WO2018107463A1

WO2018107463A1 - Communication method and device

Info

Publication number: WO2018107463A1
Application number: PCT/CN2016/110331
Authority: WO
Inventors: 李岩; 吴晓波; 辛阳; 杨娇
Original assignee: 华为技术有限公司
Priority date: 2016-12-16
Filing date: 2016-12-16
Publication date: 2018-06-21

Abstract

Provided in the embodiments of the present invention are a communication method and device, which can ensure session continuity as well as a simple interactive process after a UE is handed over from a first network to a second network, and can improve communication efficiency. The method comprises: a first control plane network element of a first network receiving a first handover request, and sending, according to the first handover request, a second handover request to a second control plane network element of a second network, the second handover request carrying the identifier of a UE, the second handover request being used for triggering to establish a packet data network (PDN) connection of the UE at the second network, the process of establishing the PDN connection comprising allocating an IP address of the UE at the second network, the IP address being used for triggering the UE to initiate a binding update process to the first control plane network element, the first control plane network element receiving a handover accept message sent by the second control plane network element, the handover accept message being used for indicating that the PDN connection has been established, the first control plane network element sending the handover accept message to the UE.

Description

Communication method and device

Technical field

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

Background technique

Interoperability between different systems is the key to ensuring business continuity. In the current situation, the debate surrounding the interoperability between 5G networks and 4G networks is confusing. Among them, one solution is: an EPC (Evolved Packet Core) network and an NG Core (Next Generation Core) network have an interworking interface, and the 4G network partially upgrades to support the 5G network, and then the 5G UE is in the The non-5G area can access the EPC to implement interoperability between the EPC and the NG Core.

Based on this scheme, if the interoperation between the 4G network and the 5G network refers to the tightly coupled switching mode between the 3G network and the 4G network, many complex processes, such as mapping of the bearer/tunnel model and mapping of QoS parameters, are lacking. Provincial bearer, conversion processing without default bearers, and so on.

Therefore, how to achieve simple interaction between 4G network and 5G network is a problem that needs to be solved.

Summary of the invention

The embodiment of the invention provides a communication method and device, which can ensure the continuity of the session while the UE is switched from the first network to the second network, and the interaction process is simple, and the communication efficiency can be effectively improved.

In one aspect, the embodiment of the present invention provides a communication method, where the method needs to: when the location of the UE changes, the UE needs to switch from the first network to the second network, and the first control plane network element of the first network receives the first And a second handover request is sent to the second control plane network element of the second network according to the first handover request, where the second handover request carries the identifier of the UE. The second handover request is used to trigger the establishment of the PDN connection of the UE in the second network. The process of establishing the PDN connection includes allocating an IP address of the UE in the second network, where the IP address is used to trigger the UE to the first control plane network element. Initiate a binding update process. After the PDN connection is established, the first control plane network element receives the handover accept message sent by the second control plane network element, where the handover accept message is used to indicate that the PDN connection is established, and the first control plane network element sends the handover accept message to the UE again. . In the embodiment of the present invention, the UE switches to the second network. Pre-establishing the connection of the UE in the second network, and allocating the address of the UE in the second network. After the UE switches to the second network, the UE is used to initiate a binding update to the first control plane network element of the first network to implement the session. Continuity ensures session continuity while the interaction process is simple and can effectively improve communication efficiency.

In a possible design, the handover accept message includes the IP address of the UE in the second network, and the UE can obtain the IP address allocated by the second network directly in the handover accept message, which simplifies the steps of the embodiment of the present invention.

In a possible design, the establishment process of the PDN connection includes establishing a dedicated bearer of the UE in the second network, the handover accept message further includes a service flow template of the proprietary bearer, and the service flow template supports the mobility management protocol. The establishment of a proprietary bearer can ensure the business continuity of QoS requirements and the interaction process is simple, and the communication efficiency can be effectively improved.

In a possible design, the service flow template uses the inner layer address of the UE message, or the service flow template uses the inner layer address and the outer layer address of the UE message. The modified service flow template can enable the UE to know which bearer to transmit the UE message.

In a possible design, the PDN connection establishment process includes establishing a dedicated bearer of the UE in the second network, and the handover accept message includes an invalid service flow template of the dedicated bearer, and the invalid service flow template is used to prevent the UE from transmitting the report through the dedicated bearer. Text. The invalid service flow template can avoid the problem caused by the UE transmitting the packet through the dedicated bearer if the handover accept message does not include the IP address of the UE in the second network.

In one possible design, the first network may be an IP-enabled network, including a 5G network, and the second network is a 4G network, a 3G network, or a 2G network. The embodiments of the present invention can simplify the interoperation process between different networks.

On the other hand, the embodiment of the present invention provides a communication method, where the method needs to switch from the first network to the second network, and the second control network of the second network, when the location of the user equipment UE changes. The element receives a second handover request from the first control plane network element of the first network, and the second handover request carries the identifier of the UE. The second control plane network element establishes a PDN connection of the UE in the packet data network of the second network according to the identifier of the UE. The process of establishing the PDN connection includes allocating an IP address of the UE in the second network, and the IP address is used to trigger the UE to the first control plane. The NE initiates a binding update process. After the PDN connection is established, the second control plane network element sends a handover accept message to the UE through the first control plane network element, and switches the accept message. Used to indicate that a PDN connection has been established. In the embodiment of the present invention, before the UE switches to the second network, the UE is connected to the second network, and the UE is allocated the address of the second network, and after the UE switches to the second network, the address is used to the first network. The first control plane network element initiates a binding update to implement session continuity, ensures the continuity of the session, and has a simple interaction process, which can effectively improve communication efficiency.

In a possible design, the handover accept message includes the IP address of the UE in the second network, and the UE can directly obtain the address allocated by the second network in the handover accept message, which can simplify the steps of the embodiment of the present invention.

In a possible design, the PDN connection establishment process includes establishing a dedicated bearer of the UE in the second network, the handover accept message further includes a service flow template of the dedicated bearer, and the service flow template supports the mobility management protocol. The establishment of a proprietary bearer can ensure the business continuity of QoS requirements and the interaction process is simple, and the communication efficiency can be effectively improved.

In a possible design, the PDN connection process includes establishing a dedicated bearer of the UE in the second network, and the handover accept message includes an invalid service flow template of the dedicated bearer, and the invalid service flow template is used to prevent the UE from transmitting the message through the dedicated bearer. . The invalid service flow template can avoid the problem caused by the UE transmitting the packet through the dedicated bearer if the handover accept message does not include the IP address of the UE in the second network.

In another aspect, the embodiment of the present invention provides a communication method, where the method needs to: when the location of the user equipment UE changes, the UE needs to switch from the first network to the second network, and the user equipment UE receives the second network. And a handover accept message sent by the second control plane network element by using the first control plane network element of the first network, where the handover accept message is used to indicate that the PDN connection of the UE in the second network has been established. The establishment process of the PDN connection includes allocating the IP address of the UE in the second network. In one case, if the handover accept message includes the IP address of the UE in the second network, after the UE switches to the second network, the binding update process is initiated to the first control plane network element according to the IP address. Or, in another case, if the handover accept message does not include the IP address of the UE in the second network, after the UE switches to the second network, the origin is initiated. The address allocation process obtains an IP address, and initiates a binding update process to the first control plane network element according to the IP address. In the embodiment of the present invention, before the UE switches to the second network, the UE is connected to the second network, and the UE is allocated the address of the second network, and after the UE switches to the second network, the address is used to the first network. The first control plane network element initiates a binding update to implement session continuity, ensures the continuity of the session, and has a simple interaction process, which can effectively improve communication efficiency.

In a possible design, the PDN connection establishment process includes establishing a dedicated bearer of the UE in the second network. If the handover accept message includes the IP address of the UE in the second network, the handover accept message further includes a service flow template of the dedicated bearer. The business flow template supports the mobility management protocol. The establishment of a proprietary bearer can ensure the business continuity of QoS requirements and the interaction process is simple, and the communication efficiency can be effectively improved.

In a possible design, the PDN connection establishment process includes establishing a dedicated bearer of the UE in the second network. If the handover accept message does not include the IP address of the UE in the second network, the handover accept message includes a private bearer invalid service flow template. The invalid service flow template is used to prevent the UE from transmitting the message through the dedicated bearer. The invalid service flow template can avoid the problem caused by the UE transmitting the packet through the dedicated bearer if the handover accept message does not include the IP address of the UE in the second network.

In a possible design, after the UE obtains the IP address by initiating the address allocation process, before the UE initiates the binding update process to the first control plane network element by using the IP address, the UE further includes: the UE accepts the update process of the service flow template, and the update process uses The service flow template is updated to use the service flow template of the inner layer address of the UE message or the service flow template of the inner layer address and the outer address of the UE message. The modified service flow template can enable the UE to know which bearer to transmit the UE message.

On the other hand, the embodiment of the present invention provides a first control plane network element, where the first control plane network element has a function of implementing the behavior of the first control plane network element in the foregoing method example. The functions may be implemented by hardware or by corresponding software implemented by hardware. The hardware or software includes one or more modules corresponding to the functions described above. The first control plane network element includes a processor and a transceiver, and further, The first control plane network element can also include a memory for coupling with the processor that retains program instructions and data necessary for the first control plane network element. The transceiver is configured to receive a first handover request, where the first handover request is used to indicate that the user equipment UE needs to be handed over from the first network to the second network, and the transceiver is further configured to use the first handover request to the second control plane network of the second network. The second handover request is sent by the UE, and the second handover request is used to trigger the establishment of the PDN connection of the UE in the packet data network of the second network. The process of establishing the PDN connection includes allocating the IP of the UE in the second network. The address and the IP address are used to trigger the UE to initiate a binding update process to the first control plane network element, and the transceiver is further configured to receive a handover accept message sent by the second control plane network element, where the handover accept message is used to indicate that the PDN connection is established. The transceiver is further configured to send a handover accept message to the UE. In the embodiment of the present invention, before the UE switches to the second network, the UE is connected to the second network, and the UE is allocated the address of the second network, and after the UE switches to the second network, the address is used to the first network. The first control plane network element initiates a binding update to implement session continuity, ensures the continuity of the session, and has a simple interaction process, which can effectively improve communication efficiency.

In a possible design, the establishment process of the PDN connection includes establishing a dedicated bearer of the UE in the second network, the handover accept message further includes a service flow template of the dedicated bearer, and the service flow template supports the mobility management protocol. The establishment of a proprietary bearer can ensure the business continuity of QoS requirements and the interaction process is simple, and the communication efficiency can be effectively improved.

In a possible design, the PDN connection establishment process includes establishing a dedicated bearer of the UE in the second network, and the handover accept message includes an invalid service flow template of the dedicated bearer, and the invalid service flow template is used to prevent the UE from transmitting through the dedicated bearer. Message. The invalid service flow template can avoid the problem caused by the UE transmitting the packet through the dedicated bearer if the handover accept message does not include the IP address of the UE in the second network.

On the other hand, the embodiment of the present invention provides a second control plane network element, where the second control plane network element has a function of implementing the behavior of the second control plane network element in the foregoing method example. The functions may be implemented by hardware or by corresponding software implemented by hardware. The hardware or software includes one or more modules corresponding to the functions described above. The second control plane network element includes a processor and a transceiver. Further, the second control plane network element may further include a memory, where the memory is configured to be coupled to the processor, where the necessary program instructions of the second control plane network element are saved. And data. The transceiver is configured to receive a second handover request from the first control plane network element of the first network, where the second handover request carries the identifier of the user equipment UE, and the processor is configured to establish, according to the identifier of the UE, the PDN connection of the packet data network of the UE in the second network. The process of establishing a PDN connection includes allocating an IP address of the UE in the second network, where the IP address is used to trigger a binding update process initiated by the UE to the first control plane network element, and the transceiver is further configured to use the first control plane network element to The UE sends a handover accept message, and the handover accept message is used to indicate that the PDN connection has been established. In the embodiment of the present invention, before the UE switches to the second network, the UE is connected to the second network, and the UE is allocated the address of the second network, and after the UE switches to the second network, the address is used to the first network. The first control plane network element initiates a binding update to implement session continuity, ensures the continuity of the session, and has a simple interaction process, which can effectively improve communication efficiency.

On the other hand, an embodiment of the present invention provides a user equipment UE, which has a function of implementing UE behavior in the foregoing method example. The functions may be implemented by hardware or by corresponding software implemented by hardware. The hardware or software includes one or more modules corresponding to the functions described above. The UE includes a processor and a transceiver. Further, the UE may further include a memory for coupling with the processor, which stores program instructions and data necessary for the second control plane network element. The transceiver is configured to receive a handover accept message sent by the second control plane network element of the second network by using the first control plane network element of the first network, where the handover accept message is used to indicate that the PDN connection of the UE in the second network is established, and the PDN connection is established. The establishing process includes allocating an IP address of the UE in the second network. In one case, if the handover accept message includes the IP address of the UE in the second network, after the UE switches to the second network, the processor is configured to use the IP address according to the IP address. A control plane network element initiates a binding update process, or in another case, if the handover accept message does not include the IP address of the UE in the second network, and the UE switches to the second network, the processor is configured to initiate the address allocation process. Obtain an IP address and initiate a binding update process to the first control plane network element according to the IP address. In the embodiment of the present invention, before the UE switches to the second network, the UE is connected to the second network, and the UE is allocated the address of the second network, and after the UE switches to the second network, the address is used to the first network. The first control plane network element initiates a binding update to implement session continuity, ensures the continuity of the session, and has a simple interaction process, which can effectively improve communication efficiency.

In a possible design, the PDN connection establishment process includes establishing a dedicated bearer of the UE in the second network. If the handover accept message does not include the IP address of the UE in the second network, the handover accept message includes a private bearer invalid service flow template. The invalid service flow template is used to prevent the UE from transmitting through the dedicated bearer. Message. The invalid service flow template can avoid the problem caused by the UE transmitting the packet through the dedicated bearer if the handover accept message does not include the IP address of the UE in the second network.

In a possible design, the processor is further configured to accept an update process of the service flow template, where the update process is used to update the invalid service flow template to a service flow template that uses an inner address of the UE message or use the UE message. The service flow template for the layer address and the outer address. The modified service flow template can enable the UE to know which bearer to transmit the UE message.

On the other hand, an embodiment of the present invention provides a first control plane network element, where the first control plane network element includes a communication unit and a processing unit. The communication unit is configured to receive a first handover request, where the first handover request is used to indicate that the user equipment UE needs to be handed over from the first network to the second network, and the communication unit is further configured to use the first handover request to the second control plane of the second network. The network element sends a second handover request, where the second handover request carries the identifier of the UE, and the second handover request is used to trigger establishment of the PDN connection of the UE in the packet data network of the second network. The process of establishing the PDN connection includes allocating the UE in the second network. The IP address, the IP address is used to trigger the UE to initiate a binding update process to the first control plane network element, and the communication unit is further configured to receive a handover accept message sent by the second control plane network element, where the handover accept message is used to indicate that the PDN connection is established. The communication unit is further configured to send a handover accept message to the UE. In the embodiment of the present invention, before the UE switches to the second network, the UE is connected to the second network, and the UE is allocated the address of the second network, and after the UE switches to the second network, the address is used to the first network. The first control plane network element initiates a binding update to implement session continuity, ensures the continuity of the session, and has a simple interaction process, which can effectively improve communication efficiency.

In a possible design, the service flow template uses the inner address of the UE message, or the service flow. The template uses the inner and outer addresses of the UE message. The modified service flow template can enable the UE to know which bearer to transmit the UE message.

In a possible design, the first network may be an IP-enabled network, including a 5G network, and the second network is a 4G network, a 3G network, or a 2G network. The embodiments of the present invention can simplify the interoperation process between different networks.

On the other hand, an embodiment of the present invention provides a second control plane network element, where the second control plane network element includes a communication unit and a processing unit. The communication unit is configured to receive a second handover request from the first control plane network element of the first network, where the second handover request carries the identifier of the user equipment UE, and the processing unit is configured to establish, according to the identifier of the UE, the packet data network of the UE in the second network. The PDN connection, the PDN connection establishment process includes allocating the IP address of the UE in the second network, and the IP address is used to trigger the UE to initiate a binding update process to the first control plane network element, and the communication unit is further configured to use the first control plane network element. A handover accept message is sent to the UE, and the handover accept message is used to indicate that the PDN connection has been established. In the embodiment of the present invention, before the UE switches to the second network, the UE is connected to the second network, and the UE is allocated the address of the second network, and after the UE switches to the second network, the address is used to the first network. The first control plane network element initiates a binding update to implement session continuity, ensures the continuity of the session, and has a simple interaction process, which can effectively improve communication efficiency.

On the other hand, an embodiment of the present invention provides a user equipment UE, where the UE includes a communication unit and a processing unit. The communication unit is configured to receive a handover accept message sent by the second control plane network element of the second network by using the first control plane network element of the first network, where the handover accept message is used to indicate that the PDN connection of the UE in the second network is established, and the PDN is The establishment process of the connection includes allocating the IP address of the UE in the second network. In one case, if the handover accept message includes the IP address of the UE in the second network, and the UE switches to the second network, the processing unit is configured to initiate a binding update procedure to the first control plane network element according to the IP address. Or, in another case, if the handover accept message does not include the IP address of the UE in the second network, after the UE switches to the second network, the communication unit is configured to obtain an IP address by initiating an address allocation process, and according to the IP address, The first control plane network element initiates a binding update process. In the embodiment of the present invention, before the UE switches to the second network, the UE is connected to the second network, and the UE is allocated the address of the second network, and after the UE switches to the second network, the address is used to the first network. The first control plane network element initiates a binding update to implement session continuity, ensures the continuity of the session, and has a simple interaction process, which can effectively improve communication efficiency.

In a possible design, the PDN connection establishment process includes establishing a dedicated bearer of the UE in the second network. If the handover accept message does not include the IP address of the UE in the second network, the handover accept message includes a private bearer invalid service flow template. . The invalid service flow template is used to prevent the UE from transmitting the packet through the dedicated bearer. The invalid service flow template can prevent the UE from transmitting the packet through the dedicated bearer if the handover accept message does not include the IP address of the UE in the second network. The problem.

In a possible design, the processing unit is further configured to receive an update process of the service flow template, where the update process is used to update the invalid service flow template to a service flow template that uses an inner address of the UE message or use the UE message. The business flow template for the inner and outer addresses. The modified service flow template can enable the UE to know which bearer to transmit the UE message.

In another aspect, an embodiment of the present invention provides a communication system, where the system includes the first control plane network element, the second control plane network element, and the user equipment.

In still another aspect, an embodiment of the present invention provides a computer storage medium for storing the computer software instructions for the first control plane network element, including a program designed to perform the above aspects.

In still another aspect, an embodiment of the present invention provides a computer storage medium for storing the computer software instructions for the second control plane network element, including a program designed to perform the above aspects.

In still another aspect, an embodiment of the present invention provides a computer storage medium for storing the above computer software instructions for use in a user equipment, including a program designed to perform the above aspects.

Compared with the prior art, in the embodiment of the present invention, before the UE switches to the second network, the UE is connected to the second network, and the UE is allocated the address of the second network, and the UE uses the second network. The address initiates a binding update to the first control plane network element of the first network to implement session continuity, ensures the continuity of the session, and has a simple interaction process, which can effectively improve communication efficiency.

DRAWINGS

FIG. 1 is a schematic diagram of a possible network architecture according to an embodiment of the present invention;

2 is a schematic diagram of communication of a communication method according to an embodiment of the present invention;

3 is a schematic diagram of communication of another communication method according to an embodiment of the present invention;

4 is a schematic diagram of communication of another communication method according to an embodiment of the present invention;

FIG. 5A is a schematic block diagram of a first control plane network element according to an embodiment of the present disclosure;

FIG. 5B is a schematic structural diagram of a first control plane network element according to an embodiment of the present disclosure;

6A is a schematic block diagram of a second control plane network element according to an embodiment of the present invention;

FIG. 6B is a schematic structural diagram of a second control plane network element according to an embodiment of the present disclosure;

FIG. 7A is a schematic block diagram of a user equipment according to an embodiment of the present invention;

FIG. 7B is a schematic structural diagram of a user equipment according to an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in the following with reference to the accompanying drawings.

The terms "first", "second", "third", "fourth", etc. (if present) in the specification and claims of the present invention and the above figures are used to distinguish similar objects without having to use To describe a specific order or order. It is to be understood that the data so used may be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than what is illustrated or described herein. In addition, the terms "comprises" and "comprises" and "the" and "the" are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or device that comprises a series of steps or units is not necessarily limited to Those steps or units may include other steps or units not explicitly listed or inherent to such processes, methods, products or devices.

Mobility management refers to the management issues involved in mobile device mobility in mobile networks. It is a key technology for mobile networks to support user mobility. It is an important aspect of networks that support user equipment mobility different from fixed networks. In the mobility management technology, the Home of Address (HoA) is an IP network address assigned by the home network to the mobile user equipment. When the user equipment moves and the network access point changes, the IP address does not change. After the mobile user equipment leaves the home network, the home agent (HA, Home Agent) forwards the IP packet with the destination address HoA to the mobile node through the tunnel. The destination IP address of the tunnel is called the care-of address (CoA, Care of Address). .

Take the user equipment (UE, User Equipment) to switch from 5G network to 4G network as an example. Figure 1 A possible network architecture is provided in the embodiment of the present invention. The network elements of the 5G network include a CP function, a UP Function, a NextGen Ran, and a policy. The function of the (Police Function) entity, the network element of the 4G network, including the Mobility Management Entity (MME), the eNode B (Evolved Node-B), the gateway (GW, Gateway), and the charging rule function (PCRF) (Policy and Charging Rules Function), wherein the gateway includes a PDN gateway (PGW, PDN GateWay) and a Serving Gate (SGW), and an Application Function (AF) entity can provide an application service for the 4G network or the 5G network. According to the present application, before the UE switches from the 5G network to the 4G network, the PDN connection is established for the UE and the IP address is allocated by the 4G network. After the UE switches to the 4G, the UE is used as the CoA to initiate mobility management to the 5G control plane network element. Binding updates to the protocol to achieve session continuity.

It should be noted that the embodiments of the present invention shown in FIG. 2 to FIG. 4 all take the first network as a 5G network, and the second network as a 4G network as an example, and the UE needs to switch from the first network to the second network. The description does not constitute a limitation on the embodiments of the present invention. The first control plane network element is a control plane function, the first user plane network element is a user plane function, the first access network element is a next generation radio access network, and the second network is in the first network. The second control plane network element is a mobility management entity, the second user plane network element is a gateway, and the second access network element is an evolved node.

Referring to FIG. 2, an embodiment of a communication method in an embodiment of the present invention includes:

201. The UE initiates a mobility management protocol registration process on the first network.

It should be noted that the mobility management protocol registration process may include the delivery of a security key.

Specifically, the mobility management protocol may be a Dual-Stack Mobile Internet Protocol (DSMIP), a Client Moblie Internet Protocol (CMIP), or a Proxy Mobile Internet Protocol (PMIP). ), there is no limit here.

Step 201 is an optional step, and can be performed at any time in the first network before the UE switches to the second network, which can save signaling interaction of the handover process.

202. The first control plane network element receives the first handover request.

In this embodiment, the UE needs to switch from the first network to the second network, and the first control plane network element receives the first handover request sent by the first access network element, and the first handover request is sent. It is used to indicate that the UE needs to switch from the first network to the second network.

203. The first control plane network element sends a second handover request to the second control plane network element.

Correspondingly, the second control plane network element receives the second handover request sent by the first control plane network element. The second handover request carries the identifier of the UE. For example, the identifier of the UE includes an International Mobile Subscriber Identification Number (IMSI) or a Mobile Subscriber ISDN Number (MSISDN), and is not limited thereto. The UE identifiers mentioned in the following are the same description and will not be described again.

204. The second control plane network element establishes a PDN connection for the UE.

The second control plane network element establishes a packet data network (PDN, Packet Data Network) connection of the UE in the second network for the UE according to the identifier of the UE. As the PDN connection is established, the default bearer of the UE is also established. In the process of establishing the default bearer, the second user plane network element will allocate the IP address of the UE in the second network to the UE. The address can be used as the forwarding address CoA. The CoA mentioned below is the IP address of the UE in the second network, and is not described here.

205. The second control plane network element sends a handover accept message to the first control plane network element.

Correspondingly, the first control plane network element receives the handover accept message sent by the second control plane network element. The handover accept message is used to indicate that the PDN connection of the UE in the second network has been established. For example, the handover accept message may be an Attach Accept message.

Optionally, before the second control plane network element sends the handover accept message to the first control plane network element, the second control plane network element further sends a handover request to the second access network element, where the handover request is used to notify the The second access network element UE is to be accessed, and after receiving the handover request, the second access network element returns a response of the handover request to the second control plane network element.

Optionally, the handover accept message may include the IP address of the UE in the second network, or may not include the IP address of the UE in the second network.

206. The first control plane network element sends a handover accept message to the UE.

The first control plane network element forwards the handover accept message sent by the second control plane network element to the UE. Correspondingly, the UE receives the handover accept message sent by the first control plane network element.

207. The UE performs handover.

Specifically, the UE switches from the first network to the second network.

208. The UE initiates a binding update process to the first control plane network element.

If the handover accept message includes the IP address of the UE in the second network, the UE initiates a binding update process to the first control plane network element according to the IP address. The binding update process is performed, after the first network receives the service packet of the UE, and sends the service packet to the second user plane network element of the second network. Otherwise, the first network still sends the service message of the UE to the first access network element of the first network.

If the handover accept message does not include the IP address of the UE in the second network, the UE obtains the IP address of the UE in the second network by initiating the address allocation process, and then sends the IP address to the first control plane according to the IP address. The meta initiates the binding update process.

It should be noted that the IP address obtained by the UE by initiating the address allocation process is the same as the IP address allocated by the second user plane network element to the UE in step 204.

Optionally, in actual implementation, the second network may also be a 2G network or a 3G network, and the first network may also be other networks that support IP in the future. It can be understood that when implementing the implementation of the present invention in other networks, The control plane network element, the user plane network element and the access network element are also the control plane network element, the user plane network element and the access network element in the corresponding network. The same descriptions are used for the first network and the second network, and will not be described again.

It can be seen that, in this embodiment, before the UE switches to the second network, establishing a connection of the UE in the second network, and allocating an address of the UE in the second network, and after the UE switches to the second network, using the address to the first network The first control plane network element initiates a binding update to implement session continuity, ensures the continuity of the session, and has a simple interaction process, which can effectively improve communication efficiency.

In some other implementations, the establishment of a PDN connection may include establishing a proprietary bearer. For example, the UE performs the IP Multimedia Subsystem (IMS) service with higher Quality of Service (QoS) requirements. In the embodiment shown in FIG. 3, a dedicated bearer is established and the handover accept message includes the IP address of the UE in the second network. In the embodiment shown in FIG. 4, the private bearer is established but the IP address of the UE in the second network is not included in the handover accept message. The details will be described below with reference to FIGS. 3 and 4.

Referring to FIG. 3, an embodiment of a communication method in an embodiment of the present invention includes:

301. The UE initiates a mobility management protocol registration process on the first network.

302. The first control plane network element receives the first handover request.

303. The first control plane network element sends a second handover request to the second control plane network element.

304. The second control plane network element establishes a PDN connection for the UE.

Steps 301 to 304 are similar to steps 201 to 204 of FIG. 2 and will not be described again.

305. The second control plane network element sends a handover notification message to the AF.

The second control plane network element sends a handover notification message to the application function entity by using the first control plane network element and the policy function entity.

306. The AF trigger establishes a dedicated bearer.

After receiving the handover notification message, the AF addresses the IPC's Policy and Charging Rules Function (PCRF) according to the type of the IP-Connectivity Access Network (IPCAN) and the identity of the UE. And trigger the establishment of a proprietary bearer.

307. The second control plane network element sends a handover accept message to the first control plane network element.

Correspondingly, the first control plane network element receives the handover accept message sent by the second control plane network element. The handover accept message is used to indicate that the PDN connection of the UE in the second network has been established. In this embodiment, the PDN connection establishes a default bearer and a dedicated bearer. The handover accept message may include an attach accept message, a PDN Connection Acceptance (PDN Conn Accept) message or a SM Request for Dedicate Bearer message. For example, the PDN connection establishment accept message includes the IP address of the UE in the second network; the session request message of the dedicated bearer includes a service flow template, and the service flow template supports the mobility management protocol.

It should be noted that the inner source address of the UE message is HoA, and the inner layer destination address is the address of the server (in this embodiment, the server refers to the AF of the 5G network), and the source address of the outer layer is CoA, and the outer destination address is Is the address of HA. In this embodiment, the HA is the first user plane network element. The outer layer encapsulation of all service flows is the same for the UE. If there are multiple bearers, the outer encapsulation cannot indicate which bearer to go from. Therefore, the service flow template needs to be modified, and the modified service flow template can be modified. The inner address of the UE message is used, or the inner address and outer address of the UE message are used. Therefore, the UE can know which bearer to transmit the UE message according to the modified service flow template.

It should be noted that, before the second control plane network element sends the handover accept message to the first control plane network element, the second control plane network element further sends a handover request to the second access network element. The handover request is used to notify the second access network element that the UE is to be accessed. After receiving the handover request, the second access network element returns a response of the handover request to the second control plane network element.

308. The first control plane network element sends a handover accept message to the UE.

Step 308 is similar to step 206 of FIG. 2 and will not be described again.

309. The UE performs handover.

Step 309 is similar to step 207 of FIG. 2 and will not be described again.

310. The UE initiates a binding update process to the first control plane network element.

The UE initiates a binding update procedure to the first control plane network element according to the IP address, because the IP address of the UE in the second network is included in the handover accept message. The binding update process is performed, after the first network receives the service packet of the UE, and sends the service packet of the UE to the second user plane network element of the second network. Otherwise, the packet of the first network is still sent to the first network. The first access network element of the network.

In this embodiment, before the UE switches to the second network, establish a connection of the UE in the second network, allocate the address of the UE in the second network, and establish a dedicated bearer of the UE in the second network, and the UE switches to the second. After the network is used, the interface is used to initiate binding update to the first control plane network element of the first network to implement session continuity, and the QoS requirement is higher, and the interaction process is simple, and the communication efficiency can be effectively improved.

Referring to FIG. 4, an embodiment of a communication method in an embodiment of the present invention includes:

401. The UE initiates a mobility management protocol registration process on the first network.

402. The first control plane network element receives the first handover request.

403. The first control plane network element sends a second handover request to the second control plane network element.

404. The second control plane network element establishes a PDN connection for the UE.

405. The second control plane network element sends a handover notification message to the AF.

406. The AF trigger establishes a dedicated bearer.

Steps 401 to 406 are similar to steps 301 to 306 of FIG. 3 and will not be described again.

407. The second control plane network element sends a handover accept message to the first control plane network element.

Correspondingly, the first control plane network element receives the handover accept message sent by the second control plane network element. The handover accept message is used to indicate that the PDN connection of the UE in the second network has been established. In this embodiment, the PDN connection establishes a default bearer and a dedicated bearer. The handover accept message may include an attach accept message, a PDN Connection Acceptance (PDN Conn Accept) message or a SM Request for Dedicate Bearer message. For example, the PDN connection establishment accept message does not include the IP address of the UE in the second network; the session request message of the dedicated bearer includes an invalid service flow template, and is used to prevent the UE from transmitting the packet through the dedicated bearer.

Optionally, before the second control plane network element sends the handover accept message to the first control plane network element, The second control plane network element further sends a handover request to the second access network element, where the handover request is used to notify the second access network element that the UE is to be accessed, and after the second access network element receives the handover request, to the second The control plane network element returns the response of the handover request.

408. The first control plane network element sends a handover accept message to the UE.

409. The UE performs handover.

Steps 408 and 409 are similar to steps 308 and 309 of FIG. 3 and will not be described again.

410. The UE initiates an address allocation process.

It should be noted that, after the UE is switched from the first network to the second network, the IP address obtained by initiating the address allocation process is the same as the IP address allocated by the second user plane network element to the UE in step 404.

411. The UE accepts a service flow template update process of the dedicated bearer.

The inner source address of the UE packet is the HoA, and the inner destination address is the address of the server. In this embodiment, the server refers to the AF of the 5G network. The source address of the outer layer is CoA, and the outer destination address is the address of the HA. In this embodiment, the HA is the first user plane network element. For the UE, the outer encapsulation of all the service flows is the same. If there are multiple bearers, the outer encapsulation cannot indicate which bearer to go from. Therefore, the service flow template needs to be modified, and the modified service flow template can be used. The inner address of the UE packet, or the inner address and outer address of the UE message. Therefore, the UE can know which bearer to transmit the UE message according to the modified service flow template.

412. The UE initiates a binding update process to the first control plane network element.

The UE has obtained the IP address of the UE in the second network through the address allocation process, and the UE initiates a binding update process to the first control plane network element according to the IP address. The binding update process is performed, after the first network receives the service packet of the UE, and sends the service packet of the UE to the user plane network element of the second network. Otherwise, the first network sends the service packet of the UE to the first network. The first access network element of a network.

It can be seen that, in this embodiment, before the UE switches to the second network, the UE is connected to the second network, and the UE is configured to be a dedicated bearer of the second network. After the UE switches to the second network, the UE obtains the address through the address allocation process. The IP address of the second network is used by the UE to initiate binding update to the first control plane network element of the first network to implement session continuity, and the QoS requirement is higher. The interaction process is simple and effective. Improve communication efficiency.

The foregoing describes the solution of the embodiment of the present invention mainly from the perspective of interaction between the network elements. It can be understood that each network element, for example, the first control plane network element, the second control plane network element, and the user equipment In order to achieve the above functions, it includes corresponding hardware structures and/or software modules for performing various functions. Those skilled in the art will readily appreciate that the present invention can be implemented in a combination of hardware or hardware and computer software in combination with the elements and algorithm steps of the various examples described in the embodiments disclosed herein. Whether a function is implemented in hardware or computer software to drive hardware depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

The embodiments of the present invention may perform functional unit division on the first control plane network element, the second control plane network element, and the user equipment according to the foregoing method. For example, each functional unit may be divided according to each function, or two or More than two functions are integrated in one processing unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit. It should be noted that the division of the unit in the embodiment of the present invention is schematic, and is only a logical function division, and the actual implementation may have another division manner.

In the case of using an integrated unit, FIG. 5A shows a possible structural diagram of the first control plane network element involved in the above embodiment. The first control plane network element 500 includes a processing unit 502 and a communication unit 503. The processing unit 502 is configured to perform control on the operation of the first control plane network element. For example, the processing unit 502 is configured to support the first control plane network element to perform steps 201-203 and 205-207 in FIG. 2, where Steps 301-303, 305, and 307-309, steps 401-403, 405, and 407-409 in FIG. 4 and/or other processes for the techniques described herein. The communication unit 503 is configured to support communication between the first control plane network element and other network entities, such as the NextGan Ran, MME, UP Function, UE, etc. shown in FIG. 2, FIG. 3 or FIG. The first control plane network element may further include a storage unit 501 for storing program codes and data of the first control plane network element.

The processing unit 502 can be a processor or a controller, and can be, for example, a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), and an application-specific integrated circuit (Application-Specific). Integrated Circuit (ASIC), Field Programmable Gate Array (FPGA) or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It is possible to implement or carry out the various illustrative logical blocks, modules and circuits described in connection with the present disclosure. The processor may also be a combination of computing functions, for example comprising one or more microprocessor combinations, DSP and micro Combination of processors and more. The communication unit 503 can be a communication interface, a transceiver, a transceiver circuit, etc., wherein the communication interface is a collective name and can include one or more interfaces. The storage unit 501 can be a memory.

When the processing unit 502 is a processor, the communication unit 503 is a transceiver, and the storage unit 501 is a memory, the first control plane network element involved in the embodiment of the present invention may be the first control plane network element shown in FIG. 5B.

Referring to FIG. 5B, the first control plane network element 510 includes a processor 512, a transceiver 513, and a memory 511. Optionally, the first control plane network element 510 may further include a bus 514. The transceiver 513, the processor 512, and the memory 511 may be connected to each other through a bus 514. The bus 514 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (abbreviated). EISA) bus and so on. The bus 514 can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is shown in Figure 5B, but it does not mean that there is only one bus or one type of bus.

The first control plane network element shown in FIG. 5A or FIG. 5B above may be a CP Function.

In the case of using an integrated unit, FIG. 6A shows a possible structural diagram of the second control plane network element involved in the above embodiment. The second control plane network element 600 includes a processing unit 602 and a communication unit 603. The processing unit 602 is configured to control and control the action of the second control plane network element. For example, the processing unit 602 is configured to support the second control plane network element to perform steps 203-205 and 207-208 in FIG. 2, where Steps 303-307 and 309-310, steps 403-407 and 409-412 in FIG. 4, and/or other processes for the techniques described herein. The communication unit 603 is configured to support communication between the second control plane network element and other network entities, such as communication with the eNode B, CP Function, GW, UE, etc. shown in FIG. 2, FIG. 3 or FIG. The second control plane network element may further include a storage unit 601 for storing program codes and data of the second control plane network element.

The processing unit 602 can be a processor or a controller, and can be, for example, a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), and an application-specific integrated circuit (Application-Specific). Integrated Circuit (ASIC), Field Programmable Gate Array (FPGA) or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It is possible to implement or carry out the various illustrative logical blocks, modules and circuits described in connection with the present disclosure. The processor It can also be a combination of computing functions, such as one or more microprocessor combinations, a combination of a DSP and a microprocessor, and the like. The communication unit 603 can be a communication interface, a transceiver, a transceiver circuit, etc., wherein the communication interface is a collective name and can include one or more interfaces. The storage unit 601 can be a memory.

When the processing unit 602 is a processor, the communication unit 603 is a transceiver, and the storage unit 601 is a memory, the second control plane network element involved in the embodiment of the present invention may be the second control plane network element shown in FIG. 6B.

Referring to FIG. 6B, the second control plane network element 610 includes a processor 612, a transceiver 613, and a memory 611. Optionally, the second control plane network element 610 may further include a bus 614. The transceiver 613, the processor 612, and the memory 611 may be connected to each other through a bus 614. The bus 614 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (abbreviated). EISA) bus and so on. The bus 614 can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is shown in Figure 6B, but it does not mean that there is only one bus or one type of bus.

The second control plane network element shown in FIG. 6A or FIG. 6B above may be an MME.

In the case of employing an integrated unit, FIG. 7A shows a possible structural diagram of the user equipment involved in the above embodiment. User equipment 700 includes a processing unit 702 and a communication unit 703. The processing unit 702 is configured to perform control management on the action of the user equipment. For example, the processing unit 702 is configured to support the user equipment to perform steps 201 and 206-208 in FIG. 2, steps 301 and 308-310 in FIG. 3, in FIG. Steps 401 and 408-412, and/or other processes for the techniques described herein. The communication unit 703 is configured to support communication between the user equipment and other network entities, such as communication with the eNode B, NextGen Ran, CP Function, MME, etc. shown in FIG. 2, FIG. 3 or FIG. The user equipment may further include a storage unit 701 for storing program codes and data of the user equipment.

The processing unit 702 can be a processor or a controller, and can be, for example, a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), and an application-specific integrated circuit (Application-Specific). Integrated Circuit (ASIC), Field Programmable Gate Array (FPGA) or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It can implement or execute a knot Various exemplary logical blocks, modules and circuits are described in conjunction with the present disclosure. The processor may also be a combination of computing functions, for example, including one or more microprocessor combinations, a combination of a DSP and a microprocessor, and the like. The communication unit 703 can be a communication interface, a transceiver, a transceiver circuit, etc., wherein the communication interface is a collective name and can include one or more interfaces. The storage unit 701 can be a memory.

When the processing unit 702 is a processor, the communication unit 703 is a transceiver, and the storage unit 701 is a memory, the user equipment involved in the embodiment of the present invention may be the user equipment shown in FIG. 7B.

Referring to FIG. 7B, the user equipment 710 includes a processor 712, a transceiver 713, and a memory 711. Optionally, the user equipment 710 may further include a bus 714. The transceiver 713, the processor 712, and the memory 711 may be connected to each other through a bus 714. The bus 714 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (abbreviated). EISA) bus and so on. The bus 714 can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is shown in Figure 7B, but it does not mean that there is only one bus or one type of bus.

The user equipment shown in FIG. 7A or 7B above may be a mobile phone.

The steps of the method or algorithm described in connection with the disclosure of the embodiments of the present invention may be implemented in a hardware manner, or may be implemented by a processor executing software instructions. The software instructions may be composed of corresponding software modules, which may be stored in a random access memory (RAM), a flash memory, a read only memory (ROM), an erasable programmable read only memory ( Erasable Programmable ROM (EPROM), electrically erasable programmable read only memory (EEPROM), registers, hard disk, removable hard disk, compact disk read only (CD-ROM) or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor to enable the processor to read information from, and write information to, the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC may be located in the first control plane network element, the second control plane network element, or the user equipment. Of course, the processor and the storage medium may also exist as discrete components in the first control plane network element, the second control plane network element, or the user equipment.

Those skilled in the art should appreciate that in one or more of the above examples, the functions described in the embodiments of the present invention may be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, these functions may be stored in a computer readable medium or as a computer readable medium. One or more instructions or code on the transfer. Computer readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one location to another. A storage medium may be any available media that can be accessed by a general purpose or special purpose computer.

The specific embodiments of the present invention have been described in detail with reference to the embodiments of the embodiments of the present invention. The scope of the present invention is defined by the scope of the present invention. Any modifications, equivalents, improvements, etc., which are included in the embodiments of the present invention, are included in the scope of the present invention.

Claims

A communication method, comprising:

The first control plane network element of the first network receives a first handover request, where the first handover request is used to indicate that the user equipment UE needs to switch from the first network to the second network;

The first control plane network element sends a second handover request to the second control plane network element of the second network according to the first handover request, where the second handover request carries the identifier of the UE, where the And the second handover request is used to trigger establishment of the PDN connection of the UE in the second network, where the establishment of the PDN connection includes allocating an IP address of the UE in the second network, where the IP address is used by The triggering the UE to initiate a binding update process to the first control plane network element;

Receiving, by the first control plane network element, a handover accept message sent by the second control plane network element, where the handover accept message is used to indicate that the PDN connection is established;

The first control plane network element sends the handover accept message to the UE.
The communication method according to claim 1, wherein said handover accept message includes an IP address of said UE in said second network.
The communication method according to claim 2, wherein the establishing process of the PDN connection comprises establishing a dedicated bearer of the UE in the second network, and the handover accept message further includes the dedicated bearer A service flow template that supports a mobility management protocol.
The communication method according to claim 3, wherein the service flow template uses an inner layer address of the UE message;

Alternatively, the service flow template uses an inner address and an outer address of the UE message.
The communication method according to claim 1, wherein the PDN connection establishment process comprises establishing a dedicated bearer of the UE in the second network, and the handover accept message includes an invalid service of the proprietary bearer. And a flow template, where the invalid service flow template is used to prevent the UE from sending a message by using the dedicated bearer.
A communication method, comprising:

The second control plane network element of the second network receives the second handover request from the first control plane network element of the first network, where the second handover request carries the identifier of the user equipment UE;

Establishing, by the second control plane network element, the UE in a packet data network PDN connection of the second network according to the identifier of the UE, where the establishing process of the PDN connection includes allocating the UE in the An IP address of the network, where the IP address is used to trigger the UE to initiate a binding update process to the first control plane network element;

The second control plane network element sends a handover accept message to the UE by using the first control plane network element, where the handover accept message is used to indicate that the PDN connection has been established.
The communication method according to claim 6, wherein the handover accept message includes an IP address of the UE in the second network.
The communication method according to claim 7, wherein the PDN connection establishment process comprises establishing a dedicated bearer of the UE in the second network, and the handover accept message further includes the service of the proprietary bearer A flow template that supports a mobility management protocol.
The communication method according to claim 8, wherein the service flow template uses an inner layer address of the UE message;

Alternatively, the service flow template uses an inner address and an outer address of the UE message.
The communication method according to claim 6, wherein the PDN connection process comprises establishing a dedicated bearer of the UE in the second network, and the handover accept message includes an invalid service flow of the proprietary bearer. The template, the invalid service flow template is used to prevent the UE from sending a message by using the dedicated bearer.
A communication method, comprising:

The user equipment UE receives a handover accept message sent by the second control plane network element of the second network by using the first control plane network element of the first network, where the handover accept message is used to indicate that the UE is in the PDN of the second network. A connection is established, and the establishing process of the PDN connection includes allocating an IP address of the UE in the second network;

If the handover accept message includes the IP address of the UE in the second network, and the UE switches to the second network, initiate a binding update process to the first control plane network element according to the IP address;

Or, if the handover accept message does not include the IP address of the UE in the second network, after the UE switches to the second network, obtain the IP address by initiating an address allocation process, and according to the IP address. Initiating a binding update process to the first control plane network element.
The communication method according to claim 11, wherein the PDN connection establishment process comprises establishing a dedicated bearer of the UE in the second network, if the handover accept message includes The IP address of the UE in the second network, the handover accept message further includes a service flow template of the dedicated bearer, and the service flow template supports a mobility management protocol.
The communication method according to claim 12, wherein the service flow template uses an inner layer address of the UE message;

Alternatively, the service flow template uses an inner address and an outer address of the UE message.
The communication method according to claim 11, wherein the PDN connection establishment process comprises establishing a dedicated bearer of the UE in the second network, if the handover accept message does not include the UE in the The IP address of the second network, the handover accept message includes an invalid service flow template of the dedicated bearer, and the invalid service flow template is used to prevent the UE from sending a message by using the dedicated bearer.
The communication method according to claim 14, wherein after the UE acquires the IP address by initiating an address allocation process, the UE initiates a binding update to the first control plane network element by using the IP address. The process also includes:

The UE accepts an update process of the service flow template, where the update process is used to update the invalid service flow template to a service flow template that uses an inner layer address of the UE message or use an inner layer of the UE message The service flow template for the address and outer address.
A first control plane network element, wherein the first control plane network element comprises a transceiver and a processor,

The transceiver is configured to receive a first handover request, where the first handover request is used to indicate that the user equipment UE needs to be handed over from the first network to the second network;

The transceiver is further configured to send, according to the first handover request, a second handover request to a second control plane network element of the second network, where the second handover request carries an identifier of the UE, and the second The handover request is used to trigger establishment of a packet data network PDN connection of the UE in the second network, and the establishing process of the PDN connection includes allocating an IP address of the UE in the second network, where the IP address is used for Triggering the UE to initiate a binding update process to the first control plane network element;

The transceiver is further configured to receive a handover accept message sent by the second control plane network element, where the handover accept message is used to indicate that the PDN connection is established;

The transceiver is further configured to send the handover accept message to the UE.
The first control plane network element according to claim 16, wherein the switching interface The received message includes the IP address of the UE in the second network.
The first control plane network element according to claim 17, wherein the establishing process of the PDN connection comprises establishing a dedicated bearer of the UE in the second network, and the handover accept message further includes the A service flow template of a proprietary bearer, the service flow template supporting a mobility management protocol.
The first control plane network element according to claim 18, wherein the service flow template uses an inner layer address of the UE message;

Alternatively, the service flow template uses an inner address and an outer address of the UE message.
The communication method according to claim 16, wherein the PDN connection establishment process comprises establishing a dedicated bearer of the UE in the second network, and the handover accept message includes an invalid service of the proprietary bearer. And a flow template, where the invalid service flow template is used to prevent the UE from sending a message by using the dedicated bearer.
A second control plane network element, wherein the second control plane network element comprises a transceiver and a processor,

The transceiver is configured to receive a second handover request from a first control plane network element of the first network, where the second handover request carries an identifier of the user equipment UE;

The processor is configured to establish, according to the identifier of the UE, a PDN connection of the UE in a packet data network of the second network, where the establishing process of the PDN connection includes allocating an IP address of the UE in the second network, The IP address is used to trigger the UE to initiate a binding update process to the first control plane network element;

The transceiver is further configured to send, by using the first control plane network element, a handover accept message to the UE, where the handover accept message is used to indicate that the PDN connection is established.
The second control plane network element according to claim 21, wherein the handover accept message includes an IP address of the UE in the second network.
The second control plane network element according to claim 22, wherein the PDN connection establishment process comprises establishing a dedicated bearer of the UE in the second network, and the handover accept message further includes the special There is a bearer service flow template, and the service flow template supports a mobility management protocol.
The second control plane network element according to claim 23, wherein the service flow template uses an inner layer address of the UE message;

Alternatively, the service flow template uses an inner address and an outer address of the UE message.
The second control plane network element according to claim 21, wherein the PDN connection process comprises establishing a dedicated bearer of the UE in the second network, and the handover accept message includes the dedicated bearer The invalid service flow template is used to prevent the UE from transmitting a message through the dedicated bearer.
A user equipment UE, characterized in that the UE comprises a transceiver and a processor,

The transceiver is configured to receive a handover accept message sent by a second control plane network element of the second network by using a first control plane network element of the first network, where the handover accept message is used to indicate that the UE is in the second network a PDN connection has been established, and the establishing process of the PDN connection includes allocating an IP address of the UE in the second network;

If the handover accept message includes the IP address of the UE in the second network, and the UE switches to the second network, the processor is configured to initiate the first control plane network element according to the IP address. Binding the update process;

Or, if the handover accept message does not include the IP address of the UE in the second network, and the UE switches to the second network, the processor is configured to acquire the IP address by initiating an address allocation process, and And performing a binding update process to the first control plane network element according to the IP address.
The user equipment according to claim 26, wherein the PDN connection establishment process comprises establishing a dedicated bearer of the UE in the second network, if the handover accept message includes the UE in the The IP address of the network, the handover accept message further includes a service flow template of the dedicated bearer, and the service flow template supports a mobility management protocol.
The user equipment according to claim 27, wherein the service flow template uses an inner layer address of the UE message;

Alternatively, the service flow template uses an inner address and an outer address of the UE message.
The user equipment according to claim 26, wherein the PDN connection establishment procedure comprises establishing a dedicated bearer of the UE in the second network, if the handover accept message does not include the UE in the The IP address of the second network, the handover accept message includes an invalid service flow template of the dedicated bearer, and the invalid service flow template is used to prevent the UE from sending a message by using the dedicated bearer.
The user equipment according to claim 29, wherein the processor is further configured to accept an update process of the service flow template, where the update process is used to update the invalid service flow template to A service flow template that uses an inner layer address of the UE message or a service flow template that uses an inner layer address and an outer address of the UE message.