which action is to be taken to increase certainty of reading of a timing synchronization status report by the user equipment; as well as Means for determining, based at least in part on information about the user equipment, actions for increasing certainty of the user equipment's reading of the timing synchronization status report.

15. The apparatus of claim 14, wherein the message comprises: an indication of an urgency level for increasing certainty of reading of the timing synchronization status report by the user equipment; and wherein the determining action is based in part on the indication of the urgency level.

16. The apparatus of claim 14, wherein the timing synchronization status report is broadcast as part of system information, wherein the information about the user equipment comprises: Information about the periodicity of reading broadcast system information by the user equipment; And wherein said apparatus comprises means for determining at least one parameter for said broadcasting of said timing synchronization status report as part of system information based on said information about the periodicity of reading of broadcast system information at said user equipment.

17. The apparatus of claim 16, wherein the at least one parameter comprises: The duration for which the timing synchronization status report is included in the system information.

18. The device according to claim 14 or 15, comprising: Means for determining whether to page the user equipment to report reading of the timing synchronization status report, wherein the determination is based at least in part on one or more of: information derived from a user equipment message, or information regarding when a user equipment message is expected.

19. An apparatus according to claim 18, wherein determining whether to page the user equipment to report the reading of the timing synchronization status report is based at least in part on one or more of the following items: information derived from one or more messages from the user equipment that include a field for indicating the reading of the timing synchronization status report, or information about when the user equipment next expects to send a message that includes a field for indicating the reading of the timing synchronization status report.

20. The apparatus of claim 14, wherein the information about the user equipment comprises: the radio resource control state of the user equipment, and wherein the apparatus comprises means for paging the broadcast of the timing synchronization status report to the user equipment in response to determining that the user equipment is in a radio resource control idle mode.

21. An apparatus comprising: means for receiving a message identifying at least one user equipment for which action is to be taken to increase certainty of reading of a timing synchronization status report by the user equipment; means for broadcasting a paging timing synchronization status report to the user equipment; as well as Means for thereafter broadcasting said timing synchronization report.

22. A user equipment, comprising: Means for sending information about the periodicity of reading of system information blocks at said user equipment.

23. A user equipment, comprising: Means for sending an indication that action is to be taken to increase certainty of reading of a timing synchronization status report by said user equipment.

24. A user equipment, comprising: means for receiving a paging message indicating a broadcast of system information including a timing synchronization status report, and Means for reading the system information indicated by the paging message.

25. An apparatus comprising: Means for sending a request identifying at least one user equipment for which action is to be taken to increase certainty of reading of a timing synchronization status report by the user equipment.

26. A computer-readable medium comprising program instructions stored thereon, wherein the program instructions, when executed by at least one processor of a device, cause the device to perform: receiving a message identifying at least one user device, taking actions for the at least one user device to increase the certainty of the user device's reading of a timing synchronization status report; and determining an action for increasing the certainty of the user device's reading of the timing synchronization status report based at least in part on information about the user device.

27. A computer-readable medium comprising program instructions stored thereon, wherein the program instructions, when executed by at least one processor of a device, cause the device to perform: receiving a message identifying at least one user device, taking actions for the at least one user device to increase the certainty of the user device's reading of a timing synchronization status report; broadcasting a paging timing synchronization status report to the user device; and thereafter broadcasting the timing synchronization report.

28. A computer readable medium comprising program instructions stored thereon, wherein the program instructions, when executed by at least one processor of a user equipment, cause the user equipment to perform: sending information regarding periodicity of reading of system information blocks at the user equipment.

29. A computer readable medium comprising program instructions stored thereon, wherein the program instructions, when executed by at least one processor of a user equipment, cause the user equipment to perform: sending an indication that an action is to be taken to increase certainty of the user equipment's reading of a timing synchronization status report.

30. A computer-readable medium comprising program instructions stored thereon, wherein the program instructions, when executed by at least one processor of a user equipment, cause the user equipment to perform: receiving a paging message indicating a broadcast of system information including a timing synchronization status report; and reading the system information indicated by the paging message.

31. A computer-readable medium comprising program instructions stored thereon, wherein the program instructions, when executed by at least one processor of a device, cause the device to execute: sending a request to identify at least one user equipment, and taking actions for the at least one user equipment to increase the certainty of the user equipment's reading of a timing synchronization status report.

32. A computer program comprising computer executable code, which, when running on at least one processor, is configured to cause the device to at least: receive a message identifying at least one user device, take action for the at least one user device to increase the certainty of the user device's reading of a timing synchronization status report; and determine an action for increasing the certainty of the user device's reading of the timing synchronization status report based at least in part on information about the user device.

33. A computer program comprising computer executable code, which, when executed on at least one processor, is configured to cause the device to at least: receive a message identifying at least one user device, for which action will be taken to increase the certainty of the user device's reading of a timing synchronization status report; broadcast a paging timing synchronization status report to the user device; and thereafter broadcast the timing synchronization report.

34. A computer program comprising computer executable code, which when executed on at least one processor is configured to cause a user equipment to at least: send information about the periodicity of reading of system information blocks at the user equipment.

35. A computer program comprising computer executable code configured, when executed on at least one processor, to cause a user equipment to at least: send an indication that action is to be taken to increase certainty of a reading of a timing synchronization status report by the user equipment.

36. A computer program comprising computer executable code, which, when executed on at least one processor, is configured to cause a user equipment to at least: receive a paging message indicating a broadcast of system information including a timing synchronization status report; and read the system information indicated by the paging message.

37. A computer program comprising computer executable code, which, when executed on at least one processor, is configured to cause a device to at least: send a request to identify at least one user device, and take actions for the at least one user device to increase the certainty of the user device's reading of a timing synchronization status report.

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