CN115915096A

CN115915096A - Communication method and communication device

Info

Publication number: CN115915096A
Application number: CN202110903825.4A
Authority: CN
Inventors: 曹德全; 陶振宇
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-08-06
Filing date: 2021-08-06
Publication date: 2023-04-04
Also published as: WO2023011087A1

Abstract

The application provides a communication method and a communication device, wherein the method comprises the following steps: the first core network device receives a first request message for requesting a first session of a terminal device to be switched from a first access technology to a second access technology, the first request message including a first EBI of the first session. And the first core network equipment sends an updating message to the PCF and/or the CHF, wherein the updating message comprises a first PDU session identifier, and the first PDU session identifier is generated according to the first EBI and the first preset value. According to the method and the device, the first PDU session identifier is carried in the updating message, so that the PCF and/or the CHF can update the PDU session identifier of the first session in time, the session identifier of the terminal equipment is prevented from being repeated, a plurality of services of the terminal equipment can be carried out at the same time, and the user experience is improved.

Description

Communication method and communication device

Technical Field

The present application relates to the field of communications, and more particularly, to a method of communication and a communication apparatus.

Background

With the formal commercialization of the 5th generation,5g network, the 5G network will appear in our daily lives. However, in the early stage of the commercial use of 5G networks, the 5G networks cannot cover a large area because of the maturity of the technology and the support degree of the terminal devices, and the 5G networks and the 4th generation (4G) networks coexist for a long time. In a typical scenario, the core network device in the system is modified into a 5G core network (5G corenet, 5gc), and the access network device in the 4G system is used, and in this networking situation, there is interoperation between the 5G network and the 4G network.

When the terminal equipment needs to establish a session, if the terminal equipment has the 4G and 5G interoperability, a Protocol Data Unit (PDU) session identifier is allocated by the terminal equipment and is carried to the network side. If the terminal device does not have the capability of interoperating between 4G and 5G, according to the protocol specification, the PDU session identifier is generated by a Session Management Function (SMF)/packet data network gateway-control plane (PGW-C) network element of the 5G network and the 4G network according to an Evolved Packet System (EPS) bearer identifier (EBI) allocated by a Mobility Management Entity (MME) or an evolved packet data gateway (ePDG).

For a terminal device without 4G and 5G interoperability, if it switches between a third generation partnership project (3 rd generation partnership project,3 gpp) access network and a non-third generation partnership project (non-3 rd generation partnership project, n3 gpp) access network, the first session it creates also switches. However, in the existing protocol, the combined SMF/PGW-C network element does not update the PDU session identifier corresponding to the first session to a Policy Control Function (PCF) network element and/or a charging function (CHF) network element. Therefore, when the terminal device creates the second session, two identical PDU session identifiers may appear on the PCF network element and/or the CHF network element for the same terminal device, which may be considered as a scenario in which the same service is repeatedly activated, so that services corresponding to the two sessions cannot be performed simultaneously, which affects user experience.

Disclosure of Invention

The application provides a communication method and a communication device, so that a plurality of services of terminal equipment can be performed simultaneously, and user experience is improved.

In a first aspect, a communication method is provided, where the method is performed by a first core network device, and may also be performed by a module or a unit included in the first core network device. The method comprises the following steps: receiving a first request message from a second core network device, wherein the first request message is used for requesting a first session of a terminal device to be switched from a first access technology to a second access technology, and the first request message comprises a first evolved packet system bearer identity (EBI) of the first session; and sending an update message to a policy control function network element and/or a charging function network element, wherein the update message comprises a first PDU session identifier, and the first PDU session identifier is generated according to the first EBI and a first preset value.

According to the scheme of the application, when the first session of the terminal equipment needs to be switched from the first access technology to the second access technology, the second core network equipment sends a first request message, the first core network equipment sends an update message to the policy control function network element and/or the charging function network element after receiving the first request message, and the update message carries the first PDU session identifier generated according to the first EBI. In other words, the first PDU session identifier is carried in the update message, so that the policy control function network element and/or the charging function network element can update the PDU session identifier of the first session in time, and avoid the repetition with the session identifier of the session established later, thereby enabling multiple services of the terminal device to be performed simultaneously, and improving user experience.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: and generating the first PDU session identification according to the first EBI and the first preset value.

With reference to the first aspect, in certain implementations of the first aspect, the first preset value is determined according to the second access technology.

With reference to the first aspect, in certain implementations of the first aspect, the first access technology is a third generation partnership project 3GPP access technology, and the second access technology is a non-third generation partnership project N3GPP access technology.

With reference to the first aspect, in certain implementations of the first aspect, the second core network device is an evolved packet data gateway ePDG.

With reference to the first aspect, in certain implementations of the first aspect, the first preset value is 80.

With reference to the first aspect, in certain implementations of the first aspect, the first access technology is an N3GPP access technology, and the second access technology is a 3GPP access technology.

With reference to the first aspect, in certain implementation manners of the first aspect, the second core network device is a mobility management entity MME.

With reference to the first aspect, in certain implementations of the first aspect, the first preset value is 64.

With reference to the first aspect, in certain implementations of the first aspect, the first core network device is a session management function, SMF, packet data network gateway-control plane, PGW-C, network element.

With reference to the first aspect, in certain implementations of the first aspect, the first EBI is used to identify the first session.

In a second aspect, a method for communication is provided, where the method is performed by a policy control function network element, and may also be performed by a module or unit included in the policy control function network element. The method comprises the following steps: receiving an update message from a first core network device, wherein the update message includes a first PDU session identifier, the first PDU session identifier is generated according to a first EBI, and the first EBI is used for identifying a first session of a terminal device; and storing the mapping relation between the identifier of the terminal equipment and the first PDU session identifier.

In a third aspect, a method for communication is provided, where the method is performed by a charging function network element, and may also be performed by a module or unit included in the charging function network element. The method comprises the following steps: receiving an update message from a first core network device, wherein the update message includes a first PDU session identifier, the first PDU session identifier is generated according to a first EBI, and the first EBI is used for identifying a first session of a terminal device; and storing the mapping relation between the identifier of the terminal equipment and the first PDU session identifier.

According to the scheme of the application, when the first session of the terminal equipment needs to be switched from the first access technology to the second access technology, the second core network equipment sends a first request message, the first core network equipment sends an update message to the policy control function network element and/or the charging function network element after receiving the first request message, and the update message carries the first PDU session identifier generated according to the first EBI. In other words, the first PDU session identifier is carried in the update message, so that the policy control function network element and/or the charging function network element can update the PDU session identifier of the first session in time, and avoid the repetition with the session identifier of the session established later, thereby simultaneously performing multiple services of the terminal device, and improving user experience.

In a fourth aspect, a communication method is provided, where the method is performed by a first core network device, and may also be performed by a module or a unit included in the first core network device. The method comprises the following steps: receiving a first request message from a second core network device, where the first request message is used to request to create a first session of a terminal device through a first access technology, and the first request message includes a first evolved packet system bearer identity (EBI) of the first session; and when determining that the first PDU session identifier is the repeated identifier of the terminal equipment, sending a creation message to a policy control function network element and/or a charging function network element, wherein the creation message comprises a second PDU session identifier, the second PDU session identifier is different from the first PDU session identifier, and the first PDU session identifier is generated according to the first EBI and a first preset value.

According to the scheme of the application, when the terminal device needs to create the first session through the first access technology, the second core network device sends a first request message, the first core network device sends a creation message to the policy control function network element and/or the charging function network element after receiving the first request message, the creation message carries a second PDU session identifier, the second PDU session identifier is different from the first PDU session identifier, and the first PDU session identifier is generated according to the first EBI and the first preset value. In other words, the second PDU session identifier different from the first PDU session identifier is carried in the creation message, so that the policy control function network element and/or the charging function network element are prevented from receiving the session identifier repeated with the PDU session identifier of the first session, thereby enabling multiple services of the terminal device to be performed simultaneously, and improving user experience.

With reference to the fourth aspect, in certain implementations of the fourth aspect, the method further includes: generating the first PDU session identifier according to the first EBI and the first preset value; and generating the second PDU session identifier according to the first EBI and a second preset value, wherein the second preset value is different from the first preset value.

With reference to the fourth aspect, in certain implementations of the fourth aspect, the method further includes: and determining the first PDU session identifier as the repeated identifier of the terminal equipment.

With reference to the fourth aspect, in some implementations of the fourth aspect, before receiving the first request message, the method further includes: receiving a second request message for requesting creation of a second session over the first access technology, the second request message including a second EBI for the second session; and generating a third PDU session identifier according to the second EBI and the first preset value. The determining that the first PDU session identifier is the duplicate identifier of the terminal device includes: and determining that the third PDU session identification is the same as the first PDU session identification.

With reference to the fourth aspect, in some implementation manners of the fourth aspect, the first preset value is determined according to the first access technology, the second preset value is determined according to the first preset value, and the second preset value is different from the first preset value.

With reference to the fourth aspect, in certain implementations of the fourth aspect, the first access technology is a 3GPP access technology.

With reference to the fourth aspect, in some implementations of the fourth aspect, the second core network device is a mobility management entity MME.

With reference to the fourth aspect, in certain implementations of the fourth aspect, the first preset value is 64.

With reference to the fourth aspect, in certain implementations of the fourth aspect, the first access technology is an N3GPP access technology.

With reference to the fourth aspect, in some implementations of the fourth aspect, the second core network device is an evolved packet data gateway ePDG.

With reference to the fourth aspect, in certain implementations of the fourth aspect, the first preset value is 80.

With reference to the fourth aspect, in some implementations of the fourth aspect, the first core network device is a session management function, SMF, packet data network gateway-control plane, PGW-C, network element.

With reference to the fourth aspect, in some implementations of the fourth aspect, the first EBI is configured to identify the first session and the second EBI is configured to identify the second session.

In a fifth aspect, a communication apparatus is provided, which may be a first core network device. The device comprises: a transceiver unit, configured to receive a first request message from a second core network device, where the first request message is used to request a terminal device to switch a first session from a first access technology to a second access technology, and the first request message includes a first evolved packet system bearer identity (EBI) of the first session; the transceiver unit is further configured to: and sending an update message to a policy control function network element and/or a charging function network element, wherein the update message comprises a first PDU session identifier, and the first PDU session identifier is generated according to the first EBI and a first preset value.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the apparatus further includes: and the processing unit is used for generating the first PDU session identifier according to the first EBI and the first preset value.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the first preset value is determined according to the second access technology.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the first access technology is a third generation partnership project 3GPP access technology, and the second access technology is a non-third generation partnership project N3GPP access technology.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the second core network device is an evolved packet data gateway ePDG.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the first preset value is 80.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the first access technology is an N3GPP access technology, and the second access technology is a 3GPP access technology.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the second core network device is a mobility management entity MME.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the first preset value is 64.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the first core network device is a session management function, SMF, packet data network gateway-control plane, PGW-C, network element.

In a sixth aspect, a communication apparatus is provided, which may be a policy control function network element. The device comprises: a transceiver unit, configured to receive an update message from a first core network device, where the update message includes a first PDU session identifier, where the first PDU session identifier is generated according to a first EBI, and the first EBI is used to identify a first session of a terminal device; and the processing unit is used for storing the mapping relation between the identifier of the terminal equipment and the first PDU session identifier.

According to the scheme of the application, when a first session of the terminal equipment needs to be switched from a first access technology to a second access technology, the second core network equipment sends a first request message, and after receiving the first request message, the first core network equipment sends an update message to the policy control function network element and/or the charging function network element respectively, wherein the update message carries a first PDU session identifier generated according to the first EBI. In other words, the first PDU session identifier is carried in the update message, so that the policy control function network element and/or the charging function network element can update the PDU session identifier of the first session in time, and avoid the repetition with the session identifier of the session established later, thereby simultaneously performing multiple services of the terminal device, and improving user experience.

In a seventh aspect, a communications apparatus is provided, which may be implemented for a charging function network element. The device includes: a transceiver unit, configured to receive an update message from a first core network device, where the update message includes a first PDU session identifier, where the first PDU session identifier is generated according to a first EBI, and the first EBI is used to identify a first session of a terminal device; and the processing unit is used for storing the mapping relation between the identifier of the terminal equipment and the first PDU session identifier.

In an eighth aspect, a communications apparatus is provided, which may be a first core network device. The device includes: a transceiver unit, configured to receive a first request message from a second core network device, where the first request message is used to request to create a first session of a terminal device through a first access technology, and the first request message includes a first evolved packet system bearer identity (EBI) of the first session; the transceiver unit is further configured to: and when determining that the first PDU session identifier is the repeated identifier of the terminal equipment, sending a creation message to a policy control function network element and/or a charging function network element, wherein the creation message comprises a second PDU session identifier, the second PDU session identifier is different from the first PDU session identifier, and the first PDU session identifier is generated according to the first EBI and a first preset value.

According to the scheme of the application, when the terminal equipment needs to establish the first session through the first access technology, the second core network equipment sends a first request message, the first core network equipment sends establishment messages to the policy control function network element and/or the charging function network element after receiving the first request message, the establishment messages carry a second PDU session identifier, the second PDU session identifier is different from the first PDU session identifier, and the first PDU session identifier is generated according to the first EBI and the first preset value. In other words, the second PDU session identifier different from the first PDU session identifier is carried in the creation message, so that the policy control function network element and/or the charging function network element are prevented from receiving the session identifier repeated with the PDU session identifier of the first session, thereby enabling multiple services of the terminal device to be performed simultaneously, and improving user experience.

With reference to the eighth aspect, in certain implementations of the eighth aspect, the apparatus further includes: the processing unit is used for generating the first PDU session identifier according to the first EBI and the first preset value; and generating the second PDU session identifier according to the first EBI and a second preset value, wherein the second preset value is different from the first preset value.

With reference to the eighth aspect, in certain implementations of the eighth aspect, the processing unit is further configured to: and determining the first PDU session identifier as the repeated identifier of the terminal equipment.

With reference to the eighth aspect, in some implementations of the eighth aspect, the transceiver unit is further configured to: receiving a second request message requesting creation of a second session over the first access technology, the second request message including a second EBI for the second session; the processing unit is further to: and generating a third PDU session identifier according to the second EBI and the first preset value. The processing unit is specifically configured to: and determining that the third PDU session identifier is the same as the first PDU session identifier.

With reference to the eighth aspect, in some implementation manners of the eighth aspect, the first preset value is determined according to the first access technology, the second preset value is determined according to the first preset value, and the second preset value is different from the first preset value.

With reference to the eighth aspect, in certain implementations of the eighth aspect, the first access technology is a 3GPP access technology.

With reference to the eighth aspect, in some implementations of the eighth aspect, the second core network device is a mobility management entity MME.

With reference to the eighth aspect, in certain implementations of the eighth aspect, the first preset value is 64.

With reference to the eighth aspect, in certain implementations of the eighth aspect, the first access technology is an N3GPP access technology.

With reference to the eighth aspect, in some implementations of the eighth aspect, the second core network device is an evolved packet data gateway ePDG.

With reference to the eighth aspect, in certain implementations of the eighth aspect, the first preset value is 80.

With reference to the eighth aspect, in some implementation manners of the eighth aspect, the first core network device is a session management function, SMF, packet data network gateway-control plane, PGW-C, network element.

In a ninth aspect, there is provided a communication apparatus comprising: at least one processor coupled with at least one memory, the at least one processor configured to execute computer programs or instructions stored in the at least one memory to cause the communication apparatus to perform the method of any of the first to fourth aspects or any possible implementation manner of the first to fourth aspects.

A tenth aspect provides a computer-readable storage medium having stored thereon a computer program or instructions which, when run on a computer, cause the computer to perform the method of any one of the first to fourth aspects or any one of the possible implementations of the first to fourth aspects.

In an eleventh aspect, there is provided a chip system comprising: a processor for executing a computer program or instructions in a memory to implement any of the first to fourth aspects described above or any of the possible implementations of the first to fourth aspects.

In a twelfth aspect, there is provided a computer program product comprising a computer program or instructions which, when executed, causes the method of any one of the first to fourth aspects or any one of the possible implementations of the first to fourth aspects to be performed.

In a thirteenth aspect, there is provided a communication system comprising: the elements of any possible implementation form of the fifth aspect or the fifth aspect; and/or, the unit of the sixth aspect; and/or the unit of the seventh aspect.

Drawings

Fig. 1 is a schematic diagram of an application scenario suitable for a method provided in an embodiment of the present application.

Fig. 2 is a schematic diagram of a network architecture of 5G and 4G interaction provided in the present application.

Fig. 3 is a schematic diagram of a network architecture of interaction between a 3GPP access technology and an N3GPP access technology provided in the present application.

Fig. 4 is a schematic flow chart of a method of communication according to an embodiment of the present application.

Fig. 5 is a further schematic flow chart of a method of communication provided by an embodiment of the present application.

Fig. 6 is a further schematic flow chart of a method of communication provided by an embodiment of the present application.

Fig. 7 is a further schematic flow chart of a method of communication provided by an embodiment of the present application.

Fig. 8 is a further schematic flow chart of a method of communication provided by an embodiment of the present application.

Fig. 9 is a further schematic flow chart of a method of communication provided by an embodiment of the present application.

Fig. 10 is a schematic block diagram of a communication device provided herein.

Fig. 11 is a block diagram of a communication device according to an embodiment of the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

The technical scheme of the embodiment of the application can be applied to various communication systems, for example: long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD), worldwide Interoperability for Microwave Access (WiMAX) communication systems, fifth generation (5g) communication systems, or future communication systems, e.g., sixth generation (6 g) communication systems, vehicle-to-other devices (vehicle-to-X, V2X), wherein V2X may include vehicle-to-internet (vehicle-to-network, V2N), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P), etc., long term evolution (LTE-V) for vehicle-to-vehicle communication, internet of vehicles (MTC), machine Type Communication (MTC), internet of things (IoT), long term evolution (LTE-M) for machine-to-machine communication, M2M, etc.

To facilitate understanding of the embodiments of the present application, terms referred to in the present application will be explained first.

1. Protocol Data Network (PDN) connection (connection or connectivity)

The PDN connection refers to a combination of Evolved Packet System (EPS) bearers (bearers) established on the UE in the 4G communication system, where the EPS bearers have the same Internet Protocol (IP) address and Access Point Name (APN), and the PDN connection is used to implement IP connectivity and transmit Service Data Flow (SDF) between the UE and the APN.

2. EPS bearing

The EPS Bearer (EPS Bearer) is a smaller tunnel contained in the PDN connection, referring to a data transmission channel within the 4G communication system. Specifically, the EPS system performs differentiated treatment on data transmitted in the same PDN connection during forwarding processing. Within the same PDN connection, different EPS bearers represent different QoS, i.e. different quality of service.

When a PDN connection is established, 1 EPS bearer is established at the same time, which is called a default bearer. The default bearer lifetime is the same as the PDN connection, and releasing the default bearer is equivalent to releasing the PDN connection. A dedicated bearer (dedicated bearer) refers to a bearer that is established after a PDN connection is established in order to meet a specific quality of service (QoS) requirement, and may or may not be a dedicated bearer.

The UE may have multiple PDN connections and multiple EPS bearers, and an EPS Bearer Identity (EBI) is used to distinguish multiple EPS bearers of the same UE, and EBIs of different UEs may be repeated. The EBI length is 4 bits, and the value range is 0-15, wherein the value of 0-4 is reserved at present, and the available value range is 5-15.

3. Protocol Data Unit (PDU) session (PDU session)

In a 5G communication system, a set of QoS flows (flows) are established on the UE that have the same IP address and Data Network Name (DNN). The QoS flow refers to a data transmission channel within the 5G communication system.

The 5G core network (5G core network, 5GC) supports PDU connection services. The PDU connection service may refer to a service for exchanging PDU packets between a terminal device and a Data Network (DN). The PDU connection service is implemented by the terminal device initiating the establishment of a PDU session. After a PDU session is established, that is, a PDU session tunnel is established, the PDU session tunnel corresponds to the UE, and the service data in the PDU session tunnel may be transmitted in the form of unicast QoS stream. In other words, the PDU session is UE level. Each end-point device may establish one or more PDU sessions. Wherein, the PDU session identity (pdussessid) can be used to distinguish different PDU sessions of the same UE.

A communication system suitable for the embodiment of the present application is described in detail below with reference to fig. 1 to 3.

Fig. 1 is a schematic diagram of a network architecture suitable for the method provided by the embodiment of the present application. Fig. 1 is a schematic diagram of a 5G network architecture based on a service interface, where the network architecture may specifically include the following network elements:

1. user Equipment (UE) 110: may include a variety of handheld devices, vehicle-mounted devices, wearable devices, computing devices or other processing devices connected to a wireless modem with wireless communication capabilities, as well as various forms of terminals, mobile Stations (MSs), terminals (terminals), or soft terminals, etc. Such as water meters, electricity meters, sensors, etc.

Illustratively, the user equipment in the embodiments of the present application may refer to an access terminal, a subscriber unit, a subscriber station, a mobile station, a relay station, a remote terminal, a mobile device, a user terminal (user terminal), a terminal device (terminal equipment), a wireless communication device, a user agent, or a user equipment. The user equipment may also be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a user equipment in a 5G network or a user equipment in a Public Land Mobile Network (PLMN) for future evolution, or a user equipment in a vehicle networking for future evolution, and the like, which is not limited in this embodiment.

By way of example and not limitation, in the embodiments of the present application, a wearable device may also be referred to as a wearable smart device, which is a generic term for intelligently designing daily wearing and developing wearable devices, such as glasses, gloves, watches, clothing, shoes, and the like, by applying wearable technology. A wearable device is a portable device that is worn directly on the body or integrated into the clothing or accessories of the user. The wearable device is not only a hardware device, but also realizes powerful functions through software support, data interaction and cloud interaction. The generalized wearable smart device includes full functionality, large size, and can implement full or partial functionality without relying on a smart phone, such as: smart watches or smart glasses and the like, and only focus on a certain type of application function, and need to be matched with other equipment such as a smart phone for use, such as various smart bracelets for physical sign monitoring, smart jewelry and the like.

In addition, in the embodiment of the present application, the user equipment may also be user equipment in an internet of Things (IoT) system, where IoT is an important component of future information technology development, and a main technical feature of the present application is to connect an article with a network through a communication technology, so as to implement an intelligent network with interconnected human-computer and interconnected objects. In the embodiment of the present application, the IOT technology may achieve massive connection, deep coverage, and power saving for the terminal through a Narrowband (NB) technology, for example. In addition, in this embodiment, the user equipment may further include sensors such as an intelligent printer, a train detector, and a gas station, and the main functions include collecting data (part of the user equipment), receiving control information and downlink data of the access network equipment, and sending electromagnetic waves to transmit uplink data to the access network equipment.

2. (radio access network, (R) AN) 120: for providing a network access function for authorized user equipment in a specific area.

The terminal device may access the core network using access networks of different access technologies, for example: the core network is accessed using the third generation partnership project (3 rd generation partnership project,3 GPP) technology and non-third generation partnership project (non-3 rd generation partnership project, N3 GPP) technology. By way of example and not limitation, the Access technology may include NR, universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), multefire, 3GPP, N3GPP, 4G, 5G, wiFi, fixed or wired Access technology, and so on. This is not limitative.

The access network using the N3GPP technology may include, but is not limited to: a wireless fidelity (Wi-Fi) system, a Wireless Local Area Network (WLAN), a MulteFire network, a wired network (e.g., a Wireless and Wired Convergence (WWC) network), or a home base station network. Correspondingly, an access network device adopting the N3GPP technology may include, for example: access Point (AP), trusted WLAN Interworking Function (TWIF) network element, trusted Non-3GPP gateway function (tngf), wired access gateway function (W-AGF), access Gateway Function (AGF), broadband Network Gateway (BNG), fixed-mobile interworking function (FMIF), non-3GPP interworking function (n-GPP interworking function, n3 iwf), and so on.

Access networks employing 3GPP technology may include, but are not limited to: an LTE network, an NR network, a 5G network, or a mobile communication network for subsequent evolution. Correspondingly, an access network device adopting 3GPP technology may include, for example, a Radio Access Network (RAN) device, g-NodeB, e-NodeB, home-NodeB.

An access network that implements access network functionality based on wireless communication technology may be referred to as a RAN. The radio access network can be responsible for functions such as radio resource management, quality of service (QoS) management, data compression and encryption on the air interface side. The wireless access network provides access service for the terminal equipment, and then completes the forwarding of the control signal and the user data between the terminal and the core network.

The radio access network devices may include, for example, but are not limited to: macro base stations, micro base stations (also called small stations), radio Network Controllers (RNCs), node bs (Node bs, NB), base Station Controllers (BSCs), base Transceiver Stations (BTSs), home base stations (e.g., home evolved NodeB, or home Node B, HNBs), base Band Units (BBUs), APs, wireless relay nodes, wireless backhaul nodes, transmission Points (TPs) or Transmission Reception Points (TRPs) in WiFi systems, and the like, and may also be a gbb or transmission point (TRP or TP) in 5G (e.g., NR) systems, one or a set (including multiple antenna panels) of base stations in 5G systems, or may also be a network Node constituting a gbb or transmission point, such as a baseband unit (BBU), or a distributed base station (BBU), or a next generation communication system, such as a BBU 6. The embodiment of the present application does not limit the specific technology and the specific device form adopted by the radio access network device.

The access network may serve the cell. A terminal device may communicate with a cell via transmission resources (e.g., frequency domain resources, or alternatively, spectrum resources) allocated by an access network device.

3. The user plane network element 130: for packet routing and forwarding, quality of service (QoS) handling of user plane data, etc.

In the 5G communication system, the user plane network element may be a User Plane Function (UPF) network element. In a future communication system, the user plane network element may still be a UPF network element, or may also have another name, which is not limited in this application.

4. Data network 140: for providing a network for transmitting data.

In a 5G communication system, the data network may be a Data Network (DN). In future communication systems, the data network may still be the DN, or may have other names, and the present application is not limited thereto.

5. Access management network element 150: the method is mainly used for mobility management, access management and the like, and can be used for realizing other functions except session management in Mobility Management Entity (MME) functions, such as access authorization/authentication and the like.

In a 5G communication system, the access management network element may be an access and mobility management function (AMF) network element. In a future communication system, the access management network element may still be an AMF network element, or may also have another name, which is not limited in this application.

6. Session management network element 160: the method is mainly used for session management, internet Protocol (IP) address allocation and management of terminal equipment, selection of a termination point capable of managing a user plane function, a policy control and charging function interface, downlink data notification and the like.

In the 5G communication system, the session management network element may be a Session Management Function (SMF) network element. In future communication systems, the session management network element may still be an SMF network element, or may also have another name, which is not limited in this application.

7. Policy control network element 170: the unified policy framework is used for guiding network behavior, and providing policy rule information for network elements (such as AMF, SMF network elements and the like) or terminal equipment.

In the 4G communication system, the policy control network element may be a Policy and Charging Rules Function (PCRF) network element. In a 5G communication system, the policy control network element may be a Policy Control Function (PCF) network element. In future communication systems, the policy control network element may still be a PCF network element, or may also have another name, which is not limited in this application.

8. The charging network element 180: and as a quota control node of online charging, rate processing of online charging is performed on various services of the user equipment.

In a 4G communication system, the charging network element may be an Online Charging System (OCS) server or an online control and charging gateway (OCG). In the 5G communication system, the charging network element may be a charging function (CHF) network element. In future communication systems, the charging network element may still be a CHF network element, or may also have another name, which is not limited in this application.

9. Network open network element 190: mainly for supporting the opening of capabilities and events.

In the 5G communication system, the network openness may be a network open function (NEF) network element. In future communication systems, the network open network element may still be an NEF network element, or may also have another name, which is not limited in this application.

10. Data management network element 1100: the method is used for processing terminal equipment identification, access authentication, registration, mobility management and the like.

In the 5G communication system, the data management network element may be a Unified Data Management (UDM) network element. In future communication systems, the unified data management may still be a UDM network element, or may also have other names, which is not limited in this application.

11. Application network element 1110: the method is used for carrying out data routing influenced by application, accessing to a network open function network element, carrying out strategy control by interacting with a strategy framework and the like.

In the 5G communication system, the application network element may be an Application Function (AF) network element. In a future communication system, the application network element may still be an AF network element, or may also have another name, which is not limited in this application.

12. Data analysis network element 1120: the method is used for realizing the network data analysis function.

The data analysis network element may be a single network element, a combination of multiple network elements, or a combination with other network elements. For example, an NWDAF network element may be collocated with an AMF or with a Session Management Function (SMF) network element.

In the 5G communication system, the data analysis network element may be a network data analysis function (NWDAF) network element. In a future communication system, the data analysis network element may still be an NWDAF network element, or may also have another name, which is not limited in this application.

13. Network slice selection network element 1130: for selecting a network slice instance serving a user equipment.

In the 5G communication system, the network slice selection element may be a Network Slice Selection Function (NSSF) element. In a future communication system, the network slice selection function network element may still be an NSSF network element, or may also have another name, which is not limited in this application.

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).

For convenience of description, in the following description of the present application, an access management function network element is an AMF network element, a data analysis network element is an NWDAF network element, and a policy control function network element is a PCF network element.

Further, the AMF network element is abbreviated as AMF, the NWDAF network element is abbreviated as NWDAF, and the PCF network element is abbreviated as PCF. That is, AMFs described later in this application may be replaced with access management function network elements, NWDAF may be replaced with data analysis function network elements, and PCF may be replaced with policy control function network elements.

For convenience of description, in the present application, the device is an AMF entity, an NWDAF entity, and a PCF entity as an example, and a method for acquiring data is described, and for an implementation method in which the device is a chip in the AMF entity, a chip in the NWDAF entity, or a chip in the PCF entity, reference may be made to specific descriptions of the device in the AMF entity, the NWDAF entity, and the PCF entity, and no repeated description is given.

In the network architecture shown in fig. 1, the terminal device is connected to the AMF through an N1 interface, the RAN is connected to the AMF through an N2 interface, and the RAN is connected to the UPF through an N3 interface. The UPFs are connected through an N9 interface, and are interconnected with a Data Network (DN) through an N6 interface. The SMF controls the UPF via the N4 interface. The NSSF is accessed to the service framework through the Nnssf interface to provide corresponding services, and in the same way, the CHF, the PCF, the UDM, the NWDAF and the AF are accessed to the service framework through respective corresponding interfaces to provide corresponding services. In fig. 1, nnef, nchf, npcf, nudm, nwdaf, naf, namf, nsmf, nssf, N1, N2, N3, N4, and N6 are interface serial numbers. The meaning of these interface serial numbers can be found in the third generation partnership project (3 rd generation partnership project,3 gpp) standard protocol, which is not limited herein.

It should be noted that the names of the network elements and the communication interfaces between the network elements referred to in fig. 1 are simply described by taking the examples defined in the current protocol as examples, but the embodiments of the present application are not limited to be applicable only to currently known communication systems. Therefore, the standard names appearing when the current protocol is described as an example are all functional descriptions, and the specific names of the network elements, the interfaces, the signaling and the like in the application are not limited, and only indicate the functions of the network elements, the interfaces or the signaling, and can be correspondingly extended to other systems, such as 2G, 3G, 4G or future communication systems.

In addition, it should be further noted that in some network architectures, network functional network element entities such as an AMF network element, an SMF network element, a PCF network element, a BSF network element, and a UDM network element are all referred to as network functional network element (NF) network elements; or, in other network architectures, a set of network elements such as an AMF network element, an SMF network element, a PCF network element, a BSF network element, and a UDM network element may all be referred to as a control plane function network element.

The interaction between 5G and 4G is briefly introduced below with reference to fig. 2, and fig. 2 is a schematic diagram of a network architecture of the interaction between 5G and 4G provided in the present application.

In fig. 2, a Home Subscriber Server (HSS) is a server in the 4G network and is used to store subscriber subscription information, and a Serving Gateway (SGW) is a service gateway for accessing a user plane in the 4G network. A packet data network gateway-control plane (PGW-C) network element and a packet data network gateway-user plane (PGW-U) network element also take on functions of session management and bearer control of the mobile phone, IP address allocation, charging support, and the like for a network element in the 4G network that is responsible for a user equipment to connect to an external network. An evolved UMTS terrestrial radio access network (E-UTRAN) is access network equipment in a 4G network, a UE may access 4G core network equipment through the E-UTRAN, an NG-RAN is access network equipment in a 5G network, and the UE may access 5G core network equipment through the NG-RAN. The MME is a 4G core network device, and is responsible for performing authentication, authorization, mobility management, and session management on the UE, and an EPS Bearer Identity (EBI) of the UE in the PDN connection of the 4G is allocated by the device.

It can be seen from fig. 2 that the 5G network implements two network interactions by interfacing with the 4G network (e.g., the SMF and PGW-C shown in fig. 2, the UDM and HSS shown in fig. 2, etc.) and/or opening an interactive interface (e.g., opening an N26 interface between the AMF and the MME shown in fig. 2).

For example: the UDM/HSS is a core network device shared by 4G and 5G, that is, a core network device combined by 4G and 5G, and includes an HSS and a UDM, and may provide at least one of the following functions for a terminal device: processing 3GPP AKA authentication credentials, user identification processing, access authorization, registration/mobility management, subscription management, short message management, and the like. The SMF/PGW-C is core network equipment combined by 4G and 5G, and comprises functions of the SMF and the PGW-C. The UPF/PGW-U is core network equipment combined by 4G and 5G, and comprises functions of SMF and PGW-C.

It should be noted that the names of the interfaces shown in fig. 2 (e.g., S1-MME, S1-U, S, N26, N3, N1, N2, N11, S5-U, S5-C, N, N7, N8, N10, S6a, N40 shown in fig. 2) are only examples and do not limit the scope of the present application, and the serial numbers of these interfaces may be defined in the standard protocol.

In an embodiment of the present application, a user equipment or an access network device includes a hardware layer, an operating system layer running on top of the hardware layer, and an application layer running on top of the operating system layer. The hardware layer includes hardware such as a Central Processing Unit (CPU), a Memory Management Unit (MMU), and a memory (also referred to as a main memory). The operating system may be any one or more computer operating systems that implement business processes through processes (processes), such as a Linux operating system, a Unix operating system, an Android operating system, an iOS operating system, or a windows operating system. The application layer comprises applications such as a browser, an address list, word processing software, instant messaging software and the like. Furthermore, the embodiment of the present application does not particularly limit the specific structure of the execution main body of the method provided in the embodiment of the present application, as long as the program recorded with the code of the method provided in the embodiment of the present application can be executed to perform communication according to the method provided in the embodiment of the present application, for example, the execution main body of the method provided in the embodiment of the present application may be a user equipment or an access network device, or a functional module capable of calling the program and executing the program in the user equipment or the access network device.

The 3GPP access technology and the N3GPP access technology are briefly introduced below with reference to fig. 3, and fig. 3 is a schematic diagram of a network architecture for interaction between the 3GPP access technology and the N3GPP access technology provided in the present application.

In the architecture shown in fig. 3, including the 3GPP and N3GPP system architectures, it is divided by a dashed line 301. Above line 301 is a 3GPP access network and below dashed line 301 is an N3GPP access network. The UE, E-UTRAN, MME, HSS, CHF, PCF, SMF/PGW-C in FIG. 3 are similar or identical to the functions in FIG. 1 and FIG. 2. The operator IP services may include an IP Multimedia service Subsystem (IMS). In the N3GPP access technology, a terminal device may establish a connection with an SMF/PGW-C through an evolved packet data gateway (ePDG), where the SMF/PGW-C provides services related to a session-related control plane. An EPS Bearer Identity (EBI) of a PDN connection of the UE in the N3GPP access is allocated by the device.

The names of the respective interfaces shown in fig. 3 (e.g., S5, S11, S2a, S2b, SWu, SWn, SWa, STa, SWm, S6b, SGi, rx, SWx shown in fig. 2) are only examples, and the meanings of the serial numbers of the interfaces can be referred to as defined in the standard protocol, and the application does not limit the names and meanings thereof.

When the terminal equipment needs to establish a session, if the terminal equipment has the 4G and 5G interoperation capability, the PDU identification is distributed by the terminal equipment and carried to the network side. If the terminal equipment does not have the 4G and 5G interoperation capability, the terminal equipment does not carry the PDU session identifier, and the PDU session identifier is generated by the SMF/PGW-C network element according to the EPS bearer identifier EBI distributed by the MME or the ePDG according to the specification of the protocol TS 29.571. The specific generation principle is as follows: for the session in the 3GPP access network, 64 is added on the basis of the default bearer identification allocated by the MME by the SMF/PGW-C network element, and for the N3GPP access network, 80 is added on the basis of the default bearer identification allocated by the ePDG by the SMF/PGW-C network element.

For a terminal device without 4G and 5G interoperability, if it switches between a 3GPP access network and an N3GPP access network, the first PDU session it creates will also switch. However, in the existing protocol, the integrated SMF/PGW-C network element does not update the first PDU session identifier to a Policy Control Function (PCF) network element and/or a charging function (CHF) network element. In this way, when the terminal device creates the second PDU session, two identical PDU session identifiers may appear on the PCF network element and/or the CHF network element for the same terminal device, which may be considered as a scenario in which the same service is repeatedly activated, so that services corresponding to two PDU sessions cannot be performed simultaneously.

For example, if a terminal device # a without 4G and 5G interoperability initiates access through a 3GPP access network, session #1 is created and the mme allocates EBI 5 for session #1. According to the foregoing, the network element of SMF/PGW-C generates PDU session identifier 69 (i.e. 5+ 64) for session #1, SMF/PGW-C sends the generated PDU session identifier 69 for session #1 to PCF and CHF via the N7 and N40 interfaces in fig. 2 and fig. 3, respectively, and PCF and CHF complete the policy rule guidance and charging process for session #1. When the terminal equipment # a is subjected to mobility switching, the terminal equipment # a is switched from the initially accessed 3GPP access network to the N3GPP access network, the session #1 is also switched to the N3GPP access network, the MME releases the EBI of the session #1, and the ePDG reallocates the EBI for the session #1, which may still be 5. The N7 interface and the N40 interface send update messages as only the handover procedure is performed. In the existing protocol, the update message of the N7 interface between the SMF/PGW-C and the PCF does not support carrying the PDU session identifier, so the update message sent to the PCF does not carry the PDU session identifier, i.e. the identifier of the PCF side stored session #1 is still 69. Although the update message of the N40 interface between the SMF/PGW-C and the CHF supports carrying the PDU session identifier, the existing protocol does not define the specific processing mode of the N40 interface under the handover condition, so that the CHF cannot update the PDU session identifier in time.

When terminal # a initiates access again through the 3GPP access network, session #2 is created, and since the EBI of session #1 has already been released, the EBI allocated by the MME for session #2 may still be 5. According to the foregoing, the network element of SMF/PGW-C generates PDU session identifier 69 (i.e. 5+ 64) for session #1, and similarly, SMF/PGW-C transmits the generated PDU session identifier 69 for session #2 to PCF and CHF through the N7 and N40 interfaces in fig. 2 and fig. 3, respectively, and PCF and CHF complete the policy rule guidance and charging process for session #2.

In this case, two session identities with the same identity 69 appear on the PCF and the CHF in relation to the terminal # a, which may be considered as a scenario where the same service is repeatedly activated, in a possible manner, the PCF deletes the session with the identity 69 that is saved first, and accesses the new session with the identity 69 that is successful, in a possible manner, the PCF continues to use the session with the identity 69 that is saved first, and deletes the new session with the identity 69 that is saved first, but in any manner, the services corresponding to the session #1 and the session #2 cannot be performed simultaneously, which affects user experience.

In view of this, the present application provides a communication method and a communication apparatus, so that multiple services of a terminal device can be performed simultaneously, and user experience is improved.

Fig. 4 is a schematic flow chart of a method of communication according to an embodiment of the present application. The method 400 illustrated in fig. 4 may be performed by any of the communication systems of fig. 1-3.

S410, the second core network device sends a first request message, and correspondingly, the first core network device receives the first request message, where the first request message is used to request the terminal device to switch the first session from the first access technology to the second access technology, and the first request message includes a first evolved packet system bearer identity EBI of the first session.

When the first session of the terminal device needs to be switched from the first access technology to the second access technology, the second core network device sends a first request message to the first core network device, where the first request message includes a session identifier of the first session, that is, the first EBI.

In an implementation manner, the first request message may be a session establishment request (create session request) message, where the session establishment request message includes a Handover Indication (HI) flag bit, and the handover indication flag bit is used to indicate whether the first session of the terminal device is a handover session, for example, the handover indication flag bit may indicate that the first session of the terminal device is a handover session, that is, the first session of the terminal device needs to be handed over from the first access technology to the second access technology, and the first core network device may analyze information of the handover indication flag bit, so as to determine that the first session of the first terminal device is handed over.

It should be understood that, in the present application, the first session of the terminal device may be a switched session or an initially established session. In the method 400, the first session is a handed-off session.

And S420, the first core network device sends an update message to the third core network device, wherein the update message comprises a first PDU session identifier, and the first PDU session identifier is generated according to the first EBI and the first preset value. Correspondingly, the third core network device receives the update message. The third core network device is a policy control function network element and/or a charging function network element.

After receiving the first request message, the first core network device may send an update message to the policy control function network element and/or the charging function network element, for example, the update message may be an update request (update request) message, where the update message carries a first PDU session identifier (PDU session identifier) generated according to the first EBI and the first preset value, in other words, the first core network device may convert the first EBI identifying the first session into the first PDU session identifier, identify the first session by using the first PDU session identifier, and carry the first PDU session identifier in the update message sent to the policy control function network element and/or the charging function network element.

In view of this, in this embodiment of the present application, when a first session of a terminal device needs to be switched from a first access technology to a second access technology, a second core network device sends a first request message, and after receiving the first request message, the first core network device sends an update message to a policy control function network element and/or a charging function network element, where the update message carries a first PDU session identifier generated according to a first EBI. In other words, the first PDU session identifier is carried in the update message, so that the policy control function network element and/or the charging function network element can update the PDU session identifier of the first session in time, and avoid the repetition with the session identifier of the session established later, thereby simultaneously performing multiple services of the terminal device, and improving user experience.

It should be understood that, in S420, only the update message may be sent to the policy control function network element, or only the update message may be sent to the charging function network element, or both the policy control function network element and the charging function network element may be sent with the update message according to an actual application situation. In addition, when the first core network device sends the update message to both the policy control function network element and the charging function network element, the order of sending the update message to the policy control function network element and sending the update message to the charging function network element is not limited, and the update message may be sent to the policy control function network element first or sent to the charging function network element first.

In one implementation, the first core network device is an SMF/PGW-C.

Optionally, the method 400 further comprises: s430, the first core network device generates a first PDU session identifier according to the first EBI and the first preset value.

The first core network device may generate a first PDU session identifier according to the first EBI and the first preset value, that is, the first core network device may convert the first EBI identifying the first session into the first PDU session identifier, and identify the first session through the first PDU session identifier. Wherein the first preset value depends on a PDU session generation rule defined in the protocol.

In one implementation, the first preset value is determined according to the second access technology.

In one implementation, the first access technology is a 3GPP access technology, and the second access technology is an N3GPP access technology.

That is, the first session of the terminal device is handed over from the 3GPP access technology to the N3GPP access technology.

In an implementation manner, the first access technology is a 3GPP access technology, the second access technology is an N3GPP access technology, and the second core network device is an ePDG.

When the first session of the terminal device is switched from the 3GPP access technology to the N3GPP access technology, the ePDG in the N3GPP access network allocates a first EBI for the switched first session, and the ePDG sends a first request message to the first core network device.

In one implementation, the first access technology is a 3GPP access technology, the second access technology is an N3GPP access technology, and the first preset value is 80.

That is to say, the first core network device generates the first PDU session identifier according to the switched access technology, that is, the generation rule of the PDU session identifier in the N3GPP access technology. In the protocol TS 29.571, it is specified that, for an access network using the N3GPP technology, the SMF/PGW-C network element adds 80 to the default bearer identifier allocated by the ePDG, that is, the first preset value is 80.

In one implementation, the first access technology is an N3GPP access technology, and the second access technology is a 3GPP access technology.

That is, the first session of the terminal device is handed over from the N3GPP access technology to the 3GPP access technology.

In an implementation manner, the first access technology is an N3GPP access technology, the second access technology is a 3GPP access technology, and the second core network device is an MME.

When the first session of the terminal device is switched from the N3GPP access technology to the 3GPP access technology, the MME in the 3GPP access network allocates a first EBI for the switched first session, and the MME sends a first request message to the first core network device.

It should be understood that, when the MME sends the first request message to the first core network device, the MME may send the first request message to the SGW, and then the SGW sends the first request message to the first core network device.

In an implementation manner, the first access technology is an N3GPP access technology, the second access technology is a 3GPP access technology, and the first preset value is 64.

That is to say, the first core network device generates the first PDU session identifier according to the generation rule of the PDU session identifier in the switched access technology, that is, the 3GPP access technology. In the protocol TS 29.571, it is specified that, for an access network using 3GPP technology, 64 is added by an SMF/PGW-C network element on the basis of a default bearer identifier allocated by an MME, that is, the first preset value is 64.

In one implementation, the method 400 further includes: s440, the third core network device stores the mapping relationship between the identifier of the terminal device and the session identifier of the first PDU.

The policy control network element and/or the charging function network element may store a mapping relationship between the identifier of the terminal device and the first PDU session identifier, so as to manage the first session of the terminal device through the first PDU session identifier.

Alternatively, the identifier of the terminal device may be an International Mobile Subscriber Identity (IMSI), which is used to identify different terminal devices.

In one possible implementation, the terminal device is not capable of 4G and 5G interoperability.

That is, for a terminal device without 4G and 5G interoperability, it will not carry the PDU session identifier.

A specific implementation of the communication method 400 provided in the present application is described below with reference to fig. 5. Fig. 5 is a further schematic flow chart of a method of communication provided by an embodiment of the present application. It should be understood that in the method 500 in fig. 5, the first access technology in the method 400 is a 3GPP access technology, and the second access technology is an N3GPP access technology.

S501, when the terminal device initiates a session #1 through the 3GPP access technology, the core network device initiates a creation procedure of the session #1 through the 3GPP technology, and at this time, the MME sends a creation request message #1 of the session #1 to the SMF/PGW-C through the SGW, where the message #1 includes an EBI #1 for identifying the session #1. For example, EBI #1 takes on a value of 5.

Optionally, the message #1 may include a HI flag bit, for example, the field takes a value of 0, which indicates that the session #1 of the terminal device is an initially established session.

For example, session #1 is a voice service, and the creation request message #1 of session #1 may be in the form of: create Session Request (APN = voice, EBI = 5).

Specifically, the EBI in the message #1 may refer to a Linked Bearer Identity (LBI), which is abbreviated as EBI in this application.

S502, the SMF/PGW-C generates a PDU session identification #1 according to the EBI #1.

Because the session #1 is a session initiated by the 3GPP access technology, the SMF/PGW-C generates the PDU session identifier #1 according to the protocol specification and the first preset value of 64. For example, the generated symbol #1 is 5+64=69.

S503, SMF/PGW-C sends a create request message #2 to CHF, the message #2 including the identifier #1.

SMF/PGW-C may send a create request message #2 to CHF over the N40 interface.

For example, the creation request message #2 may be in the form of: nchf _ ConvergedCharging _ Create Requset (PdusssionId 1=5+64=69, chargingId1= ChargingIdA).

S504, the CHF saves the mapping relationship between the identifier of the terminal device and the identifier #1.

For example, the identifier of the terminal device is IMSI #1, and chf stores mapping relation #1 between IMSI #1 and identifier #1.

S505, the SMF/PGW-C sends a create request message #3 to the PCF, the message #3 including the identity #1.

The SMF/PGW-C may send a create request message #3 to the PCF over the N7 interface.

For example, the creation request message #3 may be in the form of: npcf _ SMPolicyControl _ Create Requset (pdussessionid 1=5+64= 69).

It should be understood that the transmission order of the message #2 and the message #3 is not limited, i.e., the sequence of S503 and S504 is not limited.

S506, the PCF stores the mapping relation between the identification of the terminal equipment and the identification #1.

For example, the terminal device has an identifier of IMSI #1, and the pcf stores a mapping #2 of IMSI #1 and identifier #1.

S507, when the terminal equipment is subjected to mobility handover, the 3GPP technical access network is handed over to the N3GPP technical access network, the session #1 is handed over to the N3GPP technical access network, and at this time, the ePDG sends a creation request message #4 of the session #1 to the SMF/PGW-C, where the message #4 includes an EBI #2 to which the ePDG is reallocated. Since EBI #2 and EBI #1 are allocated by different network elements, it may occur that the values of the allocated EBIs are the same. For example, EBI #2 takes a value of 5.

The message #4 further includes an HI flag, for example, the field takes a value of 1, which indicates that the session #1 of the terminal device is a handover session. Alternatively, session #1 representing the terminal device may be handed over from the 3GPP access technology to the N3GPP access technology.

For example, the creation request message #4 of the session #1 may be in the form of: create Session Request (EBI = 5).

S508, the SMF/PGW-C generates a PDU session identification #2 according to the EBI #2.

Because the session #1 is switched to the N3GPP access technology, the SMF/PGW-C generates the PDU session identifier #2 according to the protocol specification and according to the first preset value of 80. For example, the generated symbol #2 is 5+80=85.

S509, SMF/PGW-C sends an update request message #1 to CHF, where the update request message #1 includes an identifier #2.

SMF/PGW-C may send an update request message #1 to CHF over the N40 interface.

For example, the update request message #1 may be in the form of: nchf _ ConvergedCharging _ Update Requset (PduSessionId 1=5+80=85, chargingId1= ChargingIdA).

In S510, the CHF updates the identifier #1 or, in other words, the mapping relationship #1, based on the update request message #1.

For example, the CHF updates the mapping relationship #1 to the correspondence relationship between IMSI #1 and identity #2 according to identity #2 in the update request message #1.

S511, SMF/PGW-C sends update request message #2 to PCF, and update request message #2 includes identification #2.

The SMF/PGW-C may send an update request message #2 to the PCF over the N7 interface.

For example, the update request message #2 may be in the form of: npcf _ SMPolicyControl _ Update requsset (pdussessionid 1=5+80= 85).

At S512, the PCF updates the identifier #1 or, alternatively, the mapping #2, based on the update request message #2.

For example, the PCF updates the mapping #2 to the correspondence between IMSI #1 and identity #2 according to identity #2 in the update request message #1.

It should be understood that the transmission order of the update request message #1 and the update request message #2 is not limited, i.e., the order of S509 and S511 is not limited.

For example, when session #1 is handed over to the N3GPP access technology, the method 500 further includes:

s513, the SMF/PGW-C sends a release message, for example, a delete bearer request (delete bearer request) message, to the MME through the SGW, and carries an identifier of the session where the handover occurs, that is, EBI #1.

For example, the delete bearer request message may be in the form of: delete beer Request (EBI = 5).

After receiving the release message, the MME releases EBI #1 identifying session #1.

S514, when the terminal device initiates session #2 again through the 3GPP access technology, the core network device initiates a creation procedure of session #2 through the 3GPP technology, similar to S501 to S506. At this time, the MME sends a create request message #5 for session #2 to the SMF/PGW-C through the SGW.

Similarly, the message #5 may include the EBI #3 allocated by the MME for the session #2, and since the EBI #1 generated by the MME for the session #1 has already completed the release in S513, the EBI #3 allocated by the MME for the session #2 may be the same as the EBI #1 allocated previously for the session #1, for example, the value of EBI #3 is 5.

For example, session #2 is a multimedia message service, and the creation request message #5 of session #2 may be in the form of: create Session Request (APN = mms, EBI = 5).

S515 to S519, the SMF/PGW-C generates a PDU session identifier #3 according to the EBI #3, and sends the identifier #3 to the CHF and the PCF through a creation request message #6 and a creation request message #7, so that the CHF and the PCF can store the corresponding relation between the identifier of the terminal device and the identifier #3.

For example, the creation request message #6 may be in the form of: nchf _ ConvergedCharging _ Create Requset (PdusssionId 2=5+64=69, chargingId2= ChargingIdB). The creation request message #7 may be in the form of: npcf _ SMPolicyControl _ Create Requset (pdussessionid 2=5+64= 69).

If EBI #1 and EBI #3 are the same, identification #1 and identification #3 are also the same, however, at this time in CHF and PCF, identification #3 is used to identify session #2 of the terminal device, and the PDU session identification identifying session #1 has been updated to identification #2 in S507 to S512, and no duplication occurs. That is to say, by the method of the present application, the policy control function network element and/or the charging function network element can update the PDU session identifier of the first session in time, and avoid the session identifier repetition with the session established later, so that multiple services of the terminal device can be performed simultaneously, and the user experience is improved.

The steps of S515 to S519 are similar to those of S502 to S506, and are not described herein again.

It should be understood that the values of the HI flag bits in S501 and S507 are only for illustration, and the present application is not limited thereto.

Another specific implementation of the communication method 400 provided by the present application is described below with reference to fig. 6. Fig. 6 is a further schematic flow chart of a method of communication provided by an embodiment of the present application. It should be understood that in the method 600 of fig. 6, the first access technology in the method 400 is an N3GPP access technology, and the second access technology is a 3GPP access technology.

S601, when the terminal device initiates a session #1 through the N3GPP access technology, the core network device initiates a creation procedure of the session #1 through the N3GPP technology, and at this time, the ePDG sends a creation request message #1 of the session #1 to the SMF/PGW-C, where the message #1 includes an EBI #1 for identifying the session #1. For example, EBI #1 takes on a value of 6.

Optionally, the message #1 may include an HI flag, for example, the field takes a value of 0, which indicates that the session #1 of the terminal device is a newly-established session.

For example, session #1 is a voice service, and the creation request message #1 of session #1 may be in the form of: create Session Request (APN = voice, EBI = 6).

S602, the SMF/PGW-C generates a PDU session identification #1 according to the EBI #1.

Because the session #1 is a session initiated by an N3GPP access technology, the SMF/PGW-C generates the PDU session identifier #1 according to the protocol specification and according to the first preset value of 80. For example, the generated symbol #1 is 6+80=86.

S603, SMF/PGW-C sends a create request message #2 to CHF, message #2 including the identifier #1.

SMF/PGW-C may send a create request message #2 to CHF over the N40 interface.

For example, the creation request message #2 may be in the form of: nchf _ ConvergedCharging _ Create Requset (PduSessionId 1=6+80=86, chargingId1= ChargingIdA).

S604, the CHF saves the mapping relationship between the identifier of the terminal device and the identifier #1.

S605, the SMF/PGW-C sends a create request message #3 to the PCF, the message #3 including an identifier #1.

For example, the creation request message #3 may be in the form of: npcf _ SMPolicyControl _ Create Requset (pdussessionid 1=6+80= 86).

It should be understood that the transmission order of the message #2 and the message #3 is not limited, i.e., the order of the S603 and the S604 is not limited.

S606, PCF stores the mapping relation between the terminal device identification and identification #1.

S607, when the terminal device is subjected to mobility handover, the N3GPP technology access network is handed over to the 3GPP technology access network, and the session #1 is handed over to the 3GPP technology access network, at this time, the MME sends a create request message #4 of the session #1 to the SMF/PGW-C through the SGW, where the message #4 includes EBI #2 reallocated by the MME. Since EBI #2 and EBI #1 are allocated by different network elements, it may occur that the values of the allocated EBIs are the same. For example, EBI #2 takes on a value of 6.

The message #4 further includes an HI flag, for example, the field takes a value of 1, which indicates that the session #1 of the terminal device is a session in which handover occurs. Alternatively, session #1 indicating the terminal device may be handed over from the N3GPP access technology to the 3GPP access technology.

For example, the creation request message #4 of the session #1 may be in the form of: create Session Request (EBI = 6).

S608, the SMF/PGW-C generates a PDU session identification #2 according to the EBI #2.

Because the session #1 is switched to the 3GPP access technology, the SMF/PGW-C generates the PDU session identifier #2 according to the protocol specification and the first preset value 64. For example, the generated symbol #2 is 6+64=70.

S609, the SMF/PGW-C sends an update request message #1 to the CHF, wherein the update request message #1 comprises an identifier #2.

SMF/PGW-C may send an update request message #1 to CHF over the N40 interface.

For example, the update request message #1 may be in the form of: nchf _ ConvergedCharging _ Update Requset (PduSessionId 1=6+64=70, chargingId1= ChargingIdA).

At S610, the CHF updates identifier #1 or, as it were, mapping #1 according to update request message #1.

S611, the SMF/PGW-C sends an update request message #2 to the PCF, where the update request message #2 includes the identifier #2.

For example, the update request message #2 may be in the form of: npcf _ SMPolicyControl _ Update Requset (pdussessionid 1=6+64= 70).

In S612, the PCF updates the identifier #1 or, in other words, the mapping relationship #2, according to the update request message #2.

It should be understood that the transmission order of the update request message #1 and the update request message #2 is not limited, i.e., the order of S609 and S611 is not limited.

In view of this, in this embodiment of the present application, when a first session of a terminal device needs to be switched from a first access technology to a second access technology, a second core network device sends a first request message, and after receiving the first request message, the first core network device sends an update message to a policy control function network element and/or a charging function network element, where the update message carries a first PDU session identifier generated according to a first EBI. In other words, the first PDU session identifier is carried in the update message, so that the policy control function network element and/or the charging function network element can update the PDU session identifier of the first session in time, and avoid the repetition with the session identifier of the session established later, thereby enabling multiple services of the terminal device to be performed simultaneously, and improving user experience.

For example, when session #1 is handed over to the 3GPP access technology, the method 600 further includes:

s613, the SMF/PGW-C sends a release message, for example, a delete bearer request (delete bearer request) message, to the ePDG, carrying the identifier of the session where the handover occurs, that is, EBI #1.

For example, the delete bearer request message may be in the form of: delete beer Request (EBI = 6).

S614, when the terminal device initiates session #2 again through the N3GPP access technology, similar to S601 to S606, the core network device initiates a creation procedure of session #2 through the N3GPP technology. At this time, the ePDG sends a create request message #5 for session #2 to the SMF/PGW-C.

Similarly, the message #5 may include the EBI #3 allocated by the ePDG for the session #2, and since the EBI #1 generated by the ePDG for the session #1 in S613 has already been released, the EBI #3 allocated by the ePDG for the session #2 may be the same as the EBI #1 allocated for the session #1 before, for example, the value of the EBI #3 is 6.

For example, session #2 is a multimedia message service, and the creation request message #5 of session #2 may be in the form of: create Session Request (APN = mms, EBI = 6).

S615 to S619, the SMF/PGW-C generates a PDU session identifier #3 from EBI #3, and transmits the identifier #3 to the CHF and the PCF via the creation request message #6 and the creation request message #7, so that the CHF can store the mapping relationship #3 between the identifier of the terminal device and the identifier #3, and the PCF can store the mapping relationship #4 between the identifier of the terminal device and the identifier #3.

For example, the creation request message #6 may be in the form of: nchf _ ConvergedCharging _ Create Requset (PdusssionId 2=6+80=86, chargingId2= ChargingIdB). The creation request message #7 may be in the form of: npcf _ SMPolicyControl _ Create Requset (pdussessionid 2=6+80= 86).

If EBI #1 and EBI #3 are the same, identification #1 and identification #3 are also the same, however, at this time in CHF and PCF, identification #3 is used to identify session #2 of the terminal device, and the PDU session identification identifying session #1 has been updated to identification #2 in S607 to S612, and no duplication occurs. That is to say, by the method of the present application, the policy control function network element and/or the charging function network element can update the PDU session identifier of the first session in time, and avoid the session identifier of the session established later from being repeated, so that multiple services of the terminal device can be performed simultaneously, and the user experience is improved.

The specific steps of S615 to S619 are similar to those of S602 to S606, and are not described herein again.

It should be understood that the values of the HI flag bits in S601 and S607 are only for illustration and are not limited in this application.

Fig. 7 is a schematic flow chart of a method of communication according to an embodiment of the present application. The method 700 described in fig. 7 may be performed by any of the communication systems of fig. 1-3.

S710, the second core network device sends a first request message, and correspondingly, the first core network device receives the first request message, where the first request message is used to request to create a first session of the terminal device through the first access technology, and the first request message includes a first evolved packet system bearer identity EBI of the first session.

When the terminal device needs to create the first session through the first access technology, the second core network device sends a first request message to the first core network device, where the first request message includes a session identifier of the first session, that is, the first EBI.

Optionally, the first request message may be a session creation request (create session request) message, where the session creation request message includes a Handover Indication (HI) flag bit, and the handover indication flag bit is used to indicate whether the first session of the terminal device is an initially established session, for example, the handover indication flag bit may indicate that the first session of the terminal device is an initially established session, that is, the terminal device needs to create the first session through the first access technology, and the first core network device may parse information of the handover indication flag bit, so as to determine that the first session of the first terminal device is an initially established session.

It should be understood that, in the present application, the first session of the terminal device may be a handover session or an initially established session. In method 700, the first session is an initially established session.

S720, when the first core network equipment determines that the first PDU session identifier is the repeated identifier of the terminal equipment, the first core network equipment sends a creating message to the third core network equipment, wherein the creating message comprises a second PDU session identifier, the second PDU session identifier is different from the first PDU session identifier, and the first PDU session identifier is generated according to the first EBI and the first preset value. Correspondingly, the third core network device receives the creation message. The third core network device is a policy control function network element and/or a charging function network element.

After receiving the first request message, the first core network device may send a creation message to the policy control function network element and/or the charging function network element when determining that the first PDU session identifier is the duplicate identifier of the terminal device, where the creation message may be a create request (create request) message, and the creation message carries a second PDU session identifier (PDU session identifier), and the second PDU session identifier is different from the first PDU session identifier, where the first ebpdu session identifier is generated according to the first preset value and the first PDU i. In other words, the first core network device may convert the first EBI identifying the first session into a second PDU session identifier different from the first PDU session identifier, identify the first session through the second PDU session identifier, and carry the second PDU session identifier in a creation message sent to the policy control function network element and/or the charging function network element.

In view of this, in this embodiment of the present application, when a terminal device needs to create a first session through a first access technology, a second core network device sends a first request message, and after receiving the first request message, the first core network device sends a creation message to a policy control function network element and/or a charging function network element, where the creation message carries a second PDU session identifier, and the second PDU session identifier is different from the first PDU session identifier, where the first PDU session identifier is generated according to a first EBI and a first preset value. In other words, the second PDU session identifier different from the first PDU session identifier is carried in the creation message, so that the policy control function network element and/or the charging function network element are prevented from receiving the session identifier repeated with the PDU session identifier of the first session, thereby enabling multiple services of the terminal device to be performed simultaneously, and improving user experience.

It should be understood that, in S720, only the creation message may be sent to the policy control function network element, or only the creation message may be sent to the charging function network element, or both the policy control function network element and the charging function network element may be sent with the creation message according to the actual application situation. In addition, when the first core network device sends the creation message to both the policy control function network element and the charging function network element, the order of sending the creation message to the policy control function network element and sending the creation message to the charging function network element is not limited, and the first core network device may send the creation message to the policy control function network element first or send the creation message to the charging function network element first.

In one implementation, the first core network device is an SMF/PGW-C.

Optionally, the method 700 further includes: and S730, the first core network device generates a first PDU session identifier according to the first EBI and a first preset value, and generates a second PDU session identifier according to the first EBI and a second preset value, wherein the second preset value is different from the first preset value.

The first core network device may first generate a first PDU session identifier according to the first EBI and a first preset value, select a second preset value different from the first preset value when determining that the first PDU session identifier is a duplicate identifier of the terminal device, and generate a second PDU session identifier according to the first EBI and the second preset value. That is, the first core network device may convert the first EBI identifying the first session into a second PDU session identifier different from the first PDU session identifier, and identify the first session through the second PDU session identifier. Wherein the first preset value depends on a PDU session generation rule defined in the protocol. The second preset value may be defined by a protocol or may be pre-configured in the first core network.

In other words, the generation of the first PDU session identity and the generation of the second PDU session identity may not occur simultaneously in S730.

Optionally, before S710, the method 700 further includes: s701, the second core network device sends a second request message, and accordingly, the first core network device receives the second request message, where the second request message is used to request to create a second session through the first access technology, and the second request message includes a second EBI of the second session.

That is, before creating the first session, the first core network device receives a second request message from the second core network device, where the second request message is used to request creation of a second session through the first access technology, and the second request message includes a second EBI of the second session.

S702, the first core network device generates a third PDU session identifier according to the second EBI and the first preset value.

The first core network device may generate a third PDU session identifier according to the second EBI and the first preset value, that is, the first core network device may convert the second EBI identifying the second session into the third PDU session identifier, and identify the second session through the third PDU session identifier. Wherein the first preset value depends on a PDU session generation rule defined in the protocol.

Optionally, the method 700 further includes: s740, the first core network device determines that the first PDU session identifier is a duplicate identifier of the terminal device.

The determining, by the first core network device, that the first PDU session identifier is a duplicate identifier of the terminal device includes: and the first core network equipment determines that the third PDU session identification is the same as the first PDU session identification.

In S730, the first core network device generates a first PDU session identifier according to the first EBI and the first preset value, and if the first core network device determines through comparison that the first PDU session identifier is the same as a previously generated third PDU session identifier, determines that the first PDU session identifier is a duplicate identifier of the terminal device.

Optionally, after S702, the first core network device may receive a third request message, where the third request message is used to request the terminal device to switch the second session from the first access technology to the second access technology. The first core network device sends a release message to the second core network device in the process of executing the handover, wherein the release message is used for releasing the second EBI identifying the second session. The second core network device releases the second EBI after receiving the release message, so that the first EBI allocated may be the same as the second EBI when the EBI is allocated for the first session.

In one implementation, the first preset value is determined according to a first access technology, the second preset value is determined according to the first preset value, and the second preset value is different from the first preset value.

That is, the first core network device may generate the second PDU session identification using a second preset value different from the first preset value.

That is, the terminal device needs to initiate the first session through the 3GPP access technology.

In one implementation, the first access technology is a 3GPP access technology, and the second core network device is an MME.

When the terminal device needs to initiate a first session through a 3GPP access technology, an MME in the 3GPP access network allocates a first EBI for the established first session, and the MME sends a first request message to the first core network device.

In one implementation, the first access technology is a 3GPP access technology, and the first preset value is 64.

That is to say, the first core network device generates the first PDU session identifier according to the generation rule of the PDU session identifier in the first access technology, that is, the 3GPP access technology. In the protocol TS 29.571, it is specified that, for an access network using 3GPP technology, 64 is added by an SMF/PGW-C network element on the basis of a default bearer identifier allocated by an MME, that is, the first preset value is 64.

That is, the terminal device needs to initiate the first session through the N3GPP access technology.

In an implementation manner, the first access technology is an N3GPP access technology, and the second core network device is an MME.

When the terminal device needs to initiate a first session through the N3GPP access technology, the ePDG in the N3GPP access network allocates a first EBI for the established first session, and the ePDG sends a first request message to the first core network device.

In one implementation, the first access technology is an N3GPP access technology, and the first preset value is 80.

That is to say, the first core network device generates the first PDU session identifier according to the first access technology, that is, the generation rule of the PDU session identifier in the N3GPP access technology. In the protocol TS 29.571, it is specified that, for an access network using the N3GPP technology, the SMF/PGW-C network element adds 80 to the default bearer identifier allocated by the ePDG, that is, the first preset value is 80.

In one implementation, the first access technology is a 3GPP access technology, and the second preset value is any one of 96, 128, 160, 192, and 224.

In one implementation, the first access technology is an N3GPP access technology, and the second preset value is any one of 112, 144, 176, 208, and 240.

Since the EBI value range is 0 to 15, the protocol is defined, the first preset value is 64 in the 3GPP access technology, and the first preset value is 80 in the N3GPP access technology, so that the PDU session identifier value is 64 to 79 in the 3GPP access technology, and 80 to 95 in the N3GPP access technology. Thus, upon determining that the first PDU session identity is a duplicate identity of the terminal device, the first core network device may enable a new segmentation to generate the PDU session, in particular using a second preset value different from the first preset value. For example, in the 3GPP access technology, the second preset value may be any one of 96, 128, 160, 192, and 224. In the N3GPP access technology, the second preset value is any one of 112, 144, 176, 208, and 240.

Optionally, the value of the second preset value may also be as follows: in the N3GPP access technology, the number is any one of 96, 128, 160, 192, and 224, and in the 3GPP access technology, the number is any one of 112, 144, 176, 208, and 240.

Alternatively, the second preset value may be any one of values 96 to 255.

It should be understood that the second preset value is only an example, and in practical application, the second preset value is only required to be distinguished from the first preset value and not to conflict with a value of the existing PDU session identifier, which is not limited in the present application.

In one implementation, the method 700 further includes: s740, the third core network device stores the mapping relationship between the identifier of the terminal device and the session identifier of the second PDU.

The policy control network element and/or the charging function network element may store a mapping relationship between the identifier of the terminal device and the second PDU session identifier, so as to manage the first session of the terminal device through the second PDU session identifier.

A specific implementation of the communication method 700 provided in the present application is described below with reference to fig. 8. Fig. 8 is a further schematic flow chart of a method of communication provided by an embodiment of the present application. It should be understood that in the method 800 of fig. 8, the first access technology in the method 700 is a 3GPP access technology, and the second access technology is an N3GPP access technology.

S801, when the terminal device initiates a session #2 through a 3GPP access technology, the core network device initiates a creation procedure of the session #2 through the 3GPP technology, and at this time, the MME sends a create request (create session request) message #1 of the session #2 to the SMF/PGW-C through the SGW, where the message #1 includes an EBI #2 for identifying the session #2. For example, EBI #2 takes a value of 5.

Optionally, the message #1 may include an HI flag, for example, the field takes a value of 0, which indicates that the session #2 of the terminal device is an initially established session.

For example, session #2 is a voice service, and the creation request message #1 of session #2 may be in the form of: create Session Request (APN = voice, EBI = 5).

S802, the SMF/PGW-C generates a PDU session identification #3 according to the EBI #2.

Because the session #2 is a session initiated by the 3GPP access technology, the SMF/PGW-C generates the PDU session identifier #3 according to the protocol specification and according to the first preset value of 64. For example, the generated symbol #3 is 5+64=69.

S803, SMF/PGW-C sends a create request message #2 to CHF, message #2 including the identifier #3.

SMF/PGW-C may send a create request message #2 to CHF over the N40 interface.

For example, the creation request message #2 may be in the form of: nchf _ ConvergedCharging _ Create Requset (PduSessionId 1=5+64=69, chargingId1= ChargingIdA).

S804, the CHF saves the mapping relationship between the identifier of the terminal device and the identifier #3.

For example, the identifier of the terminal device is IMSI #1, and chf stores mapping relation #1 between IMSI #1 and identifier #3.

S805, SMF/PGW-C sends a create request message #3 to PCF, message #3 including identification #3.

It should be understood that the transmission order of the message #2 and the message #3 is not limited, that is, the order of S803 and S804 is not limited.

S806, PCF stores the mapping relation between the terminal device identification and identification #3.

For example, the terminal device's identity is IMSI #1 and the PCF maintains a mapping #2 of IMSI #1 and identity #3.

S807, when the terminal equipment is subjected to mobility handover, the 3GPP technology access network is switched to the N3GPP technology access network, the session #2 is switched to the N3GPP technology access network, and at this time, the ePDG sends a creation request message #4 of the session #2 to the SMF/PGW-C, where the message #4 includes EBI #3 reallocated by the ePDG. Since EBI #3 and EBI #3 are allocated by different network elements, it may occur that the values of the allocated EBIs are the same. For example, EBI #3 takes a value of 5.

The message #4 may further include an HI flag, for example, the field takes a value of 1, which indicates that the session #2 of the terminal device is a handover session. Alternatively, session #2 representing the terminal device may be handed over from the 3GPP access technology to the N3GPP access technology.

For example, the creation request message #4 for session #2 may be in the form of: create Session Request (EBI = 5).

S808, the SMF/PGW-C generates a PDU session identification #4 according to the EBI #3.

Because the session #2 is switched to the N3GPP access technology, the SMF/PGW-C generates the PDU session identifier #4 according to the protocol specification and according to the first preset value of 80. For example, the generated symbol #4 is 5+80=85.

S809, SMF/PGW-C sends an update request message #1 to CHF.

The existing protocol does not make clear how the session identifier in the N40 interface in the handover scenario should be updated, i.e. although the identifier #4 is generated in S808, according to the existing protocol flow, the identifier #4 is not included in the update request message #1, and the identifier included in the update message #1 is still the identifier #3.

SMF/PGW-C may send an update request message #1 to CHF over the N40 interface.

For example, the update request message #1 may be in the form of: nchf _ ConvergedCharging _ Update Requset (PduSessionId 1=5+64=69, chargingId1= ChargingIdA).

S810, the CHF saves the identifier #3 according to the update request message #1.

That is, although the session #2 of the terminal device is switched to the N3GPP access technology and the SMF/PGW-C generates the identifier #4, the PDU session identifier for identifying the session #2 is still the identifier #3 at the CHF through S807 to S810.

S811, SMF/PGW-C sends an update request message #2 to PCF.

In the existing protocol, the update request message sent to the PCF does not support carrying the PDU session identifier, that is, although the identifier #2 is generated in S808, according to the existing protocol flow, the identifier #2 is not included in the update request message #2.

SMF/PGW-C may send an update request message #2 to the PCF over the N7 interface.

For example, the update request message #2 may be in the form of: npcf _ SMPolicyControl _ Update Requset ().

S812, since the PDU session identity is not included in the update request message #2, the PCF does not change the locally stored identity #3.

That is, although the session #2 of the terminal device is switched to the N3GPP access technology and the SMF/PGW-C generates the identifier #4, the PDU session identifier for identifying the session #2 is still the identifier #3 at the PCF via S807 to S812.

It should be understood that the transmission order of the update request message #1 and the update request message #2 is not limited, i.e., the order of S809 and S811 is not limited.

S813, the SMF/PGW-C sends a release message, for example, a delete bearer request (delete bearer request) message, to the MME through the SGW, and carries an identifier of the session where the handover occurs, that is, EBI #2.

For example, the delete bearer request message may be in the form of: delete Bearer Request (EBI = 5).

After receiving the release message, the MME releases EBI #2 identifying session #2.

S814, when the terminal device initiates session #1 again through the 3GPP access technology, the core network device initiates a creation procedure of session #1 through the 3GPP technology, similar to S801 to S806. At this time, the MME sends a create request message #5 for session #1 to the SMF/PGW-C through the SGW.

Similarly, the message #5 may include the EBI #1 allocated by the MME for the session #1, and since the EBI #2 generated by the MME for the session #2 has completed the release in S813, the EBI #1 allocated by the MME for the session #1 may be the same as the EBI #2 allocated for the session #2 before, for example, the value of EBI #1 is 5.

For example, the session #1 is a multimedia message service, and the creation request message #5 of the session #1 may be in the form of: create Session Request (APN = mms, EBI = 5).

S815, the SMF/PGW-C generates a PDU session identification #1 according to the EBI #1.

And S816, if the SMF/PGW-C determines that the identifier #1 is the same as the identifier #3 generated in the S802, that is, the identifier #1 is determined to be a repeated identifier of the terminal equipment, the SMF/PGW-C generates a PDU session identifier #2 for the session #1 according to a second preset value.

For example, in the 3GPP access technology, the second preset value may be 96, so that the identifier #2 is 5+96=101.

S817, SMF/PGW-C sends a create request message #6 to CHF, message #6 including the identifier #2.

SMF/PGW-C may send a create request message #6 over the N40 interface to CHF.

For example, the creation request message #6 may be in the form of: nchf _ ConvergedCharging _ Create Requset (PdusssionId 2=5+96=101, chargingId2= ChargingIdB).

S818, the CHF saves the mapping relationship between the identifier of the terminal device and the identifier #2.

For example, the identifier of the terminal device is IMSI #1, and chf stores mapping #3 of IMSI #1 and identifier #2.

S819, the SMF/PGW-C sends a create request message #7 to the PCF, the message #7 including an identity #2.

The SMF/PGW-C may send a create request message #7 to the PCF over the N7 interface.

For example, the creation request message #7 may be in the form of: npcf _ SMPolicyControl _ Create Requset (pdussessionid 2=5+96= 101).

It should be understood that the sending order of the message #6 and the message #7 is not limited, i.e., the sequence of S817 and S819 is not limited.

S820, the PCF stores the mapping relationship between the identifier of the terminal device and the identifier #2.

For example, the terminal device's identity is IMSI #1, and the PCF maintains a mapping #4 between IMSI #1 and identity #2.

At this time, in the CHF and PCF, the PDU session identification identifying session #2 is still identification #3, whereas the PDU session identification identifying session #1 is generated as identification #2 in S815 to S816, and repetition does not occur. That is to say, in the method of the present application, by carrying the second PDU session identifier different from the first PDU session identifier in the creation message, the policy control function network element and/or the charging function network element are prevented from receiving the session identifier that is duplicated to the PDU session identifier of the first session, so that multiple services of the terminal device can be performed simultaneously, and user experience is improved.

It should be understood that the values of the HI flag bits in S801 and S807 are merely illustrative, and the present application is not limited thereto.

Another specific implementation of the communication method 700 provided by the present application is described below with reference to fig. 9. Fig. 9 is a further schematic flow chart of a method 900 of communication provided by an embodiment of the present application. It should be understood that in the method 900 of fig. 9, the first access technology in the method 700 is an N3GPP access technology, and the second access technology is a 3GPP access technology.

S901, when the terminal device initiates a session #2 through the N3GPP access technology, the core network device initiates a creation procedure of the session #2 through the N3GPP technology, at this time, the ePDG sends a creation request message #1 of the session #2 to the SMF/PGW-C, where the message #1 includes an EBI #2 for identifying the session #2. For example, EBI #2 takes on a value of 6.

Optionally, the message #1 may include a HI flag bit, for example, the field takes a value of 0, which indicates that the session #2 of the terminal device is an initially established session.

For example, session #2 is a voice service, and the creation request message #1 of session #2 may be in the form of: create Session Request (APN = voice, EBI = 6).

S902, the SMF/PGW-C generates a PDU session identification #3 according to the EBI #2.

Because the session #2 is a session initiated by the 3GPP access technology, the SMF/PGW-C generates the PDU session identifier #3 according to the protocol specification and according to the first preset value of 80. For example, the generated symbol #3 is 6+80=86.

S903, SMF/PGW-C sends a create request (create request) message #2 to CHF, and the message #2 comprises an identifier #3.

SMF/PGW-C may send a create request message #2 to CHF over the N40 interface.

For example, the creation request message #2 may be in the form of: nchf _ ConvergedCharging _ Create Requset (PdusssionId 1=6+80=86, chargingId1= ChargingIdA).

S904, the CHF stores the mapping relationship between the identifier of the terminal device and the identifier #3.

S905, the SMF/PGW-C sends a create request message #3 to the PCF, wherein the message #3 comprises an identification #3.

It should be understood that the transmission order of the message #2 and the message #3 is not limited, i.e., the order of the S903 and the S904 is not limited.

S906, the PCF stores the mapping relation between the identification of the terminal equipment and the identification #3.

S907, when the terminal device is subjected to mobility handover, the N3GPP technology access network is handed over to the 3GPP technology access network, and the session #2 is handed over to the N3GPP technology access network, the MME sends a create request message #4 of the session #2 to the SMF/PGW-C through the SGW, where the message #4 includes EBI #3 reallocated by the MME. Since EBI #3 and EBI #3 are allocated by different network elements, it may occur that the values of the allocated EBIs are the same. For example, EBI #3 takes a value of 6.

For example, the creation request message #4 for session #2 may be in the form of: create Session Request (EBI = 6).

S908, the SMF/PGW-C generates a PDU session identification #4 according to the EBI #3.

Because the session #2 is switched to the 3GPP access technology, the SMF/PGW-C generates the PDU session identifier #4 according to the protocol specification and according to the first preset value of 64. For example, the generated symbol #4 is 6+64=70.

S909, SMF/PGW-C sends an update request message #1 to CHF.

The existing protocol does not make clear how the session identifier in the N40 interface in the handover scenario should be updated, i.e. although the identifier #4 is generated in S908, the identifier #4 is not included in the update request message #1 according to the existing protocol flow, and the identifier included in the update message #1 is still the identifier #3.

SMF/PGW-C may send an update request message #1 to CHF over the N40 interface.

For example, the update request message #1 may be in the form of: nchf _ ConvergedCharging _ Update Requuset (PduSessionId 1=5+64=69, chargingId1= ChargingIdA).

S910, the CHF saves the identifier #3 according to the update request message #1.

That is, although session #2 of the terminal device is switched to the 3GPP access technology and SMF/PGW-C generates identity #4, the PDU session identity for identifying session #2 is still identity #3 on CHF through S907 to S910.

S911, SMF/PGW-C sends update request message #2 to PCF.

In the existing protocol, the update request message sent to the PCF does not support carrying the PDU session identifier, that is, although the identifier #2 is generated in S908, the update request message #2 does not include the identifier #2 according to the existing protocol flow.

S912, since the update request message #2 does not include the PDU session identifier, the PCF does not change the locally stored identifier #3.

That is, although the session #2 of the terminal device is switched to the N3GPP access technology and the SMF/PGW-C generates the identifier #4, the PDU session identifier for identifying the session #2 is still the identifier #3 on the PCF through S907 to S912.

It should be understood that the transmission order of the update request message #1 and the update request message #2 is not limited, i.e., the sequence of S909 and S911 is not limited.

S913, the SMF/PGW-C sends a release message, for example, a delete bearer request (delete bearer request) message, to the ePDG, and carries an identifier of the session where the handover occurs, that is, EBI #2.

S914, when the terminal device initiates session #1 again through the N3GPP access technology, the core network device initiates a creation procedure of session #1 through the N3GPP technology, similar to S901 to S906. At this time, the ePDG sends a create request message #5 for session #1 to the SMF/PGW-C.

Similarly, the message #5 may include the EBI #1 allocated by the ePDG for the session #1, and since the EBI #2 generated by the ePDG for the session #2 in S913 has already been released, the EBI #1 allocated by the ePDG for the session #1 may be the same as the EBI #2 allocated for the session #2 before, for example, the value of the EBI #1 is 6.

For example, the session #1 is a multimedia message service, and the creation request message #5 of the session #1 may be in the form of: create Session Request (APN = mms, EBI = 6).

S915, the SMF/PGW-C generates a PDU session identification #1 according to the EBI #1.

Because the session #1 is a session initiated by an N3GPP access technology, the SMF/PGW-C generates the PDU session identifier #1 according to the protocol specification and according to the first preset value of 80. For example, the generated flag #1 is 6+80=86.

And S916, if the SMF/PGW-C determines that the identifier #1 is the same as the identifier #3 generated in S902, that is, the identifier #1 is determined to be a repeated identifier of the terminal device, the SMF/PGW-C generates a PDU session identifier #2 for the session #1 according to a second preset value.

For example, in the N3GPP access technology, the second preset value may be 112, so that #2 is identified as 6+112=118.

S917, SMF/PGW-C sends create request (create request) message #6 to CHF, message #6 includes identification #2.

SMF/PGW-C may send a create request message #6 to CHF over the N40 interface.

For example, the creation request message #6 may be in the form of: nchf _ ConvergedCharging _ Create Requset (PdusssionId 2=6+112=118, chargingId2= ChargingIdB).

S918, the CHF stores the mapping relationship between the identifier of the terminal device and the identifier #2.

S919, the SMF/PGW-C sends a create request message #7 to the PCF, the message #7 including the identifier #2.

For example, the creation request message #7 may be in the form of: npcf _ SMPolicyControl _ Create Requset (pdussessionid 2=6+112= 118).

It should be understood that the transmission order of the message #6 and the message #7 is not limited, i.e., the order of S917 and S919 is not limited.

S920, PCF stores the mapping relation between the identification of the terminal device and the identification #2.

At this time, in the CHF and PCF, the PDU session identification identifying session #2 is still identification #3, whereas the PDU session identification identifying session #1 is generated as identification #2 in S915 to S916, and repetition does not occur. That is to say, in the method of the present application, by carrying the second PDU session identifier different from the first PDU session identifier in the creation message, the policy control function network element and/or the charging function network element are prevented from receiving the session identifier that is duplicated to the PDU session identifier of the first session, so that multiple services of the terminal device can be performed simultaneously, and user experience is improved.

It should be understood that the values of the HI flag bits in S901 and S907 are only for illustration, and the application is not limited thereto.

The method for communication provided in the embodiment of the present application is described in detail above with reference to fig. 1 to 9, and the communication apparatus provided in the embodiment of the present application is described below with reference to fig. 10 to 11. It should be understood that the apparatus shown in fig. 10 to 11 can implement the steps of the above method, and for brevity, the description is omitted here.

Fig. 10 is a schematic block diagram of a communication device provided herein. As shown in fig. 10, the communication device 1000 may include a transceiver unit 1010 and/or a processing unit 1020.

The transceiving unit 1010 may include a transmitting unit and/or a receiving unit. The transceiving unit 1010 may be a transceiver (including a transmitter and/or a receiver), an input/output interface (including an input and/or an output interface), a pin or a circuit, etc. The transceiving unit 1010 may be configured to perform the steps of transmitting and/or receiving in the above-described method embodiments.

The processing unit 1020 may be a processor (which may include one or more processors), a processing circuit with a processor function, or the like, and may be configured to perform other steps besides transmitting and receiving in the above-described method embodiments.

Optionally, the communication device may further include a storage unit, which may be a memory, an internal storage unit (e.g., a register, a cache, etc.), an external storage unit (e.g., a read-only memory, a random access memory, etc.), and the like. The storage unit is configured to store instructions, and the processing unit 1020 executes the instructions stored in the storage unit to enable the communication device to perform the method.

In one design, the communications apparatus 1000 may correspond to the first core network device in the

methods

400, 500, and 600, and may perform the operations performed by the first core network device, the SMF/PGW-C, in the

methods

400, 500, and 600.

For example, the transceiving unit 1010 is configured to receive a first request message requesting a handover of a first session of a terminal device from a first access technology to a second access technology, where the first request message includes a first evolved packet system bearer identity, EBI, of the first session. The transceiving unit 1010 may further be configured to: and sending an update message to the third core network device, wherein the update message comprises a first PDU session identifier, and the first PDU session identifier is generated according to the first EBI and the first preset value.

It should be understood that the transceiver 1010 and the processing unit 1020 may also perform other operations performed by the first core network device and the SMF/PGW-C in any of the

methods

400, 500, and 600, and detailed descriptions thereof are omitted here.

In one design, the communications apparatus 1000 may correspond to the third core network device in the

methods

400, 500, and 600 described above, and may perform the operations performed by the third core network device, the PCF, or the CHF in the

methods

400, 500, and 600.

For example, the transceiving unit 1010 is configured to receive an update message from a first core network device, where the update message includes a first PDU session identifier, and the first PDU session identifier is generated according to a first EBI, and the first EBI is used to identify a first session of a terminal device. The processing unit 1020 is configured to store a mapping relationship between the identifier of the terminal device and the session identifier of the first PDU.

It should be understood that the transceiving unit 1010 and the processing unit 1020 may also perform other operations performed by the third core network device, the PCF, or the CHF in the

methods

400, 500, and 600, which are not described in detail herein.

In one design, the communications apparatus 1000 may correspond to the second core network device in the

methods

400, 500, and 600, and may perform the operations performed by the second core network device, the MME, or the ePDG in the

methods

400, 500, and 600.

For example, the transceiving unit 1010 is configured to send a first request message to a first core network device, where the first request message is used to request a first session of a terminal device to be switched from a first access technology to a second access technology, and the first request message includes a first evolved packet system bearer identity EBI of the first session.

It should be understood that the transceiving unit 1010 and the processing unit 1020 may also perform other operations performed by the second core network device, the MME or the ePDG in the

methods

400, 500 and 600, which are not described in detail herein.

methods

700, 800, and 900, and may perform the operations performed by the first core network device, the SMF/PGW-C, in the

methods

700, 800, and 900.

For example, the transceiving unit 1010 is configured to receive a first request message, where the first request message is used to request to create a first session of a terminal device through a first access technology, and the first request message includes a first evolved packet system bearer identity, EBI, of the first session. The transceiving unit 1010 may further be configured to: and when the first PDU session identifier is determined to be the repeated identifier of the terminal equipment, sending a creating message to the third core network equipment, wherein the creating message comprises a second PDU session identifier, the second PDU session identifier is different from the first PDU session identifier, and the first PDU session identifier is generated according to the first EBI and the first preset value.

methods

700, 800, and 900, and detailed description thereof is omitted here.

methods

700, 800, and 900 described above, and may perform the operations performed by the third core network device, the PCF, or the CHF in the

methods

700, 800, and 900.

For example, the transceiver unit 1010 is configured to receive a create message from a first core network device, where the create message includes a second PDU session identifier, the second PDU session identifier is different from a first PDU session identifier, the first PDU session identifier is generated according to a first EBI and a first preset value, and the first EBI is used to identify a first session of a terminal device. A processing unit 1020, configured to store a mapping relationship between the identifier of the terminal device and the second PDU session.

methods

700, 800, and 900, which are not described in detail herein.

methods

700, 800, and 900, and may perform the operations performed by the second core network device, the MME, or the ePDG in the

methods

700, 800, and 900.

For example, the transceiving unit 1010 is configured to send a first request message to the first core network device, where the first request message is used to request to create a first session of the terminal device through the first access technology, and the first request message includes a first evolved packet system bearer identity EBI of the first session.

methods

700, 800 and 900 described above, and are not described in detail here.

It should be understood that, in the apparatus 1000, the transceiver 1010 may include a receiving unit 1011 and a transmitting unit 1012, wherein the receiving unit 1011 is configured to perform a receiving function in the transceiver 1010, and the transmitting unit 1012 is configured to perform a transmitting function in the transceiver 1010.

Fig. 11 is a block diagram of a communication device according to an embodiment of the present application. The communication apparatus 1100 shown in fig. 11 includes: a processor 1110, a memory 1120, and a transceiver 1130. The processor 1110 is coupled to the memory 1120 and configured to execute instructions stored in the memory 1120 to control the transceiver 1130 to transmit and/or receive signals.

It is understood that the processor 1110 and the memory 1120 can be combined into a single processing device, and that the processor 1110 is configured to execute program code stored in the memory 1120 to implement the functions described above. In particular implementations, the memory 1120 may also be integrated into the processor 1110 or may be separate from the processor 1110. It is to be understood that the processor 1110 may also correspond to various processing units in a preceding communication device, and the transceiver 1130 may correspond to various receiving units and transmitting units in a preceding communication device.

It should also be understood that the transceiver 1130 can include a receiver (or term, receiver) and a transmitter (or term, transmitter). The transceiver may further include an antenna, and the number of antennas may be one or more. The transceiver may also be a communication interface or interface circuit.

Specifically, the communication apparatus 1100 may correspond to the first core network device in the method 400, the method 500, and the method 600, the third core network device in the method 400, the method 500, and the method 600, the second core network device in the method 400, the method 500, and the method 600, the first core network device in the method 700, the method 800, and the method 900, the third core network device in the method 700, the method 800, and the method 900, or the second core network device in the method 700, the method 800, and the method 900 according to the embodiment of the present application. The communication apparatus 1100 may include the units of the methods performed by the first core network device in the

methods

400, 500, 600, the units of the methods performed by the third core network device in the

methods

400, 500, 600, the units of the methods performed by the second core network device in the

methods

400, 500, 600, the units of the methods performed by the first core network device in the

methods

700, 800, 900, the units of the methods performed by the third core network device in the

methods

700, 800, 900, or the units of the methods performed by the second core network device in the

methods

700, 800, 900. It should be understood that the specific processes of the units for executing the corresponding steps are already described in detail in the above method embodiments, and therefore, for brevity, detailed descriptions thereof are omitted.

When the communication device 1100 is a chip, the chip includes a transceiving unit and a processing unit. The transceiving unit can be an input/output circuit or a communication interface; the processing unit may be a processor or a microprocessor or an integrated circuit integrated on the chip.

In implementation, the steps of the above method may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The steps of a method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in a processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor. To avoid repetition, it is not described in detail here.

It should be noted that the processor in the embodiments of the present application may be an integrated circuit chip having signal processing capability. In implementation, the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or by instructions in the form of software. The processor described above may be 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 device, discrete gate or transistor logic, discrete hardware components. The various methods, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software modules may be located in ram, flash, rom, prom, or eprom, registers, etc. as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

According to the method provided by the embodiment of the present application, the present application further provides a computer program product, which includes: computer program code which, when run on a computer, causes the computer to perform the method of any one of the embodiments shown in figures 4 to 9.

According to the method provided by the embodiment of the present application, a computer-readable medium is further provided, and the computer-readable medium stores program codes, and when the program codes are executed on a computer, the computer is caused to execute the method of any one of the embodiments shown in fig. 4 to 9.

According to the method provided by the embodiment of the present application, the present application further provides a system, which includes the first core network device, the second core network device, and/or the third core network device in any one of the embodiments shown in fig. 4 to 6, or includes the first core network device, the second core network device, and/or the third core network device in any one of the embodiments shown in fig. 7 to 9.

In the embodiments of the present application, the words "exemplary," "for example," and the like are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, the term using examples is intended to present concepts in a concrete fashion.

In the embodiments of the present application, "corresponding" and "corresponding" may be sometimes used in a mixed manner, and it should be noted that the intended meaning is consistent when the difference is not emphasized.

The network architecture and the service scenario described in the embodiment of the present application are for more clearly illustrating the technical solution of the embodiment of the present application, and do not form a limitation on the technical solution provided in the embodiment of the present application, and it can be known by a person skilled in the art that the technical solution provided in the embodiment of the present application is also applicable to similar technical problems along with the evolution of the network architecture and the appearance of a new service scenario.

Reference throughout this specification to "one embodiment" or "some embodiments," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," or the like, in various places throughout this specification are not necessarily all referring to the same embodiment, but rather mean "one or more but not all embodiments" unless specifically stated otherwise. The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless expressly specified otherwise.

In the present 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: including the presence of a alone, a and B together, and B alone, where a, B may be singular or plural.

It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

It should be understood that the first, second and various numerical references in the various embodiments of the present application are only for convenience of description and should not be used to limit the scope of the embodiments of the present application. E.g. to distinguish between bandwidths under different conditions, etc.

It should also be understood that the memory referred to in the embodiments of the present application may be volatile memory and/or non-volatile memory. The non-volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM). For example, RAM can be used as external cache memory. By way of example and not limitation, RAM may include the following forms: static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), synchronous Dynamic Random Access Memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous SDRAM (ESDRAM), synchronous Link DRAM (SLDRAM), and direct bus RAM (DR RAM).

It should also be noted that the memory described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

Those of ordinary skill in the art will appreciate that the various illustrative elements and steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and there may be other divisions when actually implementing, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not implemented. Furthermore, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to implement the scheme provided by the application.

In addition, functional units in the embodiments of the present application may be integrated into one unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

In the above embodiments, all or part of the implementation may be realized by software, hardware, firmware, or any combination thereof. When implemented in software, 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 instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. For example, the computer may be a personal computer, a server, or a network appliance, among others. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). 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, a data center, etc., that incorporates one or more of the available media. For example, the aforementioned usable medium may include, but is not limited to, various media capable of storing program code, such as a U disk, a removable disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of communication, the method being performed by a first core network device and comprising:

receiving a first request message from a second core network device, wherein the first request message is used for requesting a first session of a terminal device to be switched from a first access technology to a second access technology, and the first request message comprises a first evolved packet system bearer identity (EBI) of the first session;

and sending an update message to a policy control function network element and/or a charging function network element, wherein the update message comprises a first PDU session identifier, and the first PDU session identifier is generated according to the first EBI and a first preset value.

2. The method of claim 1, further comprising:

and generating the first PDU session identification according to the first EBI and the first preset value.

3. The method of claim 1 or 2, wherein the first access technology is a third generation partnership project 3GPP access technology and the second access technology is a non-third generation partnership project N3GPP access technology.

4. The method of claim 3, wherein the second core network device is an evolved packet data gateway (ePDG).

5. The method according to claim 3 or 4, wherein the first preset value is 80.

6. The method of claim 1 or 2, wherein the first access technology is an N3GPP access technology and the second access technology is a 3GPP access technology.

7. The method of claim 6, wherein the second core network device is a Mobility Management Entity (MME).

8. The method according to claim 6 or 7, wherein the first preset value is 64.

9. A method of communication, the method performed by a policy control function network element, comprising:

receiving an update message from a first core network device, wherein the update message comprises a first PDU session identifier, the first PDU session identifier is generated according to a first EBI, and the first EBI is used for identifying a first session of a terminal device;

and storing the mapping relation between the identifier of the terminal equipment and the first PDU session identifier.

10. A method of communication, wherein the method is performed by a charging function network element, and wherein the method comprises:

11. A method of communication, the method being performed by a first core network device and comprising:

receiving a first request message from a second core network device, where the first request message is used to request to create a first session of a terminal device through a first access technology, and the first request message includes a first evolved packet system bearer identity (EBI) of the first session;

and when determining that the first PDU session identifier is the repeated identifier of the terminal equipment, sending a creation message to a policy control function network element and/or a charging function network element, wherein the creation message comprises a second PDU session identifier, the second PDU session identifier is different from the first PDU session identifier, and the first PDU session identifier is generated according to the first EBI and a first preset value.

12. The method of claim 11, further comprising:

generating the first PDU session identifier according to the first EBI and the first preset value;

and generating the second PDU session identifier according to the first EBI and a second preset value, wherein the second preset value is different from the first preset value.

13. The method according to claim 11 or 12, wherein prior to receiving the first request message, the method further comprises:

receiving a second request message requesting creation of a second session over the first access technology, the second request message including a second EBI for the second session;

generating a third PDU session identifier according to the second EBI and the first preset value;

the determining that the first PDU session identifier is the duplicate identifier of the terminal device includes:

and determining that the third PDU session identification is the same as the first PDU session identification.

14. The method according to any of claims 11 to 13, wherein the first access technology is a 3GPP access technology.

15. The method of claim 14, wherein the second core network device is a Mobility Management Entity (MME).

16. The method of claim 14 or 15, wherein the first preset value is 64.

17. The method according to any of claims 11 to 13, wherein the first access technology is an N3GPP access technology.

18. The method of claim 17, wherein the second core network device is an evolved packet data gateway (ePDG).

19. The method according to claim 17 or 18, wherein the first preset value is 80.

20. A communications apparatus, comprising: means for performing each step of the method of any one of claims 1 to 8, or of claim 9 or 10, or of the method of any one of claims 11 to 19.

21. A communications apparatus, comprising:

a memory for storing computer instructions;

a processor for executing computer instructions stored in the memory to cause the apparatus to perform the method of any of claims 1 to 8, or the method of claim 9 or 10, or the method of any of claims 11 to 19.

22. A computer-readable storage medium, having stored thereon a computer program for performing the method of any of claims 1 to 8, or the method of claim 9 or 10, or the method of any of claims 11 to 19.

23. A chip system, comprising: a processor for executing a stored computer program for performing the method of any of claims 1 to 8, or the method of claim 9 or 10, or the method of any of claims 11 to 19.