CN101998540B - Method, device and system for realizing optimized switching of network - Google Patents

Abstract

The invention discloses a method, a device and a system for realizing the optimized switching of a network. The method comprises the steps of: when user equipment or a source network confirms to initiate the switching preparation to a target network, querying a corresponding target network identification from a configured mapping relation by a mobility management entity according to a received cell identification so as to confirm an access node of the target network; establishing the connection to a target network service gateway and instructing or instructing, by the service gateway, a packet data network gateway to process the uplink and downlink data channels of a user interface; after accomplishing the connection to the service gateway, initiating a resource reserving request of the access node of the target network by the mobility management entity, and instructing not to establish the air interface connection; and after accomplishing the switching preparation, instructing, by the mobility management entity or the service gateway, the packet data network gateway to switch the uplink and downlink data channels of the user interface to the target network. Through the application of the invention, the continuity of the service can be ensured and the user experience can be improved when the user equipment is switched from the source network to the target network.

Description

Method, equipment and system for realizing network optimization switching

The application is a divisional application of an original application with an application date of 2007, 11 and 9, and an application number of 200710169584.5, and is named as a method, equipment and a system for realizing network optimization switching.

Technical Field

The present invention relates to network handover technologies, and in particular, to a method, device, and system for implementing network optimized handover.

Background

Conventional telecommunication networks, especially wireless communication networks such as global System for Mobile communications (GSM), Universal Mobile Telecommunications System (UMTS), etc., have the advantages of abundant service types, strong network control capability, etc., and are widely used. With the continuous development and improvement of network technology, users have higher requirements on the speed of data services, but due to the influence of factors such as limited frequency resources, bad transmission environment and the like of a wireless communication system, higher access speed cannot be provided for the users, so that the broadband wireless access technology becomes a main technology for solving the high access speed of the users. For example, a broadband Wireless Access technology represented by a Wireless Local Area Network (WLAN) and worldwide Interoperability for microwave Access (WiMAX) can provide a high-rate broadband Wireless Access service for a user, and support nomadic and mobile applications, thereby greatly improving the Access capability of a Wireless communication Network. The convergence of mobile communication networks and broadband wireless access technologies is a trend of telecommunication network evolution.

Fig. 1 is a schematic diagram of a first structure of an evolved telecommunication network. Referring to fig. 1, an evolved architecture for trusted non-third Generation mobile communication standardization Partnership Project (3 GPP) access to a 3GPP Network includes a User Equipment (UE), a broadband wireless access Network, a Data gateway, a core control entity, and a Packet Data Network (PDN),

the UE accesses a broadband wireless access network, the broadband wireless access network can be a WiMAX network, tunnel connection to a data gateway is established through a tunnel technology (a protocol packet transmitted between two endpoint entities of a tunnel is encapsulated by another protocol to realize safe transmission and routing of data between the two endpoint entities), the data gateway establishes connection with a PDN, so that connectivity between the UE and the PDN is established, and a core control entity controls the data gateway and the broadband wireless access network. The data gateway is a large-range mobile anchor point of the UE and is an interface entity of the core network and the PDN, and the data gateway transmits the user data between the core network and the PDN after receiving the user data. In addition, the data gateway may also be responsible for implementing access policies, filtering packets for the UE, and allocating Internet Protocol (IP) addresses for the UE; the core control entity 1 is responsible for recording and managing information such as UE position information, authentication information and the like; the core control entity 2 is responsible for authentication, authorization and charging of the UE.

Fig. 2 is a schematic diagram of a second structure of an evolved telecommunication network. Referring to fig. 2, an evolved architecture of an untrusted non-3 GPP access 3GPP network includes a UE, a broadband wireless access network, a border gateway, a data gateway, a core control entity, and a PDN, wherein,

the UE establishes tunnel connection to the border gateway through a broadband Wireless access Network (IWLAN), the border gateway is connected to a data gateway through a tunnel, and the data gateway is connected to various PDNs, so that connectivity between the UE and the PDNs is established. The border Gateway is an entity located at the boundary of the core network, and is responsible for establishing a secure tunnel between the UE and the core network, and may be an Evolved Packet Data Gateway (ePDG); one data gateway may be connected to multiple border gateways, each responsible for establishing a secure tunnel for UEs within a local area. The functions performed by the data gateway, the core control entity 1 and the core control entity 2 are the same as those in fig. 1.

Fig. 3 is a schematic diagram of a third structure of an evolved telecommunication network. Referring to fig. 3, including a UE, an access network, a Mobility Management Entity (MME), a local Serving Gateway (SGW), a data Gateway, a core control Entity, and a PDN, wherein,

the UE establishes connection with an Access Network through an air interface, the Access Network can be an Evolved UMTS terrestrial Radio Access Network (E-UTRAN), connection is established between the Access Network and a local SGW through a tunnel technology under the control of the MME, connection is established between the local SGW and a data gateway through the tunnel technology, and the data gateway is connected to various PDNs, so that connectivity between the UE and the PDN is established.

In practical application, a tunnel may also be directly established between the UE and the data gateway. In fig. 3, the MME is responsible for managing UE location, access authentication, non-access stratum signaling, signaling security, and other information; the local SGW is a data anchor point of the UE moving in a small range, is an interface entity of a core network and an access network and is responsible for routing and forwarding of UE data; the core control entity records and manages the UE position information and the authentication authorization information.

In the mobile scenario of the broadband wireless access network, the UE is required to maintain service continuity when performing mobile handover between different access networks. Because the network prefixes of different access network links are different, when the UE is switched from the source network link to the target access network link, the IP address network prefix part of the target access network and the IP address network prefix part of the source network are inconsistent with each other, so that a routing technology based on the common IP network prefix cannot send a data packet to the target access network position of the UE in a mobile scene; if the UE updates the IP address during the handover, the service continuity cannot be maintained.

In order to solve the above problems, a Mobile IP (MIP) technology is proposed so that the UE may not change its home address while moving. The MIP techniques are briefly described below.

The basic principle of the MIP technology is that one UE associates two IP addresses, one is a Home-of-address (HOA) and the other is a Care-of-address (COA), so that the UE may not change its Home address when moving. The UE obtains a HOA through the home network, obtains a COA belonging to the current network through the foreign access link mobility agent when the UE moves outside the home network, and informs the COA to the home link mobility agent, which binds the HOA and COA of the UE together and establishes a tunnel between the home link mobility agent and the care-of address (foreign access link mobility agent). The home link mobility agent then tunnels the data packet destined to the HOA of the UE to the COA of the UE, thereby completing the routing. Mainly including Client Mobile IP (CMIP) and Proxy Mobile IP (PMIP). Wherein,

CMIP is a mobile IP technology based on UE, namely the UE is required to participate in the binding process of MIP; PMIP is a network-based MIP technology, and does not need UE to participate in the MIP process, and the network can proxy the behavior of the UE to replace the UE to initiate MIP binding.

The CMIP is divided into two modes: a Foreign agent care-of address (FA-CoA, Foreign AgentCoA) mode and a collocated care-of address mode (Co-CoA). In FA-CoA mode, CoA of UE is IP address of mobile agent of allopatric access link, two end points of MIP tunnel are mobile agent of mobile access link and mobile agent of local link respectively at this moment; in the Co-CoA mode, the CoA of the UE is the IP address of the UE obtained in some way, and at this time, the two endpoints of the MIP tunnel are the UE and the home link mobility agent, respectively, and the remote access link mobility agent only plays a role of a general route, that is, the mobility agent may not be deployed in the remote access link mobility agent.

An existing telecommunication network supports one or more packet data services of a UE accessing a PDN, where the multiple packet data services are identified by an Access Point Name (APN), and the APN of the packet data service that the UE needs to Access may be configured in advance on an Access network side, or may be provided to the Access network side by the UE. And the access network side establishes the connectivity of the UE to the corresponding data gateway according to the APN, and the data gateway establishes the connectivity to the corresponding PDN according to the APN.

In order to effectively manage and utilize network resources, when a UE exits a network, the resources allocated to the UE, including radio channels, bearers, various tunnels, stored information, and the like, need to be released in time to improve the utilization rate of radio resources.

After network evolution, the UE can access the network through one of three evolution network structures to acquire required service; moreover, after entering the network, if the UE needs to leave the source network where the UE is currently located and enter another target network, it needs to be able to perform handover between the three evolved networks, and the bearer in the source network needs to be handed over to the target network, including a target network bearer establishment procedure and a source network bearer release procedure. In order to ensure the continuity of the service when the UE is switched, the following requirements need to be satisfied for the switching between the three evolved networks:

the network impact on handover is minimal;

the impact on the UE is minimal;

the coupling between the switched networks is minimal;

the continuity of the service can be ensured.

In order to meet the above-mentioned requirements for handover between evolved networks, and to provide UE with multiple options of access and diversity of service implementation, a more optimized handover manner between evolved networks needs to be considered, so that handover between evolved networks can be completed quickly, accurately and in real time.

Fig. 4 is a schematic structural diagram of optimized handover between three evolved networks in the prior art. As shown in fig. 4, wherein the interface between the local serving gateway and the data gateway is an S5 interface, and the S101 interface is an interface between different evolved networks, the interface communicating through a tunneling protocol, and through which the UE communicates with the target network transparently to the source network, the impact of handover on the source network can be reduced and the coupling between the source network and the target network of handover can be minimized.

Fig. 5 is a schematic diagram of an optimized handover procedure for handover from a High Rate Packet Data (HRPD) network to a Long Term evolution planned (LTE) network described in the 3GPP standard TS 23.402. As shown in fig. 5, the process includes:

step 501, the UE and AN Access HRPD Access Node (HRPD AN, HRPD Access Node) perform a session with the HRPD network;

step 502, the UE or HRPD AN makes a Handover (HO) decision to decide on Handover;

step 503, the UE sends AN evolved packet System Attach/Service Request (evolved packet System Attach/Service Request) message to the MME through the HRPD AN, and initiates a network Attach process to the target network;

step 504, if the MME does not query the mobility Context (MMContext) corresponding to the UE, initiate an authentication procedure for the UE to the Home Subscriber System (HSS), and establish the corresponding MMContext;

this step is optional.

Step 505, if the MME attaches to the E-UTRAN network in the Evolved Packet System (EPS) for the first time, the MME initiates the location update and subscription acquisition process of the HSS;

this step is optional.

Step 506, executing the rest steps of the EPS Attach/Service Request process;

after this step, Downlink Data (DL Data) transmitted by a PDN Gateway (PDN GW, PDN Gateway) is transmitted to the E-UTRAN through the established bearer and buffered in the E-UTRAN;

step 507, after the EPS Attach/Service Request process is finished, the MME sends a Handover to E-UTRAN Command (Handover to E-UTRAN Command) message to the UE, informing the UE that the Handover air interface is configured to the E-UTRAN.

Step 508, the UE receives the message, completes the air interface configuration, and returns a Handover Complete message to the E-UTRAN;

step 509, the E-UTRAN receives the HO Complete message, and sends a relocation Complete (relocation Complete) message to the MME;

step 510, MME sends HO Complete message to HRPD AN, informing HRPD AN that UE has successfully accessed E-UTRAN;

in step 511, the HRPD AN releases resources using the standard procedures defined by the HRPD.

Fig. 5 provides an advanced optimized handover procedure for an HRPD network to an LTE network, which is a general description of an advanced optimized handover specified by a protocol, where specific procedures involved in the advanced optimized handover procedure have not been refined, that is, a mechanism and an implementation procedure for an optimized handover between complete evolved networks have not been defined, for example, there are some problems and disadvantages as follows:

firstly, in the existing flow, in the handover preparation stage, data needs to be cached in the E-UTRAN, but in the flow, there is no description about MME determining the E-UTRAN;

secondly, in the existing flow, no specific description is provided for the flow of establishing the connection between the MME and the E-UTRAN;

third, the existing flow does not explicitly describe how and when the connection between S101 and S5 is established;

in the switching process, in order to ensure the continuity of the service, the switching of the bearer layer must be transparent to the service layer, so that the transmission of Uplink (Uplink) data cannot be interrupted, and only then, the switching can be ensured to be transparent to the service layer. However, in the existing flow, when an early path switch is performed in a handover preparation phase (i.e., before the UE is handed over to the target network, the PDN GW is switched to the target network), data transmission in Uplink and downlink (downlink) directions is both switched to the target network, so that data transmission in Uplink direction is interrupted, which causes service layer interruption to the service; moreover, the lossless data transmission in the Uplink direction cannot be guaranteed;

when an early path switch is performed, how to establish a default bearer and a dedicated bearer in the switching process in the existing flow is not described;

sixth, in the case of applying Policy and Charging Control (PCC), how to apply PCC rules (PCC Rule) to implement Control (such as Charging Control) on the source network and the target network by the network Anchor (Anchor) in the handover process is not described.

Disclosure of Invention

The embodiment of the invention provides a method for realizing optimized switching between networks, which keeps the continuity of services in the switching process.

The embodiment of the invention also provides equipment of the mobile management entity, which can ensure the continuity of the service in the switching process and realize seamless switching.

The embodiment of the invention also provides a system for realizing the optimized switching among the networks, which can ensure the continuity of the service and realize the seamless switching when switching among different access networks.

To achieve the above object, an embodiment of the present invention provides a method for implementing network optimized handover, where the method includes:

when connection establishment or update is carried out between a service gateway and a packet data network gateway, a mobility management entity or the service gateway indicates that the packet data network gateway does not switch a user plane uplink and downlink data channel from a source network to a target network;

after the user equipment accesses the target network, the mobility management entity or the service gateway instructs the packet data network gateway to switch the user plane uplink and downlink data channel from the source network to the target network.

An embodiment of the present invention further provides a mobility management entity, where the mobility management entity includes:

a module for indicating the packet data network gateway not to switch the user plane uplink and downlink data channel from the source network to the target network when the connection between the serving gateway and the packet data network gateway is established or updated; and the number of the first and second groups,

and a module for instructing the packet data network gateway to switch a user plane uplink and downlink data channel from the source network to the target network after the user equipment accesses the target network.

An embodiment of the present invention further provides a service gateway, including:

a module for indicating the packet data network gateway not to switch the user plane uplink and downlink data channel from the source network to the target network when the connection between the serving gateway and the packet data network gateway is established or updated; and

and the module is used for indicating the packet data network gateway to switch the uplink and downlink data channel of the user plane from the source network to the target network after the user equipment is accessed to the target network.

As can be seen from the foregoing technical solutions, in the method, device, and system for implementing network optimized handover according to embodiments of the present invention, when a user equipment or a source network determines to initiate handover preparation to a target network, a mobility management entity queries a corresponding target network identifier from a mapping relationship between a configured cell identifier and the target network identifier according to a received cell identifier, and determines an access node of the target network; meanwhile, establishing connection to a target network service gateway, and indicating the packet data network gateway not to switch the user plane downlink data channel from the source network to the target network or only switching the user plane downlink data channel from the source network to the target network by a mobile management entity or the service gateway; after the connection to the serving gateway is completed, the mobility management entity initiates a resource reservation request with a target network access node and indicates that no air interface connection is required to be established, after the switching preparation is completed, the user equipment is accessed to the target network, and the mobility management entity or the serving gateway indicates the packet data network gateway to switch a user plane uplink and downlink data channel or a user plane uplink data channel from a source network to the target network. When the user equipment is switched among different access networks in an evolution network, the switching optimization performance is improved, the service continuity can be ensured, the seamless switching is achieved, and the user experience is improved.

Drawings

Fig. 1 is a schematic diagram of a first structure of an evolved telecommunications network;

FIG. 2 is a schematic diagram of a second structure of an evolved telecommunication network;

FIG. 3 is a schematic diagram of a third structure of an evolved telecommunication network;

fig. 4 is a schematic structural diagram of optimized handover between three evolved networks in the prior art;

fig. 5 is a schematic diagram of an optimized handover procedure for handover from an HRPD network to an LTE network described in 3GPP standard TS 23.402;

fig. 6a is a schematic diagram of a first structure of a system for implementing network optimized handover according to an embodiment of the present invention;

fig. 6b is a schematic diagram of a second structure of a system for implementing network optimized handover according to an embodiment of the present invention;

fig. 6c is a schematic diagram of a third structure of a system for implementing network optimized handover according to an embodiment of the present invention;

fig. 6d is a schematic diagram of a fourth structure of a system for implementing network optimized handover according to an embodiment of the present invention;

fig. 6e is a schematic structural diagram of a mobility management entity device according to an embodiment of the present invention;

fig. 7 is a flowchart illustrating a method for implementing network optimized handover according to an embodiment of the present invention;

fig. 8 is another flowchart illustrating a method for implementing network optimized handover according to an embodiment of the present invention;

fig. 9 is a flowchart of a method for implementing network optimized handover according to a second embodiment of the present invention;

fig. 10 is a schematic flowchart of a PMIP-based method for transmitting all bearer information in the same message between a SGW and a PDN GW in accordance with the embodiment of the present invention;

fig. 11 is a schematic flow chart of a PMIP-based method for sequentially establishing bearers between a SGW and a PDN GW in an embodiment of the present invention;

fig. 12 is a flowchart illustrating a GTP-based method for establishing bearers between a SGW and a PDN GW according to an embodiment of the present invention;

fig. 13 is a schematic flowchart of a GTP-based method for sequentially establishing bearers between a third SGW and a PDN GW in an embodiment of the present invention;

fig. 14 is a schematic flowchart of a method for indicating, by a target access gateway, an anchor gateway to process uplink and downlink data channels on a user plane on two user planes, according to an embodiment of the present invention;

FIG. 15 is a diagram illustrating an exemplary setting of indication information according to an embodiment of the present invention;

fig. 16 is a schematic flowchart of a fourth target access gateway indicating an anchor gateway to not switch a downlink data channel of a user plane to a target network according to an embodiment of the present invention;

FIG. 17 is a diagram illustrating another arrangement of indication information according to an embodiment of the present invention;

fig. 18 is a schematic flow chart of controlling source/target network PCCRule during a handover process by a PCEF on a five-anchor gateway in an embodiment of the present invention;

fig. 19 is another flowchart illustrating a process of controlling a source/target network PCCRule during a handover procedure by a PCEF on a five-anchor gateway according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and examples.

When UE is switched to a target network from a source network, an MME selects the target network through self configuration or according to information contained in a received message, and establishes connection with the target network; SGW establishes connection with PDN GW, and indicates PDN GW not to switch uplink data, when receiving downlink data, caching; in the switching process, when the UE is still in the source network, the UE is kept not to be disconnected through an uplink transmission channel of the source network, and the PCC is controlled in the switching process.

In the embodiment of the present invention, mainly taking UE handover to E-UTRAN as an example for explanation, Access gateways of source networks, such as trusted non-3 GPP network (CDMA 2000, WIMAX, etc.) and untrusted non-3 GPP network (WLAN, IWLAN, etc.), are referred to as Access points (Other, Other Access nodes) of Other Access technologies.

In order to achieve the above object, an embodiment of the present invention provides a system for implementing network optimized handover.

Fig. 6a is a schematic diagram of a first structure of a system for implementing network optimized handover according to an embodiment of the present invention. Referring to fig. 6a, the system comprises: a source network, a mobility management entity, a serving gateway and an evolved UMTS terrestrial radio access network, wherein,

the source network is used for receiving the cell identifier sent by the user equipment, inquiring the corresponding target network identifier from the cell identifier or a mapping relation between the configured cell identifier and the target network identifier, and sending the cell identifier or the corresponding target network identifier to the mobility management entity;

the mobile management entity is used for receiving the target network identification or inquiring the corresponding target network identification from the mapping relation between the configured cell identification and the target network identification according to the received cell identification, determining the corresponding evolved UMTS terrestrial radio access network and establishing the load bearing with the service gateway;

the service gateway is used for establishing a load with the mobile management entity;

evolved UMTS terrestrial radio Access network for establishing bearers with a mobility management entity.

In practical application, the system for implementing network optimized handover as shown in fig. 6a may also perform the following processing:

the source network is used for receiving a connection establishment request sent by the user equipment and sending the connection establishment request to the mobility management entity;

the mobile management entity is used for receiving a connection establishment request sent by a source network, establishing connection to a service gateway, determining that the current process is the establishment process of switching network connection after the connection to the service gateway is completed, and initiating a resource reservation request with an evolved UMTS terrestrial radio access network;

the service gateway is used for establishing connection with the mobility management entity;

the evolved UMTS terrestrial radio access network is used for receiving the resource reservation request sent by the mobile management entity, reserving resources and establishing bearing.

In practical application, the system for implementing network optimized handover as shown in fig. 6a may further perform the following processing:

the source network is used for receiving a connection establishment request sent by the user equipment and sending the connection establishment request to the mobility management entity;

a mobile management entity, configured to receive a connection establishment request sent by a source network, establish a bearer to a serving gateway, indicate the serving gateway, and establish a bearer to an evolved UMTS terrestrial radio access network;

the service gateway is used for establishing connection with the mobile management entity, caching the received downlink data and not initiating paging to the user equipment according to the received indication if the connection with the user plane bearer of the evolved UMTS terrestrial radio access network is not established;

evolved UMTS terrestrial radio Access network for establishing bearers with a mobility management entity.

Fig. 6b is a schematic diagram of a second structure of a system for implementing network optimized handover according to an embodiment of the present invention. Referring to fig. 6b, the system comprises: a source network, a mobility management entity, a serving gateway, a packet data network gateway, and an evolved UMTS terrestrial radio access network, wherein,

the source network is used for receiving a connection establishment request sent by the user equipment and sending the connection establishment request to the mobility management entity;

the mobile management entity is used for receiving a connection establishment request sent by a source network, establishing a bearer to a service gateway, receiving the bearer establishment request sent by the service gateway, sending a resource reservation message to an evolved UMTS terrestrial radio access network, and indicating that no air interface connection is required to be established; receiving a response message sent by a UMTS terrestrial radio access network, and sending the response message to a service gateway; receiving a bearing establishment completion notification message sent by a service gateway to complete bearing establishment;

the service gateway is used for establishing connection with the mobile management entity and sending an agent binding update message to the packet data network gateway according to the received response message; receiving a bearer establishment completion notification message sent by a packet data network gateway or generated by the packet data network gateway, and sending the notification message to a mobility management entity;

the packet data network gateway is used for receiving the proxy binding update message sent by the service gateway and establishing a user plane channel with the service gateway; sending a notification message of completion of bearer establishment to a service gateway;

and the evolved UMTS terrestrial radio access network is used for receiving the resource reservation message, reserving the resource and establishing the bearer.

Fig. 6c is a schematic diagram of a third structure of a system for implementing network optimized handover according to an embodiment of the present invention. Referring to fig. 6c, the system comprises: a source network, a mobility management entity, a serving gateway, and a packet data network gateway, wherein,

the source network is used for receiving a connection establishment request sent by the user equipment and sending the connection establishment request to the mobility management entity;

the mobile management entity is used for receiving a connection establishment request sent by a source network, establishing a load to a service gateway, and indicating the packet data network gateway not to switch a user plane uplink and downlink data channel from the source network to a target network when connection establishment or updating is carried out between the service gateway and the packet data network gateway; after the user equipment is accessed to a target network, indicating a packet data network gateway to switch a user plane uplink and downlink data channel from a source network to the target network;

the service gateway is used for establishing connection with the mobility management entity, establishing or updating connection with the packet data network gateway and sending the received user plane uplink and downlink data channel processing instruction or the user plane uplink and downlink data channel processing instruction generated by the service gateway to the packet data network gateway; after the user equipment is accessed to a target network, indicating a packet data network gateway to switch uplink and downlink data channels of a user plane to the target network;

the packet data network gateway is used for establishing or updating connection with the service gateway, receiving a processing instruction of an uplink and downlink data channel of a user plane, and not switching the uplink and downlink data channel of the user plane from a source network to a target network; and after the user equipment is accessed to the target network, switching the uplink and downlink data channels of the user plane from the source network to the target network.

In practical application, the system for implementing network optimized handover as shown in fig. 6c may further perform the following processing:

the mobile management entity is used for receiving a connection establishment request sent by a source network, establishing a bearer to a serving gateway, and indicating the serving gateway to switch a user plane downlink data channel from the source network to a target network while keeping a user plane uplink data channel in the source network when connection establishment or update is carried out between the serving gateway and a packet data network gateway; after the preparation of bearing switching is completed, the user equipment is accessed to a target network, and the packet data network gateway is indicated to switch a user plane uplink data channel from a source network to the target network;

the service gateway is used for establishing connection with the mobility management entity, establishing or updating connection with the packet data network gateway and sending the received user plane downlink data channel processing instruction or the user plane downlink data channel processing instruction generated by the service gateway to the packet data network gateway; after the user equipment is accessed to a target network, indicating a packet data network gateway to switch a user plane uplink data channel from a source network to the target network;

the packet data network gateway is used for establishing or updating connection with the service gateway, receiving a user plane downlink data channel processing instruction, switching a user plane downlink data channel from a source network to a target network, and keeping a user plane uplink data channel in the source network; and after the user equipment is accessed to the target network, switching the uplink data channel of the user plane from the source network to the target network.

Fig. 6d is a schematic diagram of a fourth structure of a system for implementing network optimized handover according to an embodiment of the present invention. Referring to fig. 6d, the system comprises: a source access gateway, a target access gateway, an anchor gateway, and policy and charging rules functions, wherein,

the source access gateway is used for receiving a connection establishment request sent by the user equipment and sending the connection establishment request to the target access gateway;

the target access gateway receives a connection establishment request sent by the source access gateway and initiates the bearer establishment with the anchor point gateway;

the anchor gateway receives the load establishing request, interacts with the policy and charging rule function, acquires the policy and charging rule corresponding to the target network, executes the charging rule of two sets of policy and charging control rules, and after the switching preparation is completed, the user equipment is accessed to the target network, and the anchor gateway deletes the policy and charging control rule corresponding to the source network;

in practical applications, the anchor gateway may be a packet data network gateway.

And the policy and charging rule function is used for interacting with the anchor point gateway and issuing policy and charging control rules.

Fig. 6e is a schematic structural diagram of a mobility management entity device according to an embodiment of the present invention. Referring to fig. 6e, the apparatus comprises: a receiving unit and a processing unit, wherein,

the receiving unit is used for receiving the cell identification information and sending the cell identification information to the processing unit;

and the processing unit is used for receiving the cell identification information, inquiring the corresponding target network identification from the configured mapping relation between the cell identification and the target network identification, determining an access node of the target network, and initiating the establishment of the load with the target network.

The following five embodiments are provided to describe a method flow for implementing network optimized handover according to the present invention.

Example one

In this embodiment, the MME mainly aims at how the MME selects AN Evolved Base station Node (ENB) when the UE is handed over from Other AN to E-UTRAN.

Two alternative solutions are provided for the MME to select the ENB when the UE is handed over from Other AN to E-UTRAN.

The first solution is: the Other AN configures or acquires mapping information of a Cell identification (Cell ID) and a Target network identification (Target ID) corresponding to the E-UTRAN access network, determines the corresponding Target ID according to the Cell ID when deciding to perform handover, sends the Target ID to the MME through a tunnel message of AN S101 interface, receives the Target ID and selects the ENB according to the Target ID.

The second solution is: the MME configures or acquires mapping information between the Cell ID and the Target ID, the UE or Other AN sends the Cell ID to the MME through a tunnel message of AN S101 interface, and the MME determines the corresponding Target ID according to the received Cell ID and selects the corresponding ENB.

Fig. 7 is a flowchart illustrating a method for implementing network optimized handover according to an embodiment of the present invention. In this embodiment, the mapping relationship between the Cell ID and the Target ID is configured on Other Access technology Access nodes (Other AN, Other Access Node), and the Other AN sends the Target ID to the MME, as shown in fig. 7, the process includes:

step 701, the UE or Other AN makes a handover decision;

in this step, Other AN may query and determine the corresponding Target ID from the configured mapping relationship between the Cell ID and the Target ID according to the selected Cell ID.

Step 702, UE sends Message Z Message to Other AN, carrying connection establishment request information;

in this step, the Message Z Message sent by the UE to the Other AN is defined in the HRPD network, and initiates the connection establishment procedure to the E-UTRAN.

Step 703, the Other AN sends a Direct Transfer (Direct Transfer) message to the MME;

in this step, if the Target ID is not determined in step 701, the Other AN queries and determines the corresponding Target ID from the configured mapping relationship between the Cell ID and the Target ID according to the selected Cell ID, and the Direct Transfer message carries Target ID information.

Step 704, the MME initiates authentication and location update, acquires subscription data, and establishes a corresponding mobility context;

step 705, the MME selects a corresponding SGW and initiates bearer establishment of the SGW;

in this step, the SGW may also initiate bearer establishment for the PDN GW.

In step 706, the MME selects a corresponding E-UTRAN according to the Target ID carried in the received Direct Transfer message.

In practical application, step 706 has no chronological relationship with step 705 and step 704, and step 706 may be executed before step 705 or before step 704; similarly, step 705 can be executed before step 704, and after selecting the E-UTRAN, step 707 can be further executed.

Step 707, the MME establishes a connection to the selected E-UTRAN;

step 708, the remaining procedures for the Other AN handover to the E-UTRAN network are completed.

Fig. 8 is another flowchart illustrating a method for implementing network optimized handover according to an embodiment of the present invention. In this embodiment, the mapping relationship between the Cell ID and the Target ID is configured on the MME, and the UE or Other AN sends the Cell ID information to the MME, referring to fig. 8, different from fig. 7,

in step 803, Other AN sends a Direct Transfer message to MME, carrying the selected Cell ID;

in step 806, the MME queries and determines a corresponding Target ID from the configured mapping relationship between the Cell ID and the Target ID according to the Cell ID carried in the received Direct Transfer message, and selects a corresponding E-UTRAN according to the Target ID.

Example two

In this embodiment, a specific procedure for establishing a connection with an E-UTRAN after an MME determines the corresponding E-UTRAN is mainly described.

After the MME selects and acquires the SGW information, if the connection to the selected ENB is not established for the UE, and the current flow is determined to be a switching connection flow, the connection establishment flow to the ENB is initiated, and the configuration of the uplink bearer of the user plane and the configuration of the security mode are completed.

Fig. 9 is a flowchart of a method for implementing network optimized handover according to a second embodiment of the present invention. In this embodiment, after selecting the corresponding E-UTRAN, the MME initiates connection establishment with the E-UTRAN, referring to fig. 9, the process includes:

step 901, the UE or the network makes a handover decision;

step 902, the UE sends a connection request message to the MME through the Other AN;

in this step, the Other AN passes through the connection request message.

Step 903, MME initiates an authentication process and a location updating and subscription data acquisition process, and establishes a corresponding mobility context;

step 904, the MME selects a corresponding SGW and initiates a bearer establishment procedure of the SGW;

in this step, the SGW may also initiate a bearer establishment procedure of the PDN GW.

Step 905, the MME selects a corresponding E-UTRAN according to the received Target ID.

Step 906, the MME selects and judges the E-UTRAN;

in this step, after the MME selects the E-UTRAN, it is determined whether the following three conditions are satisfied:

1. currently, the handover connection establishment procedure;

connection is established between the SGW and the MME;

MME does not establish a connection to the selected E-UTRAN for the UE.

If the three conditions are met, the MME sends a Resource reservation request (Resource reservation request) message to the E-UTRAN, and the message carries information such as SGW information, UE capability parameters and security mode configuration parameters.

Step 907, the E-UTRAN returns a Resource Reservation Response (Resource Reservation Response) message;

in this step, the E-UTRAN selects an algorithm for Radio Resource Control (RRC) ciphering, integrity protection, and user plane ciphering according to the received Resource Reservation Request message, and determines configuration information corresponding to the RRC; then, a Resource Reservation Response message is returned to the MME, the message contains the information of the selected E-UTRAN (such as TEID of the E-UTRAN) and a handover command, and the handover command comprises RRC configuration information and selected security parameters.

Step 908, the remaining procedures for the Other AN to handover to the E-UTRAN network are completed.

EXAMPLE III

In this embodiment, the establishment process of the dedicated bearer mainly includes two ways.

In the first mode, dedicated bearers are established one by one, after the default bearer establishment is completed, a bearer establishment control entity, such as an SGW or a PDN GW, where a network side Policy and Charging enhancement Function entity (PCEF) is located initiates a dedicated bearer one by one establishment procedure, and an MME processes a received bearer establishment message and indicates, by sending the message or adding an indication parameter to the message, that the E-UTRAN does not initiate an air interface bearer establishment procedure.

In the second mode, the dedicated bearer information is transmitted in a message, that is, the message carries the bearer information to be established, the dedicated bearer establishment is completed through a Round Trip of the message, and the response message for establishing the dedicated bearer carries the information of success of establishing the dedicated bearer and the information of failure of establishing the dedicated bearer.

Fig. 10 is a flowchart illustrating a method for transmitting all bearer information in the same message based on PMIP between a SGW and a PDN GW according to an embodiment of the present invention. Referring to fig. 10, the process includes:

step 1001, MME sends a bearer establishment message to SGW, carrying an indication to inform SGW that the current handover connection establishment procedure is;

step 1002, the SGW receives the bearer establishment message and initiates an IP-CAN notification process to the PCRF, and in the interaction process, the SGW brings the corresponding IP-CAN Type to the PCRF;

this step is optional.

Step 1003, the SGW receives the PCC Rule returned by the PCRF, determines that resources need to be reserved for all bearers, and simultaneously sends a bearer establishment response message to the MME, where the message carries all reserved bearer information;

in this step, the bearer information includes Tunnel Endpoint Identity (TEID) information.

Step 1004, MME and E-UTRAN establish load bearing;

in this step, the established bearer may include default bearer information and a dedicated bearer.

Step 1005, the MME sends an update bearer message to the SGW, carrying bearer information established by the E-UTRAN, including information of successful bearer establishment and information of failed bearer establishment;

step 1006, the SGW sends a Proxy Binding Update (PBU) message to the PDN GW to establish a user plane channel;

this step is optional, and only if the user plane downlink data channel needs to be switched to the E-UTRAN access network in advance, this step needs to be performed. And the PDN GW is instructed to switch the user plane downlink data channel to the E-UTRAN access network by expanding the parameters in the PBU message or the PBU message, and the user plane uplink data channel is reserved in the HRPD network. The indication may be sent by the MME, directly forwarded by the SGW, or regenerated by the SGW.

Step 1007, the PDN GW interacts with the PCRF;

this step is optional, and the PDN GW interacts with the PCRF to acquire the PCC rule.

Step 1008, the PDN GW returns a Proxy binding response (PBA, Proxy binding acknowledgment ridge) to the SGW;

the step can be selected, the user plane channels from the PDN GW to the SGW to the E-UTRAN are communicated, and if the E-UTRAN receives downlink data, the downlink data is cached.

In step 1009, the SGW sends a bearer setup complete notification message to the MME, and indicates the MME through the indication parameter or the specific message, so that the setup of the bearer is completed.

In this step, the indication parameter is an indication parameter carried in the notification message of completion of bearer establishment; the specific message is a bearer setup complete notification message.

After the terminal successfully accesses the target network, the SGW instructs the PDN GW to switch the uplink and downlink data channels of the user plane to the EUTRAN network in a PBU message or extended PBU message mode. The indication may be sent by the MME, directly forwarded by the SGW, or regenerated by the SGW.

Fig. 11 is a flowchart illustrating a method for sequentially establishing bearers based on PMIP between a SGW and a PDN GW according to an embodiment of the present invention. Referring to fig. 11, the process includes:

step 1101, the MME sends a bearer establishment message to the SGW, and carries an indication to inform the SGW that the switching connection establishment process is currently performed;

step 1102, the SGW receives the bearer establishment message and initiates an IP-CAN notification process to the PCRF, and in the interaction process, the SGW brings the corresponding IP-CAN Type to the PCRF;

this step is optional.

Step 1103, the SGW receives the PCC Rule returned by the PCRF, determines that resources need to be reserved for all bearers, and sends a bearer establishment response message to the MME, where the message carries default bearer information;

in this step, the default bearer information includes TEID information.

Step 1104, MME and E-UTRAN establish default load;

step 1105, the MME sends an update bearer message to the SGW, carrying the default bearer information established by the E-UTRAN;

in step 1106, the SGW returns an update bearer response message to the MME.

Step 1107, the SGW sends a request message for establishing dedicated bearer to the MME, and initiates dedicated bearer establishment;

in this step, the request message for establishing the dedicated bearer sent by the SGW to the MME may be multiple messages initiated in parallel, and is used to establish multiple dedicated bearers.

Step 1108, the MME informs the E-UTRAN to establish a dedicated bearer, and the message carries information indicating that the E-UTRAN does not establish an air interface connection; the indication can be a message sent by the MME to the E-UTRAN, and can also be an indication parameter of message extension sent by the MME to the E-UTRAN.

Step 1109, E-UTRAN sends response message of establishing special load to MME;

step 1110, the MME sends a dedicated bearer establishment response message to the SGW, carrying the dedicated bearer information established by the E-UTRAN;

step 1111, if it is determined that all dedicated bearers have been established, the SGW sends a PBU message to the PDN GW to establish a user plane channel;

this step is optional, and only if the user plane downlink data channel needs to be switched from the HRPD network to the E-UTRAN access network in advance, this step needs to be performed. And instructing the PDN GW to switch the user plane downlink data channel to the E-UTRAN access network in the PBU message or the extended parameters in the PBU message, and reserving the user plane uplink data channel in the HRPD network. The indication may be sent by the MME, directly forwarded by the SGW, or regenerated by the SGW.

Step 1112, the PDN GW interacts with the PCRF;

this step is optional, and the PDN GW interacts with the PCRF to acquire the PCC rule.

Step 1113, PDN GW returns PBA message to SGW;

the step can be selected, the user plane channels from the PDN GW to the SGW to the E-UTRAN are communicated, and if the E-UTRAN receives downlink data, the downlink data is cached.

In step 1114, the SGW sends a bearer setup complete notification message to the MME.

In this step, if the SGW determines that all dedicated bearers have been established, the indication parameters of all bearers being established can be carried in the sent bearer establishment completion notification message, the MME bearer establishment is indicated by a specific message or indication parameters, and the indication parameters are the indication parameters carried in the bearer establishment completion notification message; the specific message is a notification message for completing bearer establishment, and after receiving the indication parameter, the MME may initiate subsequent operations for completing establishment with all bearers.

In step 1115, the MME returns a bearer establishment completion notification response message to the SGW.

After the terminal successfully accesses the target network, the SGW instructs the PDN GW to switch the uplink and downlink data channels of the user plane to the EUTRAN network in a PBU message or extended PBU message mode. The indication may be sent by the MME, directly forwarded by the SGW, or regenerated by the SGW.

Fig. 12 is a flowchart illustrating a method for establishing bearers together based on GTP between a SGW and a PDN GW according to an embodiment of the present invention. Referring to fig. 12, the process includes:

step 1201, the MME sends a bearer establishment message to the SGW, carries an indication to inform the SGW that the switching connection establishment process is currently performed;

step 1202, after receiving the bearer establishment message, the SGW sends a bearer establishment request message to the PDN GW;

in this step, if the SGW obtains all QoS information of the bearer to be established from the received bearer establishment message, resources are reserved for all bearers, otherwise, default bearer resources are reserved; the SGW sends a connection establishment request message to the PDN GW, wherein the connection establishment request message can be a special message or can carry a special parameter; the message carries a Path not switch indication or a downlink Path switch indication: if the indication carried in the message is a Path not switch indication, the PDN GW does not switch Uplink and Downlink data channels on the user plane after receiving the indication, and only establishes the bearer; if the indication carried in the message is a downlink path switch indication, the PDN GW determines that the default bearer and the dedicated bearer in the E-UTRAN are not established completely after receiving the indication, and the PDN GW establishes the bearer first.

Step 1203, the PDN GW performs IP-CAN modification process interaction with the PCRF, in which the PDN GW carries the corresponding IP-CAN Type to the PCRF, and receives the PCC Rule issued from the PCRF;

step 1204, the PDN GW determines to reserve resources for all bearers, and sends a connection establishment response message to the SGW, carrying the reserved resource information;

in this step, the reserved resource information includes a series of TEIDs.

Step 1205, the SGW receives the connection establishment response message and sends a bearer establishment response message to the MME;

in this step, the SGW receives the connection establishment response message, if it is found that the SGW does not reserve enough resources, reserves corresponding resources again according to the resource information reserved by the PDN GW carried by the received connection establishment response message, and sends a bearer establishment response message to the MME, carrying all the resource information reserved by the SGW.

Step 1206, the MME notifies the E-UTRAN to reserve resources, and instructs the E-UTRAN not to establish an air interface connection through a message or a parameter;

in this step, the message may be a resource reservation message, and the parameter indication may be an indication parameter carried in the resource reservation message.

Step 1207, the MME sends an update bearer message to the SGW, and the update bearer message carries the bearer information established by the E-UTRAN, including the bearer establishment success information and the bearer establishment failure information;

step 1208, the SGW sends an update bearer message to the PDN GW, carrying a downlink user data handover indication;

in the step, the SGW receives the updating bearing message, and if the resource reserved by the SGW is found to be not completely corresponding to the resource reserved by the PDNGW, the SGW carries the new resource information reserved by the SGW in the updating bearing message; the incomplete correspondence may be the case that only default bearer resources are reserved by the SGW in step 1202.

After receiving the message, the PDN GW determines to complete the establishment of default and dedicated bearers of the E-UTRAN access network, and if the parameter carried in step 1202 is a downlink path switch indication, the PDN GW switches the user plane downlink data channel to the EUTRAN access network, and keeps the user plane uplink data channel in the HRPD network.

Step 1209, the PDN GW sends an update bearer response message to the SGW;

step 1210, the SGW sends a bearer establishment completion notification message to the MME, and indicates the MME by the indication parameter or the specific message, that the bearer establishment has been completed. The indication parameter is carried in the notification message of completing the establishment of the bearing; the specific message is a bearer setup complete notification message.

After the UE successfully accesses the target network, the SGW instructs the PDN GW to switch the uplink data channel reserved in the source network by using a specific message or an indication parameter. After the step, the uplink and downlink data channels of the user plane of the UE are switched to the target network.

Fig. 13 is a flowchart illustrating a method for sequentially establishing bearers based on GTP between a SGW and a PDN GW according to an embodiment of the present invention. Referring to fig. 13, the process includes:

step 1301, the MME sends a bearer establishment message to the SGW, carries an indication to inform the SGW that the switching connection establishment process is currently performed;

step 1302, the SGW receives the default bearer establishment message, reserves resources, and sends a connection establishment request message to the PDN GW;

in this step, if the SGW obtains all QoS information of the bearer to be established from the received bearer establishment message, resources are reserved for all bearers, otherwise, default bearer resources are reserved; the SGW sends a connection establishment request message to the PDN GW, wherein the connection establishment request message can be a special message or can carry a special parameter; the message carries a Path not switch indication or a downlink Path switch indication: if the indication carried in the message is a Path not switch indication, the PDN GW does not switch the Uplink and Downlink user interface data channels after receiving the indication, and only establishes the bearer; if the indication carried in the message is a downlink path switch indication, the PDN GW determines that the default bearer and the dedicated bearer in the E-UTRAN are not established completely after receiving the indication, and the PDN GW establishes the bearer first.

Step 1303, the PDN GW interacts with the PCRF to obtain all the loaded PCC rules;

step 1304, the PDN GW reserves resources for all bearers, sends a connection establishment response message to the SGW, carrying the established default bearer information;

step 1305, the SGW receives the connection establishment response message, and sends a response message for establishing a default bearer to the MME;

step 1306, the MME establishes a default bearer with the E-UTRAN;

step 1307, the MME sends an update bearer message to the SGW, carrying the default bearer information established by the E-UTRAN;

step 1308, the SGW returns an update bearer response message to the MME;

step 1309, the PDN GW sends a request message for establishing dedicated bearer to the SGW;

in this step, if there are multiple dedicated bearers to be established, the PDN GW may establish the dedicated bearers in parallel, or may establish the dedicated bearers in series.

Step 1310, the SGW reserves the dedicated bearer resource, carries the established dedicated bearer information in the establishment dedicated bearer request message, and sends the message to the MME;

step 1311, the MME establishes a dedicated bearer with the E-UTRAN and instructs the E-UTRAN not to establish an air interface connection;

in this step, the E-UTRAN reserves resources for the dedicated bearer, establishes the dedicated bearer with the MME, and instructs the E-UTRAN not to establish an air interface connection through a message or an instruction parameter sent by the MME. The message may be a resource reservation message, and the parameter indication may be an indication parameter carried in the resource reservation message.

Step 1312, the E-UTRAN sends a dedicated bearer resource reservation response message to the MME;

step 1313, the MME sends a dedicated bearer establishment response message to the SGW, carrying dedicated bearer information established by the E-UTRAN;

step 1314, the SGW sends a dedicated bearer establishment response message to the PDN GW, carrying the dedicated bearer information reserved by itself;

in this step, after receiving the message, if the PDN GW determines that the establishment of all default and dedicated bearers of the E-UTRAN access network is completed and the parameter carried in step 1402 is a downlink path switch instruction, the PDN GW switches the user plane downlink data channel to the EUTRAN access network, and keeps the user plane uplink data channel in the HRPD network.

Step 1315, the PDN GW sends all bearer establishment completion notification messages to the SGW;

in this step, if the PDN GW determines that the setup is completed for the last bearer, the PDN GW notifies the SGW that all bearers have been completed through a message or a parameter indication.

Step 1316, the SGW sends a bearer setup complete notification message to the MME, and notifies the MME that all bearers are setup complete through a specific message or an indication parameter, where the indication parameter is an indication parameter carried in the bearer setup complete notification message; the specific message is a notification message for completing the establishment of the bearer, and then the MME can initiate the subsequent operation of completing the establishment of the bearer with all the bearers;

step 1317, the MME sends a bearer setup complete notification response message to the SGW;

step 1318, the SGW sends a bearer setup complete notification response message to the PDN GW.

After the UE successfully accesses the target network, the SGW instructs the PDN GW to switch the uplink data channel reserved in the source network by means of a message or an instruction parameter.

Example four

In this embodiment, how to ensure lossless uplink and downlink data and service continuity on the user plane in the handover process is mainly addressed.

In the first mode, the SGW sends a Path not Switch indication to the PDN GW by a message, which indicates that the PDN GW does not perform user plane switching, but only performs default and/or dedicated bearer establishment.

And after the terminal accesses the target network, the PDN GW is instructed to switch the uplink and downlink data channels of the user plane from the source network to the target network.

In the second mode, the SGW sends a downlink path switch indication to the PDN GW through a message, which indicates that the PDN GW converts the downlink data transmission channel to the target network and keeps the uplink data transmission channel in the source network after determining that all bearers of the target network are established; and when the UE is accessed to the target network, the MME or the SGW sends a message or an indication parameter to indicate the PDN GW to switch the uplink data transmission channel to the target network. The Early path switch indication may be generated and sent by the MME, forwarded by the SGW, or generated and directly sent by the SGW according to the current state.

Fig. 14 is a flowchart of a method for indicating, by a target access gateway, an anchor gateway to process uplink and downlink data channels of a user plane on two user planes, respectively, in an embodiment of the present invention. In this embodiment, the uplink data channel of the source network is maintained, and the downlink data channel is switched to the target network at the stage of starting the switching. Referring to fig. 14, the process includes:

step 1401, UE accesses target network, starts switching;

in this step, when the handover is started, a data path needs to be established between the Target access gateway (Target AGW) and the Anchor gateway (Anchor GW), and if the Target AGW and the Anchor GW are based on PMIP, steps 1402a to 1403a are executed; and if the GTP is used between the Target AGW and the AnchorGW, executing the steps 1402b to 1403 b.

Step 1402a, after the Target AGW completes the establishment of all the bearers of the Target network, the targetAGW sends a PBU message to the Anchor GW;

in this step, the Target AGW carries indication information of uplink and downlink separation in the PBU message sent, the indication information can be realized by extending a flag bit E in the PBU message, setting E to 1 indicates that uplink and downlink separation operation is required, and setting E to 0 indicates that uplink and downlink separation operation is not required.

Fig. 15 is a schematic diagram of setting of indication information according to an embodiment of the present invention. The figure identifies whether the uplink and downlink separation operation is required by setting the value of a flag bit E.

Step 1403a, the Anchor GW sends a PBA message to the Target AGW;

step 1402b, before the Target network completes the establishment of all the bearers, the Target AGW sends an activate PDP Context message to the AnchorGW, and carries an indication that Context separation is required;

step 1403b, the Anchor GW sends a response message for activating PDP Context to the Target AGW;

step 1404, the Anchor GW performs separation of uplink and downlink data channels of the user plane;

in this step, the Anchor GW maintains the user plane uplink data channel of the source network and switches the user plane downlink data channel of the source network to the target network.

Step 1405, completing the remaining handover steps.

In this step, the remaining switching steps include that after the UE is switched to the Target network, the Target AGW instructs the Anchor GW to switch the user plane uplink data channel retained in the source network to the Target network by sending a normal PBU or Update PDP Context message or by extending an indication parameter carried in the PBU or Update PDP Context message, so that the user plane uplink and downlink data channels of the UE are all switched to the Target network.

Fig. 16 is a schematic flowchart of a fourth target access gateway indicating an anchor gateway to not switch a downlink data channel of a user plane to a target network according to an embodiment of the present invention. In this embodiment, the user plane uplink data channel and the user plane downlink data channel of the source network are maintained, referring to fig. 16, the process includes:

step 1601, accessing the UE to a target network, and starting switching;

in this step, when handover is started, a data path needs to be established between the Target AGW and the Anchor GW, and if the data path between the Target AGW and the Anchor GW is based on PMIP, steps 1602a to 1603a are executed; if GTP is used between the Target AGW and Anchor GW, steps 1602 b-1603 b are executed.

Step 1602a, after the Target AGW completes establishment of all bearers of the Target network, the TargetAGW sends a PBU message to the Anchor GW;

in this step, the Target AGW carries indication information that the uplink and downlink data channels of the user plane are not switched in the PBU message sent by the Target AGW, the indication information can be realized by extending a flag bit N in the PBU message, and when N is set to 1, it indicates that the uplink and downlink data channels of the user plane are not switched.

Fig. 17 is a schematic diagram of another setting of indication information according to the embodiment of the present invention. The flag bit N is set to 1 in the figure, which indicates that the uplink and downlink data channels in the user plane are not switched.

Step 1603a, the Anchor GW sends a PBA message to the Target AGW;

step 1602b, before the Target network completes the establishment of all bearers, the Target AGW sends an activate PDP Context message to the AnchorGW, carrying an indication that no switching is performed on the uplink and downlink data channels of the user plane;

step 1603b, the Anchor GW sends a response message for activating PDP Context to the Target AGW;

in step 1604, the Anchor GW performs separation of the uplink and downlink data channels of the user plane, and maintains the uplink and downlink data channels of the user plane of the source network.

In practical application, after the switching is completed, the operation of separately processing the uplink and downlink data channels of the user plane needs to be cancelled, and for PMIP, only one normal PBU message needs to be initiated to reset the flag bit; if it is GTP protocol, then initiate an UPDATE PDP CONTEX message to cancel the user plane up/down data channel separation operation.

EXAMPLE five

In this embodiment, the following technical solutions are provided for implementing PCC control (e.g., charging control) in the handover process:

firstly, an Anchor gateway (Anchor) and a PCRF (policy and charging rules function) interact to obtain PCC Rule of a corresponding target network, and at the moment, two sets of PCC Rule exist on the Anchor gateway simultaneously.

And secondly, the anchor gateway simultaneously executes two sets of PCC rules, initiates a bearing establishing process to the source network, and respectively controls the source network and the target network, for example, simultaneously performs charging control on the source network and the target network.

And thirdly, after the UE is successfully accessed to the target network, the anchor gateway deletes the PCC Rule of the corresponding source network, and at the moment, the anchor gateway executes the PCC Rule of the corresponding target network.

Fig. 18 is a flowchart illustrating a procedure for controlling PCC Rule of a source/target network during a handover procedure of a PCEF on a six-anchor gateway according to an embodiment of the present invention. In this embodiment, the connection between the SGW and the PGW is established before the bearer is established, referring to fig. 18, the procedure includes:

step 1801, the UE establishes a connection with the target network and starts to switch;

in this step, no data path is established between the Target AGW and the Anchor GW, and the Anchor GW may be a PDN GW.

Step 1802, Target AGW sends bearer establishment message to Anchor GW;

step 1803, interaction between Anchor GW and PCRF;

in the step, the Anchor GW initiates an IP-CAN Modification process to the PCRF, carries IP-CAN Type information, and acquires a PCCRule corresponding to a default bearer and a special bearer from the PCRF.

Step 1804, the PCEF on the Anchor GW initiates establishment of a target network bearer for the received pcresults corresponding to the target network, and controls using corresponding PCC Rule for the source network and the target network, respectively;

step 1805, the Anchor GW initiates the establishment of default and dedicated bearer to the Target AGW according to the obtained PCC Rule;

step 1806, the UE successfully accesses the target network;

step 1807, the PCEF of the Anchor GW deletes the PCC Rule corresponding to the source network;

in this step, after the UE accesses the target network, the PCEF of the Anchor GW deletes the PCC Rule corresponding to the source network, and only the PCC Rule corresponding to the target network is executed on the Anchor GW.

At step 1808, the remaining handover procedure is executed.

Fig. 19 is another flowchart illustrating a PCEF at a six-anchor gateway controlling PCC Rule in a source/target network during a handover procedure according to an embodiment of the present invention. In this embodiment, the connection between the SGW and the PGW is performed after the bearer establishment is completed, referring to fig. 19, the procedure includes:

1901, the UE establishes connection with the target network and starts to switch;

in this step, no data path is established between the Target AGW and the Anchor GW, and the Anchor GW may be a PDN GW.

Step 1902, the Target AGW and Anchor GW establish default bearer and special bearer;

step 1903, Target AGW sends update bearer message to Anchor GW;

in this step, after the Target AGW completes the establishment of the default bearer and the dedicated bearer, it sends an update bearer message to the AnchorGW, and requests to establish a connection.

Step 1904, the PCEF on the Anchor GW interacts with the PCRF to obtain the PCC Rule of the corresponding target network.

Step 1905, the PCEF on the Anchor GW executes PCC Rule;

in this step, after the PCEF on the Anchor GW obtains the PCC Rule corresponding to the target network, the source network and the target network are respectively controlled by using the corresponding PCC Rule, for example, the charging is respectively performed by using the corresponding charging Rule, that is, two sets of PCC rules exist on the network Anchor point at the same time.

In step 1906, the UE successfully accesses the target network.

Step 1907, the PCEF of the Anchor GW deletes the PCC Rule corresponding to the source network;

in this step, after the UE accesses the target network, the PCEF of the Anchor GW deletes the PCC Rule corresponding to the source network, and only the PCC Rule corresponding to the target network is executed on the Anchor GW.

In step 1908, the remaining handover procedure is performed.

The objects, technical solutions and advantages of the present invention have been described in further detail with reference to the preferred embodiments, it should be understood that the above description is only illustrative of the preferred embodiments of the present invention, and should not be construed as limiting the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (12)

1. A method for implementing network optimized handover, the method comprising:

when the user equipment determines that switching preparation is needed in a source network, initiating a connection establishment process to a target network through the source network;

when the connection between a service gateway and a packet data network gateway is established, a mobility management entity or the service gateway indicates that the packet data network gateway does not switch an uplink and downlink data channel of a user plane from a source network to a target network;

after the preparation of bearer switching is completed and the user equipment is accessed to the target network, the mobility management entity or the service gateway instructs the packet data network gateway to switch the uplink and downlink data channels of the user plane from the source network to the target network.

2. The method of claim 1, wherein the connection establishment between the serving gateway and the packet data network gateway comprises:

after the service gateway completes the establishment of the default bearer and/or the special bearer to the target network access node, the service gateway initiates the establishment of the connection to the packet data network gateway; or,

the serving gateway initiates a connection setup to a packet data network gateway before completing the setup of a default bearer and/or a dedicated bearer to a target network access node.

3. The method of claim 1, wherein the mobility management entity or the serving gateway instructing the packet data network gateway not to switch a user plane uplink and downlink data path from a source network to a target network comprises:

the service gateway directly forwards an instruction sent by a mobility management entity to the packet data network gateway, and the packet data network gateway is instructed not to switch a user plane uplink and downlink data channel from a source network to a target network; or,

and the service gateway generates an indication, sends the indication to the packet data network gateway and indicates the packet data network gateway not to switch the uplink and downlink data channels of the user plane from the source network to the target network.

4. The method of claim 1, wherein the mobility management entity or serving gateway instructing a packet data network gateway to hand over a user plane uplink and downlink data path from a source network to a target network comprises:

the service gateway directly forwards an instruction sent by the mobility management entity to the packet data network gateway, and instructs the packet data network gateway to switch a user plane uplink and downlink data channel from a source network to a target network; or,

and the service gateway generates an indication, sends the indication to a packet data network gateway and indicates the packet data network gateway to switch a user plane uplink and downlink data channel from a source network to a target network.

5. The method of claim 3 or 4, further comprising:

the packet data network gateway acquires the indication sent by the service gateway through the indication parameter or the specific message;

the indication parameter is a parameter expanded in a message which is sent to the packet data network gateway by the serving gateway and is used for connection establishment or update;

the specific message is a message which is sent by the service gateway to the packet data network gateway and is used for connection establishment or update.

6. The method of claim 1, wherein the mobility management entity or the serving gateway instructing the packet data network gateway not to switch a user plane uplink and downlink data path from a source network to a target network comprises:

the mobility management entity sends a bearer establishment message to a service gateway;

the service gateway receives the bearer establishing message and sends a bearer establishing request message to the packet data network gateway, wherein the bearer establishing request message carries a path nottswith instruction for not performing channel switching;

and the packet data network gateway does not switch the uplink and downlink data channels of the user plane after receiving the indication.

7. A mobility management entity, characterized in that the mobility management entity comprises:

a module for, when the user equipment determines in the source network that a handover preparation is required, initiating a connection establishment procedure to the target network through the source network, and when establishing a connection between the serving gateway and the packet data network gateway, instructing the packet data network gateway not to switch the user plane uplink and downlink data channel from the source network to the target network; and the number of the first and second groups,

and a module for instructing the packet data network gateway to switch a user plane uplink and downlink data channel from the source network to the target network after the bearer switching preparation is completed and the user equipment is accessed to the target network.

8. The mobility management entity of claim 7,

the module for indicating the packet data network gateway not to switch the uplink and downlink data channel of the user plane from the source network to the target network when the connection between the serving gateway and the packet data network gateway is established is specifically configured to:

when connection between a service gateway and a packet data network gateway is established or updated, an indication is sent to the service gateway, the indication is forwarded to the packet data network gateway through the service gateway, and the packet data network gateway is indicated not to switch a user plane uplink and downlink data channel from a source network to a target network.

9. The mobility management entity of claim 7, wherein the means for instructing the packet data network gateway to switch a user plane uplink and downlink data path from the source network to the target network after the ue accesses the target network is specifically configured to:

and after the user equipment is accessed to the target network, sending an indication to the service gateway, forwarding the indication to the packet data network gateway through the service gateway, and indicating the packet data network gateway to switch a user plane uplink and downlink data channel from a source network to the target network.

10. A serving gateway, comprising:

a module for, when the user equipment determines in the source network that a handover preparation is required, initiating a connection establishment procedure to the target network through the source network, and when establishing a connection between the serving gateway and the packet data network gateway, instructing the packet data network gateway not to switch the user plane uplink and downlink data channel from the source network to the target network; and

and the module is used for indicating the packet data network gateway to switch the uplink and downlink data channel of the user plane from the source network to the target network after the bearer switching preparation is completed and the user equipment is accessed to the target network.

11. The serving gateway of claim 10, wherein the means for instructing the packet data network gateway not to switch a user plane uplink and downlink data path from a source network to a target network when a connection is established between the serving gateway and the packet data network gateway comprises:

the device comprises a unit for receiving a message for establishing a bearer, which is sent by a mobility management entity; and

the bearer setup request message carries a path not switch instruction for not performing channel switching, and the path not switch instruction is used for indicating the packet data network gateway not to perform uplink and downlink data channel switching on the user plane.

12. A system for implementing network optimized handover, the system comprising:

a mobility management entity as claimed in any of claims 7 to 9, and a serving gateway as claimed in any of claims 10 to 11.

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