System and method for notifying synchronization status

Abstract

Systems and methods for notifying synchronization status are provided. A wireless communication device (e.g., a UE) can receive a first message including a time synchronization status threshold. The wireless communication device can receive a second message including a time status value. The wireless communication device can determine whether to switch itself to a connected state based on the time status value and the time synchronization status threshold.

Description

Technical Field

[0001] This invention generally relates to wireless communication, including but not limited to systems and methods for notifying synchronization status. Background Technology

[0002] The 3rd Generation Partnership Project (3GPP), a standards organization, is currently developing a new radio interface called 5G New Radio (5G NR) and a Next Generation Packet Core Network (NG-CN or NGC). 5G NR will have three main components: the 5G Access Network (5G-AN), the 5G Core Network (5GC), and User Equipment (UE). To facilitate the implementation of different data services and requirements, the elements of the 5GC (also known as network functions) have been simplified, some based on software and others on hardware, allowing for adaptation as needed. Summary of the Invention

[0003] The exemplary embodiments disclosed herein are intended to address problems related to one or more issues existing in the prior art, and to provide additional features that will become apparent when taken in conjunction with the accompanying drawings and the following detailed description. Example systems, methods, apparatuses, and computer program products are disclosed herein according to various embodiments. However, it should be understood that these embodiments are presented by way of example and are not limiting, and that various modifications can be made to the disclosed embodiments while remaining within the scope of this disclosure, as will be apparent to those skilled in the art upon reading this disclosure.

[0004] At least one aspect relates to a system, method, apparatus, or computer-readable medium that includes the following: A wireless communication device (e.g., a UE) may receive a first message including a time synchronization state threshold. The wireless communication device may receive a second message including a time state value. The wireless communication device may determine whether to switch itself to a connected state based on the time state value and the time synchronization state threshold. The wireless communication device may receive the first message from an Access & Mobility Management Function (AMF) or a wireless communication node (e.g., a Next Generation Radio Access Network (NG-RAN)). The wireless communication device may receive the second message from the wireless communication node via broadcast.

[0005] In some implementations, the AMF can be configured to create a time synchronization state threshold. The first message can be a Non-Access Stratum (NAS) message sent directly from the AMF. The second message can be a Radio Resource Control (RRC) message sent from the wireless communication node. The third message can be a new information element of the System Information Block (SIB) or an existing information element of the Reference Time Info.

[0006] In some implementations, the Time Sensitive Communication Synchronization Function (TSCTSF) or the Time Sensitive Networking-Adaptation Function (TSN-AF) can be configured to create time synchronization state thresholds. The TSCTSF or TSN-AF can be configured to send the time synchronization state thresholds to the AMF.

[0007] In some implementations, the wireless communication node can be configured to create a time synchronization state threshold. The wireless communication node can be configured to send the time synchronization state threshold to the AMF.

[0008] In some implementations, a network entity may send a message including a time synchronization state threshold to a wireless communication device. The wireless communication device may be configured to determine whether to switch itself to a connected state based on the time synchronization state threshold and the received time state value. The network entity may be an AMF or a wireless communication node. The time state value may be received from the wireless communication node via broadcast. The time synchronization state threshold may be created by one of the following: AMF, wireless communication node, TSCTSF, or TSN-AF.

[0009] In some implementations, the AMF may receive time synchronization status thresholds from the TSCTSF, TSN-AF, or a wireless communication node. The wireless communication node may be an NG-RAN. Attached Figure Description

[0010] Various exemplary embodiments of this solution are described in detail below with reference to the accompanying drawings. The drawings are provided for illustrative purposes only and describe only exemplary embodiments of this solution to facilitate the reader's understanding. Therefore, the drawings should not be considered as limitations on the breadth, scope, or applicability of this solution. It should be noted that these drawings are not necessarily drawn to scale for clarity and ease of explanation.

[0011] Figure 1 An exemplary cellular communication network that implements the technology disclosed herein, according to embodiments of the present disclosure;

[0012] Figure 2 A block diagram illustrating an exemplary base station (BS) and user equipment according to some embodiments of the present disclosure;

[0013] Figure 3 Exemplary implementations of a 5G System (5GS) architecture according to some embodiments of the present disclosure are shown;

[0014] Figure 4 A sequence diagram illustrating time synchronization according to some embodiments of the present disclosure is shown;

[0015] Figure 5 A sequence diagram illustrating time synchronization according to some embodiments of the present disclosure is shown;

[0016] Figure 6 A sequence diagram illustrating time synchronization according to some embodiments of the present disclosure is shown;

[0017] Figure 7 A sequence diagram illustrating time synchronization according to some embodiments of the present disclosure is shown;

[0018] Figure 8 A sequence diagram illustrating time synchronization according to some embodiments of this disclosure is shown;

[0019] Figure 9 A sequence diagram illustrating time synchronization according to some embodiments of the present disclosure is shown;

[0020] Figure 10 A flowchart illustrating an exemplary method for notifying synchronization status according to an embodiment of the present disclosure is shown. Detailed Implementation

[0021] 1. Mobile communication technology and environment

[0022] Figure 1An exemplary wireless communication network and / or system 100 implementing the techniques disclosed herein is illustrated according to embodiments of this disclosure. In the following discussion, wireless communication network 100 can be any wireless network, such as a cellular network or a narrowband Internet of Things (NB-IoT) network, and is referred to herein as "network 100". This example network 100 includes a base station 102 (hereinafter, "BS102"; also referred to as a wireless communication node) and a user equipment 104 (hereinafter, "UE 104"; also referred to as a wireless communication device), which is capable of operating via a communication link 110 (e.g., a wireless communication channel) and cell clusters 126, 130, 132, 134, 136, 138, and 140 covering a geographic area 101. Figure 1 In this context, BS102 and UE 104 are contained within the corresponding geographical boundaries of cell 126. Each of the other cells 130, 132, 134, 136, 138, and 140 may include at least one base station operating under its allocated bandwidth to provide sufficient radio coverage to its intended users.

[0023] For example, BS102 can operate within the allocated channel transmission bandwidth to provide sufficient coverage to UE 104. BS102 and UE 104 can communicate via downlink radio frame 118 and uplink radio frame 124, respectively. Each radio frame 118 / 124 can be further divided into subframes 120 / 127, which may include data symbols 122 / 128. In this disclosure, BS102 and UE 104 are described herein as non-limiting examples of "communication nodes," which typically implement the methods disclosed herein. Depending on different implementations of this solution, such communication nodes can perform wireless and / or wired communication.

[0024] Figure 2 A block diagram of an exemplary wireless communication system 200 for transmitting and receiving wireless communication signals (e.g., Orthogonal Frequency-Division Multiplexing (OFDM) / Orthogonal Frequency-Division Multiple Access (OFDMA) signals) according to some embodiments of this solution is shown. System 200 may include components and elements configured to support known or conventional operating characteristics that do not need to be described in detail herein. In one illustrative embodiment, system 200 can be used in wireless communication environments (such as...) Figure 1 In a wireless communication environment 100, communication (e.g., sending and receiving) data symbols, as described above.

[0025] System 200 typically includes a base station 202 (hereinafter "BS202") and a user equipment 204 (hereinafter "UE204"). BS202 includes a BS transceiver module 210, a BS antenna 212, a BS processor module 214, a BS memory module 216, and a network communication module 218, each module being coupled and interconnected with each other via a data communication bus 220 if necessary. UE 204 includes a UE transceiver module 230, a UE antenna 232, a UE memory module 234, and a UE processor module 236, each module being coupled and interconnected with each other via a data communication bus 240 as needed. BS202 communicates with UE 204 via a communication channel 250, which can be any wireless channel or other medium suitable for data transmission as described herein.

[0026] As those skilled in the art will understand, system 200 may further include Figure 2 Any number of other modules besides those shown. Those skilled in the art will understand that the various illustrative blocks, modules, circuits, and processing logic described in conjunction with the embodiments disclosed herein can be implemented in hardware, computer-readable software, firmware, or any actual combination thereof. To clearly illustrate the interchangeability and compatibility of hardware, firmware, and software, the components, blocks, modules, circuits, and steps are described functionally herein. Whether these functions are implemented as hardware, firmware, or software can depend on the specific application and design constraints imposed on the system as a whole. Those skilled in the art, skilled in the art, can implement such functions appropriately for each specific application; however, such implementation decisions should not be construed as limiting the scope of this disclosure.

[0027] According to some embodiments, UE transceiver 230 may be referred to herein as "uplink" (UL) transceiver 230, which includes a radio frequency (RF) transmitter and an RF receiver, each of which includes circuitry coupled to antenna 232. Alternatively, a duplex switch (not shown) may couple the uplink transmitter or receiver to the uplink antenna in a time-duplex manner. Similarly, according to some embodiments, BS transceiver 210 may be referred herein as "downlink" (DL) transceiver 210, which includes an RF transmitter and an RF receiver, each of which includes circuitry coupled to antenna 212. The downlink duplex switch may selectively couple the downlink transmitter or receiver to downlink antenna 212 in a time-division duplex manner. The operation of the two transceiver modules 210 and 230 may be time-coordinated such that the uplink receiver circuitry is coupled to the uplink antenna 232 for receiving transmissions via wireless transmission link 250 while the downlink transmitter is coupled to the downlink antenna 212. Conversely, the operation of the two transceivers 210 and 230 can be time-coordinated, such that the downlink receiver is coupled to the downlink antenna 212 for receiving transmissions via the wireless transmission link 250 while the uplink transmitter is coupled to the uplink antenna 232. In some embodiments, there is tight time synchronization with a minimum guard time between changes in duplex direction.

[0028] UE transceiver 230 and BS transceiver 210 are configured to communicate via wireless data communication link 250 and cooperate with RF antenna arrays 212 / 232 appropriately configured to support specific wireless communication protocols and modulation schemes. In some illustrative embodiments, UE transceiver 230 and BS transceiver 210 are configured to support industry standards such as Long Term Evolution (LTE) and emerging 5G standards. However, it should be understood that this disclosure is not necessarily limited to the application of specific standards and associated protocols. Rather, UE transceiver 230 and BS transceiver 210 may be configured to support alternative or additional wireless data communication protocols, including future standards or variations thereof.

[0029] Depending on the implementation, BS202 can be, for example, an evolved Node B (eNB), a serving eNB, a target eNB, a femtocell, or a picocell. In some implementations, UE 204 can be embodied in different types of user equipment, such as mobile phones, smartphones, personal digital assistants (PDAs), tablet computers, laptop computers, wearable computing devices, etc. Processor modules 214 and 236 can be implemented using a general-purpose processor, content-addressable memory, digital signal processor, application-specific integrated circuit, field-programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. In this way, the processor can be implemented as a microprocessor, a controller, a microcontroller, a state machine, etc. The processor can also be implemented as a combination of computing devices, such as a combination of a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors coupled with a digital signal processor core, or any other such configuration.

[0030] Furthermore, the steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be directly embodied in hardware, firmware, software modules executed by processor modules 214 and 236 respectively, or any actual combination thereof. Memory modules 216 and 234 can be implemented as random access memory (RAM), flash memory, read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disk, removable disk, compact disc read-only memory (CD-ROM), or any other form of storage medium known in the art. In this regard, memory modules 216 and 234 can be coupled to processor modules 214 and 236 respectively, such that processor modules 210 and 230 can read information from and write information to memory modules 216 and 234 respectively. Memory modules 216 and 234 may also be integrated into their respective processor modules 214 and 236. In some embodiments, memory modules 216 and 234 may each include a cache memory for storing temporary variables or other intermediate information during the execution of instructions to be executed by processor modules 210 and 230, respectively. Memory modules 216 and 234 may also each include non-volatile memory for storing instructions to be executed by processor modules 210 and 230, respectively.

[0031] Network communication module 218 typically refers to the hardware, software, firmware, processing logic, and / or other components of BS 202 that enable bidirectional communication between BS transceiver 210 and other network components and communication nodes configured to communicate with BS 202. For example, network communication module 218 may be configured to support Internet or WiMAX services. In a typical deployment, but not limited to, network communication module 218 provides an 802.3 Ethernet interface, enabling BS transceiver 210 to communicate with conventional Ethernet-based computer networks. In this way, network communication module 218 may include a physical interface for connecting to a computer network, such as a Mobile Switching Center (MSC). As used herein with respect to a specified operation or function, the terms “configured for”, “configured for,” and their conjugates refer to means a device, component, circuit, structure, machine, signal, etc., physically constructed, programmed, formatted, and / or arranged to perform the specified operation or function.

[0032] The Open Systems Interconnection (OSI) model (referred to herein as the "OSI model") is a conceptual and logical layout that defines network communication used by systems open to interconnect and communicate with other systems (e.g., wireless communication devices, wireless communication nodes). The model is divided into seven sub-components or layers, each representing a conceptual set of services provided to the layers above and below it. The OSI model also defines logical networks and effectively describes the transmission of computer packets using different layer protocols. The OSI model may also be referred to as the seven-layer OSI model or the seven-layer model. In some implementations, the first layer may be the physical layer. In some implementations, the second layer may be the Medium Access Control (MAC) layer. In some implementations, the third layer may be the Radio Link Control (RLC) layer. In some implementations, the fourth layer may be the Packet Data Convergence Protocol (PDCP) layer. In some implementations, the fifth layer may be the Radio Resource Control (RRC) layer. In some implementations, the sixth layer may be the NAS layer or the Internet Protocol (IP) layer, and the seventh layer may be other layers.

[0033] Various exemplary embodiments of this solution are described below with reference to the accompanying drawings to enable those skilled in the art to create and use this solution. It will be apparent to those skilled in the art that, upon reading this disclosure, different changes or modifications can be made to the examples described herein without departing from the scope of this solution. Therefore, this solution is not limited to the exemplary embodiments and applications described and shown herein. Furthermore, the specific order or hierarchy of steps in the methods disclosed herein is merely an example method. Based on design preferences, the specific order or hierarchy of steps in the disclosed methods or processes can be rearranged while remaining within the scope of this solution. Thus, those skilled in the art will understand that the methods and techniques disclosed herein present different steps or actions in a sample order, and this solution is not limited to the specific order or hierarchy presented, unless otherwise expressly stated.

[0034] 2. System and method for notifying synchronization status

[0035] In 5G systems, time synchronization services for UEs may already be supported. Next-generation radio access networks (NG-RAN) (e.g., gNB or NG-eNB) can obtain accurate time from internal 5G time sources and provide accurate time information to UEs via 5G Access Stratum (AS) signaling (e.g., 5G Access Stratum time distribution).

[0036] To support disaster recovery, the 5G 5GS system can support timing flexibility. When the internal 5G time source (e.g., the 5G Grand Master, GM) experiences a failure / degradation / upgrade / switchover, the time synchronization performance parameters of the NG-RAN may change. The NG-RAN can notify the UE of the time status.

[0037] For UEs in Connection Management-idle (CM-idle) mode or UEs in Connection Management-connected (CM-connected) mode but with RRC inactive mode, the UE can enter CM-connected mode to obtain detailed time status information. However, due to the NG-RAN time status change, when many UEs enter CM-connected mode at the same time, this can cause high load on NG-RAN. High load can negatively impact NG-RAN performance and stability. The systems and methods presented herein may include novel methods for avoiding simultaneous connection of all UEs.

[0038] Figure 3 This paper illustrates an exemplary implementation of a 5G system 5GS architecture supporting time synchronization services according to some embodiments of this disclosure. For simplicity, network functions (NFs) unrelated to time synchronization may not be described. The architecture may include at least one of the following functions: UE, 5G-AN, AMF, Session Management Function (SMF), User Plane Function (UPF), Policy Control Function (PCF), Network Exposure Function (NEF), Time-Sensitive Communication Synchronization Function (TSCTSF), and Time-Sensitive Network Adaptation Function (TSN-AF).

[0039] The UE can access the 5G system 5GS and obtain services through NG-RAN. The UE can interact with the AMF of the core network via Non-Access Stratum (NAS) signaling.

[0040] 5G-AN (e.g., 5G radio access network) can be referred to as NG-RAN. NG-RAN is responsible for air interface resource scheduling and air interface connection management of the network accessed by the UE.

[0041] The AMF may include at least one of the following functions: registration management, connection management, reachability management, and mobility management. The AMF can be a non-access stratum (NAS) security endpoint and can relay session management (SM) NAS messages between the UE and the SMF.

[0042] SMF may include at least one of the following functions: session management (e.g., session establishment, modification and / or release), UE IP address allocation and management (e.g., optional authorization), selection and control of User Plane (UP) functions, and downlink data notification.

[0043] User plane functions (UPFs) may include at least one of the following functions: anchoring for mobility within / between Radio Access Technology (RAT), packet routing and forwarding, service usage reporting, Quality of Service (QoS) processing, downlink packet buffering, and downlink data notification triggering.

[0044] The Policy Control Function (PCF) may include at least one of the following functions: a unified policy framework for managing network behavior; policy rules for control plane functions to enforce policy rules; and a front end for accessing subscription information related to policy decisions in the User Data Repository (UDR).

[0045] Optionally, the Network Capability Opening Function (NEF) can be deployed to exchange information between the 5G core network (5GC) and external application functions (AF). In this disclosure, NEF / AF may be used to briefly refer to NEF and AF.

[0046] The Time Sensitive Communications and Time Synchronization Function (TSCTSF) can control the time synchronization service by controlling the NG-RAN to enable 5G access layer time distribution, and can configure the Device-side Time Sensitive Networking Translator (DS-TT) and Network-side Time Sensitive Networking Translator (NW-TT) even when the 5GS is not integrated with the TSN network.

[0047] The Time-Sensitive Networking Adaptation (TSN-AF) feature provides interoperability and adaptation with the Centralized Network Configuration (CNC) in external Time-Sensitive Networking (TSN) systems.

[0048] A 5G internal Grand Master (GM) clock can be used as the time source (e.g., a GM clock in the Global Positioning System (GPS) or the transport network). NG-RAN and User Plane Functions (UPF) can be synchronized with the 5G internal GM clock respectively.

[0049] In existing 5G systems, NG-RAN can provide precise time information to UE through 5G Access Stratum Time Distribution (ASTI) signaling.

[0050] Figure 4 A sequence diagram illustrating time synchronization between a UE and an NG-RAN according to some embodiments of this disclosure is shown. Figure 4 This demonstrates how the UE obtains precise 5G time from NG-RAN on the air interface.

[0051] In step 401, NG-RAN may send ReferenceTimeInfo to the UE in System Information Block 9 (SIB9) or Radio Resource Control (RRC) message.

[0052] In step 402, the reference time information may contain three information elements (IEs).

[0053] referenceSFN: This field can indicate the reference system frame number (SFN) corresponding to the reference time information.

[0054] Time (Reference Time): The time field can indicate the time at the boundary of the SFN (e.g., referenceSFN).

[0055] Uncertainty: This field indicates the uncertainty of the reference time information in the time field. The uncertainty can be 25ns multiplied by this field.

[0056] The UE can use the received information to synchronize its time with the NG-RAN. After this process, we can assume that the UE and NG-RAN are time-synchronized (e.g., the UE and NG-RAN share / have the same 5G clock time).

[0057] When the 5G time state changes (e.g., the original GM clock is downgraded, upgraded, stopped, and / or a new 5G GM clock is used), this can lead to changes in the NG-RAN time synchronization performance parameters. NG-RAN can notify the UE of the latest state.

[0058] Figure 5 A sequence diagram illustrating time synchronization according to some embodiments of the present disclosure is shown. Figure 5 This demonstrates how to notify the UE of the time status. NG-RAN can notify the UE of the time status.

[0059] In step 501, time synchronization can be with Figure 4 The same sequence diagram shown.

[0060] In step 502, NG-RAN can detect 5G internal GM events (e.g., current GM clock downgrade / upgrade, original GM clock stop, and / or use of a new 5G GM clock). This will cause changes in the NG-RAN's time synchronization performance parameters.

[0061] In step 503, NG-RAN notifies the UEs within the cell coverage area via SIB. This notification may include time synchronization status events / reports.

[0062] In step 504, for a UE in idle mode, or a UE in CM-connected but RRC inactive mode and performing time synchronization, when the UE receives a time synchronization status event / report indication in step 503, it may initiate an RRC connection establishment process with NG-RAN.

[0063] In step 505, after establishing the RRC connection, the NG-RAN can notify the UE of detailed information about the time synchronization status (e.g., clock accuracy, traceability to Coordinated Universal Time (UTC), or frequency stability).

[0064] SIB resources are very limited in the air interface. In step 503, the NG-RAN can broadcast what happened. In step 505, specific details can be provided to the UE in the RRC message.

[0065] This process may cause the following problem: all UEs in idle mode, or UEs in CM-connected but RRC inactive mode and receiving time information, may simultaneously enter CM-connected mode. This may place a high load on NG-RAN, which could negatively impact NG-RAN performance and stability.

[0066] However, when there is a change in time synchronization status, all UEs may not need to be aware of the details. The following situations (where notifying all UEs is unnecessary) may include: (1) the clock synchronization accuracy requirement for idle mode UE-A is 800ns; (2) the current time synchronization accuracy provided by NG-RAN is 500ns; (3) a 5G internal GM event occurs: the time synchronization accuracy provided by NG-RAN changes to / becomes 400ns (upgrade) or 600ns (downgrade). For UE-A, it may not be necessary to move to connected mode to obtain the status details because the time synchronization QoS can still be met. A mechanism may be needed to ensure that UEs only enter / switch / change to connected mode to obtain the status details when needed. This mechanism should minimize the impact on NG-RAN.

[0067] Implementation Example 1

[0068] Figure 6 This illustrates the process by which the AMF creates and sends a time synchronization state threshold. The AMF can create a time synchronization state threshold and send it to the UE via a Non-Access Stratum (NAS) message.

[0069] In step 601, the AMF may receive a service operation carrying the UE's 5G access layer time distribution ASTI request. The AMF may receive this request from Unified Data Management (UDM) or Policy Control Function (PCF).

[0070] In step 602, the AMF may create a time synchronization state threshold for the UE (e.g., based on the UE's time synchronization error budget in step 601, or based on local configuration).

[0071] In step 603, the AMF can send the time synchronization status threshold to the UE via a Non-Access Stratum (NAS) message. For UEs in CM-connected mode, the AMF can send the NAS message directly. For UEs in idle mode, the AMF can wait for the UE to enter CM-connected mode or page the UE. After the UE enters CM-connected mode, the AMF can then send the time synchronization status threshold to the UE via a NAS message.

[0072] In step 604, the AMF may (optionally) send a time synchronization status threshold to the NG-RAN in the N2 message. This NAS message may be in the N1 container in step 604. Upon receiving the N2 message, the NG-RAN may forward the N1 container to the UE.

[0073] In step 605, NG-RAN can broadcast a 5G time status value in the SIB based on the current 5G clock state. The time status value can be a new Information Element (IE) in the SIB, or a reused uncertainty information element (IE) from the ReferenceTimeInfo.

[0074] In step 606, NG-RAN can detect 5G internal GM events (e.g., current GM clock boost / deboost, original GM clock stop, and / or use of a new 5G GM clock). This will cause changes in the NG-RAN's time synchronization performance parameters.

[0075] In step 607, NG-RAN may broadcast a 5G time status value reflecting the change in the System Information Block (SIB).

[0076] In step 608, based on the time synchronization state threshold received in step 603 and the current 5G time state value received in step 607, an idle or RRC-inactive UE can initiate an RRC connection establishment process with the NG-RAN. The UE can directly compare the time synchronization state threshold and the 5G time state value. For example, when the 5G time state value is greater than the time synchronization state threshold, the UE can be configured to enter RRC connection mode. Similarly, when the 5G time state value is less than the time synchronization state threshold, the UE can be configured to enter RRC connection mode. The UE can perform a conversion between the time synchronization state threshold and the 5G time state value. After the conversion, the UE can compare the time synchronization state threshold and the 5G time state value. For example, the 5G time state value can be converted into a "true state value" (e.g., multiplied by 25). When the "true state value" is greater than the time synchronization state threshold, the UE can be configured to enter RRC connection mode. Again, when the "true state value" is less than the time synchronization state threshold, the UE can be configured to enter RRC connection mode.

[0077] In step 609, after the RRC connection is established, the NG-RAN may notify the UE of detailed information about the time synchronization status (e.g., clock accuracy, traceability to UTC, or frequency stability).

[0078] Implementation Example 2

[0079] Figure 7This illustrates the process by which the AMF creates a time synchronization state threshold and the UE receives the time synchronization state threshold via access stratum AS (e.g., RRC) signaling. The AMF can create a time synchronization state threshold. The UE can receive the time synchronization state threshold via AS signaling.

[0080] In step 701, the AMF can receive a service operation carrying the UE's 5G access layer time distribution ASTI request. The AMF can receive the request from the unified data management UDM or the policy control function PCF.

[0081] In step 702, the AMF may create a time synchronization state threshold for the UE (e.g., based on the UE's time synchronization error budget in step 701, or based on local configuration).

[0082] In step 703, the AMF can send the time synchronization status threshold to the NG-RAN via the N2 message. For UEs in CM-connected mode, the AMF can send the N2 message directly. For UEs in idle mode, the AMF can wait for the UE to enter CM-connected mode or page the UE. Once the UE enters CM-connected mode, the AMF can send the time synchronization status threshold to the NG-RAN.

[0083] In step 704, NG-RAN can send a time synchronization status threshold to the UE via an access layer AS (e.g., RRC) message. If the UE is in RRC inactive mode, NG-RAN can first perform RAN paging.

[0084] In step 705, NG-RAN can broadcast a 5G time status value in the System Information Block (SIB) based on the current 5G clock state. The time status value can be a new Information Element (IE) in the SIB, or an existing uncertainty information element (IE) in the ReferenceTimeInfo can be reused.

[0085] In step 706, NG-RAN can detect 5G internal GM events (e.g., current GM clock downgrade / upgrade, original GM clock stoppage, or use of a new 5G GM clock). This will cause changes in the NG-RAN's time synchronization performance parameters.

[0086] In step 707, NG-RAN may broadcast a 5G time status value reflecting the change in the System Information Block (SIB).

[0087] In step 708, a UE in an idle state or an RRC inactive state can initiate an RRC connection establishment procedure with NG-RAN based on the time synchronization status threshold and the current time status value received in step 704. This step can be similar to step 608.

[0088] In step 709, after the RRC connection is established, the NG-RAN can notify the UE of detailed information about the time synchronization status (e.g., clock accuracy, traceability to UTC, frequency stability).

[0089] Implementation Example 3

[0090] Figure 8 This illustrates the process by which the NG-RAN creates a time synchronization state threshold and the UE receives the time synchronization state threshold via access layer AS (e.g., RRC) or NAS signaling. The NG-RAN can create a time synchronization state threshold and can send the time synchronization state threshold to the UE via access layer AS (e.g., RRC) or NAS signaling.

[0091] In step 801, the AMF can receive a service operation carrying the UE's 5G access layer time distribution ASTI request. The AMF can receive the request from the UDM or PCF.

[0092] In step 802, the AMF can send an N2 message with 5G access layer time distribution requirements to the NG-RAN. For UEs in CM-connected mode, the AMF can directly send the N2 message to the NG-RAN. For UEs in idle state, the AMF can wait for the UE to enter CM-connected mode, or it can page the UE. After the UE enters CM-connected mode, the AMF can send an N2 message to the NG-RAN.

[0093] In step 803, NG-RAN can create a time synchronization state threshold for the UE (e.g., based on the UE's time synchronization error budget in step 802, or based on local configuration).

[0094] In step 804, NG-RAN may send a time synchronization status threshold to the UE via an access layer AS (e.g., RRC) message. If the UE is in RRC inactive mode, NG-RAN may first perform RAN paging.

[0095] Another option for step 804 is step 804a. In step 804a, the NG-RAN can send the time synchronization state threshold to the AMF via an N2 message. The AMF can send the time synchronization state threshold to the UE via a Non-Access Stratum (NAS) message.

[0096] In step 805, NG-RAN broadcasts the 5G time status value in the SIB based on the current 5G clock state. The time status value can be a new Information Element (IE) in the SIB, or an existing uncertainty information element (IE) in the ReferenceTimeInfo can be reused.

[0097] In step 806, NG-RAN can detect 5G internal GM events (e.g., current GM clock downgrade / upgrade, original GM clock stop, use of a new 5G GM clock). This will cause changes in the NG-RAN's time synchronization performance parameters.

[0098] In step 807, NG-RAN can broadcast 5G time status values ​​in SIB that reflect the change.

[0099] In step 808, based on the time synchronization status threshold and current time status value received in steps 804 / 804a, a UE in an idle state or an RRC inactive state can initiate an RRC connection establishment process with the NG-RAN. This step can be similar to step 608.

[0100] In step 809, after the RRC connection is established, the NG-RAN can notify the UE of detailed information about the time synchronization status (e.g., clock accuracy, traceability to UTC, frequency stability).

[0101] Implementation Example 4

[0102] Figure 9 This illustrates the process of TSCTSF / TSN-AF creating a time synchronization state threshold and sending the time synchronization state threshold to the AMF.

[0103] In step 901, the TSCTSF / TSN-AF can receive service operations carrying 5G access layer time distribution ASTI requests for the UE. The TSCTSF / TSN-AF can receive requests from the NEF or AF.

[0104] In step 902, TSCTSF / TSN-AF can create a time synchronization state threshold for the UE (e.g., based on the UE's time synchronization error budget in step 901, or based on local configuration).

[0105] In step 903, the TSCTSF / TSN-AF can use the Network Function Binding Support Service (NBSF) service operation to search for / determine the UE's Policy Control Function (PCF). The TSCTSF / TSN-AF can use the Npcf_AM Policy Authorization Request (including time synchronization status thresholds) to send the UE's Access and Mobility Management (AM) policy to the PCF.

[0106] In step 904, the policy control function (PCF) can initiate an AM policy association modification procedure for the UE to provide the AMF with a time synchronization status threshold.

[0107] In step 905, the AMF can send the time synchronization state threshold to the UE. The AMF can send the time synchronization state threshold (and...) via a Non-Access Stratum (NAS) message. Figure 6 (Same as step 603 in the previous step), or send the time synchronization state threshold to NG-RAN. NG-RAN can send the time synchronization state threshold to the UE via an Access Layer AS (e.g., RRC) message (same as step 603 in the previous step), or send the time synchronization state threshold to NG-RAN. Figure 7 (Steps 703 and 704 are the same).

[0108] In step 906, the AMF (optionally) may send a time synchronization status threshold to the NG-RAN in the N2 message. In step 905, the NAS message may be in the N1 container. After receiving the N2 message, the NG-RAN may forward the N1 container to the UE.

[0109] Steps 907-911 can be the same as steps 605-609.

[0110] In some implementations, the time synchronization state threshold and the time state value can be on the same dimension or on different dimensions. The UE can directly compare the time synchronization state threshold and the 5G time state value. Alternatively, the time synchronization state threshold and the time state value can be on different dimensions. The UE can perform a conversion between the time synchronization state threshold and the 5G time state value. After the conversion, the UE can compare the time synchronization state threshold and the 5G time state value.

[0111] It should be understood that one or more features from the above embodiments are not limited to the specific embodiments, but can be combined in any way (e.g., in any priority and / or order, simultaneously or otherwise).

[0112] Figure 10 A flowchart of a method 1000 for notifying synchronization status is shown. Method 1000 can be used in conjunction with... Figures 1 to 9 It may be implemented by any one or more of the detailed components and devices. Generally, in some embodiments, method 1000 may be performed by a wireless communication device (e.g., UE). Depending on the embodiment, additional, fewer, or different operations may be performed in method 1000. At least one aspect of the operation relates to a system, method, device, or computer-readable medium.

[0113] A wireless communication device (e.g., a UE) may receive a first message including a time synchronization state threshold. The wireless communication device may also receive a second message including a time state value. The wireless communication device may determine whether to switch itself to a connected state based on the time state value and the time synchronization state threshold. The wireless communication device may receive the first message from an AMF (Advanced Feature Function) or a wireless communication node (e.g., NG-RAN). The wireless communication device may receive the second message from a broadcast of a wireless communication node.

[0114] In some implementations, the AMF can be configured to create a time synchronization state threshold. The first message can be a NAS message sent directly from the AMF. The first message can also be an RRC message sent from a wireless communication node. The second message can be a new information element in the System Information Block (SIB) or an existing information element in the ReferenceTimeInfo.

[0115] In some implementations, the Time-Sensitive Communication Synchronization Function (TSCTSF) or the Time-Sensitive Network Adaptation Function (TSN-AF) can be configured to create a time synchronization state threshold. The TSCTSF or TSN-AF can be configured to send the time synchronization state threshold to the AMF.

[0116] In some implementations, the wireless communication node can be configured to create a time synchronization state threshold. The wireless communication node can be configured to send the time synchronization state threshold to the AMF.

[0117] In some implementations, a network entity may send a message including a time synchronization state threshold to a wireless communication device. The wireless communication device may be configured to determine whether to switch itself to a connected state based on the time synchronization state threshold and the received time state value. The network entity may be an AMF or a wireless communication node. The time state value may be received from the wireless communication node via broadcast. The time synchronization state threshold may be created by one of the following: an AMF, a wireless communication node, a Time-Sensitive Communication Synchronization Function (TSCTSF), or a Time-Sensitive Network Adaptation Function (TSN-AF).

[0118] In some implementations, the AMF may receive a time synchronization status threshold from a Time-Sensitive Communications Synchronization Function (TSCTSF), a Time-Sensitive Network Adaptation Function (TSN-AF), or a wireless communication node. The wireless communication node may be an NG-RAN.

[0119] While different implementations of this solution have been described above, it should be understood that they are presented by way of example only and not as a limitation. Similarly, different figures may depict example architectures or configurations provided to enable those skilled in the art to understand example features and functionality of this solution. However, such persons will understand that the solution is not limited to the example architectures or configurations shown, but can be implemented using various alternative architectures and configurations. Furthermore, as those skilled in the art will understand, one or more features of one implementation may be combined with one or more features of another implementation described herein. Therefore, the breadth and scope of this disclosure should not be limited to any of the illustrative embodiments described above.

[0120] It should also be understood that any reference to elements in this document using names such as “first,” “second,” etc., generally does not limit the number or order of those elements. Rather, these designations may be used herein as a convenient means of distinguishing between two or more elements or instances of elements. Therefore, mentioning first and second elements does not imply that only two elements may be used, or that the first element must precede the second element in some way.

[0121] Furthermore, those skilled in the art will understand that information and signals can be represented using any of a variety of different techniques and skills. For example, the data, instructions, commands, information, signals, bits, and symbols that may be referenced in the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or light particles, or any combination thereof.

[0122] Those skilled in the art will further appreciate that any of the various illustrative logic blocks, modules, processors, devices, circuits, methods, and functions described in conjunction with the aspects disclosed herein can be implemented by electronic hardware (e.g., digital embodiments, analog embodiments, or a combination of both), firmware, program or design code in various forms of incorporated instructions (which may be referred to herein as "software" or "software module"), or any combination of these technologies. To clearly illustrate this interchangeability of hardware, firmware, and software, various illustrative components, blocks, modules, circuits, and steps have been described above in general terms of their functionality. Whether these functions are implemented as hardware, firmware, or software, or as a combination of these technologies, depends on the specific application and the design constraints imposed on the system as a whole. Those skilled in the art may implement the described functionality in different ways for each specific application, but such implementation decisions will not depart from the scope of this disclosure.

[0123] Furthermore, those skilled in the art will understand that the various illustrative logic blocks, modules, devices, components, and circuits described herein may be implemented within or executed by an integrated circuit (IC), which may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, or any combination thereof. Logic blocks, modules, and circuits may also include antennas and / or transceivers for communication with various components within a network or device. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors incorporating a DSP core, or any other suitable configuration performing the functions described herein.

[0124] If implemented as software, the functionality can be stored as one or more instructions or codes on a computer-readable medium. Therefore, the steps of the methods or algorithms disclosed herein can be implemented as software stored on a computer-readable medium. Computer-readable media include both computer storage media and communication media, with communication media including any medium capable of transferring computer programs or code from one place to another. Storage media can be any available medium accessible to a computer. By way of example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and is accessible to a computer.

[0125] In this document, the term "module" refers to software, firmware, hardware, and any combination of such elements for performing the associated functions described herein. Furthermore, for the purposes of discussion, different modules are described as discrete modules; however, as will be apparent to those skilled in the art, two or more modules may be combined to form a single module that performs the associated functions according to embodiments of this solution.

[0126] Additionally, memory or other storage and communication components may be employed in embodiments of this solution. It should be understood that, for clarity, the above description has referenced various functional units and processors in its implementation of this solution. However, it will be apparent that any suitable distribution of functionality among different functional units, processing logic elements, or domains may be used without diminishing the effectiveness of this solution. For example, a function illustrated as being performed by a separate processing logic element or controller may be performed by the same processing logic element or controller. Therefore, references to specific functional units are merely references to suitable means for providing the described functionality and do not indicate a strict logical or physical structure or organization.

[0127] Various modifications to the embodiments described in this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as set forth in the following claims.

Claims

1. A wireless communication method, comprising: The wireless communication device receives a first message including a time synchronization status threshold. The wireless communication device receives a second message including a time status value; The wireless communication device determines whether to switch itself to the connected state based on the time status value and the time synchronization status threshold.

2. The wireless communication method according to claim 1, further comprising: The wireless communication device receives the first message from the Access and Mobility Management Function (AMF) or a wireless communication node; The wireless communication device receives the second message from the wireless communication node via broadcast.

3. The wireless communication method according to claim 2, wherein, The AMF is configured to create the time synchronization state threshold.

4. The wireless communication method according to claim 2, wherein, The first message is a non-access stratum (NAS) message sent directly from the AMF.

5. The wireless communication method according to claim 2, wherein, The first message is a Radio Resource Control (RRC) message sent from the wireless communication node.

6. The wireless communication method according to claim 2, wherein, The second message is a new information element in the System Information Block (SIB) or an existing information element in the ReferenceTimeInfo.

7. The wireless communication method according to claim 2, wherein, The Time-Sensitive Communication Synchronization Function (TSCTSF) or the Time-Sensitive Network Adaptation Function (TSN-AF) is configured to create the time synchronization state threshold.

8. The wireless communication method according to claim 7, wherein, The TSCTSF or TSN-AF is configured to send the time synchronization status threshold to the AMF.

9. The wireless communication method according to claim 2, wherein, The wireless communication node is configured to create the time synchronization state threshold.

10. The wireless communication method according to claim 9, wherein, The wireless communication node is configured to send the time synchronization status threshold to the AMF.

11. A wireless communication method, comprising: The network entity sends a message to the wireless communication device, including a time synchronization status threshold. The wireless communication device is configured to determine whether to switch itself to a connected state based on the time synchronization state threshold and the received time state value.

12. The wireless communication method according to claim 11, wherein, The network entity is an Access and Mobility Management Function (AMF) or a wireless communication node, and the time status value is received from the wireless communication node via broadcast.

13. The wireless communication method according to claim 12, wherein, The time synchronization state threshold is created by one of the following: the AMF, the wireless communication node, the Time Sensitive Communication Synchronization Function (TSCTSF), or the Time Sensitive Network Adaptation Function (TSN-AF).

14. The wireless communication method according to claim 12 or 13, wherein, The AMF receives the time synchronization status threshold from the Time Sensitive Communication Synchronization Function (TSCTSF), the Time Sensitive Network Adaptation Function (TSN-AF), or the wireless communication node.

15. The wireless communication method according to claim 12, wherein, The wireless communication node is a next-generation wireless access network (NG-RAN).

16. A wireless communication device comprising a processor and a memory, wherein the processor is configured to read code from the memory and implement the method of any one of claims 1 to 15.

17. A computer program product comprising computer-readable program code stored thereon, the code causing the processor to perform the method of any one of claims 1 to 15 when executed by a processor.

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