CN105992293B

CN105992293B - Method and equipment for switching between networks

Info

Publication number: CN105992293B
Application number: CN201510067654.0A
Authority: CN
Inventors: 董学明; 路杨
Original assignee: China Academy of Telecommunications Technology CATT
Current assignee: China Academy of Telecommunications Technology CATT; Datang Mobile Communications Equipment Co Ltd
Priority date: 2015-02-09
Filing date: 2015-02-09
Publication date: 2020-01-07
Anticipated expiration: 2035-02-09
Also published as: CN105992293A

Abstract

The embodiment of the invention relates to the technical field of wireless communication, in particular to a method and equipment for switching between networks, which are used for solving the problems that the switching process between UMTS and LTE in the prior art needs longer time and the signaling load in the network can be increased. After determining that enhanced handover can be performed, the source wireless network node directly sends a handover request message to a target wireless network node; and after receiving the switching request response message from the target wireless network node, sending a switching command to the terminal. Because the source wireless network node can directly send the switching request message to the target wireless network node, the interaction of the signaling between the core networks is reduced, thereby reducing the time required by the switching process and reducing the signaling load in the network.

Description

Method and equipment for switching between networks

Technical Field

The present invention relates to the field of wireless communication technologies, and in particular, to a method and a device for performing inter-network handover.

Background

The Long-Term coexistence of the operators UMTS (Universal Mobile telecommunications system)/HSPA (High-Speed Packet Access) and LTE (Long Term Evolution) networks makes interoperability between UMTS and LTE a very important place.

In 3GPP (3rd Generation Partnership Project, third Generation mobile communication standardization organization) TS23.401 protocol, the UE switches between UMTS and LTE in a similar procedure to S1 handover in LTE.

The specific process is as follows:

(1) a switching preparation stage: a source eNB (evolved base station) first sends a handover request to a source MME (Mobility Management Entity), which determines that handover is IRAT (international Radio access Technology) and determines a Target SGSN (Serving GPRS support node; GPRS, General Packet Radio Service), according to a Target RNC Identifier in a message, and sends a relocation request to the Target SGSN, triggering the Target SGSN to establish a Service bearer in a Target SGW (Serving GW, Serving gateway), the Target SGSN, and the Target RNC.

(2) A switching execution stage: the target RNC sends a switching command to the UE (terminal), when the UE finishes the access in a target cell, the target RNC sends a relocation completion message to the target SGSN, triggers the target SGSN to send a bearer modification request to a target SGW based on each PDN (Packet Data Network) connection, indicates information such as a transport layer address (direct or indirect transport address of the RNC, SGSN), a control plane address of the target SGSN, a Radio Access Type (RAT) Type and the like of a successfully switched bearer to the SGW, and then the SGW sends a bearer modification request to a Packet Data Network gateway (PDN GW, Packet Data gateway) to indicate the SGW relocation and the RAT Type modification information based on each PDN connection.

Because the current handover between UMTS and LTE is similar to the S1 handover procedure in LTE, when a handover preparation is made between a source RAN (Radio Access Network) node and a target RAN node, a handover request message is forwarded through a core Network node SGSN and an MME, so as to transfer a UE context from the source core Network node to the target core Network node through message forwarding and complete establishment of a service channel from a target SGW to the target RAN node. This results in a long handover preparation time between UMTS and LTE, which may greatly increase the signaling load in the network during the initial LTE network setup.

In summary, the handover procedure between UMTS and LTE currently requires a relatively long time and increases the signaling load in the network.

Disclosure of Invention

The invention provides a method and equipment for switching between networks, which are used for solving the problems that the switching process between UMTS and LTE in the prior art needs longer time and the signaling load in the network can be increased.

The method for switching between networks provided by the embodiment of the invention comprises the following steps:

after the terminal needs to be switched to other networks, the source wireless network node judges whether enhanced switching can be carried out or not;

after determining that the enhanced handover can be performed, the source wireless network node directly sends a handover request message to a target wireless network node;

and the source wireless network node sends a switching command to the terminal after receiving the switching request response message from the target wireless network node.

Preferably, the source wireless network node determines that an enhanced handover is possible after the following conditions are satisfied:

a direct signaling interface is arranged between the source wireless network node and the target wireless network node;

the source wireless network node and the target wireless network node are connected with the same core network signaling service node;

the service area supported by the core network signaling service node in the source wireless network belongs to the service area supported by the core network signaling service node in the target wireless network.

Preferably, the source radio network node determines whether to connect to the same core network signaling service node as the target radio network node according to core network configuration information from the core network signaling service node.

Preferably, the source radio network node determines, by using information from the core network signaling service node or the target radio network node, that is used to determine a service area supported by the core network signaling service node in the target radio network, whether the service area supported by the core network signaling service node in the source radio network belongs to a service area supported by the core network signaling service node in the target radio network.

Preferably, after determining that the enhanced handover is possible, before directly sending the handover request message to the target radio network node, the source radio network node further includes:

and the source wireless network node places the information for determining the source wireless network node and the target cell and the information for determining the core network signaling service node into a switching request message.

Preferably, the source wireless network node is located in a long term evolution, LTE, network, and the target wireless network node is located in a universal mobile telecommunications system, UMTS, network; or

The source wireless network node is located in a UMTS network and the target wireless network node is located in an LTE network.

Another method for performing inter-network handover according to an embodiment of the present invention includes:

a target wireless network node receives a handover request message directly sent from a source wireless network node, wherein the handover request message is sent by the source wireless network node after determining that enhanced handover can be carried out;

and after determining that the terminal corresponding to the switching request message can be accepted, the target wireless network node sends a switching request response message to the source wireless network node.

Preferably, after the target radio network node sends the handover request response message to the source radio network node, the method further includes:

and the target wireless network node maps the quality of service (QoS) parameters of the source wireless network in the switching request message into QoS parameters of the target wireless network, and communicates the terminal corresponding to the admitted switching request message according to the QoS parameters of the target wireless network.

Preferably, after the target radio network node receives the handover request message directly sent from the source radio network node, and before the target radio network node sends a handover request response message to the source radio network node, the method further includes:

and the target wireless network node determines the source wireless network node and the target cell according to the information which is used for enabling the target wireless network node to determine the source wireless network node and the target cell in the switching request message.

the target wireless network node sends a path switching message to a core network signaling service node after the terminal completes the switching;

wherein the core network signaling service node is a core network signaling service node to which the source radio network node and the target radio network node are commonly connected.

Preferably, before the target radio network node sends the path switching message to the core network signaling service node after the terminal completes the handover, the method further includes:

and the target wireless network node determines the corresponding core network signaling service node according to the received identification of the core network signaling service node from the source wireless network node.

Preferably, the sending, by the target radio network node, the path switching message to the core network signaling service node after the terminal completes the switching includes:

and the target wireless network node determines the corresponding core network signaling service node according to the received identification of the core network signaling service node from the source wireless network node, and sends a path switching message to the determined core network signaling service node.

and after the target wireless network node determines that the switching is the pilot frequency switching, the terminal identification of the terminal in the core network signaling service node in the target wireless network and the bearing information of the terminal switched to the target wireless network are placed in the path switching message.

Preferably, the source radio network node is located in an LTE network, and the target radio network node is located in a UMTS network; or

a core network signaling service node receives a path switching message from a target wireless network node, wherein the path switching message is sent by the target wireless network node after a terminal in a source wireless network node completes switching, and the core network signaling service node is a core network signaling service node which is connected with the source wireless network node and the target wireless network node together;

and the core network signaling service node determines a terminal context according to the terminal identification in the path switching message and switches the service plane bearer of the terminal from a source wireless network node to a target wireless network node according to the terminal context.

Preferably, before the core network signaling service node determines the context of the terminal according to the terminal identifier in the path switching message, the method further includes:

and the core network signaling service node determines that the terminal performs pilot frequency switching according to the information in the path switching message.

Preferably, before the core network signaling service node receives the path switching message from the target radio network node, the method further includes:

and the core network signaling service node sends core network configuration information to the source wireless network node so as to inform the source wireless network node that the core network signaling service node is a service node supporting various wireless networks.

Preferably, before the core network configuration information sent by the core network signaling service node to the source radio network node, the method further includes:

the core network signaling service node places the service area information of the service source wireless network and the service area information of the service target wireless network in the core network configuration information; or

And the core network signaling service node places a combination node identifier for indicating that the core network signaling service node is a service node of a plurality of wireless networks in the core network configuration information.

The source wireless network node for switching between networks provided by the embodiment of the invention comprises:

the judging module is used for judging whether enhanced switching can be carried out or not after the terminal needs to be switched to other networks;

the first sending module is used for directly sending the switching request message to the target wireless network node after determining that the enhanced switching can be carried out;

and the second sending module is used for sending a switching command to the terminal after receiving the switching request response message from the target wireless network node.

Preferably, the determining module is specifically configured to determine that the enhanced handover can be performed after the following conditions are met:

Preferably, the determining module is specifically configured to:

and judging whether the same core network signaling service node is connected with the target wireless network node or not according to the core network configuration information from the core network signaling service node.

Preferably, the determining module is specifically configured to:

and judging whether the service area supported by the core network signaling service node in the source wireless network belongs to the service area supported by the core network signaling service node in the target wireless network or not according to the information from the core network signaling service node or the target wireless network node for determining the service area supported by the core network signaling service node in the target wireless network.

Preferably, the first sending module is further configured to:

information for determining a source radio network node and a target cell, and information for determining a core network signaling service node are placed in a handover request message.

The embodiment of the invention provides a target wireless network node for switching between networks, which comprises:

a first receiving module, configured to receive a handover request message from a direct transmission, where the handover request message is sent by the source wireless network node after determining that enhanced handover is possible;

and a third sending module, configured to send a handover request response message to the source wireless network node after determining that a terminal corresponding to the handover request message can be admitted.

Preferably, the third sending module is further configured to:

and mapping the source wireless network QoS parameter in the switching request message into a target wireless network QoS parameter, and communicating the terminal corresponding to the admitted switching request message according to the target wireless network QoS parameter.

Preferably, the third sending module is further configured to:

and determining the source wireless network node and the target cell according to the information which is used for enabling the target wireless network node to determine the source wireless network node and the target cell in the switching request message.

Preferably, the third sending module is further configured to:

after the terminal completes the switching, a path switching message is sent to a core network signaling service node;

Preferably, the third sending module is further configured to:

and determining the corresponding core network signaling service node according to the received identifier of the core network signaling service node from the source wireless network node.

Preferably, the third sending module is specifically configured to:

and determining the corresponding core network signaling service node according to the received identifier of the core network signaling service node from the source wireless network node, and sending a path switching message to the determined core network signaling service node.

Preferably, the third sending module is further configured to:

and after the switching is determined to be pilot frequency switching, the terminal identifier of the terminal in the target wireless network in the core network signaling service node and the bearing information of the terminal switched to the target wireless network are placed in the path switching message.

The embodiment of the invention provides a core network signaling service node for switching between networks, which comprises:

a second receiving module, configured to receive a path switching message from a target radio network node, where the path switching message is sent by the target radio network node after a terminal in a source radio network node completes switching, and the core network signaling service node is a core network signaling service node to which the source radio network node and the target radio network node are commonly connected;

and the processing module is used for determining the context of the terminal according to the terminal identifier in the path switching message and switching the service plane bearer of the terminal from the source wireless network node to the target wireless network node according to the terminal context.

Preferably, the processing module is further configured to:

and according to the information in the path switching message, after the terminal is determined to perform pilot frequency switching, determining the context of the terminal according to the terminal identifier in the path switching message.

Preferably, the processing module is further configured to:

and core network configuration information is sent to the source wireless network node so as to inform the source wireless network node that the core network signaling service node is a service node supporting multiple wireless networks.

Preferably, the processing module is further configured to:

placing the service area information of the service source wireless network and the service area information of the service target wireless network in the core network configuration information; or a combined node identifier for indicating that the core network signaling service node is a service node of a plurality of wireless networks is placed in the core network configuration information.

After determining that enhanced handover can be performed, the source wireless network node directly sends a handover request message to a target wireless network node; and after receiving the switching request response message from the target wireless network node, sending a switching command to the terminal. Because the source wireless network node can directly send the switching request message to the target wireless network node, the interaction of the signaling between the core networks is reduced, thereby reducing the time required by the switching process and reducing the signaling load in the network.

Drawings

Fig. 1 is a schematic structural diagram of a system for performing inter-network handover according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a second-source wireless network node according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a three-target wireless network node according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a signaling service node of a quad-core network according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a five-source wireless network node according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a sixth target wireless network node according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a signaling service node of a seven core network according to an embodiment of the present invention;

fig. 8 is a flowchart illustrating an eighth method for performing inter-network handover according to an embodiment of the present invention;

fig. 9 is a flowchart illustrating a method for performing inter-network handover according to a ninth embodiment of the present invention;

FIG. 10 is a flowchart illustrating a method for performing inter-decimal-line network handover according to an embodiment of the present invention;

fig. 11 is a flowchart illustrating an eleventh method for handover from an LTE network to a UMTS network according to an embodiment of the present invention;

fig. 12 is a flowchart illustrating a method for handover from a UMTS network to an LTE network according to a twelfth embodiment of the present invention.

Detailed Description

In practice, the source wireless network node and the target wireless network node of the embodiments of the present invention are located in different networks.

Such as the source radio network node being located in an LTE network and the target radio network node being located in a UMTS network; or the source wireless network node is located in a UMTS network and the target wireless network node is located in an LTE network.

The embodiments of the present invention will be described in further detail with reference to the drawings attached hereto.

As shown in fig. 1, a system for performing inter-network handover according to an embodiment of the present invention includes: a source radio network node 10 and a target radio network node 11.

The source wireless network node 10 is configured to determine whether enhanced handover can be performed after the terminal needs to be handed over to another network; after determining that the enhanced handover can be performed, directly sending a handover request message to a target wireless network node; and after receiving the switching request response message from the target wireless network node, sending a switching command to the terminal.

A target wireless network node 11, configured to receive a handover request message from a direct transmission, where the handover request message is sent by the source wireless network node after determining that enhanced handover is possible; and after determining that the terminal corresponding to the switching request message can be accepted, sending a switching request response message to the source wireless network node.

The embodiment of the invention does not change the core network signaling service node of the terminal after the switching.

Preferably, the system of the embodiment of the present invention further includes: the core network signals the serving node 12.

The target radio network node 11 is further configured to: after sending a switching request response message to the source wireless network node, after the terminal completes switching, sending a path switching message to a core network signaling service node;

a core network signaling service node 12, configured to receive a path switching message from a target radio network node, where the path switching message is sent by the target radio network node after a terminal in a source radio network node completes switching, and the core network signaling service node is a core network signaling service node to which the source radio network node and the target radio network node are commonly connected; and determining a context of the terminal according to the terminal identifier in the path switching message, and switching the service plane bearer of the terminal from a source wireless network node to a target wireless network node according to the terminal context.

Since the switching of the embodiment of the invention is suitable for switching between different systems, the core network signaling service node determines that the terminal performs different frequency switching according to the information in the path switching message, and then determines the context of the terminal according to the terminal identifier in the path switching message.

For example, when LTE is handed over to UMTS, when MME receives a Path switch message (i.e., Path switch request message) sent by a target eNB (i.e., target radio network node), it determines that IRAT (inter-system) handover occurs if Iu signaling Connection ID field exists.

For example, when UMTS is switched to LTE, when the SGSN receives a path switching message (i.e., Enhanced Relocation Complete request message) sent by a target RNC (i.e., a target radio network node), it determines that IRAT handover occurs if an MME UE S1AP (S1Application protocol ) ID field exists.

The MME (Mobility Management Entity) and the SGSN are one Entity, that is, a core network signaling service node.

The source wireless network node of the embodiment of the invention can perform enhanced switching after the following conditions are met:

(1) a direct signaling interface is arranged between the source wireless network node and the target wireless network node; the simultaneous connection of an RNC such as UMTS and an eNB such as LTE to a core network node is an MME/SGSN combination node with a direct signalling interface between the RNC and the eNB.

(2) The source wireless network node and the target wireless network node are connected with the same core network signaling service node.

(3) The service area supported by the core network signaling service node in the source wireless network belongs to the service area supported by the core network signaling service node in the target wireless network.

In order to enable the source wireless network node and the target wireless network node to know whether the connected core network signaling service node is a service node of various wireless networks, the core network signaling service node can exchange configuration information between the source wireless network node and/or the target wireless network node;

correspondingly, after the source wireless network node and the target wireless network node determine that the connected core network signaling service node is a service node supporting multiple wireless networks according to the configuration information, the source wireless network node can also judge whether the core network signaling service node is connected with the target wireless network node through the information transmitted between the source wireless network node and the target wireless network node.

Specifically, the core network signaling service node sends core network configuration information to the source radio network node to notify the source radio network node that the core network signaling service node is a service node supporting multiple radio networks.

Correspondingly, the source wireless network node judges whether to connect the same core network signaling service node with the target wireless network node through the core network configuration information from the core network signaling service node.

For example, when a core network signaling service node sends core network configuration information to a wireless network node providing service to the core network signaling service node, the core network signaling service node sends service area information of a network where the wireless network node is located, and also sends service area information of the core network signaling service node as other network service nodes, specifically, for example, the core network signaling service node places service area information of a service source wireless network and service area information of a service target wireless network in the core network configuration information; or

A binding node identification is sent to inform the radio network node that it is a serving node for supporting multiple radio networks. Specifically, the core network signaling service node places a combination node identifier, which is used to indicate that the core network signaling service node is a service node of multiple wireless networks, in the core network configuration information.

In implementation, a corresponding relationship between the combination node identifier and the supported wireless network may be preset, for example, the combination node identifier supporting LTE and UMTS is 11, and the wireless network node knows that the wireless network supported by the core network signaling service node is LTE and UMTS after receiving 11.

If a radio network node is connected to a service node (i.e. a signaling service combining node) supporting multiple radio networks, service area information of the connected core network side signaling service node in another radio network can be obtained.

One way is for the core network side to signal the serving node to the radio network node. If the core network side signaling service node informs that the node is the combined node, the service area identifier of the network is mapped to obtain the service area identifier of the other network after the wireless network node obtains the combined node identifier indication.

Specifically, the source radio network node determines, by using information from the core network signaling service node or the target radio network node, that is used to determine a service area supported by the core network signaling service node in the target radio network, whether the service area supported by the core network signaling service node in the source radio network belongs to a service area supported by the core network signaling service node in the target radio network.

In implementation, when two different radio network nodes establish a signaling interface, service area information supported by a core network signaling service node in the network or service area information of an opposite network supported by the core network signaling service node may be mutually transmitted as necessary information for whether enhanced handover can be performed between each other.

Such as: if the core network signaling service node only supports sending the service area information of another network related to a joint node to a radio network node, when an interface is established between the two radio network nodes, the radio network node which does not obtain the service area information of the other network supported by the core network signaling service node sends the supported service area information of the local network, and the radio network node which obtains the information sends the service area information of the other network supported by the core network signaling service node. For example, if the core network signaling service node sends the service area information of the network B (i.e., the network where the radio network node B is located) related to a joint node to the radio network node a, when the radio network node a and the radio network node B establish an interface, the radio network node a sends the service area information of the network B supported by the core network signaling service node to the radio network node B, and the radio network node B sends the service area information of the network B supported by the core network signaling service node to the radio network node a.

Preferably, after the source wireless network node determines that the terminal needs to be switched to other networks, whether a direct signaling interface is established with the target wireless network node or not can be judged firstly;

if yes, judging that the source wireless network node and the target wireless network node are connected with the same core network signaling service node;

if yes, whether the service area supported by the source wireless network belongs to the service area supported by the core network signaling service node in the target wireless network is judged.

It should be noted that the determination sequence of the above three conditions is only an example, and the determination sequence may also be adjusted as needed, for example, first determining the condition 2, then determining the condition 3, and finally determining the condition 1.

Preferably, the source wireless network node sends a core network signaling service node identifier serving the terminal to the target wireless network, and the core network signaling service node identifier is used for the target wireless network node to address the core network side signaling node serving the terminal after the terminal is switched; and the source wireless network node sends the unique identifier corresponding to the source network of the terminal in the core network signaling service node to the target wireless network node, so that the target wireless network node addresses the terminal after the switching at the terminal target side is completed.

When the switching is completed, the target wireless network node addresses the correct core network signaling service node through the core network signaling service node identifier sent by the source wireless network node, and sends a path switching request to the core network signaling service node, wherein the request message carries the unique identifier corresponding to the source network of the terminal in the core network signaling service node. The core network signaling service node is a combination node (namely, the core network signaling service node comprises a source network side core network service node and a target network side core network service node), so that the core network signaling service node can judge that the system switching is carried out through a unique identifier corresponding to a source network by a terminal, and directly obtains the context of the terminal from the source wireless network node. And the core network signaling service node switches the service plane bearing of the terminal from the source wireless network node to the target wireless network node.

Preferably, after determining that the enhanced handover can be performed, the source radio network node places information for determining the source radio network node and the target cell and information for determining the core network signaling service node in a handover request message, and directly sends the handover request message to the target radio network node;

correspondingly, the target wireless network node determines the source wireless network node and the target cell according to the information which is used for enabling the target wireless network node to determine the source wireless network node and the target cell in the switching request message.

The information used to determine the source radio network node and the target cell is also different according to different systems. Such as handover from LTE to UMTS: the method comprises the steps of determining that information of a source radio network node is a target RNC ID (identification), and determining that information of a target cell is the target cell ID;

and switching from UMTS to LTE, and determining that the information of the source wireless Network node and the target Cell is ECGI (Evolved UMTS terrestrial Radio Access Network) of the target Cell (EUTRAN Cell Global Identity; EUTRAN, Evolved UMTS terrestrial Radio Access Network).

and the target wireless network node maps the source wireless network QoS (Quality of Service) parameter in the switching request message into a target wireless network QoS parameter, and communicates the terminal corresponding to the admitted switching request message according to the target wireless network QoS parameter.

For example, when LTE is switched to UMTS, the bearer QoS in the handover request message is EPS (Evolved Packet System) QoS; when the UMTS is handed over to LTE, the bearer QoS in the handover request message is R99 QoS. When the target radio network node receives the handover request message, mapping between EPS QoS and R99 QoS is performed to obtain QoS suitable for use in the present system.

Preferably, after the terminal completes handover, the target radio network node determines a core network signaling service node according to information used for determining the core network signaling service node in the handover request message.

The information used to determine the core network signaling service node is also different depending on the system. Such as handover from LTE to UMTS, determining a core network signaling service node from RAI (routing area identity) mapped by GUMMEI (universal identity); switching from UMTS to LTE, and determining a core network signaling service node according to RAI.

In addition to the above manner, the target radio network node may determine the corresponding core network signaling service node according to the received identifier of the core network signaling service node from the source radio network node, and send a path switching message to the determined core network signaling service node.

Preferably, after the target wireless network node completes the handover of the terminal and determines that the handover is inter-frequency handover, the terminal identifier of the terminal in the target wireless network in the core network signaling service node and the bearer information of the terminal to be handed over to the target wireless network are placed in the path handover message, and the path handover message is sent to the core network signaling service node.

In the implementation, the scheme of the embodiment of the present invention is divided into four stages, namely a network configuration stage, an enhanced handover condition judgment stage, a handover preparation stage and a handover completion stage, and specifically described below with LTE handover to UMTS and UMTS handover to LTE as examples.

Firstly, a network configuration stage:

when a signaling interface is established between a UMTS node and an LTE node, information of a core network signaling service node connected with each node is interacted, and the interface between the RNC and the eNB is similar to an X2 interface between eNBs (evolved node Bs) and is used for control of switching, load balancing interference and the like.

When the MME and the eNB establish S1 connection, an S1 Setup Response (S1 establishment Response) message sent by the MME to the eNB indicates the PLMN, the pool area identity (MMEGI) and the MME identity (MMEC) supported by the MME to the eNB, and a joint node identity is added in the message to indicate whether the MME is a joint node deployed together with the SGSN. If the joint node indication mark is False, the eNB considers that the MME is independently deployed; and if the joint node identifier is True, indicating the MME is the joint node to the eNB, and simultaneously mapping the MME identifier GUMMEI to the SGSN identifier RAI by the eNB according to the existing mapping rule to obtain an RAI set supported by the MME/SGSN joint node.

When a direct communication interface is established between the eNB and the RNC of the UMTS, an RAI list can be carried in an interface establishment message sent by the eNB to the RNC, and an RAI set supported by an MME/SGSN combined node connected with the eNB is indicated; the interface establishment response message sent by the RNC to the eNB may carry the RAI set supported by the SGSN to which the RNC is connected.

II, enhancing switching condition judgment stage:

when the UE moves from the LTE network to the UMTS network, the eNB determines according to 3 conditions:

firstly, judging whether X2 connection exists between the target RNC and the target RNC, and entering the 2 nd judgment if X2 connection exists;

secondly, judging whether the MME node serving the UE currently is an SGSN combined node or not, and if so, entering the 3rd judgment;

and finally, judging whether the RAI set supported by the MME/SGSN combination node (namely a core network signaling service node, the same below) of the current service UE belongs to the RAI set supported by the SGSN connected with the target RNC node, if so, performing enhanced switching on the UE.

When the UE moves from the UMTS network to the LTE network, the RNC can also determine according to 3 conditions:

firstly, judging whether X2 connection exists between the target eNB and the target eNB, and entering the 2 nd judgment if X2 connection exists;

secondly, judging whether the SGSN node serving the UE currently is an MME node or not, and if so, entering the 3rd judgment;

and finally, judging whether the RAI of the current service UE belongs to the RAI set supported by the core network node connected with the target eNB node, if so, performing enhanced handover on the UE.

Thirdly, switching preparation stage:

in order for the target radio network node to address the MME/SGSN junction serving the UE, the handover request message needs to carry the RAI or the RAI generated from the GUMMEI mapping.

If switching from LTE to UMTS, source eNB maps GUMMEI of current service UE to RAI and sends the RAI to target RNC, RNC addresses SGSN/MME combination node through RAI; if the UE is switched from UMTS to LTE, the source RNC sends RAI of the current service UE to the target eNB, the target eNB inversely maps the RAI into GUMMEI, and the SGSN/MME combination node is addressed according to the mapped GUMMEI.

In order to address the UE in the MME/SGSN combination node after handover is completed, in the handover preparation phase, if handover is from LTE to UMTS, the source eNB sends the target RNC the identity of the UE in the MME, MME UE S1AP ID; if handover is made from UMTS to LTE, the source RNC sends the target eNB the identity Iu Signalling Connection ID (Iu interface Signalling Connection identity) of the UE in the SGSN.

Handover request message sent by source RAN node to target RAN node:

if switching from LTE to UMTS, the switching request message should carry the target RNC ID, the target cell ID, the RAI mapped by the GUMMEI, the UE context, the MME UE S1AP ID, the UE History Information and the EPS bearing Information. The EPS Bearer information includes information such as E-RAB (Evolved Radio Access Bearer) ID, LTE QoS parameter, uplink transport layer address, and whether to recommend data forwarding.

If switching from UMTS to LTE, the handover request message shall carry the ECGI, RAI, UE context, PS domain Iu signaling Connection ID, PS domain RAB (Radio Access Bearer) Bearer information, etc. PS (Packet Switched) domain RAB bearer information includes RAB ID, UMTS QoS parameters, uplink transport address (if direct transport), and information whether data forwarding is proposed.

Preferably, the QoS mapping at the target node:

the bearing parameters sent by the source wireless network node to the target wireless network node are based on a source system, and if LTE is switched to UMTS, the bearing QoS in the switching request message is EPS QoS; such as UMTS to LTE handover, the bearer QoS in the handover request message is R99 QoS. When the target radio network node receives the handover request message, mapping between EPS QoS and R99 QoS is performed to obtain QoS suitable for use in the system, i.e. the target eNB maps EPS QoS to R99 QoS and the target eNB maps R99 QoS to EPS QoS. The mapping rule can be the existing mapping rule.

Fourthly, a switching completion stage:

switching from UMTS to LTE, after UE completes access at target eNB node, target eNB needs to send path switch request message to MME/SGSN combination node, if it is an IRAT switching, the message should carry mark Iu Signalling Connection ID in SGSN of UE sent by source eNB in switching preparation phase and EPS bearing information successfully switched to LTE.

When an MME/SGSN combination node receives a Path switch request message sent by a target eNB, judging whether an Iu Signalling Connection ID domain exists, indicating that IRAT switching occurs, addressing UE in the combined SGSN node according to the Iu Signalling Connection ID and acquiring UE Context, wherein the UE Context comprises information such as IMSI of the UE, mobility management Context MME Context, EPS bearing Context, control Connection address and TEID (Tunnel End Point identifier) between the UE and SGW, and whether ISR (Idle State Signalling Reduction) is supported or not; if the Iu Signalling Connection ID does not exist, it indicates that the handover is not an IRAT handover, and the processing may be performed according to the existing method. And the MME compares the bearer context obtained from the combining node SGSN with the successfully switched EPS bearer obtained from the path switch message and initiates a process of locally deactivating the unsuccessfully switched EPS bearer. Here, the EPS bearer which is not used after the comparison is deactivated, and if not, the EPS bearer is not needed. The flow of deactivation is consistent with that specified in the present standard.

After the UE completes access at the target RNC node, the target RNC needs to send an Enhanced Relocation Complete request message to the MME/SGSN combining node, and if the request message is an IRAT handover, the message carries an identity MME UE S1AP ID of the UE in the MME and RAB bearer information that the handover has been successfully performed to the UMTS, which are sent by the source eNB in the handover preparation phase.

When an SGSN receives an Enhanced Relocation Complete request message sent by a target RNC, judging whether an MME UE S1AP ID domain exists, indicating that IRAT switching occurs, addressing UE in a combined MME node according to the MME UE S1AP ID and acquiring UE Context, wherein the UE Context comprises information such as IMSI, mobility management Context MM Context, RAB Context of the UE, control connection address and TEID between the UE Context and SGW, and whether the UE supports ISR; if the IuSignalling Connection ID does not exist in the message, it indicates that the handover is not an IRAT handover, and the processing is performed according to the existing method. SGSN compares the loading context obtained from combining node MME with the successful switching RAB loading obtained from Enhanced Relocation Complete message, and initiates the process of local deactivation of unsuccessfully switching RAB loading.

In an implementation, the source wireless network node and the target wireless network node may be deployed together or separately. If deployed together, the message between the source and target wireless network nodes is an intra-device message; if deployed separately, the messages between the source and target wireless network nodes are inter-device messages.

As shown in fig. 2, a source wireless network node according to a second embodiment of the present invention includes: a judging module 201, a first sending module 202 and a second sending module 203.

A judging module 201, configured to judge whether enhanced handover is possible after the terminal needs to be handed over to another network;

a first sending module 202, configured to send a handover request message directly to a target wireless network node after determining that enhanced handover is possible;

a second sending module 203, configured to send a handover command to the terminal after receiving the handover request response message from the target wireless network node.

Preferably, the determining module 201 is specifically configured to determine that the enhanced handover can be performed after the following conditions are satisfied:

Preferably, the determining module 201 is specifically configured to:

Preferably, the first sending module 202 is further configured to:

As shown in fig. 3, a target wireless network node according to a third embodiment of the present invention includes: a first receiving module 301 and a third transmitting module 302.

A first receiving module 301, configured to receive a handover request message from a direct sending, where the handover request message is sent by the source wireless network node after determining that enhanced handover is possible;

a third sending module 302, configured to send a handover request response message to the source wireless network node after determining that the terminal corresponding to the handover request message can be admitted.

Preferably, the third sending module 302 is further configured to:

Preferably, the third sending module 302 is specifically configured to:

Preferably, the third sending module 302 is further configured to:

As shown in fig. 4, a core network signaling service node according to a fourth embodiment of the present invention includes: a second receiving module 401 and a processing module 402.

A second receiving module 401, configured to receive a path switching message from a target radio network node, where the path switching message is sent by the target radio network node after a terminal in a source radio network node completes switching, and the core network signaling service node is a core network signaling service node to which the source radio network node and the target radio network node are commonly connected;

a processing module 402, configured to determine a context for the terminal according to the terminal identifier in the path switching message, and switch the service plane bearer of the terminal from the source wireless network node to the target wireless network node according to the terminal context.

Preferably, the processing module 402 is further configured to:

In implementation, in different application scenarios, the source wireless network node may also be the target wireless network node; the target radio network node may also be a source radio network node. The modules of fig. 3 and 4 may be combined in one entity, using the modules of fig. 3 if the current scenario requires as a source wireless network node; the modules of fig. 4 are used if the current scenario requires as a target wireless network node.

As shown in fig. 5, a source wireless network node according to a fifth embodiment of the present invention includes:

the processor 501 is configured to read the program in the memory 504, and execute the following processes:

after the terminal needs to be switched to other networks, whether enhanced switching can be carried out is judged; after determining that enhanced handover is possible, directly sending a handover request message to the target wireless network node through the transceiver 502; after receiving the handover request response message from the target wireless network node through the transceiver 502, a handover command is sent to the terminal through the transceiver 502.

A transceiver 502 for receiving and transmitting data under the control of the processor 501.

Preferably, the processor 501 is specifically configured to determine that the enhanced handover is enabled after the following conditions are satisfied:

Preferably, the processor 501 is specifically configured to:

Preferably, the processor 501 is further configured to:

In fig. 5, a bus architecture (represented by bus 500), bus 500 may include any number of interconnected buses and bridges, bus 500 linking together various circuits including one or more processors, represented by processor 501, and memory, represented by memory 504. The bus 500 may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. A bus interface 503 provides an interface between the bus 500 and the transceiver 502. The transceiver 502 may be one element or may be multiple elements, such as multiple receivers and transmitters, providing a means for communicating with various other apparatus over a transmission medium. Data processed by processor 501 is transmitted over a wireless medium via antenna 505. further, antenna 505 receives data and transmits data to processor 501.

The processor 501 is responsible for managing the bus 500 and general processing and may also provide various functions including timing, peripheral interfaces, voltage regulation, power management, and other control functions. And memory 504 may be used to store data used by processor 501 in performing operations.

Alternatively, the processor 501 may be a CPU (central processing unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a CPLD (Complex Programmable Logic Device).

As shown in fig. 6, a target radio network node according to a sixth embodiment of the present invention includes:

the processor 601, configured to read the program in the memory 604, executes the following processes:

receiving, by a transceiver 602, a handover request message from a direct transmission, wherein the handover request message is transmitted by the source radio network node after determining that enhanced handover is possible; after determining that the terminal corresponding to the handover request message can be admitted, a handover request response message is sent to the source radio network node through the transceiver 602.

A transceiver 602 for receiving and transmitting data under the control of the processor 601.

Preferably, the processor 601 is further configured to:

Preferably, the processor 601 is specifically configured to:

Preferably, the processor 601 is further configured to:

In fig. 6, a bus architecture (represented by bus 600), bus 600 may include any number of interconnected buses and bridges, and bus 600 links together various circuits including one or more processors, represented by processor 601, and memory, represented by memory 604. The bus 600 may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. A bus interface 603 provides an interface between the bus 600 and the transceiver 602. The transceiver 602 may be one element or may be multiple elements, such as multiple receivers and transmitters, providing a means for communicating with various other apparatus over a transmission medium. The data processed by the processor 601 is transmitted over a wireless medium via the antenna 605, and further, the antenna 605 receives the data and transmits the data to the processor 601.

The processor 601 is responsible for managing the bus 600 and general processing and may also provide various functions including timing, peripheral interfaces, voltage regulation, power management, and other control functions. And memory 604 may be used to store data used by processor 601 in performing operations.

Alternatively, the processor 601 may be a CPU, ASIC, FPGA or CPLD.

In implementation, in different application scenarios, the source wireless network node may also be the target wireless network node; the target radio network node may also be a source radio network node. The modules of fig. 5 and 6 may be combined in one entity, using the modules of fig. 5 if the current scenario requires as a source wireless network node; the modules of fig. 6 are used if the current scenario requires as a target wireless network node.

As shown in fig. 7, a seven core network signaling service node according to an embodiment of the present invention includes:

a processor 701, configured to read the program in the memory 704, and execute the following processes:

receiving a path switching message from a target radio network node through a transceiver 702, wherein the path switching message is sent by the target radio network node after a terminal in a source radio network node completes switching, and the core network signaling service node is a core network signaling service node commonly connected with the source radio network node and the target radio network node; and determining a context of the terminal according to the terminal identifier in the path switching message, and switching the service plane bearer of the terminal from a source wireless network node to a target wireless network node according to the terminal context.

A transceiver 702 for receiving and transmitting data under the control of the processor 701.

Preferably, the processor 701 is further configured to:

In fig. 7, a bus architecture (represented by bus 700), bus 700 may include any number of interconnected buses and bridges, bus 700 linking together various circuits including one or more processors, represented by processor 701, and memory, represented by memory 704. The bus 700 may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. A bus interface 703 provides an interface between the bus 700 and the transceiver 702. The transceiver 702 may be one element or multiple elements, such as multiple receivers and transmitters, providing a means for communicating with various other apparatus over a transmission medium. Data processed by processor 701 is transmitted over a wireless medium via antenna 705, which antenna 705 receives data and transmits data to processor 701.

The processor 701 is responsible for managing the bus 700 and general processing, and may also provide various functions including timing, peripheral interfaces, voltage regulation, power management, and other control functions. And memory 704 may be used to store data used by processor 701 in performing operations.

Alternatively, the processor 701 may be a CPU, ASIC, FPGA or CPLD.

Based on the same inventive concept, the embodiment of the present invention further provides a method for performing inter-network handover, and since the device corresponding to the method of the embodiment of the present invention is a device in the system for performing inter-network handover in the embodiment of the present invention, and the principle of the method for solving the problem is similar to that of the system, the implementation of the method can refer to the implementation of the system, and repeated details are not described.

As shown in fig. 8, the eighth method for performing inter-network handover according to the embodiment of the present invention includes:

step 801, after a terminal needs to be switched to other networks, a source wireless network node judges whether enhanced switching can be performed;

step 802, after determining that the enhanced handover can be performed, the source wireless network node directly sends a handover request message to a target wireless network node;

step 803, the source wireless network node sends a handover command to the terminal after receiving the handover request response message from the target wireless network node.

As shown in fig. 9, a method for performing inter-network handover according to the ninth embodiment of the present invention includes:

step 901, a target wireless network node receives a handover request message directly sent from a source wireless network node, wherein the handover request message is sent by the source wireless network node after determining that enhanced handover can be performed;

step 902, after determining that the terminal corresponding to the handover request message can be admitted, the target wireless network node sends a handover request response message to the source wireless network node.

As shown in fig. 10, the method for switching between decimal networks according to the embodiment of the present invention includes:

1001, a core network signaling service node receiving a path switching message from a target wireless network node, wherein the path switching message is sent by the target wireless network node after a terminal in a source wireless network node completes switching, and the core network signaling service node is a core network signaling service node connected with the source wireless network node and the target wireless network node together;

step 1002, the core network signaling service node determines a context of the terminal according to the terminal identifier in the path switching message, and switches the service plane bearer of the terminal from a source wireless network node to a target wireless network node according to the terminal context.

In an implementation, the source radio network node and the target radio network node may be in the same physical node or in different physical nodes. The following are examples respectively.

In case one, the UE is handed over from the LTE network to the UMTS network, and the source eNB target RNC node is not in the same physical node.

As shown in fig. 11, a method for handover from an LTE network to a UMTS network according to an eleventh embodiment of the present invention includes:

step 1: the source eNB decides to initiate IRAT HO (handover) according to IRAT (Inter Radio Access Technology) measurement results, and determines that enhanced handover can be performed according to enhanced handover judgment conditions.

Step 2: the source eNB sends a handover request message to the target RNC.

The handover request message includes a target RNC ID, a target cell ID, an RAI (Routing Area Identification) mapped by the GUMMEI, a UE context, an MME UE S1AP ID (mobility management entity terminal S1application protocol Identification), a UE History Information, and an EPS (Evolved Packet System) bearer Information.

The EPS Bearer information includes information such as an E-RAB (Evolved Radio Access Bearer) ID, an LTE QoS (Quality of Service) parameter, an uplink transport layer address, and whether to recommend data forwarding.

And step 3: after receiving the handover request message, the target RNC maps a Radio Access Bearer (RAB) QoS parameter with an EPS QoS parameter, performs RRM (Radio resource Management) procedures such as handover Access decision and air interface resource allocation to generate a handover command, and encapsulates the handover command in a handover response message.

And 4, step 4: the target RNC sends a handover response message to the source eNB.

And 5: and after receiving the switching request response, the source eNB sends a switching command to the UE.

Step 6: and after the UE finishes accessing in the target cell, the UE sends a switching completion message to the target RNC.

And 7: the target RNC addresses the SGSN (Serving GPRS Support Node; GPRS, General Packet Radio Service) combined with the MME according to the RAI in the handover request message.

And 8: the target RNC sends an Enhanced Relocation Complete Request message to the SGSN.

The message carries MME UE S1AP ID, RAB bearer ID successfully switched, and RAB bearer downlink transport layer address.

And step 9: because the Enhanced Relocation Complete Request message has an MME UE S1AP ID domain, the SGSN judges that the message is IRAT handover, addresses the UE according to the MME UE S1AP ID and acquires the UE context, generates security parameters according to the UE context, and maps the QoS carried by the EPS in the context to RAB QoS.

Step 10: the SGSN sends a Modify Bearer Request message to the target SGW.

The message includes an RAB bearer downlink transport layer address (an RNC transport layer address if direct transmission is supported, or an SGSN transport layer address if direct transmission is supported) and a current RAT type (i.e., UTRAN (Universal mobile telecommunications system)).

Step 11: the target SGW (Serving GW) modifies the UE downlink transport layer address and the RAT type.

Step 12: the target SGW sends a Modify Bearer Request message to the PGW (PDN GW, packet data network manager) indicating that the PGW has changed the RAT type of the serving UE.

If the SGW is changed, the PGW may also be indicated with a downlink traffic plane SGW address and a control plane SGW address.

Step 13: the PGW modifies the RAT type and updates the charging rules.

Step 14: the PGW sends a Modify Bearer Response message to the target SGW, indicating the address of the PGW on the uplink service plane.

Step 15: and the SGW sends a Modify Bearer Response to the SGSN to indicate the address of the uplink service plane.

Step 16: the SGSN replies an Enhanced Relocation Complete Response message to the target RNC, containing the security parameters and uplink transport layer address of the UE (the SGW transport layer address if direct transport is supported, otherwise the SGSN transport layer address).

And step 17: the target RNC sends a UE context release request to the source eNB.

And in the second case, the UE is switched to the LTE network from the UMTS network, and the source RNC and the target eNB node are not in the same physical node.

As shown in fig. 12, a method for switching from a UMTS network to an LTE network according to a twelfth embodiment of the present invention includes:

step 1: and the source RNC determines to initiate IRAT HO according to the IRAT measurement result and determines that the enhanced handover can be carried out according to the enhanced handover judgment condition.

Step 2: the source RNC sends a handover request message to the target eNB.

The handover request message includes target cell ECGI, RAI, UE context, PS (Packet Switched ) domain Iu Signalling Connection ID (Iu interface Signalling Connection identifier), PS domain RAB bearer information, and the like.

The PS domain RAB bearer information includes RAB ID, UMTS QoS parameters, and information (if direct transmission is performed, uplink transmission address may also be included) whether data forwarding is suggested.

And step 3: and after receiving the switching request message, the target eNB uses the RAB QoS parameter to map the EPS bearer QoS parameter, then performs RRM processes such as switching access judgment, air interface resource allocation and the like to generate a switching command, and encapsulates the switching command into a switching response message.

And 4, step 4: the target eNB sends a handover response message to the source RNC.

And 5: and after receiving the switching request response, the source RNC sends a switching command to the UE.

Step 6: and after the UE finishes accessing in the target cell, the UE switches to the target eNB to finish the message.

And 7: and the target eNB reflects the GUMMEI according to the RAI in the switching request message and addresses the MME combined with the SGSN according to the mapped GUMMEI.

And 8: the target eNB sends a Path Switch Request message to the MME.

Wherein, the message carries information such as Iu Signalling Connection ID, successfully switched EPS bearer identification, EPS bearer downlink transport layer address, etc.

And step 9: because the Path switching Request message has the Iu Signalling Connection ID domain, the MME judges that the message is IRAT switching, addresses the UE in the combined SGSN node according to the Iu Signalling Connection ID and acquires the UE context, generates the security parameters according to the UE context, and maps the QoS loaded by the context RAB into the EPSQoS.

Step 10: and the MME sends a Modify Bearer Request message to the target SGW.

Wherein, the message includes the EPS bearer downlink transport layer address and the current RAT type (i.e., E-UTRAN).

Step 11: and the target SGW modifies the downlink transport layer address and the RAT type of the UE.

Step 12: the target SGW sends a Modify Bearer Request to the PGW indicating that the PGW has changed the RAT type of the serving UE.

If the SGW is changed, the PGW is indicated with the downlink traffic plane SGW address and the control plane SGW address.

Step 13: the PGW modifies the RAT type and updates the charging rules.

Step 14: and the PGW sends a Modify Bearer Response to the target SGW to indicate the address of the PGW of the uplink service plane.

Step 15: and the SGW sends a Modify Bearer Response indication uplink service plane address to the MME.

Step 16: the MME replies a Path Switch Acknowledge message to the target eNB, which contains the security parameters and the uplink service transport layer address of the UE. If the transmission is indirect, the SGSN of the same node is required to be instructed to release the original service connection.

And step 17: the target eNB sends a UE context release request to the source RNC.

And in the third case, the UE is switched to the UMTS network from the LTE network, and the source eNB and the target RNC node are in the same physical node.

Step 1: the source eNB determines to initiate IRAT HO according to IRAT (Inter Radio Access Technology) measurement results, and determines to perform enhanced handover according to enhanced handover judgment conditions.

Step 2 to step 4: step 2-4 of case one. The difference is that these procedures are performed inside the RAN node and the handover preparation message becomes the device internal interface message. Another possibility is that the source eNB and the target RNC share the UE context information under centralized management, so that the target RNC only needs to map the EPS bearer QoS to RAB QoS information, and the device internal interface information may also be omitted.

And 7: the target RNC addresses the SGSN for RAI according to the GUMMEI mapping served by the UE when the source eNB is.

Step 10 to step 16: step 10 to step 16 in the same manner.

And step 17: the source eNB deletes UE context information, or deletes UE context information related to LTE in case that the source eNB and the target RNC are managed centrally.

And in case IV, the UE is switched to the LTE network from the UMTS network, and the source RNC and the target eNB node are in the same physical node.

Step 2 to step 4: step 2 to step 4 in the same case two, the difference is that these procedures are performed inside the RAN node, and the handover preparation message becomes the device internal interface message. Another possibility is that the source RNC and the target eNB may share the UE context information under centralized management, so that the target eNB only needs to map the RAB bearer QoS to the EPS QoS information, and the device internal interface message may also be omitted.

And 7: and the target eNB reflects the GUMMEI according to the RAI of the UE in the original UMTS system and addresses the combined MME with the source SGSN according to the mapped GUMMEI.

And 8: the target eNB sends a Path Switch Request message to the MME.

Step 9 to step 16: and 9-16 in the same way.

And step 17: the source RNC deletes the UE context information or deletes the context information of the UE related to the UMTS under the condition that the source RNC and the target eNB are managed in a centralized way

From the above, it can be seen that: after determining that enhanced switching can be performed, a source wireless network node directly sends a switching request message to a target wireless network node; and after receiving the switching request response message from the target wireless network node, sending a switching command to the terminal. Because the source wireless network node can directly send the switching request message to the target wireless network node, the interaction of the signaling between the core networks is reduced, thereby reducing the time required by the switching process and reducing the signaling load in the network.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A method for performing an inter-network handover, the method comprising:

the source wireless network node sends a switching command to a terminal after receiving a switching request response message from the target wireless network node;

wherein the source wireless network node determines that an enhanced handover can be performed after the following conditions are satisfied:

a source wireless network node and a target wireless network node are connected with the same core network signaling service node, wherein the core network signaling service node is a node which has signaling connection with the source wireless network node and processes a path switching message sent by the target wireless network node;

2. The method of claim 1, wherein the source radio network node determines whether to connect to the same core network signaling service node as the target radio network node through core network configuration information from the core network signaling service node.

3. The method of claim 1, wherein the source radio network node determines whether the service area supported by the core network signaling service node in the source radio network belongs to the service area supported by the core network signaling service node in the target radio network through information from the core network signaling service node or the target radio network node for determining the service area supported by the core network signaling service node in the target radio network.

4. The method of claim 3, wherein the source radio network node, after determining that the enhanced handover is possible, before sending the handover request message directly to the target radio network node, further comprises:

5. The method according to any of claims 1 to 4, wherein the source radio network node is located in a Long term evolution, LTE, network and the target radio network node is located in a Universal Mobile Telecommunications System, UMTS, network; or

6. A method for performing an inter-network handover, the method comprising:

a target wireless network node receives a switching request message directly sent from a source wireless network node, wherein the switching request message is sent after the source wireless network node determines that a direct signaling interface exists between the source wireless network node and the target wireless network node, and determines that the same core network signaling service node is connected with the target wireless network node, and determines that the core network signaling service node belongs to a service area supported by the target wireless network in a service area supported by the source wireless network, and then determines that enhanced switching can be carried out;

after determining that the terminal corresponding to the switching request message can be accepted, the target wireless network node sends a switching request response message to the source wireless network node;

after the target radio network node sends a handover request response message to the source radio network node, the method further includes:

the target wireless network node sends a path switching message to the core network signaling service node after the terminal completes the switching;

the core network signaling service node is a node which is connected with the source wireless network node and the target wireless network node together, has signaling connection with the source wireless network node, and processes a path switching message sent by the target wireless network node.

7. The method of claim 6, wherein after the target radio network node sends a handover request reply message to the source radio network node, further comprising:

8. The method as claimed in claim 6, wherein after the target radio network node receives the handover request message directly transmitted from the source radio network node, and before transmitting a handover request response message to the source radio network node, further comprising:

9. The method of claim 6, wherein the target radio network node further comprises, before sending a path switch message to a core network signaling service node after the terminal completes the handover:

10. The method of claim 6, wherein the target radio network node sending a path switch message to a core network signaling service node after the terminal completes the handover, comprising:

11. The method of claim 6, wherein the target radio network node further comprises, before sending a path switch message to a core network signaling service node after the terminal completes the handover:

12. The method according to any of claims 8 to 11, wherein the source radio network node is located in an LTE network and the target radio network node is located in a UMTS network; or

13. A method for performing an inter-network handover, the method comprising:

a core network signaling service node receives a path switching message from a target wireless network node, wherein the path switching message is sent after the target wireless network node determines that the target wireless network node can accept a source wireless network node and determines that a direct signaling interface is arranged between the target wireless network node and the target wireless network node, and determines that the target wireless network node is connected with the same core network signaling service node as the target wireless network node, and determines that a service area supported by the source wireless network by the core network signaling service node belongs to a service area supported by the target wireless network by the core network signaling service node, and determines that a terminal corresponding to a switching request message which can be sent after enhanced switching is switched, and the core network signaling service node is connected with the source wireless network node and the target wireless network node together and has signaling connection with the source wireless network node, and a node for processing the path switching message sent by the target wireless network node;

14. The method of claim 13, wherein before the core network signaling service node determines a context for the terminal according to the terminal identifier in the path switch message, the method further comprises:

15. The method of claim 13, wherein before the core network signaling serving node receives the path switch message from the target radio network node, further comprising:

16. The method of claim 13, wherein the core network signaling service node precedes the core network configuration information sent to the source radio network node, further comprising:

17. The method according to any of claims 13 to 16, wherein the source radio network node is located in an LTE network and the target radio network node is located in a UMTS network; or

18. A source radio network node for performing an inter-network handover, the source radio network node comprising:

the second sending module is used for sending a switching command to the terminal after receiving a switching request response message from the target wireless network node;

the determining module is specifically configured to determine that enhanced handover can be performed when the following conditions are satisfied:

19. The source wireless network node in claim 18, wherein the determining module is specifically configured to:

20. The source wireless network node in claim 18, wherein the determining module is specifically configured to:

21. The source wireless network node of claim 20, wherein the first transmitting module is further to:

22. The source radio network node according to any of claims 18 to 21, wherein the source radio network node is located in an LTE network and the target radio network node is located in a UMTS network; or

23. A target wireless network node for performing an inter-network handover, the target wireless network node comprising:

the first receiving module is used for receiving a switching request message directly sent by a source wireless network node, wherein the switching request message is sent after the source wireless network node determines that a direct signaling interface exists between the source wireless network node and a target wireless network node, and determines that the same core network signaling service node is connected with the target wireless network node, and determines that the core network signaling service node can be subjected to enhanced switching after a service area supported by the source wireless network belongs to a service area supported by the target wireless network;

a third sending module, configured to send a handover request response message to the source wireless network node after determining that a terminal corresponding to the handover request message can be admitted;

wherein the third sending module is further configured to:

after the terminal completes switching, sending a path switching message to the core network signaling service node;

24. The target wireless network node of claim 23, wherein the third sending module is further to:

25. The target wireless network node of claim 23, wherein the third sending module is further to:

26. The target wireless network node of claim 23, wherein the third sending module is further to:

27. The target wireless network node of claim 23, wherein the third sending module is specifically configured to:

28. The target wireless network node of claim 23, wherein the third sending module is further to:

29. A target radio network node according to any of claims 23 to 28, wherein the source radio network node is located in an LTE network and the target radio network node is located in a UMTS network; or

30. A core network signaling service node for performing an inter-network handover, the core network signaling service node comprising:

a second receiving module, configured to receive a path switching message from a target radio network node, where the path switching message is sent after the target radio network node determines that the target radio network node can accept a source radio network node and determines that a direct signaling interface exists between the target radio network node and the source radio network node, and determines that the target radio network node is connected to a same core network signaling service node, and determines that a service area supported by the source radio network at the core network signaling service node belongs to a service area supported by the target radio network at the core network signaling service node, and determines that a terminal corresponding to a handover request message that can be sent after enhanced handover is completed, where the core network signaling service node is connected to the source radio network node and the target radio network node together and has signaling connection with the source radio network node, and a node for processing the path switching message sent by the target wireless network node;

31. The core network signaling service node of claim 30, wherein the processing module is further to:

32. The core network signaling service node of claim 30, wherein the processing module is further to:

33. The core network signaling service node of claim 30, wherein the processing module is further to:

34. The core network signaling service node of any of claims 30 to 33, wherein the source radio network node is located in an LTE network and the target radio network node is located in a UMTS network; or