CN107005929B

CN107005929B - Packet data gateway selection method, related device and system

Info

Publication number: CN107005929B
Application number: CN201580066278.1A
Authority: CN
Inventors: 于游洋; 李欢; 靳维生
Original assignee: 温峻峰
Current assignee: Zhongke Tianwang (Guangdong) standard technology research Co.,Ltd.
Priority date: 2015-04-03
Filing date: 2015-04-03
Publication date: 2020-09-22
Anticipated expiration: 2035-04-03
Also published as: WO2016155011A1; CN107005929A

Abstract

The embodiment of the invention provides a method for selecting a packet data gateway, a related device and a system, which can fuse part/all logic functions of a 3GPP AAA Server into a mobility management network element, and realize the selection of a target P-GW by the mobility management network element or the mobility management network element and a non-3GPP access gateway aiming at UE accessed from a non-3GPP side, thereby not only simplifying a network architecture, but also being capable of adapting to the simplified network architecture to realize the selection of the P-GW.

Description

Packet data gateway selection method, related device and system

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method, a related apparatus, and a system for a packet data gateway.

Background

In order to meet the challenges of wireless broadband technology, and maintain the leading advantages of the 3rd generation partnership Project (3 GPP) network, the 3GPP made the Long Term Evolution (LTE) plan of the mobile communication network in 2004, and under the guidance of the LTE plan, a new mobile communication network architecture was defined, as shown in fig. 1. The architecture is more flat than Second Generation (2G) and third Generation (3G) networks, and only Packet Switching (PS) Domain is reserved, so it may be referred to as Evolved 3GPP Packet Switched Domain (Evolved 3GPP Packet Switched Domain) or Evolved Packet System (EPS).

The core network of the new mobile communication network, namely, the Evolved Packet Core (EPC), not only supports 3GPP Access technology, but also supports Non-3GPP (Non 3GPP) Access technology, such as Code Division Multiple Access 2000 (CDMA 2000), Worldwide Interoperability for Microwave Access (WiMAX), and Wireless Local Area Network (WLAN).

Under the existing network architecture (as shown in fig. 1), when a User Equipment (UE) accesses an EPC from a non-3GPP side, it may access from a trusted non-3GPP side and may also access from an untrusted 3GPP side. Taking an example that the UE accesses from an untrusted 3GPP side (for example, the UE accesses from an untrusted WLAN), an Evolved Packet Data Gateway (ePDG) first selects a Packet Data Gateway (P-GW) by using a corresponding P-GW selection mechanism according to whether the UE accesses through an initial attach (initial attach) procedure, a multiple access (multiple access) procedure, or a handover (handover) procedure, and initiates a Packet Data Network (PDN) connection establishment procedure to the selected P-GW; the P-GW needs to send the identifier of the P-GW (i.e., P-GW ID) to the 3GPP AAA Server through an S6b interface between itself and the 3GPP Authentication, Authorization, and accounting Server (3GPP Authentication, Authorization, and accounting Server, 3GPP AAA Server); the 3GPP AAAServer registers the received P-GW id with a Home Subscriber Server (HSS). And then, the process of selecting the P-GW to register is completed.

However, in the prior art, the process of registering the identity of the P-GW with the HSS requires that an S6b interface is supported between the P-GW and the 3GPP AAA Server. However, when deploying subsequent networks, operators want to simplify the network architecture as much as possible, for example, no S6b interface is deployed or no 3GPP AAA Server is deployed separately. Therefore, based on the existing scheme, the registration of the P-GW ID to the HSS or even the selection of the P-GW cannot be realized, and further the service continuity of the UE moving from the Non 3GPP side to the 3GPP side cannot be ensured, and the user experience is influenced.

Disclosure of Invention

In view of the foregoing problems in the prior art, embodiments of the present invention provide a method, a related apparatus, and a system for selecting a packet data gateway, which can adapt to a new simplified network architecture and implement selection of a packet data gateway.

In a first aspect, an embodiment of the present invention provides a method for selecting a packet data gateway P-GW, including:

after the UE accesses the EPC from the non-3GPP network, the mobility management network element receives a request message sent by the non-3GPP access gateway;

the mobility management network element determines a request type of the UE, wherein the request type comprises the EPC accessed through an initial attachment process, the EPC accessed through a handover process or the EPC accessed through a multi-access process;

the mobility management network element selects a target P-GW for the APN of the UE according to the request type;

and the mobility management network element returns a response message to the non-3GPP access gateway according to the request message, wherein the response message comprises the target APN and the identification of the target P-GW.

With reference to the first aspect, in a first possible implementation manner, before the selecting, by the mobility management network element, a target P-GW for a target access point name APN of the UE according to the request type, the method further includes: and the mobility management network element determines the target APN of the UE.

With reference to the first aspect or the first possible implementation manner of the first aspect, in a second possible implementation manner, before the determining, by the mobility management network element, the request type of the UE, the method further includes: the mobility management network element determines that the UE accesses the EPC from a non-3GPP network.

With reference to the first aspect or the first or second possible implementation manner of the first aspect, in a third possible implementation manner, the returning, by the mobility management network element, a response message to the non-3GPP access gateway according to the request message, where the response message includes the target APN and the identifier of the target P-GW, includes:

if the APN configuration parameter corresponding to the target APN in the subscription data of the UE does not contain the identification of the P-GW, adding the identification of the target P-GW in the APN configuration parameter corresponding to the target APN; if the identifier of the P-GW contained in the APN configuration parameter corresponding to the target APN is not the identifier of the target P-GW, replacing the identifier of the P-GW in the APN configuration parameter corresponding to the target APN by the identifier of the target P-GW by the mobility management network element; and the mobility management network element sends the response message to the non-3GPP access gateway, wherein the response message contains APN configuration parameters corresponding to the target APN, and the APN configuration parameters corresponding to the target APN contain the identification of the target APN and the target P-GW.

In a second aspect, an embodiment of the present invention provides a method for selecting a packet data gateway P-GW, including:

after User Equipment (UE) is accessed to an Evolved Packet Core (EPC) from a non-third generation partnership project (3 GPP) network, a non-3GPP access gateway sends a request message to a mobility management network element;

the non-3GPP access gateway receives a response message sent by the mobility management network element according to the request message, wherein the response message comprises a target Access Point Name (APN) of the UE and an identifier of a target P-GW selected for the target APN;

and the non-3GPP access gateway establishes a Packet Data Network (PDN) connection between the non-3GPP access gateway and the target P-GW for the target APN according to the identification of the target APN and the target P-GW.

With reference to the second aspect, in a first possible implementation manner, before the sending, by the non-3GPP access gateway, the request message to a mobility management network element, the method further includes: and the non-3GPP access gateway selects the mobility management network element.

With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner, the method further includes:

the non-3GPP access gateway selects the mobility management network element according to pre-configuration information; wherein the preconfigured information includes a corresponding relationship between the location information of the UE and the identifier of the mobility management network element, or the preconfigured information includes a corresponding relationship between the identifier of the non-3GPP access gateway and the identifier of the mobility management network element;

alternatively, the first and second electrodes may be,

the non-3GPP access gateway sends the international mobile subscriber identity IMSI of the UE to a routing agent node, so that the routing agent node selects the mobility management network element for the UE according to the IMSI of the UE;

alternatively, the first and second electrodes may be,

and the non-3GPP access gateway constructs a fully qualified domain name of a mobility management network element according to the position information of the UE, sends the fully qualified domain name to a domain name resolution server (DNS), receives an identifier of the mobility management network element determined by the DNS according to the fully qualified domain name, and selects the mobility management network element from the mobility management network elements determined by the DNS as the mobility management network element.

In a third aspect, an embodiment of the present invention provides a method for selecting a packet data gateway P-GW, including: after User Equipment (UE) is accessed to an Evolved Packet Core (EPC) from a non-third generation partnership project (3 GPP) network, a mobile management network element receives a request message sent by a non-3GPP access gateway;

the mobility management network element selects a P-GW according to the name APN of the target access point of the UE;

the mobility management network element acquires a P-GW identifier in APN configuration parameters corresponding to the target APN in subscription data of the UE;

and the mobility management network element returns a response message to the non-3GPP access gateway according to the request message, wherein the response message comprises a target APN of the UE, an identifier of a P-GW selected by the mobility management network element and an identifier of a P-GW in APN configuration parameters corresponding to the target APN, so that the non-3GPP access gateway selects the target P-GW for the target APN from the P-GW selected by the mobility management network element and the P-GW in the APN configuration parameters corresponding to the target APN.

With reference to the third aspect, in a first possible implementation manner, before the selecting, by the mobility management network element, the P-GW according to the target access point name APN of the UE, the method further includes: and the mobility management network element determines the target APN of the UE.

With reference to the third aspect, or the first possible implementation manner of the third aspect, in a second possible implementation manner, before the selecting, by the mobility management network element, the P-GW according to the target access point name APN of the UE, the method further includes: the mobility management network element determines that the UE accesses the EPC from a non-3GPP network.

In a fourth aspect, an embodiment of the present invention provides a registration method for a packet data gateway P-GW, including:

the non-3GPP access gateway receives a response message sent by the mobility management network element according to the request message, wherein the response message comprises a target Access Point Name (APN) of the UE, an identifier of a P-GW selected by the mobility management network element and an identifier of the P-GW in APN configuration parameters corresponding to the target APN in subscription data of the UE;

the non-3GPP access gateway selects a target P-GW for the target APN of the UE from the P-GW selected by the mobility management network element and the P-GW in the APN configuration parameters corresponding to the target APN according to the request type of the UE; wherein the request type includes the EPC accessed through an initial attach procedure, the EPC accessed through a handover procedure, or the EPC accessed through a multi-access procedure;

With reference to the fourth aspect, in a first possible implementation manner, before the sending, by the non-3GPP access gateway, the request message to a mobility management network element, the method further includes: and the non-3GPP access gateway selects the mobility management network element.

With reference to the first possible implementation manner of the fourth aspect, in a second possible implementation manner, the method further includes:

alternatively, the first and second electrodes may be,

In a fifth aspect, an embodiment of the present invention provides a mobility management network element, including:

a receiving unit, configured to receive a request message sent by a non-3GPP access gateway after a user equipment UE accesses an evolved packet core EPC from a non-third generation partnership project 3GPP network;

a determining unit, configured to determine a request type of the UE, where the request type includes the EPC accessed through an initial attach procedure, the EPC accessed through a handover procedure, or the EPC accessed through a multiple access procedure;

a selecting unit, configured to select a target P-GW for a target access point name APN of the UE according to the request type;

a sending unit, configured to return a response message to the non-3GPP access gateway according to the request message, where the response message includes the target APN and the identifier of the target P-GW.

In a sixth aspect, an embodiment of the present invention provides an access gateway, where the access gateway is an access gateway of a non-third generation partnership project 3GPP network, and the access gateway includes:

a sending unit, configured to send a request message to a mobility management network element after a user equipment UE accesses an evolved packet core EPC from the non-3GPP network;

a receiving unit, configured to receive a response message sent by the mobility management network element according to the request message, where the response message includes a target access point name APN of the UE and an identifier of a target P-GW selected for the target APN;

and the establishing unit is used for establishing a Packet Data Network (PDN) connection between the access gateway and the target P-GW for the target APN according to the identification of the target APN and the target P-GW.

With reference to the sixth aspect, in a first possible implementation manner, the sending unit is further configured to select the mobility management network element before sending the request message to the mobility management network element.

In a seventh aspect, an embodiment of the present invention provides a mobility management network element, including:

a selecting unit, configured to select a P-GW according to a target access point name APN of the UE;

an obtaining unit, configured to obtain a P-GW identifier in APN configuration parameters corresponding to the target APN in subscription data of the UE;

a sending unit, configured to return a response message to the non-3GPP access gateway according to the request message, where the response message includes the target APN of the UE, an identifier of the P-GW selected by the mobility management network element, and an identifier of the P-GW in the APN configuration parameter corresponding to the target APN, so that the non-3GPP access gateway selects the target P-GW for the target APN from the P-GW selected by the mobility management network element and the P-GW in the APN configuration parameter corresponding to the target APN.

In an eighth aspect, an embodiment of the present invention provides an access gateway, where the access gateway is an access gateway of a non-third generation partnership project 3GPP network, and the access gateway includes:

a receiving unit, configured to receive a response message sent by the mobility management network element according to the request message, where the response message includes a target access point name APN of the UE, an identifier of a P-GW selected by the mobility management network element, and an identifier of the P-GW in APN configuration parameters corresponding to the target APN in subscription data of the UE;

a selecting unit, configured to select, according to the request type of the UE, a target P-GW for a target APN of the UE from a P-GW selected by the mobility management network element and a P-GW in APN configuration parameters corresponding to the target APN; wherein the request type includes the EPC accessed through an initial attach procedure, the EPC accessed through a handover procedure, or the EPC accessed through a multi-access procedure;

and the establishing unit is used for establishing a Packet Data Network (PDN) connection between the access gateway and the target P-GW for the target APN according to the identification of the target APN and the identification of the target P-GW.

With reference to the eighth aspect, in a first possible implementation manner, the sending unit is further configured to select the mobility management network element before sending the request message to the mobility management network element.

With reference to any one of the above aspects or any possible implementation manner of any aspect, the request message is an authentication and authorization request message sent by the non-3GPP access gateway; the response message is an authentication and authorization reply message.

With reference to any one of the above aspects or any possible implementation manner of any aspect, the mobility management element supports an authentication and authorization function of a non-3GPP access network.

In each embodiment of the present invention, the fact that the mobility management element supports the authentication and authorization function of the non-3GPP access network means that the mobility management element can authenticate and authorize the UE accessed from the non-3GPP access network (such as WLAN, CDMA2000, or WiMAX).

In the embodiment of the invention, part/all logic functions of the 3GPP AAA Server are fused into the mobility management network element, and the selection of the P-GW at the non-3GPP side is realized by the mobility management network element or the mobility management network element and the non-3GPP access gateway, thereby not only simplifying the network architecture, but also being capable of adapting to the simplified network architecture to realize the selection of the P-GW.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a system architecture diagram of an evolved packet system;

fig. 2(a) is a schematic diagram of a 3GPP AAA Server and MME converged architecture provided in an embodiment of the present invention;

fig. 2(b) is a schematic diagram of a 3GPP AAA Server and SGSN converged architecture provided in the embodiment of the present invention;

fig. 3 is a flowchart of a method for selecting a packet data gateway according to an embodiment of the present invention;

fig. 4 is a flowchart of a method for selecting a packet data gateway according to an embodiment of the present invention;

fig. 5 is a flowchart of a method for selecting a packet data gateway according to an embodiment of the present invention;

fig. 6 is a flowchart of a method for selecting a packet data gateway according to an embodiment of the present invention;

fig. 7 is a schematic diagram of a mobility management network element according to an embodiment of the present invention;

fig. 8 is a schematic diagram of an access gateway according to an embodiment of the present invention;

fig. 9 is a schematic diagram of another mobility management network element according to an embodiment of the present invention;

fig. 10 is a schematic diagram of another access gateway provided by an embodiment of the present invention;

fig. 11 is a schematic structural diagram of a P-GW selection apparatus according to an embodiment of the present invention.

Detailed Description

The embodiment of the invention provides a method for selecting a packet data gateway, which can realize the selection of the packet data gateway based on a simplified network architecture.

As shown in fig. 1, under the existing network architecture, the core network EPC mainly includes a Mobility Management Entity (MME), a General Packet Radio Service (GPRS) Service Support Node (SGSN), a Serving Gateway (S-GW), and a P-GW; the MME is mainly responsible for Non-Access Stratum (NAS) signaling between the MME and user equipment, allocates temporary identity identifiers for the user equipment, and selects core network elements such as S-GW and P-GW for the user equipment accessed by 3 GPP; the S-GW is a mobility anchor point switched between local eNodeBs and provides related functions of lawful interception; the P-GW is mainly responsible for user address allocation, policy control and execution of charging rules and related functions of lawful interception.

When the UE accesses the EPC from the non-3GPP network, the UE may access through an interface between the trusted non-3GPP access network and the P-GW, for example, access through an S2a interface between the Trusted WLAN Access Network (TWAN) and the P-GW, or access through an interface between the untrusted non-3GPP access network and the P-GW, for example, access through an S2b interface between the ePDG and the P-GW, where the ePDG/TWAN is mainly responsible for forwarding an Internet Protocol (IP) address of interconnection between the mobile networks of the UE allocated by the P-GW, registering a local IP address of the UE, and binding the mobile IP address and the local IP address of the UE. When accessing from a non-3GPP network, another important network element is a 3GPP AAA server, which is mainly responsible for implementing authentication and authorization operations on the UE through interaction with the HSS, and registering the P-GW identification information used by each PDN connection established by the UE in the HSS, where the HSS is mainly used for storing subscription information of the user.

Because an operator wants to simplify a network architecture as much as possible during subsequent network deployment, for example, an S6b interface is no longer deployed or a 3GPP AAA Server is no longer deployed alone and functions thereof are fused with an existing EPC network element, registration of a P-GW ID to an HSS or even selection of a P-GW cannot be realized by using the prior art, and service continuity when a UE moves from a Non 3GPP side to a 3GPP side cannot be guaranteed. In view of this, an embodiment of the present invention provides a method for selecting a P-GW, which can merge part/all of logic functions of a 3GPP AAA Server into a mobility management network element, and the mobility management network element or the mobility management network element and a non-3GPP access gateway jointly implement selection of a P-GW on a non-3GPP side, so that not only is a network architecture simplified, but also selection and registration of the P-GW can be implemented without deploying an S6b interface or deploying a 3GPP AAA Server separately.

In the embodiment of the present invention, the mobility management network element may be an MME, and may also be an SGSN (such as GnGp-SGSN or S4-SGSN); the non-3GPP access Gateway, that is, the access Gateway of the non-3GPP network, may be an ePDG, and may also be a TWAN or a High Rate Packet Data (HRPD) Serving Gateway (HRPD Serving Gateway, HSGW).

In the embodiment of the present invention, an architecture diagram in which a 3GPP AAA Server and an MME are merged is provided, taking a mobility management network element as an MME and a non-3GPP access gateway as an ePDG, as shown in fig. 2 (a). The logic function of the 3GPP AAA Server is deployed to the MME, an S6a interface between the MME and the HSS is upgraded to support an SWx interface between the 3GPP AAA Server and the HSS or an independent SWx interface is added between the MME and the HSS, an SWm interface between the ePDG and the 3GPP AAA Server can be deployed between the MME and the ePDG, an S6b interface between the ePDG and the 3GPP AAA Server is not deployed any more, and an SWa interface between the 3GPP AAA Server and a non-credible 3GPP access network can also not be deployed any more, so that the network architecture is greatly simplified.

Similarly, the MME may be replaced by the SGSN, that is, the logical function of the 3GPP AAA Server is deployed to the SGSN, and accordingly, the S6a interface between the MME and the HSS is replaced by the S6d interface or the Gr interface between the SGSN and the HSS (if the MAP protocol is supported), and the S11 interface between the MME and the S-GW is replaced by the S4 interface between the SGSN and the S-GW (as shown in fig. 2(b), which is an architecture diagram of the 3GPP AAA Server and the SGSN fusion.

Optionally, the ePDG may also be replaced by a TWAN/HSGW, and accordingly, the SWm interface between the ePDG and the MME/SGSN is replaced by an STa interface between the TWAG/HSGW and the MME/SGSN, and the S2b interface between the ePDG and the P-GW is replaced by an S2a interface between the TWAN/HSGW and the P-GW, which is not shown in the figure, then the S6b interface between the TWAN/HSGW and the 3GPP AAA Server is not deployed, and the SWa interface between the 3GPP AAA Server and the trusted 3GPP access network is also not deployed, so that the network architecture is greatly simplified.

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

As shown in fig. 3, an embodiment of the present invention provides a method for selecting a packet data gateway P-GW, which may merge part or all of logic functions of a 3gpp aaa Server into a mobility management network element, and implement selection of the P-GW by using the mobility management network element, where the specific method is as follows.

S301: after the UE accesses the EPC from the non-3GPP network, the mobility management element receives a request message sent by the non-3GPP access gateway.

Normally, the mobility management element can only receive messages sent by the 3GPP network. In the embodiment of the present invention, since part/all of the logic functions of the 3GPP AAA Server are merged into the mobility management element, for example, as shown in fig. 2(a) or fig. 2(b), the mobility management element may receive a request message, such as an Authentication and authorization request (Authentication and authorization request) message, sent by a non-3GPP access gateway (i.e., an access gateway of the non-3GPP network).

Under the framework of the convergence of the 3GPP AAA Server and the mobility management element, an interface may be added between the mobility management element and the non-3GPP access gateway to perform message/signaling interaction, for example, an SWm interface or an STa interface, and then the request message and the response message of the subsequent request message may be transmitted through the interface added between the mobility management element and the non-3GPP access gateway.

S302: the mobility management network element determines a request type of the UE, where the request type includes the EPC accessed through an initial attach procedure, the EPC accessed through a handover procedure, or the EPC accessed through a multi-access procedure.

When selecting a target P-GW, the mobility management network element may adopt different P-GW selection mechanisms for the EPC of which the UE accesses through an initial attach procedure, a handover procedure, or a multi-access procedure. Thus, the MME may determine the request type of the UE, i.e., determine that the UE is the EPC accessed through an initial attach procedure or through a handover procedure or through an access procedure.

Specifically, the mobility management network element may receive the request type or the information of the request type sent by the non-3GPP access gateway to determine, or may determine by itself determining whether a context corresponding to the target APN of the UE exists, which is not limited in this embodiment of the present invention, where the information of the request type may be information generated according to the request type, and the mobility management network element determines the request type of the UE according to the information of the request type. For example, the non-3GPP access gateway may determine the request type, and notify the mobility management element of the request type or the information of the request type through the request message or other type messages, so that the mobility management element may determine the request type of the UE. For another example, the mobility management element may determine, by using an International Mobile Subscriber Identity (IMSI) of the UE and a target APN, whether a context of the UE corresponding to the target APN already exists on the mobility management element, and if so, determine that the request type is the EPC accessed through a handover procedure or the EPC accessed through a multiple access procedure, otherwise determine that the request type is the EPC accessed through an initial attach procedure.

S303: and the mobility management network element selects a target P-GW for the APN of the UE according to the request type.

Before selecting a target P-GW, the mobility management network element may determine a target APN of the UE, specifically, if the UE requests an APN, the MME may use the APN requested by the UE as the target APN; otherwise, the MME may use a default APN in the subscription data of the UE as a target APN.

When selecting a target P-GW for the target APN, if the mobile management element determines that the UE is the EPC accessed through an initial attach procedure (i.e., determines that the request type is the EPC accessed through an initial attach procedure), the mobility management element may select the target P-GW according to the target APN, or may select the target P-GW according to the identifiers of the target APN and a non-3GPP access gateway or according to the target APN and a local IP address of the UE, so that a P-GW closer/closest to the UE may be selected as the target P-GW, where the local IP address of the UE refers to an IP address allocated to the UE by the non-3GPP access network (e.g., WLAN, CDMA2000, WiMAX, or the like).

If the mobile management element determines that the UE is the EPC accessed through a handover procedure or a multiple access procedure (i.e., determines that the request type is the EPC accessed through a handover procedure or a multiple access procedure), the mobile management element may obtain an identifier of a P-GW in an APN Configuration parameter (APN-Configuration, AVP) corresponding to the target APN in subscription data of the UE, that is, an identifier of a P-GW corresponding to the target APN in the subscription data of the UE, and use the P-GW in the APN Configuration parameter corresponding to the target APN as the target P-GW.

It should be noted that, in the embodiment of the present invention, S301 may be executed before S302 and S303, or may be executed after S302 and S303, which is not limited herein.

S304: and the mobility management network element returns a response message to the non-3GPP access gateway according to the request message, wherein the response message comprises the target APN and the identification of the target P-GW.

The mobility management network element may send the target APN and the identifier of the target P-GW to a non-3GPP access gateway through a response message in response to the request message, such as an Authentication and authorization reply (Authentication and authorization Answer) message, thereby saving signaling interaction. The non-3GPP access gateway can establish a Packet Data Network (PDN) connection between the non-3GPP access gateway and the target P-GW for the target APN according to the identification of the target APN and the target P-GW.

For example, if the target P-GW selected by the mobility management network element is a P-GW in the APN configuration parameters corresponding to the target APN in the subscription data of the UE, the APN configuration parameters corresponding to the target APN in the subscription data of the UE include the identifier of the target P-GW and the target APN, otherwise, the APN configuration parameters corresponding to the target APN only include the identifier of the target APN and do not include the identifier of the target P-GW. Therefore, when the response message is sent, the APN configuration parameters corresponding to the target APN can be utilized. For example, if the APN configuration parameter corresponding to the target APN in the subscription data of the UE does not include an identifier of a P-GW, the identifier of the target P-GW is added to the APN configuration parameter corresponding to the target APN; if the identifier of the P-GW contained in the APN configuration parameter corresponding to the target APN is not the identifier of the target P-GW, the mobility management network element replaces the identifier of the P-GW in the APN configuration parameter corresponding to the target APN with the identifier of the target P-GW; and the mobility management network element sends a response message to the non-3GPP access gateway, wherein the response message contains APN configuration parameters corresponding to the target APN, and the APN configuration parameters corresponding to the target APN contain the identification of the target APN and the target P-GW.

In the embodiment of the invention, partial/all logic functions of the 3GPP AAA Server are integrated into the mobility management network element, so that the network architecture is simplified, the mobility management network element can receive a request message sent by a non-3GPP access gateway, can select a target P-GW for UE accessed from the non-3GPP network, and returns a response message containing a target APN of the UE and an identifier of the target P-GW to the non-3GPP access network, thereby adapting to the simplified network architecture and realizing the selection of the P-GW.

In the embodiment of the present invention, the identifier of the target P-GW may not be registered to the HSS. This is because, in the prior art, the identity of the target P-GW must be registered with the HSS in order to ensure that the UE uses the same P-GW when handing over between a 3GPP network and a non-3GPP network. In the invention, because a new simplified network framework is adopted, no matter UE accessed from a 3GPP network or UE accessed from a non-3GPP network, the target P-GW is selected by a mobility management network element, so that the same P-GW can be used by the 3GPP network and the non-3GPP network during switching, and the P-GW does not need to be registered to the HSS.

Optionally, the identifier of the target P-GW may also be registered to the HSS to complete the selection and registration process of the target P-GW, and accordingly, the method may further include:

s305: and the mobility management network element sends a notification message (NotifyRequest) to a Home Subscriber Server (HSS), wherein the notification message comprises the target APN and the identifier of the target P-GW, so that the identifier of the target P-GW is registered to the HSS. Different from the prior art that the process of registering the P-GW identifier to the HSS requires the P-GW and the 3GPP AAAServer to support the S6b interface, in the embodiment of the present invention, the P-GW identifier is directly registered to the HSS through the interface between the mobility management network element and the HSS.

Optionally, the mobility management network element may register the identity of the P-GW with the HSS only when the PDN establishment is successful. For example, the non-3GPP access gateway may send a notification message to the mobility management network element after the PDN connection is successfully established, where the notification message includes indication information used to indicate that the PDN is successfully established, and then the MME may determine that the PDN is successfully established according to the indication information, and register the identifier of the target P-GW in the HSS.

In the above embodiment, for a UE accessed through a non-3GPP network, a mobility management network element selects a target P-GW for a target APN of the UE, and when the mobility management network element selects the target P-GW, the mobility management network element needs to determine a request type of the UE, and for the UE accessed through an initial attach procedure, the mobility management network element selects the target P-GW based on the target APN, and for the UE accessed through a handover procedure or a multiple access procedure, the P-GW in APN configuration parameters corresponding to the target APN in subscription data of the UE is used as the target P-GW. The embodiment of the invention also provides a method for selecting the P-GW, which is different from the previous embodiment, in the embodiment of the invention, MME does not need to judge the request type of UE, MME only needs to determine a target APN, selects the P-GW based on the target APN, sends the identification of the P-GW selected by the MME, the identification of the target APN and the identification of the P-GW in APN parameters corresponding to the target APN to a non-3GPP access gateway, and the non-3GPP access gateway selects the target P-GW from the P-GW selected by the MME and the P-GW in the APN configuration parameters corresponding to the target APN according to the request type of the UE. In particular, the method may be as shown in fig. 4.

S401: after the user equipment UE accesses the evolved packet core EPC from the non-third generation partnership project 3GPP network, the mobility management network element receives a request message sent by the non-3GPP access gateway. S401 may refer to S301, and is not described herein again in the embodiments of the present invention.

S402: and the mobility management network element selects the P-GW according to the name APN of the target access point of the UE.

Different from the previous embodiment, in the embodiment of the present invention, the mobility management element does not need to determine the access type of the UE, and may select the P-GW directly according to the target APN, for example, the mobility management element may select the P-GW according to the target APN and the identifier of the non-3GPP access gateway, or according to the target APN and the local IP address of the UE.

The mobility management network element may also determine a target APN for the UE, and other embodiments may be referred to as to how to determine the target APN and how to select a P-GW based on the target APN.

S403: and the mobility management network element acquires the identifier of the P-GW in the APN configuration parameters corresponding to the target APN in the subscription data of the UE.

The mobility management network element may obtain subscription data of the UE from an HSS, where the subscription data of the UE includes at least one set of APN configuration parameters, and the APN configuration parameters include an APN and an identifier of a P-GW corresponding to the APN, and if the UE accesses through an initial procedure, the identifier of the P-GW may be a default identifier. The mobility management network element may determine, from subscription data of the UE, an APN configuration parameter corresponding to the target APN, where the APN configuration parameter corresponding to the target APN includes identifiers of the target APN and the P-GW.

S404: and the mobility management network element returns a response message to the non-3GPP access gateway according to the request message, wherein the response message comprises the target APN of the UE, the identifier of the P-GW selected by the mobility management network element and the identifier of the P-GW in the APN configuration parameters corresponding to the target APN.

The mobility management network element may send the information to the non-3GPP access gateway through a response message of the request message, such as an authentication and authorization reply message, so that the non-3GPP access gateway selects a target P-GW from a P-GW selected by the mobility management network element and a P-GW in APN configuration parameters corresponding to the target APN.

S405: and the non-3GPP access gateway selects a target P-GW from the P-GW selected by the mobility management network element and the P-GW in the APN configuration parameters corresponding to the target APN according to the request type of the UE.

The non-3GPP access gateway may determine a request type for the UE. Optionally, if the request type is the EPC accessed through an initial attach procedure, the non-3GPP access gateway may select the P-GW selected by the mobility management element as the target P-GW. If the request type is the EPC accessed through a handover procedure or a multi-access procedure, the non-3GPP access gateway may select a P-GW in APN configuration parameters corresponding to the target APN as the target P-GW.

S406: and the non-3GPP access gateway establishes a Packet Data Network (PDN) connection between the non-3GPP access gateway and the target P-GW for the target APN according to the identification of the target APN and the target P-GW.

In the embodiment of the invention, part/all logic functions of the 3GPP AAA Server are merged into the mobility management network element, thereby simplifying the network architecture. Based on the converged network architecture, the mobility management network element can receive a request message sent by the non-3GPP access gateway, can select a P-GW for UE accessed from the non-3GPP network, and returns a response message containing a target APN of the UE, an identifier of the P-GW selected by the mobility management network element and an identifier of the P-GW in APN configuration parameters corresponding to the target APN to the non-3GPP access gateway, and the non-3GPP access gateway selects the P-GW from the P-GW selected by the mobility management network element and the P-GW in the APN configuration parameters corresponding to the target APN according to the request type of the UE, so that the simplified network architecture is adapted to realize the selection of the P-GW.

Optionally, because a converged network architecture is adopted, in the embodiment of the present invention, the identifier of the P-GW may not be registered to the HSS, and it is also ensured that the same P-GW is used by the 3GPP network and the non-3GPP network.

Optionally, the identifier of the P-GW may be registered to an HSS without changing an existing HSS network element, and the method may further include:

the mobility management network element receives the identifier of the target P-GW sent by the non-3GPP access gateway, or the mobility management network element may also determine the request type of the UE, and according to the request type of the UE, determines the target P-GW from the P-GW selected by the mobility management network element and the P-GW in the APN configuration parameter corresponding to the target APN, so that the mobility management network element may send a notification message to a home subscriber server HSS, where the notification message includes the identifier of the target APN and the identifier of the target P-GW, so as to register the identifier of the target P-GW to the HSS; optionally, the non-3GPP access gateway may send the identifier of the target P-GW to the mobility management network element after the PDN connection is successfully established.

It should be noted that the APN configuration parameter corresponding to the target APN originally includes the target APN and the identifier of the P-GW corresponding to the target APN (i.e. the identifier of the P-GW in the APN configuration parameter corresponding to the target APN in the subscription data of the UE), so that the mobility management network element may use the APN configuration parameter corresponding to the target APM when sending the identifier of the target APN of the UE, the identifier of the P-GW selected by the mobility management network element, and the identifier of the P-GW in the APN configuration parameter corresponding to the target APN to the non-3GPP access gateway. For example, the mobility management element may add, in the response message, a first parameter used to indicate an identifier of a P-GW selected by the mobility management element, and send the response message to the non-3GPP access gateway, where the response message includes an APN configuration parameter corresponding to the target APN and the first parameter. For another example, the mobility management element may add, to the APN configuration parameter corresponding to the target APN, a second parameter for indicating an identifier of a P-GW selected by the mobility management element, and send a response message to the non-3GPP access gateway, where the response message includes an APN configuration parameter corresponding to the target APN, and the APN configuration parameter corresponding to the target APN includes the second parameter. Optionally, the response message may be an authentication and authorization reply message.

Optionally, in the embodiment of the present invention and the method embodiment corresponding to fig. 3, the mobility management network element supports an authentication authorization function of a non-3GPP access network.

Optionally, in this embodiment of the present invention and in the method embodiment corresponding to fig. 3, before the non-3GPP access gateway sends the request message to the mobility management network element, the method further includes: and the non-3GPP access gateway selects the mobility management network element. For example, the non-3GPP access gateway selects the mobility management network element according to preconfigured information; wherein the preconfigured information includes a corresponding relationship between the location information of the UE and the identifier of the mobility management network element, or the preconfigured information includes a corresponding relationship between the identifier of the non-3GPP access gateway and the identifier of the mobility management network element;

or, the non-3GPP access gateway sends the international mobile subscriber identity IMSI of the UE to a routing agent node, so that the routing agent node selects the mobility management network element for the UE according to the IMSI of the UE;

or, the non-3GPP access gateway constructs a fully qualified domain name of a mobility management network element according to the location information of the UE, sends the fully qualified domain name to a domain name resolution server DNS, receives an identifier of the mobility management network element determined by the DNS according to the fully qualified domain name, and selects a mobility management network element from the mobility management network elements determined by the DNS as the mobility management network element, so that a mobility management network element closer to the location of the UE can be selected.

In the following, a mobility management element is taken as an MME, and a non-3GPP access gateway is taken as an ePDG for example, to describe, when the mobility management element is an SGSN or the non-3GPP access gateway is a TWAN/HSGW, the following method may also be referred to select and register a P-GW, which is not described herein again in the embodiments of the present invention. In conjunction with the network architecture described in fig. 2(a), an embodiment of the present invention provides a method for selecting a P-GW, as shown in fig. 5.

S501: the UE sends an IKE authentication request message (Internet Key Exchange _ authentication request message, IKE _ AUTH request message) to the ePDG.

When a UE accesses an EPC from a non-3GPP network, an IKE authentication request message may be sent to the ePDG, which may contain an IP address, e.g., if the UE accesses the EPC through an initial attach procedure, the IP address is an IP address (IPv4 address or IPv6 address) with a value of all zeros; and if the UE is accessed to the EPC through a switching process, the IP address is the IP address of the UE, wherein the IP address of the UE is the IP address of the UE obtained from a 3GPP network side before the UE is accessed to the EPC. Optionally, if the UE has the requested APN, the message may further include the APN requested by the UE.

Optionally, when the non-3GPP access gateway is not ePDG, for example, TWAN/HSGW, the IKE authentication request message interacted between the UE and the evolved packet data network element may be replaced by another type of message. When the non-3GPP access gateway is not an ePDG, for example, TWAN/HSGW, or the mobility management network element is not MM, for example, SGSN, the method of S502-S514 may be directly adopted, or the P-GW selection method in the embodiment of the present invention may be adopted instead of some message names.

S502: the ePDG sends an authentication and authorization request message to an MME, wherein the authentication and authorization request message contains a request type, and the request type comprises the EPC accessed through an initial attachment process, the EPC accessed through a switching process or the EPC accessed through a multi-access process.

After receiving the IKE authentication request message, the ePDG may determine a request type of the UE according to whether the IKE authentication request message includes an IP address of the UE or an all-zero IP address, where the request type may indicate an EPC through which the UE accesses, and for example, the request type includes the EPC accessed through a handover procedure or an initial attach procedure or a multi-access procedure. Specifically, if the IKE authentication request message includes the IP address of the UE, that is, the IP address that is not all zero, it is determined that the UE is an EPC accessed through a handover procedure or a multiple access procedure, and otherwise, it is determined that the UE is an EPC accessed through an initial attach procedure.

The ePDG may send the request type to the MME through the authentication and authorization request message, where the authentication and authorization request message is used to request authentication and authorization for the UE. When implemented, the ePDG may define a parameter, such as a Request Type (Request Type) or an attach Type (AttachType), in the authentication and authorization Request message, and when the UE accesses through a handover procedure or a multiple access procedure, the ePDG may set a value of the Request Type or the attach Type to "handover" (handover) "or" multiple access "(multiple access)", and when the UE accesses through an initial attach procedure, set a value of the Request Type or the attach Type to "initial attach" (initial) or "initial Request" (initial Request) ", so that the MME may know the Request Type of the UE according to the value of the parameter (i.e., the Request Type or the attach Type) in the authentication and authorization Request message; for another example, the ePDG may define a 32-bit unsigned integer parameter, such as DER-SWm-Flags, in the authentication and authorization request message, set bit 0 of the parameter to 1 when the UE accesses through an initial attach procedure, and set bit 0 of the parameter to 0 when the UE accesses through a handover procedure or a multiple access procedure, or vice versa. The specific implementation manner of the request type is not limited herein. Optionally, the ePDG may also send the request type to an MME through other messages. It should be noted that, instead of sending the request type of the UE to the MME, the ePDG may determine the request type of the UE by itself.

Optionally, if the IKE authentication request message received by the ePDG includes the APN requested by the UE, the ePDG may send the APN requested by the UE to the MME through the authentication and authorization request message, and the authentication and authorization request message may further include the APN requested by the UE, or the ePDG may also send information of the APN requested by the UE to the MME through another message.

Optionally, the authentication and authorization request message may further include access type (RAT type) information, where the access type information is used to indicate which access technology the UE employs for access. For example, when the UE is accessed through a Wireless Local Area Network (WLAN), the access type information may be set to WLAN, a trusted WLAN, an untrusted WLAN, or the like.

Optionally, the authentication and authorization request message may further include a local IP address (UE localp) of the UE, where the local IP address of the UE is an IP address allocated by the non-3GPP access network to the UE. Since the local IP address of the UE is used to establish the IPSec procedure with the ePDG, the ePDG may obtain the local IP address of the UE and send this address to the MME.

S503: the MME sends an authentication request (authentication request) message to the HSS to request to acquire an authentication vector of the UE.

S504: and the HSS returns an authentication response (authentication response) message to the MME, wherein the authentication response message contains an authentication vector of the UE.

S505: and the MME authenticates the UE by utilizing the authentication vector of the UE.

The authentication process of S503-S505 is similar to the process of authenticating the UE by the 3GPP AAA Server in the prior art, and the embodiment of the present invention is not described herein again.

S506: when the UE is successfully authenticated, the MME sends a Non-3GPP IP Access Registration request (Non-3GPP IP Access Registration request) message or an Update location request (Update location request) message to the HSS so as to request to acquire subscription data of the UE.

Since the MME and the HSS support an S6a interface and an SWx interface, the MME may request to acquire subscription data of the UE through a non-3GPP IP access registration request message or an update location request message, where the non-3GPP IP access registration request message or the update location request message may include an IMSI of the UE and an identity of the MME.

S507: the HSS returns a Non-3GPP IP access registration response (Non-3GPP IP access registration response) message or an Update location response (Update location response) message to the MME, wherein the Non-3GPP IP access registration corresponding message or the Update location response message carries subscription data of the UE.

After receiving the non-3GPP IP access registration request message or the location update request message sent by the MME, the HSS may store the identity of the MME, and complete registration of the MME to the HSS.

After acquiring the subscription data of the UE, the MME may authorize the UE according to the subscription data of the UE.

S508: the MME determines that the UE is accessing EPC from a non-3GPP network.

In the prior art, for a UE accessed from a 3GPP network, an MME selects a target P-GW for the UE, and for a UE accessed from a non-3GPP network, an ePDG selects a target P-GW for the UE, and the mechanisms for selecting the target P-GW by the MME and the ePDG are different.

Different from the prior art, in the embodiment of the present invention, for a UE accessed from a non-3GPP network, the MME may also select a target P-GW for the UE. Therefore, before selecting the target P-GW for the UE, the MME may determine whether the UE is accessed from the 3GPP network or the non-3GPP network, and for the UE accessed from the non-3GPP network, S509 may be performed to select the P-GW. For the UE accessed to the 3GPP network, the P-GW can be selected by using the method in the prior art.

There may be various ways for how to determine whether the UE accesses from the non-3GPP network, and the embodiment of the present invention is not limited herein. For example, if the MME receives an authentication and authorization request message sent by the ePDG for the UE, it may be determined that the UE is accessed from a non-3GPP network; for another example, the MME may determine that the UE is accessed from a non-3GPP network according to a RAT type or a request type provided by the ePDG.

S509: and the MME determines a target APN and selects a target P-GW according to the request type.

Specifically, if the UE requests an APN, for example, the IKE authentication request message includes an APN requested by the UE, the MME may match the APN requested by the UE with an APN in APN configuration parameters in subscription data of the UE, if the APN requested by the UE is matched with the APN, the MME may take the APN requested by the UE as a target APN, otherwise, the MME may reject the authentication and authorization request of the UE; if the UE does not request an APN, the MME may use a default APN in subscription data as a target APN.

When selecting a target P-GW, the MME may employ different P-GW selection mechanisms for the EPC of which the UE is accessed through an initial attach procedure or a handover procedure or a multiple access procedure. Accordingly, the MME may determine whether the UE is the EPC accessed through an initial attach procedure or a handover procedure or a multiple access procedure according to a request type of the UE.

For a UE accessed through an initial attach procedure, the MME may select a target P-GW according to the target APN, for example, the MME may send the target APN to a DNS server, the DNS server may return a P-GW list (PGW list or P-GW list) capable of connecting the target APN to the MME, and the MME may select an appropriate P-GW from the P-GW list; further, the MME may select a target P-GW according to the identification (ePDG ID) of the target APN and the ePDG or may select a P-GW closer to the UE according to the identification (ePDG ID) of the target APN and the IP address of the UE, for example, the MME may send a DNS query message to a DNS server to request to acquire a P-GW that may be connected to the target APN, receive a P-GW list returned by the DNS server, and select a P-GW closest to/closer to the UE from the P-GW list according to the identification (ePDG ID) of the ePDG or the IP address of the UE.

For a UE accessed through a handover procedure or a multi-access procedure, the MME may use a P-GW in APN configuration parameters corresponding to the target APN in subscription data of the UE (i.e., a P-GW corresponding to the target APN in a subscription number of the UE) as a target P-GW.

S510: the MME sends an authentication and authorization reply message to the ePDG, wherein the authentication and authorization reply message contains APN configuration parameters corresponding to the target APN, and the APN configuration parameters corresponding to the target APN contain the identification of the target APN and the identification of the target P-GW.

If the APN configuration parameter corresponding to the target APN already contains the target APN, the MME may determine, for the UE accessed through the initial attach procedure, whether the APN configuration parameter corresponding to the target APN contains the identifier of the target P-GW, replace the identifier of the P-GW contained in the APN configuration parameter corresponding to the target APN with the identifier of the target P-GW if the APN configuration parameter corresponding to the target APN contains the identifier of the P-GW, and add the identifier of the target P-GW to a location for indicating the identifier of the P-GW in the APN configuration parameter corresponding to the target APN if the APN configuration parameter corresponding to the target APN does not contain the identifier of the P-GW.

For the UE accessed through the handover procedure or the multiple access procedure, since the target P-GW is the P-GW in the APN configuration parameters corresponding to the target APN (i.e. the P-GW corresponding to the target APN in the subscription data of the UE), the APN configuration parameters corresponding to the target APN already include the identifier of the target P-GW and the target APN.

S511: and the ePDG establishes PDN connection with the target P-GW for the target APN.

Different from the prior art, the ePDG does not need to determine whether the UE accesses through an initial attach procedure or a handover procedure or a multiple access procedure, nor needs to select a target APN and a target P-GW. And only the identification of the target APN and the identification of the target PGW are needed to be obtained from the APN configuration parameters corresponding to the target APN, and PDN connection is established according to the target APN and the target P-GW.

S512: the ePDG sends an Authentication and authorization Acknowledgement (ACK) message to the MME, wherein the Authentication and authorization acknowledgement message contains an indication message for indicating that the PDN connection is successfully established.

S513: the MME sends a notification Request (Notify Request) message to the HSS, wherein the notification Request message comprises the target APN and the identification of the target P-GW, so as to register the identification of the target P-GW to the HSS.

The MME may register the identifier of the target P-GW with the HSS after the PDN connection establishment is successful, so as to avoid registering the identifier of the target P-GW with the HSS when the PDN connection establishment fails.

S512 is an optional step, and the MME may also register an identifier of a target P-GW with the HSS after selecting the target P-GW for the target APN, without determining whether the PDN connection is successfully established.

S514: the HSS returns a notification Response (Notify Response) message to the MME.

S512-S514 are optional steps, and the MME may not register the identifier of the target P-GW with the HSS, or may ensure that the same P-GW is used by the 3GPP and the non-3 GPP.

In conjunction with the network architecture described in fig. 2(a), an embodiment of the present invention further provides a method for selecting a P-GW, as shown in fig. 6. Different from the scheme in the previous embodiment in which the MME selects the target P-GW for the target APN, in the embodiment of the present invention, the MME selects the P-GW for the target APN, and the ePDG decides whether to use the P-GW selected by the MME as the target P-GW according to the current flow of the UE, where a specific method is as follows, S501 to S508 may be referred to in S601 to S608, and details of the embodiment of the present invention are not repeated here. When the mobility management network element is SGSN or the non-3GPP access gateway is TWAN/HSGW, the P-GW selection may also be performed by referring to the following method.

S601: the UE sends an IKE authentication request message to the ePDG.

S602: and the ePDG sends an authentication and authorization request message to the MME.

Unlike S502, the ePDG need not send the request type of the UE to the MME, and the authentication and authorization request message may not include the request type of the UE. The MME supports the authentication and authorization functions of the non-3GPP access network.

S603: and the MME sends an authentication request message to the HSS to request to acquire the authentication vector of the UE.

S604: and the HSS returns an authentication response message to the MME, wherein the authentication response message contains an authentication vector of the UE.

S605: and the MME authenticates the UE by utilizing the authentication vector of the UE.

S606: and when the UE is successfully authenticated, the MME sends a non-3GPP IP access registration request message or a location updating request message to the HSS so as to request to acquire subscription data of the UE.

S607: and the HSS returns an IP access registration response message or a location updating response message of the non-3GPP to the MME, wherein the IP access registration corresponding message or the location updating response message of the non-3GPP carries subscription data of the UE.

The MME may authorize the UE according to subscription data of the UE.

S608: the MME determines that the UE is accessing EPC from a non-3GPP network.

S609: and the MME determines a target APN and selects P-GW according to the target APN.

The mode of determining the target APN by the MME may specifically refer to S509, and details of the embodiment of the present invention are not described herein.

However, unlike S509, the MME does not determine the request type of the UE, but selects the P-GW according to the target APN; further, the MME may select a P-GW according to an identity (ePDG ID) of the target APN and the ePDG or may select a P-GW according to the target APN and an IP address of the UE to select a P-GW closer to the UE. S509 may be referred to by the MME based on a manner of selecting a P-GW by a target APN, according to the target APN and an identifier (ePDG ID) of the ePDG, and according to the target APN and an IP address of the UE.

S610: the MME sends an authentication and authorization reply message to the ePDG, wherein the authentication and authorization reply message comprises the target APN, the identification of the P-GW selected by the MME and the identification of the P-GW in the APN configuration parameters corresponding to the target APN in the subscription data of the UE.

Specifically, the APN configuration parameter corresponding to the target APN in the subscription data of the UE already includes the target APN and an identifier of a P-GW corresponding to the target APN in the subscription data of the UE (that is, an identifier of a P-GW in the APN configuration parameter corresponding to the target APN), then the MME may define a new parameter PGW ID-MME for indicating an identifier of the P-GW selected by the MME in the authentication and authorization reply message, and then the authentication and authorization reply message includes the APN configuration parameter and a PGW ID-MME, where the APN configuration parameter includes the identifier of the target APN and the identifier of the P-GW (the identifier of the P-GW corresponding to the target APN in the subscription data of the UE); or, the MME may define, in the APN configuration parameter, a new parameter PGW ID-MME for indicating an identifier of a P-GW selected by the MME, and then the authentication and authorization reply message includes the APN configuration parameter, where the APN configuration parameter includes the target APN, an identifier of the P-GW (an identifier of the P-GW corresponding to the target APN in the subscription data of the UE), and a PGW ID-MME; and the value of the PGW ID-MME is the identification of the P-GW selected by the MME.

S611: and the ePDG selects a target P-GW from the P-GW selected by the MME and the identification of the P-GW in the APN configuration parameters corresponding to the target APN according to the request type of the UE.

Unlike the prior art, if the ePDG determines that the UE is an EPC accessed through an initial attach procedure, the ePDG takes the P-GW selected by the MME as the target P-GW; and if the ePDG determines that the UE is an EPC accessed through a switching process or a multi-access process, the ePDG takes the identification of the P-GW in the APN configuration parameters corresponding to the target APN as the target P-GW.

S612: and the ePDG establishes PDN connection with the target P-GW for the target APN.

S613: and after the PDN connection is successfully established, the ePDG sends the identification of the target P-GW to the MME.

After the PDG is successfully established, the ePDG may notify the MME that the PDN connection is successfully established, and may send the identifier of the target P-GW to the MME in the above message.

S613 is an optional step, the MME may determine the target P-GW by determining the request type of the UE without acquiring from the ePDG. It is determined whether the UE is in the initial attach procedure, and the determination scheme is as described in S502. If so, the target PGW identity is registered with the HSS via S614-S615.

S614: and the MME sends a notification request message to the HSS, wherein the notification request message contains the identification of the target P-GW, so that the identification of the target P-GW is registered to the HSS.

S615: the HSS returns a notification Response (Notify Response) message to the MME.

S613-S615 are optional steps, and the MME may not register the identity of the target P-GW with the HSS.

Corresponding to the P-GW selection method described in fig. 3 or fig. 5, an embodiment of the present invention provides a mobility management element 70, where part or all of logic functions of a 3GPP AAA Server are merged into the mobility management element 70, as shown in fig. 7, the mobility management element 70 may include a receiving unit 701, a determining unit 702, a selecting unit 703, and a sending unit 704;

the receiving unit 701 is configured to receive a request message sent by a non-3GPP access gateway after a user equipment UE accesses an EPC from a non-3GPP network. Since part/all of the logic functions of the 3GPP AAA Server are merged into the mobility management network element, the receiving unit 701 may receive a request message from the non-3GPP network, such as an authentication and authorization request message sent by the non-3GPP access gateway.

The determining unit 702 is configured to determine a request type of the UE, where the request type includes the EPC accessed through an initial attach procedure, the EPC accessed through a handover procedure, or the EPC accessed through a multi-access procedure. The determining unit 702 may determine the request type by: determining the request type by determining whether a context of the UE corresponding to the target APN exists in the mobility management network element; or, the request message includes the request type or the information of the request type, and the request type is determined through the request message; or receiving the request type or the information of the request type sent by the non-3GPP access gateway. The information of the request type may be information generated according to the request type, so that the mobility management network element may determine the request type of the UE according to the information of the request type. Further, the selecting unit 703 may select the target P-GW according to the target APN, including: the selecting unit 703 selects a target P-GW according to the target APN and the identifier of the non-3GPP access gateway; or, the selecting unit 703 selects the target P-GW according to the protocol IP address interconnected between the target APN and the local network of the UE, where the local IP address of the UE is an IP address allocated by the non-3GPP access network to the UE.

The selecting unit 703 is configured to select a target P-GW for the target APN of the UE according to the request type. The selecting unit 703 may also determine the APN of the UE before selecting the target P-GW. When selecting a target P-GW, if the request type is the EPC accessed through an initial attach procedure, the selecting unit 703 may select the target P-GW according to the target APN; or, if the request type is the EPC accessed through a handover procedure or a multiple access procedure, the selecting unit 703 may obtain an identifier of a P-GW in APN configuration parameters corresponding to the target APN in subscription data of the UE, and use the P-GW in the APN configuration parameters corresponding to the target APN as the target P-GW.

The sending unit 704 is configured to return a response message to the non-3GPP access gateway according to the request message, where the response message includes the target APN and the identifier of the target P-GW. For example, if the APN configuration parameter corresponding to the target APN in the subscription data of the UE does not include an identifier of a P-GW, the sending unit 704 may add the identifier of the target P-GW to the APN configuration parameter corresponding to the target APN, and if the identifier of the P-GW included in the APN configuration parameter corresponding to the target APN is not the identifier of the target P-GW, replace the identifier of the P-GW in the APN configuration parameter corresponding to the target APN with the identifier of the target P-GW, so that the APN configuration parameter corresponding to the target APN includes the identifiers of the target APN and the target P-GW; the sending unit 704 may send a response message to the non-3GPP access gateway, where the response includes an APN configuration parameter corresponding to the target APN. When the request message is an authentication and authorization request message, the response message may be an authentication and authorization reply message.

Optionally, the mobility management network element supports an authentication and authorization function of a non-3GPP access network.

In the embodiment of the present invention, the mobility management network element may not register the identifier of the target P-GW in the HSS, and may also ensure that the UE uses the same P-GW when switching between the 3GPP network and the non-3GPP network. Optionally, the mobility management network element may further register the identifier of the target P-GW with an HSS, and then the sending unit 704 is further configured to send, after returning a response message to the non-3GPP access gateway, a notification message to a home subscriber Server HSS, where the notification message includes the target APN and the identifier of the target P-GW, so as to avoid that a process of registering the identifier of the P-GW with the HSS in the prior art needs to support an S6b interface between the P-GW and the 3GPP AAA Server.

Optionally, the mobility management network element may register the identity of the P-GW with the HSS only when the PDN establishment is successful. The determining unit 702 is further configured to determine that the PDN establishment between the non-3GPP access gateway and the target P-GW established for the target APN is successful before the sending unit 704 sends the notification message to the HSS.

Optionally, as for a UE accessed from a 3GPP network, a mobility management network element selects a target P-GW for the UE in the prior art, and for a UE accessed from a non-3GPP network, the mobility management network element selects a target P-GW for the UE in the P-GW selection scheme of the embodiment of the present invention, but the mechanisms for selecting a target P-GW are different between a UE accessed from a 3GPP network and a UE accessed from a non-3GPP network. Thus, the determining unit 702 is further configured to determine that the UE accesses the EPC from a non-3GPP network before determining the request type of the UE. The P-GW selection scheme in the embodiment of the invention is ensured to be adopted only by the UE accessed from the non-3 GPP.

In the embodiment of the present invention, part/all of the logic functions of the 3GPP AAA Server are integrated into the mobility management network element 70, so that the network architecture is simplified, the receiving unit 701 of the mobility management network element 70 can receive the request message sent by the non-3GPP access gateway, the selecting unit 703 can select the target P-GW for the UE accessed from the non-3GPP network, and the sending unit 704 returns the response message including the target APN of the UE and the identifier of the target P-GW to the non-3GPP access network, thereby adapting to the simplified network architecture and realizing the selection of the P-GW.

Corresponding to the P-GW selection method described in fig. 3 or fig. 5, an embodiment of the present invention provides an access gateway 80, as shown in fig. 8, where the access gateway 80 is an access gateway of a non-3GPP network, such as an ePDG, a TWAN, or an HSGW, and the access gateway 80 may include a sending unit 801, a receiving unit 802, and an establishing unit 803;

the sending unit 801 is configured to send a request message to a mobility management element after the UE accesses the EPC from the non-3GPP network. In the embodiment of the present invention, part/all of the logic functions of the 3GPP AAA Server are integrated into the mobility management element, so that the access gateway 80 can directly perform signaling interaction with the mobility management element. Optionally, the mobility management network element supports an authentication and authorization function of a non-3GPP access network.

The receiving unit 802 is configured to receive a response message sent by the mobility management network element according to the request message, where the response message includes a target APN of the UE and an identifier of a target P-GW selected for the target APN.

The establishing unit 803 is configured to establish a PDN connection between the access gateway and the target P-GW for the target APN according to the identifier of the target APN and the identifier of the target P-GW.

Optionally, the access gateway further includes:

a determining unit 804, configured to determine a request type of the UE before the receiving unit 802 receives an identifier of a target access point name APN and a target P-GW of the UE sent by a mobility management network element, where the request type includes the EPC accessed through an initial attach procedure, the EPC accessed through a handover procedure, or the EPC accessed through a multiple access procedure; the sending unit 801 is further configured to send the request type or the information of the request type to the mobility management network element before the receiving unit 802 receives the identifier of the target P-GW and the target access point name APN of the UE sent by the mobility management network element. The information of the request type may be information generated according to the request type, and the mobility management network element determines the request type of the UE according to the information of the request type.

Optionally, the sending unit 801 is further configured to send, after the PDN connection is successfully established, a notification message to the mobility management network element, where the notification message includes indication information used for indicating that the PDN connection is successfully established. Therefore, the mobility management network element can determine that the PDN connection is successfully established according to the notification message.

Optionally, the sending unit is further configured to select the mobility management network element before sending the request message to the mobility management network element. For example, selecting the mobility management network element according to pre-configured information; wherein the preconfigured information includes a corresponding relationship between the location information of the UE and the identifier of the mobility management network element, or the preconfigured information includes a corresponding relationship between the identifier of the non-3GPP access gateway and the identifier of the mobility management network element;

or sending the International Mobile Subscriber Identity (IMSI) of the UE to a routing agent node so that the routing agent node can select the mobility management network element for the UE according to the IMSI of the UE;

alternatively, the first and second electrodes may be,

In the embodiment of the present invention, part/all of the logic functions of the 3GPP AAA Server are integrated into the mobility management network element, so that the network architecture is simplified, the sending unit 801 of the access gateway can send a request message to the mobility management network element, and the receiving unit 802 can receive a response message of the request message, where the response message includes the target APN of the UE and the identifier of the target P-GW selected for the target APN, so that the establishing unit 803 can establish the PDN connection between the access gateway and the target P-GW according to the identifiers of the target APN and the target P-GW, thereby adapting to the simplified network architecture to realize the selection of the P-GW.

Corresponding to the selection method of the P-GW described in fig. 4 or fig. 6, an embodiment of the present invention provides a mobility management element 90, where part of/all of the logic functions of a 3GPP AAA Server are merged into the mobility management element 90, as shown in fig. 9, the mobility management element 90 may include a receiving unit 901, a selecting unit 902, an obtaining unit 903, and a sending unit 904;

the receiving unit 901 is configured to receive a request message sent by a non-3GPP access gateway after a user equipment UE accesses an evolved packet core EPC from a non-3GPP network.

The selecting unit 902 is configured to select a P-GW according to a target APN of the UE. The selecting unit 902 may determine a target APN for the UE before selecting a target P-GW. When selecting a P-GW according to a target APN of the UE, the selecting unit 902 may select a target P-GW according to the target APN, for example, the MME may send the target APN to a DNS server, the DNS server may return a P-GW list (PGW list or P-GW list) capable of connecting the target APN to the MME, and the MME may select an appropriate P-GW from the P-GW list. The selecting unit 902 may further select a target P-GW according to the target APN and the identifier of the non-3GPP access gateway; or selecting a target P-GW according to the target APN and the local IP address of the UE; and selecting the P-GW which is closer to the UE, wherein the local IP address of the UE is the IP address allocated to the UE by the non-3GPP access network.

The acquiring unit 903 acquires an identifier of a P-GW in APN configuration parameters corresponding to the target APN in the subscription data of the UE;

the sending unit 904 is configured to return a response message to the non-3GPP access gateway according to the request message, where the response message includes the target APN of the UE, the identifier of the P-GW selected by the mobility management network element, and the identifier of the P-GW in the APN configuration parameter corresponding to the target APN, so that the non-3GPP access gateway selects the target P-GW for the target APN from the P-GW selected by the mobility management network element and the P-GW in the APN configuration parameter corresponding to the target APN. Optionally, the request message may be an authentication and authorization request message sent by the non-3GPP access gateway; the response message may be an authentication and authorization reply message.

Optionally, the sending unit 904, according to the request message, returning a response message to the non-3GPP access gateway may include: the sending unit 904 adds a first parameter used for indicating an identifier of a P-GW selected by the mobility management network element to the response message, and sends the response message to the non-3GPP access gateway, where the response message includes an APN configuration parameter corresponding to the target APN and the first parameter; or, the sending unit 904 adds a second parameter for indicating an identifier of a P-GW selected by a mobility management network element to an APN configuration parameter corresponding to the target APN, and sends the response message to the non-3GPP access gateway, where the response message includes an APN configuration parameter corresponding to the target APN, and the APN configuration parameter corresponding to the target APN includes the second parameter.

Optionally, the identifier of the P-GW may also be registered in an HSS, without changing an existing HSS network element, and then the receiving unit 901 is further configured to receive the identifier of the target P-GW sent by the non-3GPP access gateway; the sending unit 904 is further configured to send a notification message to a home subscriber server HSS, where the notification message includes the target APN and the identifier of the target P-GW. Or, the selecting unit 902 may further determine a request type of the UE, and determine a target P-GW from P-GWs in APN configuration parameters corresponding to a P-GW selected by the mobility management network element and the target APN according to the request type of the UE, then the sending unit 904 is further configured to send a notification message to a home subscriber server HSS, where the notification message includes identifiers of the target APN and the target P-GW.

Optionally, the selecting unit 902 may further determine that the UE accesses the EPC from a non-3GPP network before selecting a P-GW according to an APN of the UE. Therefore, the P-GW selection scheme provided by the invention is ensured to be adopted for the UE accessed from the non-3 GPP.

In the embodiment of the invention, part/all logic functions of the 3GPP AAA Server are merged into the mobility management network element, thereby simplifying the network architecture. Based on the converged network architecture, the receiving unit 901 of the mobility management element may receive a request message sent by a non-3GPP access gateway, the selecting unit 902 may select a P-GW for a UE accessed from the non-3GPP network, the sending unit 904 may return a response message to the non-3GPP access gateway, where the response message includes a target APN of the UE, an identifier of the P-GW selected by the mobility management element, and an identifier of the P-GW in APN configuration parameters corresponding to the target APN, and the non-3GPP access gateway selects a P-GW from the P-GW selected by the mobility management element and the P-GW in APN configuration parameters corresponding to the target APN according to the request type of the UE, so as to adapt to the simplified network architecture and implement the selection of the P-GW.

Corresponding to the P-GW selection method described in fig. 4 or fig. 6, an embodiment of the present invention provides an access gateway 100, as shown in fig. 10, where the access gateway 100 is an access gateway of a non-3GPP network, such as an ePDG, a TWAN, or an HSGW, and the access gateway 100 may include: transmitting section 1001, receiving section 1002, selecting section 1003, and establishing section 1004.

The sending unit 1001 is configured to send a request message to a mobility management network element after the UE accesses the EPC from the non-3GPP network, for example, send an authentication and authorization request message to the mobility management network element. Optionally, the mobility management network element supports an authentication and authorization function of a non-3GPP access network.

The receiving unit 1002 is configured to receive a response message sent by the mobility management network element according to the request message, where the response message includes a target APN of the UE, an identifier of a P-GW selected by the mobility management network element, and an identifier of a P-GW in APN configuration parameters corresponding to the target APN in subscription data of the UE. Optionally, when the request message is an authentication and authorization request message, the response message may be an authentication and authorization reply message.

The selecting unit 1003 is configured to select, according to the request type of the UE, a target P-GW for the target APN of the UE from the P-GW selected by the mobility management network element and the P-GW in the APN configuration parameters corresponding to the target APN; wherein the request type includes the EPC accessed through an initial attach procedure, the EPC accessed through a handover procedure, or the EPC accessed through a multi-access procedure. For example, if the request type is the EPC accessed through an initial attach procedure, the selecting unit 1003 may select the P-GW selected by the MME as the target P-GW; or, if the request type is the EPC accessed through a handover procedure or a multiple access procedure, the selecting unit 1003 may select a P-GW in APN configuration parameters corresponding to the target APN as the target P-GW.

The establishing unit 1004 is configured to establish a PDN connection between the access gateway and the target P-GW for the target APN according to the identifier of the target APN and the identifier of the target P-GW.

Optionally, the sending unit 1001 may further send the identifier of the target P-GW to the mobility management network element, so that the mobility management network element may obtain the identifier of the target P-GW and register the identifier of the target P-GW with the HSS. Further, the sending unit 1001 may send the identifier of the target P-GW to the mobility management network element only when the PDN connection is successfully established.

Optionally, the sending unit 1001 is further configured to select a mobility management network element before sending the request message to the mobility management network element. The specific implementation manner may refer to the sending unit 801 in fig. 8.

In the embodiment of the invention, part/all logic functions of the 3GPP AAA Server are merged into the mobility management network element, thereby simplifying the network architecture. Based on a converged network architecture, a sending unit 1001 of an access gateway of a non-3GPP network can send a request message to a mobility management element, a receiving unit 1002 can receive a response message returned by the mobility management element and containing a target APN of the UE, an identifier of a P-GW selected by the mobility management element, and an identifier of a P-GW in APN configuration parameters corresponding to the target APN, a selecting unit 1003 selects a P-GW from a P-GW selected by the mobility management element and a P-GW in APN configuration parameters corresponding to the target APN according to a request type of the UE, and an establishing unit 1004 establishes a PDN connection between the access gateway and the target P-GW according to the identifiers of the target APN and the target P-GW.

The embodiments of the apparatuses in fig. 7-10 may also refer to the embodiments of the methods in fig. 3-6, for example, how to determine a target APN of a UE, how to select a target P-GW, and the like, which are not described herein again in the embodiments of the present invention.

As shown in fig. 11, an apparatus for P-GW selection according to an embodiment of the present invention may include:

a processor 1101, a memory 1102, a bus 1104, and a communication interface 1105. The processor 1101, the memory 1102 and the communication interface 1105 are coupled via a bus 1104 and communicate with each other.

The processor 1101 may be a single or multi-core central processing unit, or a specific integrated circuit, or one or more integrated circuits configured to implement an embodiment of the present invention.

The memory 1102 may be a high-speed RAM memory or a non-volatile memory (non-volatile memory), such as at least one disk memory.

The memory 1102 is used for computer execution of instructions 1103. In particular, the computer executable instructions 1103 may include program code therein.

When the apparatus is operated, the processor 1101 executes the computer-executable instruction 1103, and may execute the method flow of P-GW selection according to the method embodiment corresponding to any one of fig. 3 to fig. 6. When the steps of the mobility management network element or MME in fig. 3-6 are performed, the apparatus may be a mobility management network element, such as an MME or SGSN; when performing the steps of the non-3GPP gateway or ePDG in fig. 3-6, the apparatus may be an access gateway of a non-3GPP network, such as ePDG or TWAN or HSGW.

An embodiment of the present invention provides a computer-readable medium, which includes a computer execution instruction, so that when a processor of a computer executes the computer execution instruction, the computer executes a method for selecting a P-GW described in any one of the method embodiments shown in fig. 3 to fig. 6.

The embodiment of the invention provides a system for selecting P-GW, which comprises: a mobility management network element 70 and an access gateway 80; or comprises a mobility management network element 90 and an access gateway 100; the actions performed by the mobility management element 70 and the access gateway 80 and the interaction between them may refer to the description of the method embodiments corresponding to fig. 3 and 5, or may refer to the description of the apparatus embodiments corresponding to fig. 7 and 8, and the actions performed by the mobility management element 90 and the access gateway 100 and the interaction between them may refer to the description of the method embodiments corresponding to fig. 4 and 6, or may refer to the description of the apparatus embodiments corresponding to fig. 9 and 10, and are not described again here.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention essentially or partially contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the examples described in connection with the embodiments disclosed herein may be embodied in electronic hardware, computer software, or combinations of both, and that the components and steps of the examples have been described in a functional general in the foregoing description for the purpose of illustrating clearly the interchangeability of hardware and software. 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 invention.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, 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 also be an electric, mechanical or other form of connection.

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 achieve the purpose of the solution of the embodiment of the present invention.

While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for selecting a packet data gateway P-GW is characterized by comprising the following steps:

after User Equipment (UE) is accessed to an Evolved Packet Core (EPC) from a non-third generation partnership project (3 GPP) network, a mobile management network element receives a request message sent by a non-3GPP access gateway;

2. The method of claim 1, wherein after the mobility management network element returns a response message to the non-3GPP access gateway according to the request message, the method further comprises:

and the mobility management network element sends a notification message to a Home Subscriber Server (HSS), wherein the notification message comprises the identification of the target APN and the identification of the target P-GW.

3. The method according to claim 2, wherein before the mobility management element sends the notification message to the home subscriber server HSS, the method further comprises:

and the mobility management network element determines that the packet data network PDN between the non-3GPP access gateway and the target P-GW established for the target APN is successfully established.

4. The method according to any of claims 1-3, wherein the request message is an authentication and authorization request message sent by the non-3GPP access gateway; the response message is an authentication and authorization reply message.

5. A method for selecting a packet data gateway P-GW, wherein the method has all the features of any one of claims 1 to 4, and wherein the returning, by the mobility management network element, a response message to the non-3GPP access gateway according to the request message, where the response message includes the target APN and an identifier of the target P-GW, includes:

if the APN configuration parameter corresponding to the target APN in the subscription data of the UE does not contain the identification of the P-GW, adding the identification of the target P-GW in the APN configuration parameter corresponding to the target APN;

if the identifier of the P-GW contained in the APN configuration parameter corresponding to the target APN is not the identifier of the target P-GW, replacing the identifier of the P-GW in the APN configuration parameter corresponding to the target APN by the identifier of the target P-GW by the mobility management network element;

and the mobility management network element sends the response message to the non-3GPP access gateway, wherein the response message contains APN configuration parameters corresponding to the target APN, and the APN configuration parameters corresponding to the target APN contain the identification of the target APN and the target P-GW.

6. A method of packet data gateway, P-GW, selection, characterized in that the method has all the features of any one of claims 1 to 5, and in that the mobility management network element determining the request type of the UE comprises:

the mobility management network element determines the request type by determining whether a context of the UE corresponding to the target APN exists in the mobility management network element; alternatively, the first and second electrodes may be,

the request message contains the request type or the information of the request type, and the mobility management network element determines the request type through the request message; alternatively, the first and second electrodes may be,

and the mobility management network element receives the request type or the information of the request type sent by the non-3GPP access gateway.

7. A method for selecting a packet data gateway, P-GW, characterized in that the method has all the features of any one of claims 1 to 6, and that before the mobility management network element determines the request type of the UE, it further comprises:

the mobility management network element determines that the UE accesses the EPC from a non-3GPP network.

8. A method for selecting a packet data gateway, P-GW, characterized in that the method has all the features of any one of claims 1 to 7, and that the selecting, by the mobility management network element, a target P-GW for the target APN according to the request type comprises:

if the request type is the EPC accessed through an initial attach process, the mobility management network element selects the target P-GW according to the target APN; alternatively, the first and second electrodes may be,

and if the request type is the EPC accessed through a switching process or a multi-access process, the mobility management network element acquires the identifier of the P-GW in the APN configuration parameters corresponding to the target APN in the subscription data of the UE, and takes the P-GW in the APN configuration parameters corresponding to the target APN as the target P-GW.

9. The method of claim 8, wherein the selecting the target P-GW based on the target APN comprises:

the mobility management network element selects a target P-GW according to the target APN and the identification of the non-3GPP access gateway; alternatively, the first and second electrodes may be,

the mobility management network element selects a target P-GW according to a protocol IP address interconnected between the target APN and a local network of the UE; and the local IP address of the UE is the IP address allocated to the UE by the non-3GPP access network.

10. A method for selecting a packet data gateway P-GW, characterized in that the method has all the features of any one of claims 1 to 9, and before the mobility management network element selects a target P-GW for a target access point name APN of the UE according to the request type, the method further comprises:

and the mobility management network element determines the target APN of the UE.

11. A PDN connection establishment method is characterized by comprising the following steps:

12. The method of claim 11, wherein before the non-3GPP access gateway receives the UE's target access point name APN and the target P-GW's identification sent by the mobility management element, the method comprises:

the non-3GPP access gateway determining a request type of the UE, the request type including the EPC accessed through an initial attach procedure, the EPC accessed through a handover procedure, or the EPC accessed through a multi-access procedure;

and the non-3GPP access gateway sends the request type or the information of the request type to the mobility management network element.

13. The method according to claim 11 or 12, characterized in that the method further comprises:

and after the PDN connection is successfully established, the non-3GPP access gateway sends a notification message to the mobility management network element, wherein the notification message contains indication information for indicating that the PDN connection is successfully established.

14. A PDN connection establishment method having all the features of the method of any one of claims 11 to 13, and further comprising, before the non-3GPP access gateway sends the request message to a mobility management network element:

alternatively, the first and second electrodes may be,

15. A method for selecting a packet data gateway P-GW is characterized by comprising the following steps:

16. The method of claim 15, further comprising:

the mobility management network element receives the identification of the target P-GW sent by the non-3GPP access gateway;

17. The method according to claim 15 or 16, wherein the request message is an authentication and authorization request message sent by the non-3GPP access gateway; the response message is an authentication and authorization reply message.

18. A method for selecting a packet data gateway P-GW, wherein the method has all the features of any one of claims 15 to 17, and the step of returning, by the mobility management network element, a response message to the non-3GPP access gateway according to the request message, where the response message includes a target APN of the UE, an identifier of the P-GW selected by the mobility management network element, and an identifier of the P-GW in APN configuration parameters corresponding to the target APN includes:

the mobility management network element adds a first parameter used for indicating an identifier of a P-GW selected by the mobility management network element in the response message, and sends the response message to the non-3GPP access gateway, wherein the response message contains APN configuration parameters corresponding to the target APN and the first parameter; or, the mobility management network element adds a second parameter for indicating an identifier of a P-GW selected by the mobility management network element to an APN configuration parameter corresponding to the target APN, and sends the response message to the non-3GPP access gateway, where the response message includes an APN configuration parameter corresponding to the target APN, and the APN configuration parameter corresponding to the target APN includes the second parameter.

19. A method for packet data gateway P-GW selection, characterized in that the method has all the features of any one of claims 15 to 18, and before the mobility management network element selects a P-GW according to a target access point name APN of the UE, the method further comprises:

20. A method for packet data gateway P-GW selection, characterized in that the method has all the features of any one of claims 15 to 19, and in that the mobility management network element selects a P-GW according to a target access point name APN of the UE, comprising:

the mobility management network element selects a target P-GW according to the target APN and the local IP address of the UE; and the local IP address of the UE is the IP address allocated to the UE by the non-3GPP access network.

21. A method for packet data gateway P-GW selection, characterized in that the method has all the features of any one of claims 15 to 20, and before the mobility management network element selects a P-GW according to a target access point name APN of the UE, the method further comprises:

22. A registration method of a packet data gateway P-GW is characterized by comprising the following steps:

23. The method of claim 22, wherein the non-3GPP access gateway selects a target P-GW from the P-GW selected by the mobility management element and the P-GW in the APN configuration parameters corresponding to the target APN according to the request type of the UE, comprising:

if the request type is the EPC accessed through an initial attach process, the non-3GPP access gateway selects the P-GW selected by the MME as the target P-GW; alternatively, the first and second electrodes may be,

and if the request type is the EPC accessed through a switching process or a multi-access process, the non-3GPP access gateway selects the P-GW in the APN configuration parameters corresponding to the target APN as the target P-GW.

24. The method according to any one of claims 22 or 23, further comprising:

and if the PDN connection is successfully established, the non-3GPP access gateway sends the identification of the target P-GW to the mobility management network element.

25. A method of registration of a packet data gateway, P-GW, having all the features of any one of claims 22 to 24 and further comprising, before the non-3GPP access gateway sends a request message to a mobility management element:

alternatively, the first and second electrodes may be,

26. A mobility management network element, comprising:

27. The element of claim 26, wherein the sending unit is further configured to send a notification message to a home subscriber server HSS after returning a response message to the non-3GPP access gateway, where the notification message includes the target APN and the identity of the target P-GW.

28. The element of claim 27, wherein the determining unit is further configured to determine that the PDN establishment between the non-3GPP access gateway and the target P-GW established for the target APN is successful before the sending unit sends a notification message to the HSS.

29. The mobility management element according to any of claims 26-28, wherein the request message is an authentication and authorization request message sent by the non-3GPP access gateway; the response message is an authentication and authorization reply message.

30. A mobility management network element, wherein the mobility management network element has all the features of any one of claims 26 to 29, and the sending unit is specifically configured to, if an APN configuration parameter corresponding to the target APN in subscription data of the UE does not include an identifier of a P-GW, add the identifier of the target P-GW in an APN configuration parameter corresponding to the target APN; if the identification of the P-GW contained in the APN configuration parameter corresponding to the target APN is not the identification of the target P-GW, replacing the identification of the P-GW in the APN configuration parameter corresponding to the target APN with the identification of the target P-GW; and sending an authentication and authorization reply message to the non-3GPP access gateway, wherein the authentication and authorization reply message comprises APN configuration parameters corresponding to the target APN, and the APN configuration parameters corresponding to the target APN comprise the identification of the target APN and the identification of the target P-GW.

31. A mobility management network element, characterized in that the mobility management network element has all the features of any one of claims 26 to 30, and in that the determining unit is specifically configured to determine the request type by determining whether a context of the UE corresponding to the target APN exists in the mobility management network element; alternatively, the first and second electrodes may be,

the request message contains the request type or the information of the request type, and the request type is determined through the request message; alternatively, the first and second electrodes may be,

and receiving the request type or the information of the request type sent by the non-3GPP access gateway.

32. A mobility management element, characterized in that it has all the features of any of claims 26 to 31, and that said determining unit is further configured to determine that said UE accesses said EPC from a non-3GPP network before determining the type of request of said UE.

33. A mobility management element, characterized in that the mobility management element has all the features of any one of claims 26 to 32, and in that the selecting unit is specifically configured to select the target P-GW according to the target APN if the request type is the EPC accessed through an initial attach procedure; alternatively, the first and second electrodes may be,

and if the request type is the EPC accessed through a switching process or a multi-access process, acquiring the identifier of the P-GW in the APN configuration parameters corresponding to the target APN in the subscription data of the UE, and taking the P-GW in the APN configuration parameters corresponding to the target APN as the target P-GW.

34. The mobility management network element of claim 33, wherein the selecting unit selects the target P-GW according to the target APN comprises:

the selection unit selects a target P-GW according to the target APN and the identification of the non-3GPP access gateway; alternatively, the first and second electrodes may be,

the selection unit selects a target P-GW according to a protocol IP address interconnected between the target APN and a local network of the UE; and the local IP address of the UE is the IP address allocated to the UE by the non-3GPP access network.

35. A mobility management network element, characterized in that it has all the features of any one of claims 26 to 34, and in that said selection unit is further configured to determine a target APN for said UE before selecting a target P-GW for said target APN according to said request type determined by said determination unit.

36. An access gateway, wherein the access gateway is an access gateway of a non-third generation partnership project, 3GPP, network, the access gateway comprising:

37. The access gateway of claim 36, further comprising:

a determining unit, configured to determine a request type of the UE before the receiving unit receives an identifier of a target access point name APN and a target P-GW of the UE sent by a mobility management network element, where the request type includes the EPC accessed through an initial attach procedure, the EPC accessed through a handover procedure, or the EPC accessed through a multiple access procedure;

the sending unit is further configured to send the request type or the information of the request type to the mobility management network element before the receiving unit receives the identifier of the target access point name APN and the target P-GW of the UE sent by the mobility management network element.

38. The access gateway according to claim 36 or 37, wherein the sending unit is further configured to send a notification message to the mobility management network element after the PDN connection is successfully established, where the notification message includes indication information indicating that the PDN connection is successfully established.

39. A mobility management network element, comprising:

40. The mobility management element according to claim 39, wherein said receiving unit is further configured to receive an identifier of the target P-GW sent by the non-3GPP access gateway;

the sending unit is further configured to send a notification message to a home subscriber server HSS, where the notification message includes the target APN and an identifier of the target P-GW.

41. The mobility management element according to claim 39 or 40, wherein the request message is an authentication and authorization request message sent by the non-3GPP access gateway; the response message is an authentication and authorization reply message.

42. A mobility management element, characterized in that it has all the features of any one of claims 39 to 41, and that said sending unit, according to said request message, returns a response message to said non-3GPP access gateway, including:

the sending unit adds a first parameter used for indicating an identifier of a P-GW selected by the mobility management network element in the response message, and sends the response message to the non-3GPP access gateway, wherein the response message includes APN configuration parameters corresponding to the target APN and the first parameter; alternatively, the first and second electrodes may be,

the sending unit adds a second parameter for indicating an identifier of a P-GW selected by a mobility management network element in the APN configuration parameters corresponding to the target APN, and sends the response message to the non-3GPP access gateway, wherein the response message includes APN configuration parameters corresponding to the target APN, and the APN configuration parameters corresponding to the target APN include the second parameter.

43. A mobility management element, characterized in that it has all the features of any one of claims 39 to 42, and in that said selection unit is further configured to determine that said UE accesses said EPC from a non-3GPP network before selecting a P-GW according to the APN of said UE.

44. A mobility management element, characterized in that it has all the features of any one of claims 39 to 43, and in that said selecting unit is specifically configured to select a target P-GW according to the target APN and the identity of the non-3GPP access gateway; or selecting a target P-GW according to the target APN and the local IP address of the UE; and the local IP address of the UE is the IP address allocated to the UE by the non-3GPP access network.

45. A mobility management network element, characterized in that it has all the features of any one of claims 39 to 44, and in that said selection unit is further configured to determine a target APN for said UE before selecting a P-GW based on the APN of said UE.

46. An access gateway, wherein the access gateway is an access gateway of a non-third generation partnership project, 3GPP, network, the access gateway comprising:

47. The access gateway according to claim 46, wherein the selecting unit is specifically configured to select the MME-selected P-GW as the target P-GW if the request type is the EPC accessed through an initial attach procedure; alternatively, the first and second electrodes may be,

and if the request type is the EPC accessed through a switching process or a multi-access process, selecting the P-GW in the APN configuration parameters corresponding to the target APN as the target P-GW.

48. The access gateway according to claim 46 or 47, wherein said sending unit is further configured to send an identity of said target P-GW to said mobility management network element if said PDN connection establishment is successful.

49. A mobility management network element, wherein the mobility management network element comprises a processor, a memory, a bus, and a communication interface;

the memory is configured to store computer-executable instructions, the processor is connected to the memory via the bus, and when the mobility management element is running, the processor executes the computer-executable instructions stored in the memory to cause the mobility management element to perform the method for P-GW selection according to any one of claims 1-10 or the method for P-GW selection according to any one of claims 15-21.

50. An access gateway, wherein the access gateway is an access gateway of a non-third generation partnership project, 3GPP, network, the access gateway comprising a processor, a memory, a bus, and a communication interface;

the memory is configured to store computer-executable instructions, the processor is coupled to the memory via the bus, and when the access gateway is operating, the processor executes the computer-executable instructions stored in the memory to cause the access gateway to perform the method for P-GW selection of any one of claims 11-14 or the method for P-GW selection of any one of claims 22-25.

51. A system for packet data gateway, P-GW, selection, comprising a mobility management network element according to any of claims 26-35 and an access gateway according to any of claims 36-38; or

Comprising a mobility management network element according to any of claims 39-45 and an access gateway according to any of claims 46-48.

52. A computer-readable storage medium, characterized in that it stores a computer program which, when executed by hardware, is able to implement the method of any one of claims 1 to 25.