CN115915219A

CN115915219A - Communication method, communication device and communication system

Info

Publication number: CN115915219A
Application number: CN202111160112.XA
Authority: CN
Inventors: 臧昕; 周润泽; 王远
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-09-30
Filing date: 2021-09-30
Publication date: 2023-04-04
Also published as: WO2023051620A1

Abstract

The application provides a communication method, a communication device and a communication system. The method comprises the following steps: the first network element receives time requirement information from the second network element; the first network element acquires the time information of a first clock according to the time requirement information, wherein the first clock is a clock matched with the time requirement information in a plurality of clocks of the first network element; and the first network element sends the time information of the first clock to the second network element. According to the scheme, as the first network element stores the information of the plurality of clocks, when a certain clock fails, other clocks can be used, and the situation that accurate time information cannot be provided to the outside is avoided. In addition, since the information of the plurality of clocks is stored in the first network element, the first network element can provide the time information of one clock which is most matched with the time requirement information for the second network element based on the time requirement information sent by the second network element, and the provision of accurate time information can be realized.

Description

Communication method, communication device and communication system

Technical Field

The present application relates to the field of communications technologies, and in particular, to a communication method, a communication apparatus, and a communication system.

Background

The 5G network manages information of one clock, and the 5G network has time service capability and can provide time information of the clock to the outside.

However, when the clock fails, accurate time information of the clock cannot be provided to the outside.

Disclosure of Invention

The embodiment of the application provides a communication method, a communication device and a communication system, which are used for providing time information.

In a first aspect, an embodiment of the present application provides a communication method, which may be performed by a first network element or a module (e.g., a chip) in the first network element, where the first network element may be a clock network function network element. Taking the first network element as an example to execute the method, the method includes: the first network element receives time requirement information from the second network element; the first network element acquires the time information of a first clock according to the time requirement information, wherein the first clock is a clock matched with the time requirement information in a plurality of clocks of the first network element; and the first network element sends the time information of the first clock to the second network element.

According to the scheme, as the first network element stores the information of the plurality of clocks, when a certain clock fails, other clocks can be used, and the condition that accurate time information cannot be provided to the outside is avoided. In addition, since the information of the plurality of clocks is stored in the first network element, the first network element can provide the time information of one clock which is most matched with the time requirement information for the second network element based on the time requirement information sent by the second network element, and the provision of accurate time information can be realized.

As a possible implementation method, the first network element continuously sends the time information of the first clock to the second network element according to a set period.

According to the above scheme, the first network element can keep the second network element synchronized with the first clock by continuously sending the time information of the first clock to the second network element.

As a possible implementation method, the first network element receives a time keeping capability of the second network element from the second network element, where the time keeping capability of the second network element indicates a duration for continuously providing accurate time after the second network element loses a clock source signal; and the first network element sends the time information of the first clock to the second network element according to the time keeping capability of the second network element.

According to the above scheme, on one hand, the second network element can keep synchronization with the first clock, and on the other hand, the signaling overhead of the first network element sending the time information of the first clock to the second network element can be reduced.

As a possible implementation method, the first network element determines time information of at least two clocks of the multiple clocks according to the time requirement information, where the at least two clocks both match the time requirement information; the first network element selects the first clock from the at least two clocks.

As a possible implementation method, the first network element sends configuration information of the first clock to the second network element, where the configuration information includes one or more of a clock source of the first clock, a clock precision of the first clock, a time keeping capability of the first clock, a time service object allowed by the first clock, a service area of the first clock, a clock transfer capability of the first clock, or a quality level of the first clock.

As a possible implementation method, the time requirement information includes one or more of the following information: clock source, clock accuracy, time keeping capability of the clock, or service area.

As a possible implementation method, the second network element is an application function network element, a terminal device, an access network device, or a core network device.

In a second aspect, an embodiment of the present application provides a communication method, which may be performed by a second network element or a module (e.g., a chip) in the second network element, where the second network element may be a terminal device, an access network device, a core network device, or an application function network element. The method comprises the following steps: the second network element sends time requirement information to the first network element; the second network element receives time information of a first clock from the first network element, wherein the first clock is a clock which is matched with the time requirement information in a plurality of clocks of the first network element.

According to the scheme, as the first network element stores the information of the plurality of clocks, when a certain clock fails, other clocks can be used, and the condition that accurate time information cannot be provided to the outside is avoided. In addition, since the information of a plurality of clocks is stored in the first network element, the second network element can acquire the time information of one clock which is most matched with the time requirement information from the first network element according to the time requirement information of the second network element, and the accurate time information can be provided.

As a possible implementation method, the second network element receives configuration information of the first clock from the first network element, where the configuration information includes one or more of a clock source of the first clock, a clock precision of the first clock, a time keeping capability of the first clock, a time object allowed by the first clock, a service area of the first clock, a clock transfer capability of the first clock, or a quality level of the first clock.

In a third aspect, an embodiment of the present application provides a communication method, which may be performed by a third network element or a module (e.g., a chip) in the third network element, where the third network element may be a mobility management network element or a network open capability network element. The method comprises the following steps: the third network element receives the time requirement information from the second network element; the third network element acquires address information of a first network element according to the time requirement information, wherein the first network element comprises information of a clock matched with the time requirement information; the third network element sends the time requirement information to the first network element according to the address information of the first network element; the third network element receives time information of a first clock from the first network element, wherein the first clock is a clock matched with the time requirement information in a plurality of clocks of the first network element; the third network element sends the time information of the first clock to the second network element.

According to the scheme, as the first network element stores the information of the plurality of clocks, when a certain clock fails, other clocks can be used, and the situation that accurate time information cannot be provided to the outside is avoided. And, because the information of a plurality of clocks is stored on the first network element, the third network element can obtain the time information of one clock which is most matched with the time requirement information from the first network element based on the time requirement information sent by the second network element, and provide the time information of the clock to the second network element, thereby realizing the purpose of providing accurate time information.

As a possible implementation method, the third network element sends a query message to the data management network element, where the query message includes the time requirement information; the third network element receives address information of the first network element from the data management network element.

According to the scheme, the third network element acquires the address information of the first network element from the data management network element, and the address information of the first network element can be accurately and quickly acquired.

As a possible implementation method, the third network element receives configuration information of the first clock from the first network element, where the configuration information includes one or more of a clock source of the first clock, a clock precision of the first clock, a time keeping capability of the first clock, a time service object allowed by the first clock, a service area of the first clock, a clock transfer capability of the first clock, or a quality level of the first clock; the third network element sends the configuration information of the first clock to the second network element.

In a fourth aspect, the present application provides a communication method, which may be performed by a data management network element or a module (e.g., a chip) in the data management network element. The method comprises the following steps: the data management network element receives a query message from a third network element, wherein the query message contains time requirement information; the data management network element determines a first network element according to the time requirement information, wherein the first network element comprises information of a clock matched with the time requirement information; the data management network element sends the address information of the first network element to the third network element.

As a possible implementation method, the third network element is a mobility management network element or a network capability open network element.

In a fifth aspect, an embodiment of the present application provides a communication apparatus, which may be a first network element or a module (e.g., a chip) applied in the first network element. The apparatus has a function of implementing any of the implementation methods of the first aspect described above. The function can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

In a sixth aspect, an embodiment of the present application provides a communication apparatus, which may be a second network element or a module (e.g., a chip) applied in the second network element. The apparatus has a function of implementing any of the implementation methods of the second aspect described above. The function can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

In a seventh aspect, an embodiment of the present application provides a communication apparatus, where the apparatus may be a third network element or a module (e.g., a chip) applied in the third network element. The apparatus has a function of implementing any of the implementation methods of the third aspect described above. The function can be realized by hardware, and can also be realized by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the functions described above.

In an eighth aspect, an embodiment of the present application provides a communication apparatus, where the apparatus may be a data management network element or a module (e.g., a chip) applied in the data management network element. The apparatus has a function of implementing any of the implementation methods of the fourth aspect described above. The function can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

In a ninth aspect, an embodiment of the present application provides a communication apparatus, including a processor and a memory; the memory is configured to store computer instructions, and when the apparatus is running, the processor executes the computer instructions stored in the memory to cause the apparatus to perform any of the implementation methods of the first aspect to the fourth aspect.

In a tenth aspect, an embodiment of the present application provides a communication apparatus, which includes means or units (means) for performing each step of any implementation method in the first to fourth aspects.

In an eleventh aspect, an embodiment of the present application provides a communication device, which includes a processor and an interface circuit, where the processor is configured to communicate with another device through the interface circuit, and perform any implementation method in the first to fourth aspects. The processor includes one or more.

In a twelfth aspect, an embodiment of the present application provides a communication apparatus, including a processor coupled to a memory, where the processor is configured to call a program stored in the memory to execute any implementation method in the first aspect to the fourth aspect. The memory may be located within the device or external to the device. And the processor may be one or more.

In a thirteenth aspect, the present application further provides a computer-readable storage medium, which stores instructions that, when executed on a communication device, cause any implementation method in the first to fourth aspects to be performed.

In a fourteenth aspect, the present application further provides a computer program product, which includes a computer program or instructions, and when the computer program or instructions are executed by a communication device, the method of any implementation method in the first to fourth aspects is executed.

In a fifteenth aspect, an embodiment of the present application further provides a chip system, including: a processor configured to perform any of the implementation methods of the first to fourth aspects.

In a sixteenth aspect, an embodiment of the present application further provides a communication system, which includes a first network element configured to perform any implementation method of the first aspect, and a second network element configured to perform any implementation method of the second aspect.

In a seventeenth aspect, an embodiment of the present application further provides a communication system, including a third network element configured to perform any implementation method of the third aspect, and a data management network element configured to perform any implementation method of the fourth aspect.

Drawings

FIG. 1 is a schematic diagram of a 5G network architecture based on a service-oriented architecture;

FIG. 2 is a schematic diagram of a 5G network architecture based on a point-to-point interface;

fig. 3 is a flowchart of a communication method according to an embodiment of the present application;

fig. 4 is a flowchart of a communication method according to an embodiment of the present application;

fig. 5 is a schematic diagram of a communication device according to an embodiment of the present application;

fig. 6 is a schematic diagram of a communication device according to an embodiment of the present application.

Detailed Description

Fig. 1 is a schematic diagram of a 5G network architecture based on a service architecture. The 5G network architecture shown in fig. 1 may include a terminal device, an access network device, and a core network device. The terminal device accesses a Data Network (DN) through the access network device and the core network device. The core network device comprises part or all of the following network elements: a Unified Data Management (UDM) Network element, a Unified Database (UDR) Network element, a Network open Function (NEF) Network element (not shown in the drawings), an Application Function (AF) Network element, a Policy Control Function (PCF) Network element, an access and mobility management Function (AMF) Network element, a Session Management Function (SMF) Network element, a User Plane Function (UPF) Network element, a Network storage Function (NRF) Network element (not shown in the drawings), a clock Network Function (TNF) Network element.

The terminal device (also referred to as User Equipment (UE)) of the present application is a device with a wireless transceiving function, and can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can also be deployed on the water surface (such as a ship and the like); and may also be deployed in the air (e.g., airplanes, balloons, satellites, etc.). The terminal device may be a mobile phone (mobile phone), a tablet computer (pad), a computer with a wireless transceiving function, a Virtual Reality (VR) terminal, an Augmented Reality (AR) terminal, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote medical (remote medical), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety (transportation safety), a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), and the like.

The terminal device may establish a connection with the operator network through an interface (e.g., N1, etc.) provided by the operator network, and use a service such as data and/or voice provided by the operator network. The terminal device may also access the DN via an operator network, use operator services deployed on the DN, and/or services provided by a third party. The third party may be a service party other than the operator network and the terminal device, and may provide services such as data and/or voice for the terminal device. The specific expression form of the third party may be specifically determined according to an actual application scenario, and is not limited herein.

An access network device is a device for providing a wireless communication function for a terminal device. Access network equipment includes, for example but not limited to: next generation base station (G node B, gNB), evolved node B (eNB), radio Network Controller (RNC), node B (NB), base Station Controller (BSC), base Transceiver Station (BTS), home base station (e.g., home evolved node B, or home node B, HNB), base Band Unit (BBU), transmission point (TRP), transmission Point (TP), mobile switching center, etc. in 5G.

The access network equipment and the terminal equipment may be fixed or mobile. The access network equipment and the terminal equipment can be deployed on the land, including indoor or outdoor, handheld or vehicle-mounted; can also be deployed on the water surface; it may also be deployed on airborne airplanes, balloons and satellite vehicles. The embodiment of the application does not limit the application scenes of the access network equipment and the terminal equipment.

In this application, the mobility management network element is a control plane network element provided by an operator network, and is responsible for access control and mobility management of terminal equipment accessing the operator network, for example, including functions of mobility state management, user temporary identity assignment, user authentication and authorization, and the like. In 5G, the mobility management element may be an AMF element, and in future communications such as the sixth generation (6G), the mobility management element may still be an AMF element, or may have another name, which is not limited in this application.

In this application, the session management network element is a control plane network element provided by an operator network and is responsible for managing a Protocol Data Unit (PDU) session of the terminal device. A PDU session is a channel for transmitting PDUs, and a terminal device needs to transfer PDUs to and from the DN through the PDU session. The PDU session is established, maintained, deleted and the like by the SMF network element. The Session management network element includes Session management (e.g., session establishment, modification, and release, including tunnel maintenance between the user plane network element and the access network device), selection and control of the user plane network element, service and Session Continuity (SSC) mode selection, roaming, and other Session-related functions. In 5G, the session management network element may be an SMF network element, and in future communications such as 6G, the session management network element may still be an SMF network element, or have another name, which is not limited in this application.

In this application, the user plane network element is a gateway provided by an operator, and is a gateway for communication between an operator network and a DN. The UPF network element comprises user plane related functions such as data packet routing and transmission, packet detection, service usage reporting, quality of service (QoS) processing, legal monitoring, uplink packet detection, downlink data packet storage and the like. In 5G, the user plane network element may be a UPF network element, and in future communications such as 6G, the user plane network element may still be a UPF network element or have another name, which is not limited in this application.

In this application, the data management network element is a control plane network element provided by an operator, and is responsible for storing information such as a subscriber permanent identifier (SUPI), a credential (trusted context), a security context (security context), and subscription data of a subscription user in an operator network. These information stored by the data management network element may be used for authentication and authorization of the terminal device to access the operator network. The subscriber of the operator network may be specifically a user using a service provided by the operator network, for example, a user using a mobile phone core card of china telecommunications, or a user using a mobile phone core card of china mobile, and the like. The above-mentioned Permanent Subscription Identifier (SUPI) of the subscriber may be the number of the mobile phone core card, etc. The credentials and security context of the subscriber may be a small file stored with an encryption key of the core card of the mobile phone or information related to encryption of the core card of the mobile phone, and used for authentication and/or authorization. The security context may be data (cookie) or token (token) stored on the user's local terminal (e.g., cell phone), etc. The subscription data of the subscriber may be a service associated with the mobile phone core card, such as a traffic package or a network using the mobile phone core card. It should be noted that the information related to the permanent identifier, the credential, the security context, the authentication data (cookie), and the token equivalent authentication and authorization is not distinguished or limited in the present document for convenience of description. Unless otherwise specified, the embodiments of the present application will be described in the context of security, but the embodiments of the present application are also applicable to authentication, and/or authorization information in other expressions. In 5G, the data management network element may be a UDM network element, and in future communications such as 6G, the data management network element may still be a UDM network element, or have another name, which is not limited in this application.

In this application, the unified database network element is a control plane network element provided by an operator, and includes an access function for executing type data such as subscription data, policy data, and application data. In 5G, the unified database network element may be a UDR network element, and in future communications such as 6G, the unified database network element may still be a UDR network element, or may have another name, which is not limited in this application.

In this application, the network open network element is a control plane network element provided by an operator. The network open network element opens the external interface of the operator network to the third party in a safe way. When the session management network element needs to communicate with the network element of the third party, the network open network element can be used as a relay for the communication between the session management network element and the network element of the third party. When the network open network element is used as a relay, the translation of the identification information of the subscriber and the translation of the identification information of the network element of the third party can be used. For example, when the network open network element transmits the SUPI of the subscriber from the carrier network to the third party, the SUPI may be translated into its corresponding external Identity (ID). Conversely, when the network open network element transmits an external ID (a network element ID of a third party) to the operator network, it can be translated into SUPI. In 5G, the network open network element may be an NEF network element, and in future communications such as 6G, the network open network element may still be an NEF network element, or have another name, which is not limited in this application.

In this application, the application function network element is configured to deliver a requirement of an application side on a network side, for example, a QoS requirement or a user state event subscription. The application function network element may be a third-party function entity, or may be an application server deployed by an operator. In 5G, the application function network element may be an AF network element, and in future communications such as 6G, the application function network element may still be an AF network element or have another name, which is not limited in this application.

In this application, the policy control network element is a control plane function provided by an operator, and is configured to provide a PDU session policy to the session management network element. The policies may include charging related policies, qoS related policies, authorization related policies, and the like. In 5G, the policy control network element may be a PCF network element, and in future communications such as 6G, the policy control network element may still be a PCF network element, or have another name, which is not limited in this application.

In this application, the network storage function network element may be configured to provide a network element discovery function, and provide network element information corresponding to a network element type based on a request of another network element. The network storage function network element also provides network element management services, such as network element registration, updating, de-registration, network element state subscription and pushing and the like. In 5G, the network storage function network element may be an NRF network element, and in future communications such as 6G, the network storage function network element may still be an NRF network element, or may have another name, which is not limited in this application.

In this application, the clock network function network element may be configured to manage information of one or more clocks of the 5G network, and may provide time information of the clock to the outside through its own port, for example, directly or indirectly provide time information of the clock to the terminal device, the access network device, the core network device, or the third-party application function network element. Wherein the time information represents the time, moment or point in time of the clock. In 5G, the clock network function network element may be a TNF network element, and in future communications such as 6G, the clock network function network element may still be a TNF network element, or may have another name, which is not limited in this application.

The DN is a network outside the operator network, the operator network can access a plurality of DNs, and the DN can deploy a plurality of services and provide services such as data and/or voice for the terminal device. For example, the DN is a private network of a certain intelligent factory, a sensor installed in a workshop of the intelligent factory can be a terminal device, a control server of the sensor is deployed in the DN, and the control server can provide services for the sensor. The sensor can communicate with the control server, obtain the instruction of the control server, transmit the sensor data gathered to the control server, etc. according to the instruction. For another example, the DN is an internal office network of a company, the mobile phone or computer of the employee of the company may be a terminal device, and the mobile phone or computer of the employee may access information, data resources, and the like on the internal office network of the company.

In fig. 1, npcf, nurr, nudm, naf, namf, nsmf, and Ntnf are service interfaces provided by the PCF, UDR, UDM, AF, AMF, SMF, and TNF, respectively, and are used to invoke corresponding service operations. N1, N2, N3, N4, and N6 are interface serial numbers, and the meaning of these interface serial numbers can be referred to the description in fig. 2.

Fig. 2 is a schematic diagram of a 5G network architecture based on a point-to-point interface, where introduction of functions of network elements may refer to introduction of functions of corresponding network elements in fig. 1, and details are not repeated. The main differences between fig. 2 and fig. 1 are: the interfaces between the various control plane network elements in fig. 1 are served interfaces, and the interfaces between the various control plane network elements in fig. 2 are point-to-point interfaces.

In the architecture shown in fig. 2, the interface names and functions between the network elements are as follows:

1) And N1: the interface between the AMF and the terminal device may be used to deliver NAS signaling (e.g., including QoS rules from the AMF) to the terminal device, etc.

2) N2: the interface between the AMF and the RAN may be used to transfer radio bearer control information from the core network side to the RAN, and the like.

3) N3: the interface between RAN and UPF is mainly used for transmitting the uplink and downlink user plane data between RAN and UPF.

4) And N4: the interface between the SMF and the UPF may be used for transmitting information between the control plane and the user plane, including controlling the sending of forwarding rules, qoS control rules, traffic statistics rules, etc. for the user plane and reporting information for the user plane.

5) And N5: the interface between the AF and the PCF may be used for application service request issue and network event report.

6) N6: and the UPF and DN interface is used for transmitting the uplink and downlink user data stream between the UPF and the DN.

7) N7: the interface between the PCF and the SMF may be used to issue a Protocol Data Unit (PDU) session granularity and a service data stream granularity control policy.

8) And N8: the interface between the AMF and the UDM may be used for the AMF to obtain subscription data and authentication data related to access and mobility management from the UDM, and for the AMF to register the current mobility management related information of the terminal device with the UDM.

9) And N9: and the user interface between the UPF and the UPF is used for transmitting the uplink and downlink user data streams between the UPFs.

10 N10: the interface between the SMF and the UDM may be used for the SMF to acquire the subscription data related to session management from the UDM, and for the SMF to register the current session related information of the terminal device with the UDM.

11 N11), N11: the interface between the SMF and the AMF may be used to transfer PDU session tunnel information between the RAN and the UPF, to transfer control messages sent to the terminal device, to transfer radio resource control information sent to the RAN, and so on.

12 N15), N15: the interface between PCF and AMF can be used to send down terminal equipment strategy and access control related strategy.

13 N35): the interface between the UDM and the UDR may be used for the UDM to obtain the user subscription data information from the UDR.

14 N36, N36: the interface between the PCF and the UDR may be used for the PCF to obtain policy related subscription data and application data related information from the UDR.

It is to be understood that the above network elements or functions may be network elements in a hardware device, or may be software functions running on dedicated hardware, or virtualization functions instantiated on a platform (e.g., a cloud platform). As a possible implementation method, the network element or the function may be implemented by one device, or may be implemented by multiple devices together, or may be a functional module in one device, which is not specifically limited in this embodiment of the present application.

Referring to fig. 3, a flowchart of a communication method provided in an embodiment of the present application is shown, where the method includes the following steps:

step 301, the second network element sends time requirement information to the first network element. Accordingly, the first network element receives the time requirement information.

And the second network element sends the time requirement information to the first network element, and the time requirement information is used for requesting to acquire the time information of the clock matched with the time requirement information.

In one implementation, the first network element is a clock network function network element, and may be other network elements of a core network.

In one implementation, the second network element is a third party Application Function (AF) network element, a terminal device, an access network device, or a core network device (e.g., an AMF network element, an SMF network element, a UPF network element, etc.).

Step 302, the first network element obtains time information of a first clock according to the time requirement information, where the first clock is a clock matching the time requirement information among the multiple clocks of the first network element.

As one implementation method, profile information of multiple clocks is stored on a first network element, and the information of each clock stored on the first network element includes one or more of the following information:

1) Clock source (source): the source of the clock may be, for example, a Global Navigation Satellite System (GNSS), a Time Synchronization Network (TSN), a local clock, or the like.

2) Clock precision (accuracy): represents the error between the clock and the master clock, which may be, for example, 1 microsecond (us) or 500 nanoseconds (ns). Wherein the master clock is one of a plurality of clocks at the first network element.

3) Time retention (holiver): the duration of the time that the clock continuously provides accurate time after losing the clock source signal is shown, for example, the clock source of the clock 1 is GNSS, and the time keeping capability is 24 hours, which indicates that the clock 1 can still provide accurate time within 24 hours after losing the GNSS signal.

4) Allowed time service objects: the term "time-providing object" refers to an object that can time-transfer a device in a specific AF or 5G system, for example.

5) Service area: refers to the service range of the clock, such as defining service areas at a Public Land Mobile Network (PLMN) granularity or defining service areas at a Tracking Area (TA) list granularity.

6) Quality class (clock class) output quality class 6 when tracking Global Positioning System (GPS), output 7 when maintaining and satisfying the performance requirement, and output 52 when oscillating freely.

7) Clock transfer capability: such as time service over the air interface or time service over the 1588 protocol.

Among the multiple clocks on the first network element, multiple clocks from the same clock source may be included, such as clocks including multiple GNSS or clocks including multiple TSNs, and so on.

Specifically, the first network element determines, according to the received time requirement information and according to stored profile information of multiple clocks, a clock, such as a first clock, which matches the time requirement information, and then the first network element obtains the time information of the first clock. The time requirement information sent in step 301 includes one or more of the following information: clock source, clock accuracy, time keeping capability of the clock, or service area.

The method for the first network element to determine the clock according to the time requirement information may be, for example: and acquiring a clock matched with all the information in the time requirement information or acquiring a clock matched with part of the information in the time requirement information. Wherein, if the first network element determines that at least two clocks match the time requirement information according to the time requirement information, the first network element may select a best-performing clock according to the performance (such as one or more of clock accuracy, quality level, and time keeping capability) of the at least two clocks, or randomly select a clock from the at least two clocks. Illustratively, the time requirement information includes a TSN clock source and 1us clock precision, and the first network element acquires 3 clock sources satisfying the time requirement information according to the time requirement information, which are TSN clock source 1, TSN clock source 2, and TSN clock source 3, respectively. Then, the first network element may randomly select one clock source from the 3 TSN clock sources, or the first network element selects one TSN clock source with the highest clock precision from the 3 TSN clock sources, for example, the clock precisions of TSN clock source 1, TSN clock source 2, and TSN clock source 3 are 1us, 0.9us, and 0.8us, respectively, then the first network element selects TSN clock source 3, or the first network element selects one TSN clock source with the highest time keeping capability from the 3 TSN clock sources, for example, the time keeping capabilities of TSN clock source 1, TSN clock source 2, and TSN clock source 3 are 24 hours, 23 hours, and 22 hours, then the first network element selects TSN clock source 1.

The "matching" in the embodiment of the present application may mean "the same", or "the difference is smaller than a preset threshold".

Step 303, the first network element sends the time information of the first clock to the second network element. Correspondingly, the second network element receives the time information of the first clock.

In this embodiment, the time information of the first clock may be a specific time, such as the time, the time instant, or the time point of the first clock. The following describes an implementation method of the time information with reference to an example. For example, the time information of the first clock is represented by fields in the following format:

ReferenceTime-r16::＝SEQUENCE{

refDays-r16 INTEGER(0..72999)，

refSeconds-r16 INTEGER(0..86399)，

refMilliSeconds-r16 INTEGER(0..999)，

refTenNanoSeconds-r16 INTEGER(0..9999-9)

}

among them, the refDays-r16 field is used to indicate "day" in the time information, the refSecons-r 16 field is used to indicate "second" in the time information, the refMillisSecons-r 16 field is used to indicate "millisecond" in the time information, and the refTenNanoSecons-r 16 field is used to indicate "nanosecond" in the time information. For example, the four fields take the values: 10950 36066, 500, 10, then the corresponding time information is: 10 o 6 min 6 sec 500 ms 100 ns in 12 months and 26 days in 2000. After receiving the ReferenceTime-r16 information, the second network element may calculate, according to the conversion rule, that the time information of the first clock is: 10 o 6 min 6 sec 500 ms 100 ns in 12 months and 26 days in 2000.

As another implementation method, the time information of the first clock may also be related information used for determining time, for example, a difference between the time of the first clock and the time of the second network element, and the second network element may calibrate the time of the second network element according to the difference and the time of the second network element, so as to implement clock synchronization between the second network element and the first network element.

According to the above steps 301 to 303, since the first network element stores information of multiple clocks, when a certain clock fails, other clocks can be used, so as to avoid a situation that accurate time information cannot be provided to the outside. In addition, since the information of multiple clocks is stored in the first network element, the first network element can provide the time information of one clock that is most matched with the time requirement information for the second network element based on the time requirement information sent by the second network element, so that accurate time information can be provided.

As an implementation method, in order to implement that the second network element maintains synchronization with the first clock, the first network element may continuously perform the step 303, for example, the first network element continuously sends the time information of the first clock to the second network element according to a set period, where the continuous means that the latest time information of the first clock is always sent to the second network element according to the set period. The period here refers to a time interval which is very short, and may be, for example, 1ns,2ns, and so on.

As another implementation method, in step 301, the second network element further sends a time keeping capability of the second network element to the first network element, where the time keeping capability of the second network element indicates a duration for continuously providing accurate time after the second network element loses the clock source signal. To implement that the second network element keeps synchronization with the first clock, the first network element may perform the step 303 according to the time keeping capability of the second network element, for example, if the time keeping capability of the second network element is 24 hours, the first network element sends the time information of the first clock to the second network element every 24 hours.

As an implementation method, after step 302, the first network element may further send configuration information of the first clock to the second network element, where the configuration information includes one or more of a clock source of the first clock, a clock precision of the first clock, a time keeping capability of the first clock, a time service object allowed by the first clock, a service area of the first clock, a clock transfer capability of the first clock, or a quality level of the first clock. After receiving the configuration information of the first clock, the second network element may determine whether to maintain the content of the time requirement information (i.e. the time requirement information in step 301) or update the content of the time requirement information according to the configuration information. For example, after the second network element receives the configuration information of the first clock, and determines that the configuration information of the first clock is completely matched with the time requirement information sent in step 301, the second network element determines to receive the time information of the first clock and maintain the time requirement information. For another example, after receiving the configuration information of the first clock, the second network element determines that the configuration information of the first clock is not completely matched with the time requirement information sent in step 301, and then the second network element determines to accept the time information of the first clock and maintain the time requirement information according to a local policy, or to reject the time information of the first clock, and sends the time requirement information again or sends updated time requirement information after updating the time requirement information.

Referring to fig. 4, a flowchart of a communication method provided in an embodiment of the present application is shown, where the method includes the following steps:

step 401, the second network element sends time requirement information to the third network element. Accordingly, the third network element receives the time requirement information.

And the second network element sends time requirement information to the third network element, and the time requirement information is used for requesting to acquire the time information of the clock matched with the time requirement information. The time demand information includes one or more of the following information: clock source, clock accuracy, time keeping capability of the clock, or service area.

In one implementation, the second network element is a third party Application Function (AF) network element, and the third network element is a network capability openness network element, which may be an NEF network element or another network element having the function of the NEF network element in a future communication system.

In one implementation method, the second network element is a terminal device, an access network device, or a core network device (e.g., an SMF network element, a UPF network element, etc.), and the third network element is a mobility management network element, which may be an AMF network element or another network element having a function of the AMF network element in a future communication system.

Step 402, the third network element obtains address information of the first network element according to the time requirement information, wherein the first network element comprises information of a clock matched with the time requirement information.

As an implementation method, the third network element may locally obtain, according to the time requirement information, the first network element matched with the time requirement information, and further obtain the address information of the first network element. The first network element contains information of a clock matched to the time requirement information.

As another implementation method, the third network element may send a query message to a data management network element (such as NRF, UDM, or UDR, etc.), where the query message includes time requirement information. The query message requests a query for address information of a network element capable of providing a time matching the time requirement information, and the network element may provide time information of a clock matching the time requirement information. And the data management network element determines a first network element matched with the time requirement information according to the time requirement information, wherein the first network element comprises the information of the clock matched with the time requirement information. And then the data management network element sends the address information of the first network element to the third network element. For example, the data management network element stores address information of a plurality of first network elements and configuration information of each clock managed by each first network element, where the configuration information of each clock includes one or more of a clock source, clock precision, time keeping capability of the clock, time service objects allowed by the clock, service area of the clock, clock transmission capability, or quality level of the clock. After receiving the time requirement information, the data management network element may acquire a clock matched with the time requirement information, and further acquire address information of the first network element managing the clock.

In step 403, the third network element sends the time requirement information to the first network element according to the address information of the first network element. Accordingly, the first network element receives the time requirement information.

And the third network element sends time requirement information to the first network element, and the time requirement information is used for requesting to acquire the time information of the clock matched with the time requirement information.

Step 404, the first network element obtains time information of a first clock according to the time requirement information, where the first clock is a clock matching the time requirement information in multiple clocks of the first network element.

This step is the same as step 302 described above, and reference may be made to the description above.

In step 405, the first network element sends time information of the first clock to the third network element. Correspondingly, the third network element receives time information of the first clock.

Step 405, the third network element sends the time information of the first clock to the second network element. Correspondingly, the second network element receives the time information of the first clock.

According to the above steps 401 to 405, since the first network element stores information of a plurality of clocks, when a certain clock fails, other clocks can be used, thereby avoiding a situation that accurate time information cannot be provided to the outside. And, because the information of a plurality of clocks is stored on the first network element, the third network element can obtain the time information of one clock which is most matched with the time requirement information from the first network element based on the time requirement information sent by the second network element, and provide the time information of the clock to the second network element, thereby realizing the purpose of providing accurate time information.

As an implementation method, in order to implement that the second network element maintains synchronization with the first clock, the above steps 405 to 406 may be continuously performed, for example, the first network element continuously sends the time information of the first clock to the third network element according to a set period, and then the third network element continuously sends the time information of the first clock to the second network element. The period here refers to a time interval which is very short, and may be, for example, 1ns,2ns, and so on.

As another implementation method, in step 401, the second network element further sends the time keeping capability of the second network element to the third network element, and in step 403, the third network element also sends the time keeping capability of the second network element to the first network element, where the time keeping capability of the second network element indicates a duration for continuously providing accurate time after the second network element loses the clock source signal. In order to keep the second network element synchronized with the first clock, the first network element may execute step 405 according to the time keeping capability of the second network element, and the third network element forwards the time information of the first clock from the first network element to the second network element after receiving the time information of the first clock from the first network element. For example, if the time keeping capability of the second network element is 24 hours, the first network element sends the time information of the first clock to the third network element every 24 hours, and then the third network element sends the time information of the first clock to the second network element.

As an implementation method, after step 402, the first network element may further send configuration information of the first clock to the third network element, where the configuration information includes one or more of a clock source of the first clock, a clock precision of the first clock, a time keeping capability of the first clock, a time service object allowed by the first clock, a service area of the first clock, a clock transfer capability of the first clock, or a quality level of the first clock, and then the third network element sends the configuration information of the first clock to the second network element. After receiving the configuration information of the first clock, the second network element may determine whether to maintain the content of the time requirement information (i.e., the time requirement information in step 401) or update the content of the time requirement information according to the configuration information. For example, after receiving the configuration information of the first clock, the second network element determines that the configuration information of the first clock is completely matched with the time requirement information sent in step 301, and then the second network element determines to receive the time information of the first clock and maintain the time requirement information. For another example, after receiving the configuration information of the first clock, the second network element determines that the configuration information of the first clock is not completely matched with the time requirement information sent in step 301, and then the second network element determines to accept the time information of the first clock and maintain the time requirement information according to a local policy, or refuse the time information of the first clock and resend the time requirement information or send updated time requirement information after updating the time requirement information.

The relationship between the embodiment corresponding to fig. 4 and the embodiment corresponding to fig. 3 is: the embodiment corresponding to fig. 4 and the embodiment corresponding to fig. 3 are both that the second network element initiates a request for time information of a clock corresponding to the time requirement information, and the first network element provides the time information of the clock corresponding to the time requirement information, but different from that, in the embodiment corresponding to fig. 3, the second network element interacts directly with the first network element, for example, refer to the above step 301 and step 303, whereas in the embodiment corresponding to fig. 4, the second network element interacts with the first network element via a third network element, for example, refer to the above steps 401 to 403 and steps 405 to 406. The descriptions of similar steps in the two embodiments may be referred to one another.

It is to be understood that, in order to implement the functions in the foregoing embodiments, the first network element, the second network element, the third network element and the data management network element include corresponding hardware structures and/or software modules for performing the respective functions. Those of skill in the art will readily appreciate that the various illustrative elements and method steps described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is performed in hardware or computer software driven hardware depends on the specific application scenario and design constraints of the solution.

Fig. 5 and fig. 6 are schematic structural diagrams of a possible communication device provided in an embodiment of the present application. These communication devices may be used to implement the functions of the first network element, the second network element, the third network element, or the data management network element in the foregoing method embodiment, so that the beneficial effects of the foregoing method embodiment can also be achieved. In an embodiment of the present application, the communication device may be a first network element, a second network element, a third network element, or a data management network element, and may also be a module (e.g., a chip) applied to a first network element module (e.g., a chip), a second network element module (e.g., a chip), a third network element module (e.g., a chip), or a data management network element.

As shown in fig. 5, the communication device 500 includes a processing unit 510 and a transceiving unit 520. The communication device 500 is configured to implement the functions of the first network element, the second network element, the third network element, or the data management network element in the foregoing method embodiments.

When the communication apparatus 500 is used to implement the function of the first network element in the above method embodiments, the transceiver 520 is configured to receive the time requirement information from the second network element; a processing unit 510, configured to obtain time information of a first clock according to the time requirement information, where the first clock is a clock that matches the time requirement information among multiple clocks of the first network element; a transceiving unit 520, configured to send the time information of the first clock to the second network element.

As a possible implementation method, the transceiver 520 is configured to continuously send the time information of the first clock to the second network element according to a set period.

As a possible implementation method, the transceiver 520 is further configured to receive a time keeping capability of a second network element from the second network element, where the time keeping capability of the second network element indicates a duration for continuously providing accurate time after the second network element loses a clock source signal; a processing unit 510, configured to send, according to the time keeping capability of the second network element, the time information of the first clock to the second network element through a transceiving unit 520.

As a possible implementation method, the processing unit 510 is configured to obtain time information of at least two clocks of the multiple clocks according to the time requirement information, where the at least two clocks both match the time requirement information; the first clock is selected from the at least two clocks.

As a possible implementation method, the transceiver 520 is configured to send configuration information of the first clock to the second network element, where the configuration information includes one or more of a clock source of the first clock, a clock precision of the first clock, a time keeping capability of the first clock, a time service object allowed by the first clock, a service area of the first clock, a clock transfer capability of the first clock, or a quality level of the first clock.

When the communication apparatus 500 is used to implement the function of the second network element in the above method embodiment, the transceiver 520 is configured to send the time requirement information to the first network element; and receiving time information of a first clock from the first network element, wherein the first clock is a clock which is matched with the time requirement information in a plurality of clocks of the first network element.

As a possible implementation method, the transceiver unit 520 is configured to receive configuration information of the first clock from the first network element, where the configuration information includes one or more of a clock source of the first clock, a clock precision of the first clock, a time keeping capability of the first clock, a time service object allowed by the first clock, a service area of the first clock, a clock transfer capability of the first clock, or a quality level of the first clock.

When the communication apparatus 500 is used to implement the function of the third network element in the above method embodiments, the transceiver 520 is configured to receive the time requirement information from the second network element; a processing unit 510, configured to obtain address information of a first network element according to the time requirement information, where the first network element includes information of a clock matched with the time requirement information; and according to the address information of the first network element, sending the time requirement information to the first network element through the transceiving unit 520; a transceiver 520, configured to receive time information of a first clock from the first network element, where the first clock is a clock matching the time requirement information among the multiple clocks of the first network element; and sending the time information of the first clock to the second network element.

As a possible implementation method, the transceiver 520 is configured to send an inquiry message to the data management network element, where the inquiry message includes the time requirement information; address information of the first network element is received from the data management network element.

As a possible implementation method, the transceiver unit 520 is configured to receive configuration information of the first clock from the first network element, where the configuration information includes one or more of a clock source of the first clock, a clock precision of the first clock, a time keeping capability of the first clock, a time service object allowed by the first clock, a service area of the first clock, a clock transfer capability of the first clock, or a quality level of the first clock; the third network element sends the configuration information of the first clock to the second network element.

When the communication apparatus 500 is used to implement the functions of the data management network element in the above method embodiments, the transceiver 520 is configured to receive an inquiry message from a third network element, where the inquiry message includes time requirement information; a processing unit 510, configured to determine, according to the time requirement information, a first network element, where the first network element includes information of a clock matched with the time requirement information; a transceiving unit 520, configured to send address information of the first network element to the third network element.

More detailed descriptions about the processing unit 510 and the transceiver unit 520 may be directly obtained by referring to the related descriptions in the foregoing method embodiments, and are not repeated herein.

As shown in fig. 6, the communication device 600 includes a processor 610 and an interface circuit 620. The processor 610 and the interface circuit 620 are coupled to each other. It is understood that the interface circuit 620 may be a transceiver or an input-output interface. Optionally, the communication device 600 may further include a memory 630 for storing instructions to be executed by the processor 610 or for storing input data required by the processor 610 to execute the instructions or for storing data generated by the processor 610 after executing the instructions.

When the communication device 600 is used to implement the above method embodiments, the processor 610 is configured to implement the functions of the processing unit 510, and the interface circuit 620 is configured to implement the functions of the transceiving unit 520.

It is understood that the processor in the embodiments of the present application may be a Central Processing Unit (CPU), other general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. The general purpose processor may be a microprocessor, but may be any conventional processor.

The method steps in the embodiments of the present application may be implemented by hardware, or may be implemented by software instructions executed by a processor. The software instructions may be comprised of corresponding software modules that may be stored in random access memory, flash memory, read only memory, programmable read only memory, erasable programmable read only memory, electrically erasable programmable read only memory, registers, a hard disk, a removable hard disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. Of course, the storage medium may also be integral to the processor. The processor and the storage medium may reside in an ASIC. Of course, the processor and the storage medium may reside as discrete components in a base station or terminal.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are performed in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, a base station, user equipment, or other programmable device. The computer program or instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer program or instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire or wirelessly. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that integrates one or more available media. The usable medium may be a magnetic medium, such as a floppy disk, a hard disk, a magnetic tape; optical media such as digital video disks; but may also be a semiconductor medium such as a solid state disk. The computer readable storage medium may be volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage media.

In the embodiments of the present application, unless otherwise specified or conflicting with respect to logic, the terms and/or descriptions in different embodiments have consistency and may be mutually cited, and technical features in different embodiments may be combined to form a new embodiment according to their inherent logic relationship.

In this application, "at least one" means one or more, "a plurality" means two or more. "and/or" describes the association relationship of the associated object, indicating that there may be three relationships, for example, a and/or B, which may indicate: a exists alone, A and B exist simultaneously, and B exists alone, wherein A and B can be singular or plural. In the text description of the present application, the character "/" generally indicates that the preceding and following associated objects are in an "or" relationship; in the formula of the present application, the character "/" indicates that the preceding and following related objects are in a relationship of "division".

It is to be understood that the various numerical references referred to in the embodiments of the present application are merely for convenience of description and distinction and are not intended to limit the scope of the embodiments of the present application. The sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of the processes should be determined by their functions and inherent logic.

Claims

1. A method of communication, comprising:

the first network element receives time requirement information from the second network element;

the first network element acquires time information of a first clock according to the time requirement information, wherein the first clock is a clock matched with the time requirement information in a plurality of clocks of the first network element;

and the first network element sends the time information of the first clock to the second network element.

2. The method of claim 1, wherein the first network element sending time information of the first clock to the second network element comprises:

and the first network element continuously sends the time information of the first clock to the second network element according to a set period.

3. The method of claim 1, wherein the method further comprises:

the first network element receiving a time keeping capability of the second network element from the second network element;

the sending, by the first network element, the time information of the first clock to the second network element includes:

and the first network element sends the time information of the first clock to the second network element according to the time keeping capacity of the second network element.

4. The method as claimed in any one of claims 1 to 3, wherein the obtaining, by the first network element, the time information of the first clock according to the time requirement information comprises:

the first network element acquires time information of at least two clocks in the plurality of clocks according to the time requirement information, wherein the at least two clocks are matched with the time requirement information;

the first network element selects the first clock from the at least two clocks.

5. The method of any of claims 1 to 4, further comprising:

the first network element sends configuration information of the first clock to the second network element, where the configuration information includes one or more of a clock source of the first clock, a clock precision of the first clock, a time keeping capability of the first clock, a time service object allowed by the first clock, a service area of the first clock, a clock transfer capability of the first clock, or a quality level of the first clock.

6. The method of any of claims 1 to 5, wherein the time demand information comprises one or more of the following information:

clock source, clock accuracy, time keeping capability of the clock, or service area.

7. The method of any of claims 1 to 6, wherein the second network element is an application function network element, a terminal device, an access network device, or a core network device.

8. A method of communication, comprising:

the second network element sends the time requirement information to the first network element;

and the second network element receives time information of a first clock from the first network element, wherein the first clock is a clock which is matched with the time requirement information in a plurality of clocks of the first network element.

9. The method of claim 8, wherein the method further comprises:

the second network element receives configuration information of the first clock from the first network element, where the configuration information includes one or more of a clock source of the first clock, a clock precision of the first clock, a time keeping capability of the first clock, a time service object allowed by the first clock, a service area of the first clock, a clock transfer capability of the first clock, or a quality level of the first clock.

10. A method according to claim 8 or 9, wherein the time demand information comprises one or more of the following:

11. The method of any one of claims 8 to 10, wherein the second network element is an application function network element, a terminal device, an access network device, or a core network device.

12. A method of communication, comprising:

the third network element receives the time requirement information from the second network element;

the third network element acquires address information of a first network element according to the time requirement information, wherein the first network element comprises information of a clock matched with the time requirement information;

the third network element sends the time requirement information to the first network element according to the address information of the first network element;

the third network element receives time information of a first clock from the first network element, wherein the first clock is a clock matched with the time requirement information in a plurality of clocks of the first network element;

and the third network element sends the time information of the first clock to the second network element.

13. The method as claimed in claim 12, wherein said third network element obtaining the address information of the first network element according to the time requirement information comprises:

the third network element sends a query message to a data management network element, wherein the query message contains the time requirement information;

the third network element receives address information of the first network element from the data management network element.

14. The method of claim 12 or 13, further comprising:

the third network element receives configuration information of the first clock from the first network element, where the configuration information includes one or more of a clock source of the first clock, a clock precision of the first clock, a time keeping capability of the first clock, a time service object allowed by the first clock, a service area of the first clock, a clock transfer capability of the first clock, or a quality level of the first clock;

and the third network element sends the configuration information of the first clock to the second network element.

15. The method according to any of claims 12 to 14, wherein the time demand information comprises one or more of the following information:

16. The method according to any of claims 12 to 15, wherein the second network element is an application function network element, a terminal device, an access network device or a core network device.

17. The method according to any of claims 12 to 16, wherein the third network element is a mobility management network element or a network capability open network element.

18. A method of communication, comprising:

a data management network element receives a query message from a third network element, wherein the query message contains time requirement information;

the data management network element determines a first network element according to the time requirement information, wherein the first network element comprises information of a clock matched with the time requirement information;

and the data management network element sends the address information of the first network element to the third network element.

19. The method of claim 18, wherein the time demand information includes one or more of the following:

20. The method according to claim 18 or 19, wherein the third network element is a mobility management network element or a network capability openness network element.

21. A communications device comprising means for performing a method according to any one of claims 1 to 7, or means for performing a method according to any one of claims 8 to 11, or means for performing a method according to any one of claims 12 to 17, or means for performing a method according to any one of claims 18 to 20.

22. A communications device comprising a processor and interface circuitry for receiving and transmitting signals from or sending signals to other communications devices than the communications device, the processor being configured to implement the method of any one of claims 1 to 7, or to implement the method of any one of claims 8 to 11, or to implement the method of any one of claims 12 to 17, or to implement the method of any one of claims 18 to 20, by logic circuitry or executing code instructions.

23. A communication device comprising a processor and a memory; the memory is for storing computer instructions which, when executed by the apparatus, cause the apparatus to perform the method of any one of claims 1 to 7, or to perform the method of any one of claims 8 to 11, or to perform the method of any one of claims 12 to 17, or to perform the method of any one of claims 18 to 20.

24. A computer-readable storage medium, in which a computer program or instructions are stored which, when executed by a communication apparatus, carry out the method of any one of claims 1 to 20.

25. A communication system comprising a first network element for performing the method of any of claims 1 to 7 and a second network element for performing the method of any of claims 8 to 11.