CN101730072B

CN101730072B - Packet data web gateway identification saving method and system in multi-access scene

Info

Publication number: CN101730072B
Application number: CN2009101361769A
Authority: CN
Inventors: 毕以峰; 周晓云
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2009-04-30
Filing date: 2009-04-30
Publication date: 2012-05-23
Anticipated expiration: 2029-04-30
Also published as: CN101730072A; WO2010124551A1

Abstract

The invention discloses a packet data web gateway identification saving method and system in multi-access scene. The method includes that: when user equipment simultaneously accesses a packet data network by two access networks, namely a first access network and a second access network, and the identical packet data network connection is established, an affiliation user or authentication charging server saves the identification of the packet data web network; the first access network is a third generation partner plan 3GPP access network, and the second access network is a non-3GPP access network; or the first access network is a non-3GPP access network, and the second access network is a 3GPP access network; when releasing the access of one access network of the two access networks, the affiliation user or authentication charging server saves the identification of the packet data web gateway. The method can reasonably notify HSS/AAA, P-GW identification can be correctly stored or deleted, and the system is ensured to normally operate in related P-GW identification operation in multi-access scene.

Description

Method and system for storing packet data network gateway identifier in multi-access scene

Technical Field

The present invention relates to the field of communications, and in particular, to a method and a system for storing a packet data network gateway identifier in a multi-access scenario in an Evolved Packet System (EPS).

Background

A Packet system evolved by the third Generation Partnership Project (3rd Generation Partnership Project, abbreviated as 3GPP) is composed of an evolved universal mobile telecommunications system Terrestrial Radio Access Network (evolved universal Terrestrial Radio Access Network, abbreviated as E-UTRAN), a Mobility Management unit (Mobility Management Entity, abbreviated as MME), a serving Gateway (S-GW), a Packet Data Network Gateway (Packet Data Gateway, abbreviated as P-GW or PDN GW), a Home Subscriber Server (Home Subscriber Server, abbreviated as HSS), an Authentication Authorization and accounting (Authentication and Authorization accounting, abbreviated as AAA) Server of 3GPP, a Policy and charging rules Function (Policy and charging rules Function, abbreviated as PCRF) Entity and other support nodes.

Fig. 1 is a schematic diagram of a system architecture of an EPS supporting a plurality of different access technologies. The E-UTRAN is a 3GPP radio access network of the EPS system, and includes a plurality of evolved base stations (evolved NodeB, abbreviated eNB) therein, and the MME is responsible for the related operations of the control planes such as mobility management, processing of non-access stratum signaling, and management of user mobility management context; the S-GW is an access gateway device connected with the E-UTRAN, forwards data between the E-UTRAN and the P-GW, and is responsible for caching paging waiting data; the P-GW is a border gateway between the EPS and a Packet Data Network (PDN) (i.e., a Network where an operator provides an IP service), and is responsible for accessing the PDN and forwarding Data between the EPS and the PDN; the PCRF is a policy and charging rule function entity, and is connected to an operator network Protocol (Internet Protocol, abbreviated as IP) Service network through a receiving interface Rx to obtain Service information, and is connected to a gateway device in the network through a Gx/Gxa/Gxc interface to initiate establishment of an IP bearer, ensure Quality of Service (QoS) of Service data, and perform charging control. Wherein the terminal can access to the P-GW through the E-UTRAN, MME and S-GW and interwork with the external PDN, and thus the E-UTRAN, MME and S-GW are referred to herein as 3GPP access system or 3GPP access (this is only one of the 3GPP access systems, and indeed other 3GPP access systems, to name just one).

The EPS also supports the access of a non-3 GPP access system, wherein the access of the non-3 GPP system is realized through an S2a/b/c interface, and the P-GW is used as a data anchor point of the 3GPP access and the non-3 GPP access. In the system architecture diagram of EPS, non-3 GPP systems can be divided into trusted non-3 GPP IP access and untrusted non-3 GPP IP access. The trusted non-3 GPP IP access can be directly connected with the P-GW through an S2a interface; an untrusted non-3 GPP IP access needs to be connected to a P-GW through an Evolved Packet data gateway (ePDG), an interface between the ePDG and the P-GW is S2b, S2c provides User Equipment (UE) and a User plane related control and mobility Support between the P-GW, and a supported mobility management protocol is Dual-Stack Mobile IPv6(Mobile IPv6 Support for Dual Stack Hosts and Routers, DSMIPv6 for short).

In the 3GPP access system, a 3GPP mobile management unit MME is connected with HSS/AAA through an interface S6a, and the function of the MME is to finish user access authentication when the 3GPP is accessed, and report the information of the 3GPP access network and the identification information of P-GW to the HSS/AAA; a non-3 GPP access gateway (positioned in a trusted or non-trusted access network) and an evolved packet data gateway ePDG are respectively connected with an HSS/AAA through STa, SWa and SWm interfaces (certainly, the middle of the gateway can pass through an AAA server proxy), and the functions of the gateway are that when the non-3 GPP is accessed, the access authentication of a user node is completed and the information of the non-3 GPP access network is reported to the HSS/AAA; the packet data network gateway P-GW is connected with the HSS/AAA through the access S6b, and is used for reporting the identification information of the P-GW to the HSS/AAA when the non-3 GPP is accessed.

The next generation of the EPS system needs to support the UE to Access one PDN, i.e. Multiple Access, through Multiple Access networks, which is a new function in the EPS evolution process, and the related technology is not mature yet and needs to be improved continuously. As shown in fig. 2, the UE accesses the PDN through the same P-GW through the non-3 GPP IP access network and the 3GPP access network under the coverage of both non-3 GPP and 3GPP accesses. In this scenario, the P-GW allocates an IP address to the UE, that is, there is only one IP Connectivity Access Network session (IP-CAN) between the UE and the PDN. As shown in fig. 2, it is assumed that the UE initially attaches to the 3GPP Access network, and the UE establishes a PDN connection corresponding to a default Access Point Name (APN). In the process, a GTP data channel or a PMIPv6 data channel is established between the S-GW and the P-GW for transmitting service data, a 3GPP mobile management unit MME establishes a session with a home subscriber server/an authentication and authorization charging server HSS/AAA, and transmits related user and network information; when UE determines to establish connection to the PDN through a trusted non-3 GPP access network for transmitting some new services, a PMIPv6 data channel is established between the trusted non-3 GPP access gateway and a P-GW, the data channel between the original S-GW and the original P-GW is required to be kept to be deleted and services can be continuously transmitted, and the access gateway of the trusted non-3 GPP system establishes a session with a home subscriber server/an authentication and authorization charging server (HSS/AAA) to transmit user and network information related to the trusted non-3 GPP access network; alternatively, if the UE decides to establish a connection to the PDN via the untrusted non-3 GPP access network for transmitting some new services, then a PMIPv6 data channel is established between the ePDG and the P-GW, and it is necessary to keep the data channel between the original S-GW and the P-GW from being deleted and able to continue transmitting services, and the untrusted non-3 GPP system ePDG will establish a session with the home subscriber server/authentication and authorization charging server/HSS/AAA, passing user and network information related to the untrusted non-3 GPP access network.

The above-described scenarios are the basic scenario of the multi-access research topic, and there are many problems in the prior art in supporting the above functions, among which a problem related to the storage of user information and network information.

The information stored in the current HSS/AAA stores the relevant information of the P-GW in addition to the subscription information of the UE, and specifically includes the following relevant contents:

1. the identification information of the P-GW needs to be stored in the HSS/AAA, when the UE is switched across systems or initiates multi-access, the identification of the P-GW which is strived for can be obtained from the HSS/AAA, so that the P-GW can be ensured not to be changed and the service is continuous;

2. when the user initially accesses the network, the HSS/AAA registers the P-GW identification information, and when the user initiates the off-line operation, the HSS/AAA deletes the information of the P-GW. Specifically, the method comprises the following steps: when 3GPP is accessed, MME reports and updates the identification information of P-GW to HSS/AAA; when 3GPP is off-line, MME sends signaling to HSS/AAA to delete the identification information of P-GW. When non-3 GPP accesses, P-GW reports and updates the identification information to HSS/AAA; when non-3 GPP is off-line, P-GW sends signaling to HSS/AAA to delete its identification information;

3. when a user is switched from a non-3 GPP access network to a 3GPP access network, the P-GW does not send a signaling to the HSS/AAA to delete the identification information of the HSS/AAA; when the user is switched from the 3GPP access network to the non-3 GPP access network, the MME does not send signaling to the HSS/AAA to delete the identification information.

According to the above requirements, the following problems can occur in the multi-access scenario in the prior art:

1. the UE establishes multiple accesses of the same PDN connection from a 3GPP access system and a non-3 GPP access system. At a certain moment, if the UE disconnects the access network from the 3GPP access system but not the connection of the 3GPP access system is reserved, at this moment, the MME sends a notification request signaling to the HSS/AAA to notify the HSS/AAA to delete the identification information of the P-GW, after the identification of the P-GW is deleted from the HSS/AAA, when the UE establishes the multi-access of the PDN connection from the 3GPP access system again or switches to the 3GPP, the correct identification of the P-GW cannot be obtained from the HSS/AAA, the P-GW cannot be ensured not to be changed, and the multi-access/switching failure is caused;

2. the UE establishes multiple accesses of the same PDN connection from a 3GPP access system and a non-3 GPP access system. At a certain moment, if the UE disconnects the access network from the non-3 GPP access system and the connection of the 3GPP access system is reserved, at this time, the P-GW sends a 'P-GW address update' signaling to the HSS/AAA to inform the HSS/AAA to delete the identification information of the P-GW, after the identification of the P-GW is deleted from the HSS/AAA, when the UE establishes the multi-access of the PDN connection from the non-3 GPP access system again or switches to the non-3 GPP, the correct identification of the P-GW cannot be obtained from the HSS/AAA, and the P-GW cannot be ensured to be unchanged, thereby causing the multi-access/switching failure.

Therefore, the operation of the multi-access scenario is greatly different from the prior art, and how to reasonably notify the HSS/AAA and enable the HSS/AAA to correctly store/delete the P-GW identifier so as to ensure that the subsequent process can normally work is a problem that cannot be realized by the prior art and is inevitable to be solved for a multi-access research topic.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a method and a system for storing a packet data network gateway identifier in a multi-access scene, and to ensure the normal operation of the system when the operation of the P-GW identifier is involved in the multi-access scene.

In order to solve the above problem, the present invention provides a method for storing a packet data network gateway identifier in a multi-access scenario, including: when user equipment simultaneously accesses a packet data network through two access networks, namely a first access network and a second access network and establishes the same packet data network connection, an attribution user or an authentication authorization charging server stores the identifier of the packet data network gateway; when the packet data network gateway detects that the user equipment simultaneously accesses the packet data network through two access networks and establishes the same packet data network connection, the packet data network gateway informs the home subscriber or an authentication and authorization charging server that the packet data network connection is in a multi-access state; after receiving the notice, the home subscriber or the authentication authorization charging server changes the recorded access state of the packet data network connection from a single access state to a multi-access state and keeps the identifier of the packet data network gateway; and when the access of one of the two access networks is released, the home subscriber or the authentication authorization charging server changes the recorded multi-access state into a single-access state and keeps the identifier of the packet data network gateway.

Further, the preservation method also has the following characteristics:

the packet data network gateway informs the home subscriber or the authentication authorization accounting server that the packet data network connection is in a multi-access state, and the packet data network gateway sends a packet data network gateway address updating request signaling to the home subscriber or the authentication authorization accounting server and carries a multi-access indication.

Further, the preservation method also has the following characteristics:

the user equipment initiates the release of the access of the 3GPP access network through a mobile management unit, a service gateway and the grouped data network gateway, and the home subscriber or the authentication authorization charging server changes the access state of the grouped data network connection into a single access state and keeps the identification of the grouped data network gateway when detecting that the access state of the grouped data network connection is a multi-access state after receiving the notification request signaling sent by the mobile management unit.

Further, the preservation method also has the following characteristics:

when the user equipment initiates the release of the access of the non-3 GPP access network through a non-3 GPP access network gateway and the packet data network gateway, the home subscriber or the authentication authorization charging server receives a packet data network gateway address updating instruction sent by the packet data network gateway, and when the access state of the packet data network connection is detected to be a multi-access state, the access state of the packet data network connection is changed into a single-access state, and the identification of the packet data network gateway is reserved.

Further, the preservation method also has the following characteristics:

when the user equipment directly initiates the release of the access of the non-3 GPP access network through the packet data network gateway, after the home subscriber or the authentication authorization charging server receives a packet data network gateway address updating instruction sent by the packet data network gateway, when the access state of the packet data network connection is detected to be a multi-access state, the access state of the packet data network connection is changed into a single-access state, and the identification of the packet data network gateway is reserved.

Further, the preservation method also has the following characteristics:

when the packet data network gateway initiates the release of the access of one of the two access networks, after receiving a packet data network gateway address updating instruction sent by the packet data network gateway, the home subscriber or the authentication authorization charging server changes the access state of the packet data network connection into a single access state when detecting that the access state of the packet data network connection is a multi-access state, and keeps the identifier of the packet data network gateway.

Further, the preservation method also has the following characteristics:

when the user equipment or the packet data network gateway initiates the release of the access of another access network, the home subscriber or the authentication authorization charging server deletes the identifier of the packet data network gateway when receiving a release indication signaling and detecting that the recorded access state of the packet data network connection is a single access state.

Further, the preservation method also has the following characteristics:

when the user equipment accesses a packet data network connection through the 3GPP access network or the non-3 GPP access network, the home subscriber or the authentication authorization charging server records that the access state of the packet data network connection is a single access state, and saves a packet data network gateway identifier; and when releasing the access of the access network, the home subscriber or the authentication authorization charging server deletes the gateway identifier of the packet data network after detecting that the recorded access state of the packet data network connection is a single access state.

Further, the preservation method also has the following characteristics:

the home subscriber or the authentication authorization accounting server records the access state of the packet data network connection by using one of the following modes; setting a flag bit for recording the access state of the packet data network connection, and recording different access states of the packet data network connection by changing the value of the flag bit; or, different access states of the packet data network connection are indicated by storing different numbers of identifiers of the packet data network gateways.

Further, the preservation method also has the following characteristics:

the first access network is a third generation partnership project, 3GPP, access network, and the second access network is a non-3 GPP access network; or, the first access network is a non-3 GPP access network and the second access network is a 3GPP access network.

In order to solve the above technical problem, the present invention further provides a system for storing a packet data network gateway identifier in a multi-access scenario, including a packet data network gateway and a home subscriber or an authentication authorization accounting server, where the home subscriber or the authentication authorization accounting server is configured to store the packet data network gateway identifier when a user equipment is simultaneously connected to a packet data network through two access networks, i.e. a first access network and a second access network; the packet data network gateway is used for notifying the home subscriber or the authentication authorization charging server that the packet data network connection is in a multi-access state when detecting that the user equipment simultaneously accesses the packet data network through two access networks and establishes the same packet data network connection; the home subscriber or the authentication authorization charging server is further configured to change the recorded access state of the packet data network connection from a single access state to a multi-access state after receiving the notification, and retain an identifier of the packet data network gateway; and the gateway is further configured to change the recorded multi-access state to a single-access state and retain the identifier of the packet data network gateway when access to one of the two access networks is released.

Further, the system also has the following characteristics:

the home subscriber or the authentication authorization charging server is further configured to initiate, by the user equipment through a mobility management unit, a serving gateway, and the packet data network gateway, to release the access of the 3GPP access network, and after receiving a notification request signaling sent by the mobility management unit; or; the user equipment initiates the release of the access of the non-3 GPP access network through a non-3 GPP access network gateway and the packet data network gateway, and receives a packet data network gateway address updating instruction sent by the packet data network gateway; or; the user equipment initiates the release of the access of the non-3 GPP access network through the packet data network gateway, and receives a packet data network gateway address updating instruction sent by the packet data network gateway; or the packet data network gateway initiates the release of the access of one of the two access networks, detects that the access state of the packet data network connection is in a multi-access state after receiving a packet data network gateway address updating instruction sent by the packet data network gateway, changes the access state of the packet data network connection into a single-access state, and retains the identifier of the packet data network gateway.

The method of the invention can reasonably inform HSS/AAA and make it correctly store or delete P-GW identification, and ensure normal operation of the system when P-GW identification operation is involved in a multi-access scene.

Drawings

FIG. 1 is a diagram of a prior art EPS system architecture;

fig. 2 is a schematic diagram of a multiple access scenario according to the related art in the prior art;

FIG. 3 is a first flowchart illustrating simultaneous access of a 3GPP access network and a non-3 GPP access network in the first embodiment;

FIG. 4 is a second flowchart illustrating simultaneous access of a 3GPP access network and a non-3 GPP access network in the first embodiment;

FIG. 5 is a third flowchart illustrating simultaneous access of a 3GPP access network and a non-3 GPP access network in the first embodiment;

fig. 6 is a flowchart of a method for storing a P-GW id in the first embodiment;

fig. 7 is a flowchart of a method for storing a P-GW id in the second embodiment;

fig. 8 is a flowchart of a method for storing a P-GW id in the third embodiment;

fig. 9 is a flowchart of a method for storing a P-GW id in the fourth embodiment.

Detailed Description

According to different orders of accessing the access network by the UE, the 3GPP access network can be called a first access network, and the non-3 GPP access network can be called a second access network; alternatively, the non-3 GPP access network is referred to as a first access network and the 3GPP access network is referred to as a second access network. UE is connected to the same PDN through a first access network and a second access network simultaneously, and HSS/AAA stores a packet data network gateway identifier when the same PDN connection is established; when UE releases the access of one of the two access networks, HSS/AAA does not delete P-GW identification, but keeps P-GW identification. When UE establishes the access of PDN connection from released access network again or switches the access network, the UE can obtain the correct P-GW identification from HSS/AAA to ensure the correct execution of re-access or switch.

There are many ways to implement the above operation by HSS/AAA, and in order to minimally affect the information interaction flow in the existing protocol, the following ways may be adopted: UE establishes the same PDN connection through two access networks, and when accessing a PDN at the same time, HSS/AAA records the access state of the PDN connection as a multi-access state; when UE or P-GW initiates the release of the access of one access network of two access networks, HSS/AAA detects that the previous access state of PDN connection recorded by HSS/AAA is multi-access state, and changes the access state of PDN connection to single access state. When UE or P-GW initiates the release of the last access network, HSS/AAA detects that the previous access state of PDN connection recorded by HSS/AAA is single access state, and deletes the P-GW identification.

The HSS/AAA can set a flag bit of the PDN connection access state, and change the PDN connection access state by changing the value of the flag bit. For example, the flag bit is 1 to indicate the multi-access state; the flag bit is set to 0, indicating a single access state. The access status of the current PDN connection may also be indicated by storing two or one P-GW identities. For example, storing the identities of two P-GWs indicates a multi-access state; storing an identification of a P-GW indicates a single access state.

The system for storing the grouped data network gateway identifier in the multi-access scene comprises a grouped data network gateway and an attribution user or an authentication authorization charging server;

the packet data network gateway is used for notifying the home subscriber or the authentication authorization charging server that the packet data network connection is in a multi-access state when detecting that the user equipment simultaneously accesses the packet data network through two access networks and establishes the same packet data network connection;

the home subscriber or the authentication authorization charging server is used for storing a packet data network gateway identifier when the user equipment is simultaneously accessed to a packet data network connection through two access networks, namely a first access network and a second access network; the access control unit is further configured to change the recorded access state of the packet data network connection from a single access state to a multiple access state after receiving the multiple access indication, and retain an identifier of the packet data network gateway; and the gateway is further configured to change the recorded multi-access state to a single-access state and retain the identifier of the packet data network gateway when access to one of the two access networks is released. The network element is also used for initiating the release of the access of the 3GPP access network by the user equipment through a mobile management unit, a service gateway and the packet data network gateway, and receiving a notification request signaling sent by the mobile management unit; or; the user equipment initiates the release of the access of the non-3 GPP access network through a non-3 GPP access network gateway and the packet data network gateway, and receives a packet data network gateway address updating instruction sent by the packet data network gateway; or; the user equipment initiates the release of the access of the non-3 GPP access network through the packet data network gateway, and receives a packet data network gateway address updating instruction sent by the packet data network gateway; or the packet data network gateway initiates the release of the access of one of the two access networks, detects that the access state of the packet data network connection is in a multi-access state after receiving a packet data network gateway address updating instruction sent by the packet data network gateway, changes the access state of the packet data network connection into a single-access state, and retains the identifier of the packet data network gateway.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

Example one

When UE initially accesses from a single access network, the PDN connection state of the UE in HSS/AAA is defaulted to be a single access state, the UE accesses the PDN through a second access network, a 3GPP access network and a non-3 GPP access network are simultaneously linked to the PDN, when the same PDN connection is established, P-GW informs the HSS/AAA that the PDN connection state of the UE is a multi-access state, and the HSS/AAA stores the P-GW identification and the current state, namely the multi-access state, in the PDN connection. After UE initiates the multi-connection removal operation of 3GPP access network, HSS/AAA receives the 'notice request' message sent by MME, and detects that the previous state of PDN connection is multi-access state, only changes the multi-access state to single-access state, but not deletes P-GW identification.

The process of the UE accessing a certain PDN through the 3GPP access network and the non-3 GPP access network may be any one of the access processes shown in fig. 3 (the UE accesses a PDN through the non-3 GPP access network first and then accesses the PDN through the 3GPP access network), fig. 4 (the UE accesses the PDN through the 3GPP access network first and then accesses the PDN through the non-3 GPP access network (S2a mode)) and fig. 5 (the UE accesses a PDN connection through the 3GPP access network first and then accesses the PDN connection through the non-3 GPP access network (S2c mode)). The access procedures of fig. 3, 4, and 5 are described in detail below:

as shown in fig. 3, the UE has been attached to the EPS through the non-3 GPP access network, and may have one or several services transmitted, then the terminal initiates an access request to the EPS through the 3GPP access network, and after the P-GW receives the proxy binding update/default bearer creation request signaling, the P-GW notifies the HSS/AAA that the current scenario is a multi-access scenario. The specific access process comprises the following steps:

step 301, the UE accesses to the EPS through the non-3 GPP access network, and may have related services transmitted over the connection; according to the existing flow, HSS/AAA has stored P-GW identification, and the default access state is single access state;

step 302, UE sends an 'attach request' signaling to MME, requesting to access EPS through a 3GPP access system;

step 303, the UE completes access authentication, location update and authorization operations through a 3GPP access network (MME);

step 304, MME sends signaling of 'establishing default load bearing request' to S-GW;

the above steps 302 to 304 are the attachment steps initiated by the UE in the 3GPP access network, and if the UE has completed the attachment in the 3GPP access network, the UE only initiates the multi-access of another PDN connection in the 3GPP access network, then the signaling of "PDN connection establishment request" is sent in step 302, and step 303 does not need to be performed.

Step 305, after receiving the signaling of 'establishing default bearer request' sent by MME, S-GW sends a signaling of 'establishing default bearer request' or 'proxy binding update' to P-GW (PMIPv6) to request to establish tunnel binding;

step 306, after determining that the current PDN connection of the UE is a multi-access situation according to the corresponding mechanism, the P-GW sends a "P-GW address update request" signaling to the HSS/AAA, and carries a "multi-access indication";

step 307, after the HSS/AAA receives the "multiple access indication", and knows that the PDN connection of the current UE is multiple access, records that the PDN connection state of the UE is multiple access, and maintains the stored P-GW id.

Step 308, the P-GW responds to the S-GW with a "setup default bearer response" signaling (GTP) or a "proxy binding answer" (PMIPv6) signaling to notify that the S-GW tunnel binding is completed;

step 309, S-GW responds "default bearer setup response" to MME;

in step 310, radio bearer establishment and bearer update operations are performed between the UE and the MME.

As shown in fig. 4, the terminal has attached to the EPS through a 3GPP access network and may have one or several traffic transmissions. Then, the terminal initiates an access request (based on an S2a interface) to the EPS through a trusted non-3 GPP access network, and after the P-GW receives the proxy binding update, the P-GW notifies that the HSS/AAA is currently a multi-access scenario, and the specific access process includes the following steps:

step 401, the UE accesses to the EPS system through the 3GPP access network, and may have related services transmitted over the connection, where a data channel is established between the S-GW and the P-GW through a GTP or PMIPv6 protocol; according to the existing flow, HSS/AAA has stored P-GW identification, and the default access state is single access state;

step 402, UE and non-3 GPP access gateway execute specific non-3 GPP access network air interface link establishment operation;

step 403, the UE completes access authentication and authorization operations through the non-3 GPP access network;

step 404, the UE initiates an attach request to the non-3 GPP access network according to its specific mode;

the above steps 402 to 404 are the attachment steps initiated by the UE in the 3GPP access network, and if the UE has completed the attachment in the non-3 GPP access network and the UE only initiates the multi-access of another PDN connection in the non-3 GPP access network, then the signaling "PDN connection establishment request" is sent in step 402, and step 403 does not need to be performed.

Step 405, after receiving the attach request/PDN connection establishment request sent by the UE, the non-3 GPP access gateway sends an "agent binding update" message to the P-GW, requesting to establish tunnel binding;

step 406, after determining that the PDN connection of the current UE is a multi-access situation according to the corresponding mechanism, the P-GW sends a "P-GW address update request" signaling to the HSS/AAA, and carries a "multi-access indication";

step 407, after the HSS/AAA receives the "multiple access indication", and knows that the PDN connection of the current UE is multiple access, it records that the PDN connection state of the UE is multiple access, and maintains the stored P-GW id;

step 408, the P-GW responds a 'proxy binding acknowledgement' signaling to the non-3 GPP access gateway to notify that the non-3 GPP access gateway tunnel binding is completed;

step 409, the UE successfully attaches to the non-3 GPP access network.

As shown in fig. 5, the same as that shown in fig. 4, both indicate that the UE accesses through the 3GPP access network first and then accesses through the non-3 GPP access network, and different from the access mode shown in fig. 4, the UE accesses through the S2c interface of the non-3 GPP access network, and the P-GW notifies that the HSS/AAA is currently a multi-access scenario, where the specific access process includes the following steps:

steps 501 to 503 are the same as steps 401 to 403 in fig. 4;

step 504, the UE initiates an attach request to the non-3 GPP access network according to its specific mode, and performs operations such as local address allocation and bootstrapping;

if the attachment has been completed, the UE simply wants to initiate multiple accesses of another PDN connection in the second access network, and then step 502 and step 503 can be omitted. This step, step 504, initiates a non-3 GPP access system specific "PDN connection request" signaling;

step 505, UE sends 'binding update' message to P-GW to request to establish tunnel binding;

step 506, after determining that the PDN connection of the current UE is a multi-access situation according to the corresponding mechanism, the P-GW sends a "P-GW address update request" signaling to the HSS/AAA, and carries a "multi-access indication";

step 507, after HSS/AAA receives the multi-access indication, it knows that the PDN connection of UE is multi-access, records that the PDN connection state of UE is multi-access, and maintains the stored P-GW identification;

step 508, the P-GW responds to the UE with a "binding acknowledgement" signaling to notify the UE that the tunnel binding is complete.

After any access procedure in fig. 3, fig. 4, or fig. 5 is performed, the UE accesses a PDN connection through the 3GPP access network and the non-3 GPP access network at the same time, as shown in fig. 6, the procedure for the UE to initiate release of the 3GPP access network access includes the following steps:

step 601, after passing through the processes shown in fig. 3, fig. 4 or fig. 5, the UE accesses a PDN through the 3GPP access network and the non-3 GPP access network simultaneously, and establishes the same PDN connection;

step 602, the UE sends a detach request signaling to the MME through the 3GPP access network;

the above step 602 is a detach step initiated by the UE in the 3GPP access network, and if the UE only wants to initiate the removal of a certain PDN connection in the 3GPP access network, the step is a "PDN connection deletion request" signaling;

step 603, the MME sends a request signaling for deleting the bearer to the S-GW;

step 604, after receiving the request signaling for deleting the bearer sent by the MME, the S-GW sends a request signaling for deleting the bearer or a proxy binding update message to the P-GW, where the lifetime in the proxy binding update message is set to zero to indicate that tunnel binding is requested to be deleted;

step 605, the P-GW responds to the S-GW with a delete bearer response or a proxy binding update response, and notifies the S-GW of completion of tunnel unbinding;

step 606, the S-GW sends a delete bearer response signaling to the MME;

step 607, the S-GW responds to the UE with detach response, notifying that detach was successful;

step 608, the MME knows that the current UE will delete the connection from the 3GPP access network, sends an announcement request signaling to HSS/AAA, and the HSS/AAA returns a response to the MME;

step 609, after the HSS/AAA detects that the recorded PDN connection access state of the UE is a multi-access state, changes the PDN connection state of the UE to a single-access state, and keeps the P-GW id.

If after step 609, when the UE or the P-GW initiates the non-3 GPP access network to initiate the procedure of releasing the non-3 GPP access network, the HSS/AAA detects that the access state of the PDN connection is the single access state, and deletes the P-GW identity.

By the method, when the UE establishes the access of the PDN connection from the 3GPP access network again or is switched from the non-3 GPP, the accurate P-GW identification can be obtained from the HSS/AAA, and the accurate execution of the re-access or the switching is ensured.

The first embodiment of the present invention illustrates a scenario where after a UE accesses a certain PDN through a 3GPP access network and a non-3 GPP access network, the UE initiates removal of access from the 3GPP access network. The following describes a scenario in which the UE initiates the removal of an access from a non-3 GPP access network in embodiments two and three. In the second embodiment, the non-3 GPP access network is based on the S2a port, and in the third embodiment, the non-3 GPP access network is based on the S2c port.

Example two

When UE initially accesses from a single access network, the PDN connection state of the UE in HSS/AAA is defaulted to be a single access state, the UE accesses the PDN through a second access network, a 3GPP access network and a non-3 GPP access network are simultaneously linked to a certain PDN, when the same PDN connection is established, P-GW informs the HSS/AAA that the PDN connection state of the UE is a multi-access state, and the HSS/AAA stores the P-GW identification and the current state, namely the multi-access state, in the PDN connection. After UE initiates the multi-connection removal operation of non-3 GPP access network, HSS/AAA receives the 'update P-GW address request' message sent by P-GW, and detects that the previous state of PDN connection is multi-access state, only changes the multi-access state to single-access state, but not deletes the P-GW identification.

In the second embodiment, the UE completes the procedure of accessing a PDN connection simultaneously through the 3GPP access network and the non-3 GPP access network, which may be any one of the procedures shown in fig. 3, fig. 4, or fig. 5. As shown in fig. 7, the process of UE initiating release of non-3 GPP access network access (based on S2a interface) includes the following steps:

step 701, after passing through the processes shown in fig. 3, fig. 4, or fig. 5, the UE accesses a PDN through the 3GPP access network and the non-3 GPP access network (through the S2a interface) at the same time, and establishes the same PDN connection;

step 702, UE initiates a non-3 GPP access network specific detach request through a non-3 GPP access gateway;

the step 702 is a detach step initiated by the UE in the second access network, and if the UE only wants to initiate the removal of a PDN connection in the second access network, the step is a "PDN connection deletion request" signaling specific to the non-3 GPP access system.

Step 703, after receiving the detach request/PDN connection delete request sent by the UE, the non-3 GPP access gateway sends an "agent binding update" message to the P-GW, where the lifetime in the signaling is set to zero to request to delete tunnel binding;

step 704, the P-GW sends a 'P-GW address update request' signaling to the HSS/AAA;

step 705, after the HSS/AAA detects that the recorded PDN connection status of the UE is a multi-access status, the PDN connection status of the UE is changed to a single-access status, and the P-GW id is reserved.

Step 706, the P-GW responds the 'proxy binding acknowledgement' signaling to the non-3 GPP access gateway, and notifies the non-3 GPP access gateway that the tunnel is unbound;

step 707, the UE realizes successful detach in the non-3 GPP access network.

If after step 707, the UE or the P-GW initiates a 3GPP access network to initiate a procedure of releasing the 3GPP access network, and the HSS/AAA detects that the access state of the PDN connection is the single access state, the P-GW identity is deleted.

EXAMPLE III

The main difference between the third embodiment and the second embodiment is that the UE initiates a procedure of releasing the non-3 GPP access network access based on the S2c interface. As shown in fig. 8, the method comprises the following steps:

step 801, after the processes shown in fig. 3, fig. 4, or fig. 5, the UE accesses a PDN through the 3GPP access network and the non-3 GPP access network (through the S2c interface) simultaneously, and establishes the same PDN connection;

step 802, the UE decides to delete the non-3 GPP access part of the PDN connection, and then sends a binding update signaling to the P-GW, and sets the lifetime to zero in the signaling;

step 803, the P-GW sends a 'P-GW address update request' signaling to the HSS/AAA;

step 804, after the HSS/AAA detects that the recorded PDN connection status of the UE is a multi-access status, the PDN connection status of the UE is changed to a single-access status, and the P-GW identity is reserved.

Step 805, the P-GW responds a binding acknowledgement signaling to the UE to notify the UE that the UE is unbound;

step 806, non-3 GPP access network resource release is carried out between the UE and the P-GW.

If after step 806, when the UE or P-GW initiates the 3GPP access network to initiate the procedure of releasing the 3GPP access network, the HSS/AAA detects that the access state of the PDN connection is the single access state, and deletes the P-GW identity.

Example four

In the first, second, and third embodiments, an access procedure initiated by a UE to release a 3GPP access network or a non-3 GPP access network is described, and in the fourth embodiment, an access procedure initiated by a P-GW to release a 3GPP access network or a non-3 GPP access network is described, as shown in fig. 9, the method includes the following steps:

step 901, after passing through the processes shown in fig. 3, fig. 4 or fig. 5, the UE accesses a PDN through the 3GPP access network and the non-3 GPP access network at the same time, establishes the same PDN connection, and may transmit service data on different access systems;

step 902, the P-GW makes a decision or needs to delete the access of one of the access networks according to the trigger of other network elements;

the PDN connection deletion initiated by the P-GW may be because, after the UE initiates the IP flow migration, all IP flows of a certain access network are migrated to another access network, and the access network has no service data transmission, or for other reasons.

Step 903, P-GW sends 'P-GW address update request' signaling to HSS/AAA;

step 904, after the HSS/AAA detects that the recorded PDN connection status of the UE is a multi-access status, the PDN connection status of the UE is changed to a single-access status, and the P-GW id is reserved.

Step 905, the P-GW initiates a deletion process of a certain access network with PDN multi-access;

except for the cases described in the first to fourth embodiments, if the UE accesses a certain PDN connection through only one access network, i.e., through a 3GPP access network or a non-3 GPP access network, the HSS/AAA defaults that the access state of the PDN connection is a single access state, and stores the P-GW identifier, and when the UE or the P-GW initiates an access removal procedure of the access network, and the HSS/AAA detects that the recorded access state of the PDN connection is the single access state, the access of the access network is released and the P-GW identifier is deleted.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The method for storing the packet data network gateway identifier in the multi-access scene comprises the following steps:

when user equipment simultaneously accesses a packet data network through two access networks, namely a 3GPP access network and a non-3 GPP access network and establishes the same packet data network connection, an attribution user server or an authentication authorization charging server stores the identifier of the packet data network gateway;

when the packet data network gateway detects that the user equipment simultaneously accesses the packet data network through two access networks and establishes the same packet data network connection, the packet data network gateway informs the home subscriber server or the authentication authorization charging server that the packet data network connection is in a multi-access state; after receiving the notice, the home subscriber server or the authentication authorization charging server changes the recorded access state of the packet data network connection from a single access state to a multi-access state and keeps the identifier of the packet data network gateway;

and when the access of one of the two access networks is released, the home subscriber server or the authentication authorization charging server changes the recorded multi-access state into a single-access state and keeps the identifier of the packet data network gateway.

2. The saving method according to claim 1,

the packet data network gateway informs the home subscriber server or the authentication authorization accounting server that the packet data network connection is in a multi-access state, and the packet data network gateway sends a packet data network gateway address updating request signaling to the home subscriber server or the authentication authorization accounting server and carries a multi-access indication.

3. The saving method according to claim 1,

the user equipment initiates the release of the access of the 3GPP access network through a mobile management unit, a service gateway and the grouped data network gateway, and the home subscriber server or the authentication authorization charging server changes the access state of the grouped data network connection into a single access state and keeps the identification of the grouped data network gateway when detecting that the access state of the grouped data network connection is a multi-access state after receiving the notification request signaling sent by the mobile management unit.

4. The saving method according to claim 1,

when the user equipment initiates the release of the access of the non-3 GPP access network through a non-3 GPP access network gateway and the packet data network gateway, the home subscriber server or the authentication authorization charging server receives a packet data network gateway address updating instruction sent by the packet data network gateway, and when the access state of the packet data network connection is detected to be a multi-access state, the access state of the packet data network connection is changed into a single-access state, and the identifier of the packet data network gateway is reserved.

5. The saving method according to claim 1,

when the user equipment directly initiates the release of the access of the non-3 GPP access network through the packet data network gateway, after the home subscriber server or the authentication authorization charging server receives a packet data network gateway address updating instruction sent by the packet data network gateway, when the access state of the packet data network connection is detected to be a multi-access state, the access state of the packet data network connection is changed into a single-access state, and the identification of the packet data network gateway is reserved.

6. The saving method according to claim 1,

when the packet data network gateway initiates the release of the access of one of the two access networks, after receiving a packet data network gateway address updating instruction sent by the packet data network gateway, the home subscriber server or the authentication authorization charging server changes the access state of the packet data network connection into a single access state when detecting that the access state of the packet data network connection is a multi-access state, and keeps the identifier of the packet data network gateway.

7. The preservation method according to any one of claims 1 to 6,

and when the user equipment or the packet data network gateway initiates the release of the access of another access network, the home subscriber server or the authentication authorization charging server deletes the identifier of the packet data network gateway when receiving a release indication signaling and detecting that the recorded access state of the packet data network connection is a single access state.

8. The preservation method according to any one of claims 1 to 6,

when the user equipment accesses a packet data network connection through the 3GPP access network or the non-3 GPP access network, the home subscriber server or the authentication authorization charging server records that the access state of the packet data network connection is a single access state, and saves a packet data network gateway identifier;

and when releasing the access of the access network, the home subscriber server or the authentication authorization charging server deletes the gateway identifier of the packet data network after detecting that the recorded access state of the packet data network connection is a single access state.

9. The preservation method according to any one of claims 1 to 6,

the home subscriber server or the authentication authorization charging server records the access state of the packet data network connection in one of the following modes;

setting a flag bit for recording the access state of the packet data network connection, and recording different access states of the packet data network connection by changing the value of the flag bit; or,

and representing different access states of the packet data network connection by storing different numbers of the identifiers of the packet data network gateways.

10. The system for storing the grouped data network gateway identification under the multi-access scene comprises the grouped data network gateway and a home subscriber server or an authentication authorization charging server, wherein the home subscriber server or the authentication authorization charging server is used for storing the grouped data network gateway identification when user equipment is simultaneously accessed into a grouped data network connection through two access networks, namely a 3GPP access network and a non-3 GPP access network; it is characterized in that the preparation method is characterized in that,

the packet data network gateway is used for notifying the home subscriber server or the authentication authorization charging server that the packet data network connection is in a multi-access state when detecting that the user equipment simultaneously accesses the packet data network through two access networks and establishes the same packet data network connection;

the home subscriber server or the authentication authorization charging server is further configured to change the recorded access state of the packet data network connection from a single access state to a multi-access state after receiving the notification, and retain an identifier of the packet data network gateway; and the gateway is further configured to change the recorded multi-access state to a single-access state and retain the identifier of the packet data network gateway when access to one of the two access networks is released.

11. The system of claim 10,

the home subscriber server or the authentication authorization charging server is further configured to initiate, by the user equipment through a mobility management unit, a serving gateway, and the packet data network gateway, an access to release the 3GPP access network, and after receiving a notification request signaling sent by the mobility management unit; or; the user equipment initiates the release of the access of the non-3 GPP access network through a non-3 GPP access network gateway and the packet data network gateway, and receives a packet data network gateway address updating instruction sent by the packet data network gateway; or; the user equipment initiates the release of the access of the non-3 GPP access network through the packet data network gateway, and receives a packet data network gateway address updating instruction sent by the packet data network gateway; or the packet data network gateway initiates the release of the access of one of the two access networks, and after receiving a packet data network gateway address updating instruction sent by the packet data network gateway; and when detecting that the access state of the packet data network connection is a multi-access state, changing the access state of the packet data network connection into a single-access state, and reserving the identifier of the packet data network gateway.