WO2011085668A1

WO2011085668A1 - Method, device and system for handover control

Info

Publication number: WO2011085668A1
Application number: PCT/CN2011/070147
Authority: WO
Inventors: 刘海; 吴晓波; 帅扬来
Original assignee: 华为技术有限公司
Priority date: 2010-01-13
Filing date: 2011-01-10
Publication date: 2011-07-21
Also published as: CN102131259B; CN102131259A

Abstract

The present invention discloses a method, device and system for handover control. The method includes the following steps: a Mobile Switching Center (MSC) receives the first message from a Mobility Management Entity (MME), and the first message carries an Evolved Packet System (EPS) bearer identifier (ID) of a Voice over Internet Protocol (VoIP) of the first User Equipment (UE), a control plane bearer information of the first UE corresponding to a Packet Data Network Gateway (PGW) and a user plane bearer information of the VoIP of the first UE corresponding to the PGW (210); according to the control plane bearer information of the first UE corresponding to the PGW, a bearer modification request message is sent to the PGW, and the bearer modification request message carries the EPS bearer ID of the VoIP of the first UE and a user plane bearer information of the VoIP of the first UE corresponding to a Media Gateway (MGW), and the user plane bearer of the VoIP of the first UE corresponding to the PGW is updated with the user plane bearer of the VoIP of the first UE corresponding to the MGW (220); the user plane bearer information of the VoIP of the first UE corresponding to the PGW is notified to the MGW, and the user plane bearer of the VoIP of the first UE corresponding to the MGW is updated with the user plane bearer of the VoIP of the first UE corresponding to the PGW (230). The present invention is beneficial to the maintenance of the voice continuity during the network handover.

Description

The present invention claims the priority of the Chinese application filed on Jan. 13, 2010, with the application number of 201010004249.1, and the name of the invention as "switching control method and related equipment and system", the entire contents of which are The citations are incorporated herein by reference. Technical field

The present invention relates to the field of communication technologies, specific handover control methods, and related devices and systems. BACKGROUND Currently, many areas have been widely deployed second generation GSM technology / global third generation mobile communication technology ^{(2G / 3G, 2 nd Generation} / 3 rd Generation) network, in a way be seen as a Comprehensive coverage.

Based on the needs of communication development, the third-generation partner project standards organization launched a new generation of evolution network architecture, in which the core network part is the System Architecture Evolution (SAE) network, and the access network part is long-term evolution (LTE, Long). Term Evolution) The evolution of the network of the universal mobile communication system Terrestrial Radio Access Network (E-UTRAN). A new generation of evolutionary networks has covered some urban and traffic hotspots.

For convenience of description, a network such as SAE/LTE that provides only a PS domain is called a pure PS domain network. For different network bearer mechanisms, mobile communication services can be divided into:

Services carried by the CS (Circuit Switching) domain, such as voice calls, short messages, and supplementary services;

The services carried by the packet switching (PS, Packet Switching) domain include data services and session services, and the session services include Voice over Internet Protocol (VoIP) services.

In practical applications, voice services can be carried in the CS domain or in the PS domain. Based on different network coverage scenarios, users may often need to switch from LTE network to 2G/3G network during communication. Therefore, how to maintain the voice continuity of the network handover process is a technical problem to be solved. Summary of the invention The embodiments of the present invention provide a handover control method and related devices and systems, which are beneficial for maintaining voice continuity in a network handover process.

The present invention provides the following technical solutions:

A handover control method includes:

The mobile switching center MSC receives the first message from the mobility management entity MME, where the first message carries the VoIP EPS bearer ID of the first user equipment, the control data bearer information corresponding to the first UE of the packet data gateway PGW, and the PGW corresponding to the first message. User plane bearer information of the VoIP of the UE;

Transmitting, according to the control plane bearer information of the PGW to the first UE, a bearer modification request message, where the bearer modification request message carries a VoIP EPS bearer ID of the first user equipment and a VoIP corresponding to the first UE of the media gateway MGW The user plane bearer information, and the user plane bearer corresponding to the VOIP of the first UE is updated to the MGW;

And notifying the user plane bearer information of the VoIP corresponding to the VoIP of the first UE to the MGW, and updating the user plane bearer of the VOIP corresponding to the first UE to the PGW.

A handover control method includes:

The MME receives an attach request message or a PDN activation request message from the first UE;

Obtaining the address information of the MSC;

Sending a GTP-C message to the SGW, where the GTP-C message carries the address information of the MSC, and triggers the SGW to establish a control plane bearer corresponding to the first UE with the MSC.

A PS to CS switching control method includes:

The MSC receives a request from the SGW to establish a first session establishment request message corresponding to the control plane bearer of the first UE, and establishes a control plane bearer corresponding to the first UE corresponding to the SGW;

The MSC obtains the address information of the PGW;

Sending a second session setup request message to the PGW, and establishing a control plane bearer corresponding to the first UE with the PGW.

A handover control method includes:

The MME sends a second message to the MSC, where the second message carries the user plane bearer information of the VoIP corresponding to the first UE of the SGW;

Receiving a third message from the MSC, where the third message carries user plane bearer information of the VoIP corresponding to the first UE of the MGW;

Sending a bearer modification message to the SGW, where the bearer modification message carries the user plane bearer information of the VoIP corresponding to the VoIP of the first UE, and the user plane bearer of the VoIP corresponding to the first UE of the SGW is further New to MGW.

A handover control method includes:

The MME sends a fourth message to the MSC, where the fourth message carries the user plane bearer information of the VoIP corresponding to the first UE of the SGW;

The MME receives a fifth message from the MSC, where the fifth message carries user plane bearer information of the VoIP corresponding to the first UE of the MGW;

The MME sends a sixth message to the SGSN, where the sixth message carries the user plane bearer information of the VoIP corresponding to the VoIP of the first UE.

A handover control method includes:

The SGSN receives the sixth message from the MME, where the sixth message carries the user plane bearer information of the VoIP corresponding to the first UE of the MGW.

Sending a bearer modification message to the SGW, where the bearer modification message carries the user plane bearer information of the VoIP corresponding to the first UE of the MGW, and updates the user plane bearer of the VoIP corresponding to the VoIP of the SGW to the MGW.

A mobile switching center, including:

a receiving module, configured to receive a first message from the mobility management entity MME, where the first message carries a VoIP EPS bearer ID of the first user equipment, and the control data bearer information of the first UE and the PGW corresponding to the packet data gateway PGW User plane bearer information of a UE's VoIP;

a sending module, configured to send, according to the control plane bearer information of the PGW to the first UE, a bearer modification request message, where the bearer modification request message carries a VoIP EPS bearer ID of the first user equipment and a corresponding corresponding to the media gateway MGW User plane bearer information of the VoIP of the first UE, and updating the user plane bearer of the VOIP corresponding to the VOIP of the first UE to the MGW;

The notification module is configured to notify the MGW of the user plane bearer information of the VoIP corresponding to the VoIP of the first UE, and update the user plane bearer of the VOIP corresponding to the first UE to the PGW.

A mobility management entity that includes:

a receiving module, configured to receive an attach request message or a PDN activation request message from the first UE, where the acquiring module is configured to obtain address information of the MSC;

And a sending module, configured to send a GTP-C message to the SGW, where the GTP-C message carries the address information of the MSC, and triggers the SGW to establish a control plane bearer corresponding to the first UE with the MSC.

A mobile switching center, including:

a first receiving module, configured to receive a request from the SGW to establish a control plane bearer corresponding to the first UE a first session establishment request message, and a control plane bearer corresponding to the first UE corresponding to the SGW; and an obtaining module, configured to acquire, by the MSC, address information of the PGW;

The first sending module is configured to send a second session establishment request message to the PGW, and establish a control plane bearer corresponding to the first UE with the PGW.

A mobility management entity, including:

a third sending module, configured to send a second message to the MSC, where the second message carries user plane bearer information of the VoIP corresponding to the first UE by the SGW;

The receiving module receives a third message from the MSC, where the third message carries information about the user plane of the VoIP corresponding to the first UE of the MGW;

a fourth sending module, configured to send a bearer modification message to the SGW, where the bearer modification message carries the user plane bearer information of the VoIP corresponding to the VoIP of the first UE, and the user of the VoIP corresponding to the first UE is updated on the surface of the SGW. To the MGW.

A mobility management entity, including:

a fifth sending module, configured to send a fourth message to the MSC, where the fourth message carries user plane bearer information of the VoIP corresponding to the first UE by the SGW;

a third receiving module, configured to receive a fifth message from the MSC, where the fifth message carries user plane bearer information of the VoIP corresponding to the first UE of the MGW;

And a sixth sending module, configured to send, by the MME, a sixth message to the SGSN, where the sixth message carries user plane bearer information of the VoIP corresponding to the first UE of the MGW.

A service general packet service support node, comprising:

The receiving module is configured to receive a sixth message from the MME, where the sixth message carries user plane bearer information of the VoIP of the first UE corresponding to the MGW.

And a sending module, configured to send a bearer modification message to the SGW, where the bearer modification message carries the user plane bearer information of the VoIP corresponding to the first UE of the MGW, and updates the user plane of the VoIP corresponding to the first UE to the MGW.

A communication system, comprising: the apparatus as in the above embodiment.

As can be seen from the above, in an aspect of the embodiment of the present invention, the MSC obtains the PGW corresponding first from the MME.

The control plane bearer information of the UE and the PPG correspond to the user plane bearer information of the VoIP of the first UE, and the user plane bearer of the VoIP corresponding to the VoIP of the first UE is updated to the MGW by the bearer modification request message, and the MSC is not carried in the bearer modification message. The control plane carries information, and does not correspond to the PGW corresponding to the first UE. The control plane bearer is updated to the MSC, and the management node can maintain the order of the first UE control link. Since the control plane on the PGW is not converted to the MSC, the control message after the PGW is sent to the SGW, so that Interrupting the data service at the same time is beneficial to maintain the voice continuity of the network switching process. DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings to be used in the embodiments or the description of the prior art will be briefly described below. 1 is a schematic diagram of a PS to CS switching architecture according to an embodiment of the present invention;

2 is a flowchart of a handover control method according to Embodiment 1 of the present invention;

3 is a flowchart of a handover control method according to Embodiment 2 of the present invention;

4 is a flowchart of another handover control method according to Embodiment 2 of the present invention;

FIG. 5 is a flowchart of a handover control method according to Embodiment 3 of the present invention; FIG.

6 is a flowchart of a handover control method according to Embodiment 3 of the present invention;

7 is a flowchart of a handover control method according to Embodiment 4 of the present invention;

8 is a flowchart of another handover control method according to Embodiment 4 of the present invention;

9 is a flowchart of a handover control method according to Embodiment 5 of the present invention;

10 is a flowchart of a handover control method according to Embodiment 6 of the present invention;

11 is a flowchart of a handover control method according to Embodiment 7 of the present invention;

12 is a flowchart of a handover control method according to Embodiment 8 of the present invention;

13 is a flowchart of another handover control method according to Embodiment 8 of the present invention;

14 is a schematic diagram of a mobile switching center according to Embodiment 9 of the present invention;

15 is a schematic diagram of a mobility management entity according to Embodiment 10 of the present invention;

16 is a schematic diagram of a mobile switching center according to Embodiment 11 of the present invention;

17 is a schematic diagram of a mobility management entity according to Embodiment 12 of the present invention;

18 is a schematic diagram of a mobility management entity according to Embodiment 13 of the present invention;

FIG. 19 is a schematic diagram of an SGSN according to Embodiment 9 of the present invention. Embodiments of the present invention provide a handover control method and related equipment and system, which are beneficial for maintaining network switching. Change the voice continuity of the process.

The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. The embodiments are merely a part of the embodiments of the invention, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without departing from the inventive work are all within the scope of the present invention.

To facilitate understanding by those skilled in the art, a network diagram is shown in FIG. 1 , where the E-UTRAN is mainly composed of an evolved base station (eNB, Evolution-NodeB). The core network part of the evolved network includes the Mobility Management Entity (MME) and the SEE Gateway (SAE Gateway). The SAE gateway includes a Serving Gateway (SGW, Serving Gateway) and a Packet Data Network Gateway (PGW, PDN Gateway).

The MME is a control plane node of the core network part of the evolved network system, and bears the management function of the user equipment (UE) context and the user plane bearer; the SGW mainly bears the transmission function of the service data, and the PGW mainly bears the signaling transmission function. The UTRAN/GERAM is the access network of the 2G/3G network. The Mobile Switching Center (MSC) is mainly responsible for the bearer control of the voice service. The SGSN is mainly responsible for the bearer control of the data service.

An Sv interface is introduced between the MME and the MSC. For convenience of description, both the MSC and the MSC server are collectively referred to as MSCs herein. The VoIP VoIP can be switched to the CS domain through the Sv interface. At the same time, the data service needs to be processed. According to the different 2G/3G network capabilities, there are three ways to process the data service:

(1) If the target 2G/3G network supports PS handover, perform a PS handover operation;

(2) If the target 2G network does not support the DTM, the UE performs the PS service suspension operation after switching to the 2G network;

(3) If the target 2G network does not support DTM HO but can support DTM, the UE performs a routing area update operation after accessing the 2G network to continue the data service.

The GTP protocol is introduced below. The GTP protocol is a bearer protocol and includes two types: GTP-C and GTP-U. GTP uses a tunnel ID (TEID) to distinguish between users or bearers.

GTP tunnels are identified by (IP, TEID) pairs. A set of IP/TEIDs is called F-TEID. GTP-C is the control plane protocol of GTP, and one GTP-C tunnel corresponds to one user. GTP-U is the user plane protocol of GTP. A GTP-U tunnel represents a certain bearer of a certain user. For example, for a certain user, the MME and the SGW need to establish a GTP-C tunnel to serve the user, if the user is in the same When multiple services are performed, multiple GTP-U tunnels can be established to carry different services of the user. The following describes the establishment of a bearer by using the main GTP protocol between network entities. Embodiment 1

Referring to FIG. 2, a handover control method provided in Embodiment 1 may include:

The MSC receives the first message from the MME, where the first message carries the VoIP EPS bearer ID of the first UE, the control plane bearer information of the PGW corresponding to the first UE, and the user-side information of the VoIP corresponding to the VoIP of the first UE.

In an application scenario, the control plane bearer information of the PGW corresponding to the first UE includes the GTP-C F-TEID of the PGW corresponding to the first UE, and the user plane bearer information of the VoIP corresponding to the VoIP of the PGW includes the PGW corresponding to the first UE. GTP-U F-TEID for VoIP. The VoIP evolved packet system bearer ID (EPS bearer ID) of the first UE is a global identifier corresponding to the VoIP of the first UE. It can be considered that the VoIP EPS bearer ID of the first UE in the PGW is corresponding to the VoIP GTP-U F-TEID of the first UE.

The first message sent by the MME may be, for example, a PS to CS handover request message, and of course, the message may carry other information.

The MSC sends a bearer modification request message to the PGW based on the control plane bearer information of the PGW corresponding to the first UE, where the bearer modification request message may carry the VoIP EPS bearer ID of the first UE and the user plane of the VoIP corresponding to the VoIP of the first UE. Carrying information, updating the user plane bearer corresponding to the VOIP of the first UE to the MGW;

In an actual application, the MSC may obtain the user plane bearer information (including the GTP-U F-TEID) of the VoIP corresponding to the first UE allocated by the MGW, and the bearer corresponds to the control plane bearer information of the first UE (including GTP- C F-TEID ), sending a bearer modification request message carrying the VoIP EPS bearer ID of the first UE and the user plane bearer information of the VoIP corresponding to the VoIP of the first UE to the PGW, and updating the user plane bearer corresponding to the VOIP of the first UE to the PGW To the MGW.

After receiving the bearer modification request message from the MSC, the PGW may update the user plane bearer corresponding to the VOIP of the first UE to the MGW according to the VoIP EPS bearer ID of the first UE. The subsequent PGW may send the VoIP data stream of the first UE to the MGW based on the user plane bearer updated to the MGW.

230. The MSC notifies the MGW of the user plane bearer information of the VoIP corresponding to the VoIP of the first UE, and updates the user plane bearer of the VOIP corresponding to the VOIP of the first UE to the PGW. After the MGW and the PGW respectively obtain the user plane bearer information of the VoIP corresponding to the first UE, the two-way user plane bearer between the MGW and the PGW is established.

It can be understood that, in this embodiment, the MSC obtains, from the MME, the control plane bearer information of the PGW corresponding to the first UE and the user plane bearer information of the VoIP corresponding to the VoIP of the first UE, and the PGW is separately associated with the first UE by using the bearer modification request message. The user plane of the VoIP bearer is updated to the MGW, and the control plane bearer information of the MSC is not carried in the bearer modification message, so that the control plane bearer of the PGW corresponding to the first UE is not updated to the MSC, and the management node can be kept corresponding to the first UE control link. The ordering, because the control plane on the PGW is not converted to the MSC, the control message after the PGW is still sent to the SGW, so that the data service that is being performed at the same time is not interrupted, which is beneficial to maintain the voice continuity of the network switching process. Sex.

Embodiment 2

In this embodiment, the MSC only performs the process of updating the user plane bearer corresponding to the UE-A of the PGW to the MGW in the process of the UE-A switching from the PS domain to the CS domain.

The following is a first example of the PS2 handover supported by the target 2G/3G network. Referring to FIG. 3, a handover control method provided in Embodiment 3 may include:

301. UE-A sends a measurement report to ENB.

In an application scenario, the ENB can send a message indicating that the UE-A measures the signal quality of the 2G/3G network. The UE-A performs measurement reporting. If the ENB confirms that the signal quality of the 2G/3G network reported by the UE-A meets the preset signal quality requirement, step 302 is performed.

302. The ENB sends a handover request message to the MME.

In an application scenario, the ENB carries the information required for the PS handover and the information required for the CS handover in the handover request message. The ENB can separately construct the PS transparent container and the CS transparent container, respectively, for carrying the information required for the PS handover and the CS handover. Information needed. The information required for the PS handover and the CS handover, respectively, encapsulated in the PS transparent container and the CS transparent container, follows the existing 2G/3G network specifications, and is generally the target ID corresponding to the PS handover and the target ID corresponding to the CS handover. , ENB can guarantee the same.

303. The MME selects an MSC, and sends a PS to CS handover request message to the MSC, where the message can carry a £01-$8? bearer ID of 11£-eight, and a GTP-C F-TEID of the PGW corresponding UE-A. The PGW corresponds to the VOIP GTP-U F-TEID of UE-A, and of course can carry other information.

The MME can distinguish which bearers belong to the PS service and which bearers according to the bearer information. It belongs to the CS service to initiate CS service switching and PS service switching respectively.

If the MSC selected by the MME is consistent with the MSC corresponding to the location area (LA, Local Area) of the target cell, the inconsistency will result in a cross-MSC handover (Inter MSC handover).

The MSC sends a GTP-U F-TEID corresponding to the VoIP of the UE-A to the MGW, and updates the user plane bearer of the VOIP corresponding to the first UE to the PGW.

304. The MSC receives the PS to CS handover request message from the MME. If the MSC determines that it is not the target MSC (which can be determined according to the target ID), the MSC initiates an Inter MSC handover, and sends an inter-MSC handover request to the target MSC.

305. The target MSC sends a handover request message to the target BSS/RNS, indicating that the target BSS/RNS prepares the CS resource.

306. The MME sends a handover request message to the serving general packet service support node (SGSN), where the handover request message may include information required for PS handover.

In a specific implementation, the PS transparent container may be used to carry information required for PS handover, such as a target ID required for PS handover;

307. The SGSN sends a handover request message to the target BSS/RNS, indicating that the target BSS/RNS prepares the PS resource.

308. If the target BSS/RNS determines that the PS resource is sufficient, the target BSS/RNS prepares the PS resource, and returns a handover request response message to the SGSN, where the prepared PS resource information is carried.

309. The SGSN returns a handover response message to the MME, where the handover response message includes PS resource information prepared by the target BSS/RNS.

In a specific implementation, the PS resource information prepared by the target BSS/RNS may include: a PS service air interface channel, a system message, and the like, and may be encapsulated in a PS transparent container, following an existing 2G/3G network CS domain specification.

Among them, steps 306 ~ 309 can be considered as the PS switching preparation phase of UE-A.

After receiving the handover request message from the target MSC, if the target BSS/RNS determines that the CS resource is sufficient, the target BSS/RNS prepares the CS resource, and feeds back a handover request response message to the target MSC, where the message may include the target BSS. CS resource information prepared by /RNS;

311. The target MSC sends an inter-MSC handover response to the MSC, where the message may include CS resource information prepared by the target BSS/RNS.

312. Establish a bearer between the MSC and the target MSC.

It can be understood that if the MSC determines that the target MSC is itself, the MSC and the target are omitted. The MSC sends a handover request message to the target BSS/RNS to indicate that the target BSS/RNS prepares the CS resource. If the CS resource is sufficient, the target BSS/RNS prepares the CS resource, and feeds back the handover request response message to the MSC. The CS resource information prepared by the target BSS/RNS may be included in the message.

The MSC further triggers the IMS domain to perform session domain conversion; the IMS can notify the calling peer to update the media plane to the media gateway of the CS domain, and release the LTE access network session.

313. The MSC sends a PS to CS handover request response message to the MME, where the message may include CS resource information prepared by the target BSS/RNS.

In a specific implementation, the CS resource information prepared by the target BSS/RNS may include: a CS voice service, an air interface dedicated channel, and a system message, etc., which may be encapsulated in a CS transparent container and conform to the existing 2G/3G network CS domain specification.

Among them, steps 303 ~ 304, 310 ~ 313 can be considered as the 8 switch preparation phase of 11 £-eight. It can be understood that there is no necessary sequence between the PS switching preparation and the CS switching preparation, for example, it can be performed simultaneously.

314. The MME may combine the PS resource information received in steps 309 and 313 with the CS resource information, and the MME sends a handover command message to the ENB, where the handover command message may include the merged resource information.

In the specific implementation process, the PS to CS handover complete message includes the CS resource information prepared by the target BSS/RNS (mainly including the CS voice service air interface dedicated channel and system message, etc., encapsulated in a CS transparent container, and follows the existing 2G/ The 3G network CS domain specification and the handover request response message contain PS resource information (mainly including PS service air interface channel and system message, etc., encapsulated in a PS transparent container, follow the existing 2G/3G network CS domain specification), and CS The transparent container is merged with the PS transparent container, which is called a merged transparent container, and carries the resources prepared by the target BSS/RNS.

315. The ENB sends a handover command message to the UE-A, where the handover command message includes resource information prepared by the target BSS/RNS.

316. The UE-A accesses the 2G/3G network according to the resource information prepared by the target BSS/RNS, and may send a handover complete message to the target BSS/RNS. The target BSS/RNS may send a handover complete message to the target MSC. Sending a handover complete message to the MSC; the target MSC may further send an ISUP response message to the MSC to complete bearer establishment between the MSCs.

317. The MSC sends a modify bearer request message to the PGW. The bearer modification request carries the VOIP EPS bearer ID of the UE-A and the GTP-U F-TEID of the VoIP corresponding to the VoIP of the UE-A. Previously, the MGW prepares a GTP-U bearer corresponding to UE-A VoIP, and the MSC acquires the VoIP GTP-U F-TEID of the MGW corresponding UE-A from the MGW.

The PGW receives the bearer modification request message from the MSC, and updates the GTP-U corresponding to the UE-A VoIP to the MGW.

Here, the MSC only separately updates the GTP-U of the VoIP corresponding to the UE-A of the PGW to the MGW, and does not update the GTP-C of the PGW corresponding to the UE-A to the MSC.

This step can be performed after 303 without strict time limits.

318. The MSC sends a PS domain to the CS domain handover complete message to the MME, to notify the MME that the handover is complete.

319. Optionally, the MSC initiates a location update to the HSS.

320, 2G/3G access network notification target SGSN handover completed;

321. The target SGSN sends a handover complete message to the MME, and the MME responds to the acknowledgement message.

322. The SGSN sends a bearer modification request message to the SGW, where the message carries the GTP-C F-TEID of the UE-A corresponding to the SGSN, and updates the control plane bearer of the SGW corresponding to the UE-A to the SGSN.

The SGW receives the bearer modification request message sent by the SGSN, and updates the control plane bearer corresponding to the UE-A to the SGSN.

So far, both the CS service and the PS service of the UE-A are switched to the 2G/3G network, and the SGW corresponding UE-A only establishes the control plane bearer with the SGSN, and does not establish a control plane bearer with the MSC. In the following, the target switching 2G/3G network does not support the PS switching as an example. Referring to FIG. 4, another switching control method in the second embodiment may include:

401 ~ 405 can be the same as steps 301 ~ 305, and will not be described here.

406 ~ 409 can be the same as steps 310 ~ 313, and will not be described here.

The MME sends a handover command message to the ENB, where the handover command message may include CS resource information prepared by the target BSS/RNS.

411. The ENB sends a handover command message to the UE, where the handover command message includes resource information prepared by the target BSS/RNS.

412. The UE accesses the 2G/3G network, and sends a handover complete message to the target BSS/RNS. The target BSS/RNS sends a handover complete message to the target MSC. The target MSC sends a handover complete message to the MSC.

413. The UE initiates a PS service suspension process, and the MME and the SGW suspend the PS service of the UE.

414. The MSC sends a bearer modification request message to the PGW.

The bearer modification request carries the VOIP EPS bearer ID of the UE-A, and the MGW pair. GTP-U F-TEID for UE-A VoIP;

Previously, the MGW prepares a GTP-U bearer corresponding to UE-A VoIP, and the MSC acquires the VoIP GTP-U F-TEID of the MGW corresponding UE-A from the MGW.

415. The MSC sends a PS domain to the CS domain handover complete message to the MME, to notify the MME that the handover is complete.

416. Optionally, the MSC initiates a location update to the HSS.

It can be seen that, in this embodiment, the MSC obtains the control plane bearer information of the PGW corresponding to the UE-A and the user plane bearer information of the VoIP corresponding to the UE-A of the PGW from the MME, and separately uses the PGW to correspond to the UE-A VoIP by using the bearer modification request message. The user plane carries the update to the MGW, and does not update the control plane bearer of the PGW corresponding to the UE-A to the MSC, and the SGW and the SGSN of the 2G/3G network establish a control plane bearer, and the handover control manner can keep the management node corresponding to the UE- A controls the order of the link, which is conducive to maintaining the voice continuity of the network switching process.

Embodiment 3

In this embodiment, the MSC is inserted between the SGW and the PGW. Referring to FIG. 5, a handover control method provided in Embodiment 3 may include:

510. The MME receives the first UE attach request message or the PDN activation request message.

520. The MME obtains address information of the MSC.

530. The MME sends a GTP-C message to the SGW, where the GTP-C message carries the address information of the MSC, and the SGW is triggered to establish a control plane bearer corresponding to the first UE.

After receiving the GTP-C message from the MME, the SGW initiates a process of establishing a control plane bearer corresponding to the first UE with the MSC.

In addition, another switching control method provided by this embodiment, as shown in FIG. 6, may include:

610. The MSC receives a request from the SGW to establish a first session setup request message corresponding to the control plane bearer of the first UE, and establishes a control plane bearer corresponding to the first UE of the SGW.

620. The MSC obtains address information of the PGW.

630. The MSC sends a second session setup request message to the PGW, and establishes a control plane bearer corresponding to the first UE with the PGW. After receiving the second session establishment request message from the MSC, the PGW establishes a control plane bearer corresponding to the first UE with the MSC.

At this point, the MSC is successfully inserted between the SGW and the PGW, and all the packets related to the UE-A that the subsequent SGW and the PGW interact with will pass through the MSC.

Further, during the PS-to CS handover process of the UE-A, the method may further include:

The MSC receives a PS to CS handover request message from the MME;

The MSC sends a bearer modification request message to the PGW, where the bearer modification message carries the user plane bearer information of the VoIP corresponding to the first UE of the MGW;

After receiving the bearer modification request message from the MSC, the PGW updates the user plane bearer corresponding to the VoIP of the first UE to the MGW;

The MSC notifies the MGW of the user plane bearer information of the VoIP corresponding to the VoIP of the first UE, and updates the user plane bearer of the VOIP corresponding to the first UE of the PGW to the MGW.

If the SGW sends a bearer modification request message to the MSC to modify the data service bearer, the MSC sends a bearer modification message to the PGW, where the SGW corresponds to the user plane bearer information of the first UE.

It can be seen that, in this embodiment, when the first UE initiates the network attachment or the PDN activation, the MSC is inserted between the SGW and the PGW, and the subsequent MSC can offload the VoIP data stream of the first UE to the MGW or directly correspond to the PGW. The user plane bearer of the VoIP of the first UE is updated to the MGW, and the handover control manner can maintain the order of the control node corresponding to the first UE control link, which is beneficial to maintaining the voice continuity of the network handover process.

Embodiment 4

In the embodiment, a specific process of inserting the MSC into the SGW and the PGW in the process of initiating the network attachment or the PDN activation in the UE-A is taken as an example for description.

Among them, the MSC can be inserted into the SGW and the PGW only when connected to a specific service network, such as an IMS APN.

Referring to Figure 7, the process of inserting the MSC into the SGW and the PGW may include:

701. The UE-A sends an attach (PDN activation) request message to the MME.

When the UE-A power-on request is attached to the network or a new PDN connection is activated, the UE-A may send an attach (or PDN activation) request message to the MME.

702. The MME obtains an MSC address. In a specific implementation, one way may be to modify the PGW address corresponding to the IMS APN to the address of the MSC in the DNS. When the MME requests the activation of the IMS PDN connection, the MME uses the IMS APN to look up the PGW address in the DNS, and the DNS feeds back the address of the MSC to the MME, and the MME obtains the address of the MSC and uses it as the address of the PGW to perform the subsequent process;

Alternatively, the address of the MSC and the PGW address corresponding to the IMS APN may be configured in the DNS. When the UE requests to activate the IMS PDN connection, the MME uses the IMS APN to look up the PGW address in the DNS, and the DNS feeds back the address of the MSC to the MME. And the address of the PGW, the MME chooses to obtain the address of the MSC as the address of the PGW for the subsequent process;

Another way is to configure the MSC address directly in the MME. When the UE requests to activate the IMS PDN connection, the MME uses the address of the MSC as the PGW address for the subsequent process.

703. The MME selects the SGW and sends a GTP-C message to the SGW, where the MME sends the MSC address information, and triggers the SGW to establish a control plane bearer corresponding to the U E-A.

704. The SGW initiates a session establishment procedure corresponding to the UE-A, and sends a session establishment request message to the MSC, requesting to establish a control plane bearer corresponding to the UE-A.

The SGW sends the session establishment request message to the MSC by directly using the MSC address as the address of the PGW, and the GW sends the MSC address information instead of the PGW address.

705. The MSC acquires address information of the PGW.

The MSC may use the IMS APN to look up the PGW address in the DNS after receiving the session establishment request message from the SGW; the DNS feeds back the real PGW address to the MSC, and the MSC obtains the real PGW address.

Alternatively, the PGW address may be directly configured in the MSC. When the UE requests to activate the IMS PDN connection, the MSC directly obtains the PGW address from the local configuration information.

Alternatively, the MME may send the obtained real PGW address to the MSC through the SGW.

706. The MSC sends a session establishment request message to the PGW according to the searched PGW address, and requests to establish a control plane bearer corresponding to the UE-A.

707. The PGW receives a session establishment request message from the MSC, and establishes a control plane bearer corresponding to the UE-A, and sends a session establishment response message to the MSC.

708. The MSC sends a session establishment response message to the SGW.

So far, in the UE-A network attachment or PDN activation process, the MSC is successfully inserted between the SGW and the PGW. All data packets related to UE-A that are exchanged between the subsequent SGW and the PGW pass through the MSC, MSC. It can be controlled or shunted.

The following describes UE-A's PS to CS switching control flow. See Figure 8, including:

801 ~ 802 can be the same as steps 301 ~ 302, and will not be described here.

803. The MME selects an MSC, and sends a PS to CS handover request message to the MSC.

The MME may distinguish which bearers belong to the PS service according to the bearer information, and which bearers belong to the CS service, to initiate the CS service handover and the PS service handover respectively.

804 ~ 805 can be the same as steps 804 ~ 804, and will not be described here.

806. The MME sends a handover request message to the SGSN, where the handover request message may include information required for the PS handover, and may specifically include a PDP bearer context of the UE-A, where the PDP bearer context includes the GTP-C F of the MSC corresponding to the UE-A. -TEID.

807 ~ 816 can be the same as steps 307 ~ 316, and will not be described here.

817. The MSC sends a bearer modification request message to the PGW.

The bearer modification request carries the VOIP EPS bearer ID of the UE-A, and the GTP-U F-TEID of the VoIP corresponding to the UE-A of the MGW;

818. The MSC sends a PS domain to CS domain handover complete message to the MME, to notify the MME that the handover is complete.

819. Optionally, the MSC initiates a location update to the HSS.

820, 2G/3G access network notification target SGSN handover completed;

821. The target SGSN sends a handover complete message to the MME, and the MME responds to the acknowledgement message.

822, the SGSN sends a bearer modification request message to the SGW, where the message carries the GTP-C F-TEID of the UE-A corresponding to the SGSN, and updates the control plane bearer corresponding to the UE-A of the SGW to the SGSN;

823. The SGW receives the bearer modification request message sent by the SGSN, and updates the control plane bearer corresponding to the UE-A to the SGSN, and sends a bearer modification request message to the MSC, where the SGW carries the GTP-U F-TEID information corresponding to the UE-A.

824. The MSC receives the bearer modification request message from the SGW, and sends a bearer modification request message to the PGW, where the SGW carries the GTP-U F-TEID information of the UE-A. So far, both the CS service and the PS service of the UE-A are switched to the 2G/3G network, and the control plane bearer corresponding to the UE-A includes the SGSN-SGW-MSC-PGW, which realizes the continuity of the control plane bearer corresponding to the UE-A. . The user plane of the VoIP corresponding to the UE established between the PGW and the MGW carries the GTP-U, and the PGW can send the VoIP data stream of the UE-A to the MGW through the bearer.

In particular, if the SGW and the PGW are based on the PMIP protocol, and the PMIP protocol is a protocol that does not distinguish between the control plane and the data plane bearer, at this time, the user of the UE-A VoIP may not be established between the PGW and the MGW. GTP-U on the surface. The MSC can distinguish the VoIP data stream corresponding to the UE-A from the PMIP tunnel with the PGW and forward it to the MGW, and the other data packets can be transparently transmitted between the SGW and the PGW.

It can be seen that, in this embodiment, when the UE-A initiates the network attachment or the PDN activation, the MSC is inserted between the SGW and the PGW, and the subsequent MSC can offload the VoIP data stream of the UE-A to the MGW or directly correspond to the PGW. The UE-A VoIP user plane bearer is updated to the MGW. The handover control mode can maintain the order of the UE-A control bearer corresponding to the management node, and is beneficial to maintaining the voice continuity of the network handover process.

Embodiment 5

In this embodiment, the MME updates the VoIP bearer of the first UE to the MGW by using the PGW. Referring to FIG. 9, a handover control method in Embodiment 5 may include:

910. The MME sends a second message to the MSC, where the second message carries the user plane bearer information of the VoIP corresponding to the first UE of the SGW.

In an application scenario, the user plane bearer information of the VoIP corresponding to the first UE of the SGW includes the GTP-U F-TEID of the VoIP corresponding to the first UE of the SGW.

The second message sent by the MME may be, for example, a PS to CS handover request message. Of course, the message may also carry other information.

The MSC further notifies the MGW of the user plane bearer information of the VoIP corresponding to the first UE by the SGW.

920. The MME receives a third message from the MSC, where the third message carries user plane bearer information of the VoIP corresponding to the first UE of the MGW.

In an actual application, the MSC may first obtain the user plane bearer information (including the GTP-U F-TEID) of the VoIP corresponding to the first UE allocated by the MGW, and notify the user of the VoIP of the first UE to the VoIP. MME.

930. The MME sends a bearer modification message to the SGW, where the bearer modification message carries the MGW corresponding to the first The user plane bearer information of the VoIP of one UE updates the user plane bearer of the VoIP corresponding to the PDCCH of the first UE to the MGW.

After receiving the bearer modification message from the MME, the SGW updates the user plane bearer of the VoIP corresponding to the first UE to the MGW, and then forwards the VoIP data stream of the first UE to the MGW.

Embodiment 6

In this embodiment, in the PS to CS handover process of the UE-A, the MME updates the VoIP bearer of the PGW to the MGW by using the PGW as an example. Referring to FIG. 10, a handover control method in Embodiment 6 may include:

1001 ~ 1002 can be the same as steps 301 ~ 302, and will not be described here.

1003. The MME selects an MSC, and sends a PS to CS handover request message to the MSC, where the message may carry the VOIP GTP-U F-TEID of the UE-A corresponding to the SGW, and may of course carry other information.

1004 ~ 1012 are the same as steps 304 ~ 312, and will not be described here.

1013. The MSC sends a PS to CS handover request response message to the MME, where the message may include the CS resource information prepared by the target BSS/RNS, and the GTP-U F-TEID of the VoIP corresponding to the VoIP of the UE-A; UE-A VoIP GTP-U bearer, the MSC obtains the MGW corresponding UE-A VoIP GTP-U F-TEID from the MGW;

1014. The MME sends a bearer modification request message to the SGW.

The SGW receives the tampering request message from the MME, and updates the GTP-U corresponding to the UE-A VoIP to the MGW.

1015. The MME may combine the PS resource information and the CS resource information, and the MME sends a handover command message to the ENB, where the handover command message may include the merged resource information.

1016. The ENB sends a handover command message to the UE-A, where the handover command message includes a target. Resource information prepared by BSS/RNS;

1017. The UE-A accesses the 2G/3G network according to the resource information prepared by the target BSS/RNS, and may send a handover complete message to the target BSS/RNS. The target BSS/RNS may send a handover complete message to the target MSC. Sending a handover complete message to the MSC; the target MSC may further send an ISUP response message to the MSC to complete bearer establishment between the MSCs.

1018. Optionally, the MSC initiates a location update to the HSS.

1019, 2G/3G access network notification target SGSN handover completed;

1020. The target SGSN sends a handover complete message to the MME, and the MME responds to the acknowledgement message.

1021, the SGSN sends a bearer modification request message to the SGW, where the message carries the GTP-C F-TEID of the UE-A corresponding to the SGSN, and updates the control plane bearer corresponding to the UE-A of the SGW to the SGSN;

So far, both the CS service and the PS service of the UE-A are switched to the 2G/3G network, and the SGW corresponding UE-A only establishes the control plane bearer with the SGSN, and does not establish a control plane bearer with the MSC.

Example 7

In this embodiment, the SGSN updates the VoIP bearer of the first UE to the MGW by using the SGW. Referring to FIG. 11, a handover control method in Embodiment 7 may include:

The MME sends a fourth message to the MSC, where the fourth message carries the user plane bearer information of the VoIP corresponding to the first UE of the SGW.

In an application scenario, the user plane bearer information of the VoIP corresponding to the first UE of the SGW includes the GTP-U F-TEID of the VoIP corresponding to the first UE by the SGW.

The fourth message sent by the MME may be, for example, a PS to CS handover request message, and of course, the message may carry other information. The MSC further notifies the MGW of the user plane bearer information of the VoIP corresponding to the first UE by the SGW.

1120. The MME receives a fifth message from the MSC, where the fifth message carries information about the user plane of the VoIP corresponding to the first UE of the MGW.

In an actual application, the MSC may first obtain the user plane bearer information (including the GTP-U F-TEID) of the VoIP corresponding to the first UE allocated by the MGW, and notify the MME of the user plane bearer information. Optionally, the MME sends a bearer modification message to the SGW, where the user plane information of the VoIP corresponding to the first UE allocated by the MGW is included. 1130. The MME sends a sixth message to the SGSN, where the sixth message carries the user plane bearer information of the VoIP corresponding to the VoIP of the first UE.

The sixth message sent by the MME may be, for example, a handover request message. Of course, the message may further carry other information.

The SGSN may update the user plane bearer of the VoIP corresponding to the VoIP of the first UE to the MGW in the process of initiating the bearer modification to the SGW.

This implementation provides another handover control method from the perspective of the processing of the SGSN, and may include:

The SGSN sends a bearer modification message to the SGW, and the bearer modification message carries the user plane bearer information of the VoIP corresponding to the first UE of the MGW, and updates the user plane bearer of the VoIP corresponding to the first UE to the MGW.

The SGW receives the bearer modification message from the SGSN, and updates the user plane bearer corresponding to the VoIP of the first UE to the MGW.

Example eight

In this embodiment, during the PC-to-CS handover process in the UE-A, the SGSN updates the VoIP bearer of the SGW to the first UE to the MGW. First, the target 2G/3G supports PS switching.

Referring to FIG. 12, a handover control method in Embodiment 8 may include:

1201 ~ 1202 can be the same as steps 301 ~ 302, and will not be described here.

1203. The MME selects an MSC, and sends a PS to CS handover request message to the MSC, where the message may carry the GTP-U F-TEID of the UE-A corresponding to the SGW, and may of course carry other information.

1204 ~ 1205 can be the same as steps 304 ~ 305,

1206. The MSC notifies the MME of the GTP-U F-TEID of the MGW corresponding to the UE-A.

The MGW prepares a GTP-U bearer corresponding to the UE-A, and the MSC obtains the GTP-U F-TEID of the MGW corresponding to the UE-A from the MGW.

The MSC also notifies the MGW of the VoIP GTP-U F-TEID corresponding to the UE-A of the SGW. 1207. The MME sends a handover request message to the SGSN, where the handover request message may include information required for the PS handover, and specifically carries information such as the GTP-U F-TEID of the UE-A corresponding to the MGW.

In a specific implementation, the PS transparent container may be used to carry information required for the foregoing PS handover, such as a target ID required for PS handover;

1208. The SGSN sends a handover request message to the target BSS/RNS, indicating that the target BSS/RNS prepares the PS resource.

1209. If the target BSS/RNS determines that the PS resource is sufficient, the target BSS/RNS prepares the PS resource, and returns a handover request response message to the SGSN, where the prepared PS resource information is carried;

1210. The SGSN returns a handover request response message to the MME, where the handover response message includes PS resource information prepared by the target BSS/RNS.

If the SGSN finds that the SGW is changed, the SGSN acquires a new GTP-U F-TEID that is allocated by the SGSN to the VoIP bearer of the UE-A, and the handover request response message returned by the SGSN to the MME carries the new SGW as the UE. -A VoIP bearer allocates new GTP-U F-TEID information.

The MME allocates a new GTP-U F-TEID allocated by the SGSN to the VoIP bearer of the UE-A and notifies the MSC, and the MSC can allocate the new SGW to the VoIP bearer of the UE-A. The GTP-U F-TEID is notified to the MGW. At this point, a user plane bearer corresponding to the UE-A VoIP is established between the MGW and the SGW, and the subsequent SGW can send the UE-A VoIP data stream to the MGW based on the user plane bearer. .

1211. After receiving the handover request message from the target MSC, if the target BSS/RNS determines that the CS resource is sufficient, the target BSS/RNS prepares the CS resource, and feeds back a handover request response message to the target MSC, where the message may include the target BSS. CS resource information prepared by /RNS;

1212. The target MSC sends an inter-MSC handover response to the MSC, where the message may include CS resource information prepared by the target BSS/RNS.

1213. A bearer is established between the MSC and the target MSC.

It can be understood that if the MSC determines that the target MSC is itself, the interaction between the MSC and the target MSC is omitted, and the MSC directly sends a handover request message to the target BSS/RNS, indicating that the target BSS/RNS prepares CS resources; The target BSS/RNS prepares the CS resource, and feeds back a handover request response message to the MSC, where the message may include CS resource information prepared by the target BSS/RNS. The MSC further triggers the IMS domain to perform session domain conversion; the IMS may notify the calling peer to update the media plane to the media gateway of the CS domain, and release the LTE access network session.

1214. The MSC sends a PS to CS handover request response message to the MME, where the message may include CS resource information prepared by the target BSS/RNS.

Among them, steps 1203 ~ 1204, 1210 ~ 1214 can be considered as the CS switching preparation phase of UE-A. It can be understood that there is no necessary sequence between the PS switching preparation and the CS switching preparation, for example, it can be performed simultaneously.

1215. The MSC sends a modify bearer request message to the SGW, where the message carries the GTP-U F-TEID of the UE-A corresponding to the MGW and the VOIP EPS bearer ID of the UE-A.

The SGW receives the bearer modification request message from the MSC, and updates the GTP-U corresponding to the UE-A VoIP to the MGW.

If the control plane bearer information of the UE-A corresponding to the SGW and the VoIP GTP-U F-TEID of the corresponding UE-A are not obtained, the step 1214 may not be performed.

Here, the MSC only updates the GTP-U of the SGW corresponding to the UE-A VoIP to the MGW, and does not update the GTP-C corresponding to the UE-A to the MSC.

1216. The MME may combine the received PS resource information and the CS resource information, and the MME sends a handover command message to the ENB, where the handover command message may include the merged resource information.

1217. The ENB sends a handover command message to the UE-A, where the handover command message includes resource information prepared by the target BSS/RNS.

1218. The UE-A accesses the 2G/3G network according to the resource information prepared by the target BSS/RNS, and may send a handover complete message to the target BSS/RNS. The target BSS/RNS may send a handover complete message to the target MSC. Sending a handover complete message to the MSC; the target MSC may further send an ISUP response message to the MSC to complete bearer establishment between the MSCs.

1219. The MSC sends a PS domain to the CS domain handover complete message to the MME, to notify the MME that the handover is complete.

1220. Optionally, the MSC initiates a location update to the HSS.

1221, 2G/3G access network notification target SGSN handover completed;

1222: The target SGSN sends a handover complete message to the MME, and the MME responds to the acknowledgement message.

1223. The SGSN sends a bearer modification request message to the SGW, where the message carries the SGSN corresponding The GTP-C F-TEID of UE-A and the obtained MGW correspond to the GTP-U F-TEID of UE-A.

The SGW receives the bearer modification request message sent by the SGSN, updates the control plane bearer corresponding to the UE-A to the SGSN, and updates the VoIP bearer corresponding to the UE-A of the SGW to the MGW.

In addition, if the SGSN determines that the SGW has changed, the SGSN sends a session establishment request message to the SGW, where the message carries the GTP-C F-TEID of the UE-A corresponding to the SGSN and the obtained GTPU F-TEID of the UE-A corresponding to the MGW. ;

The SGW receives the session establishment request message from the SGSN, establishes the control plane bearer corresponding to the UE-A to the SGSN, and establishes the VoIP bearer corresponding to the UE-A of the SGW to the MGW.

So far, both the CS service and the PS service of the UE-A are switched to the 2G/3G network, and the SGW corresponding UE-A only establishes the control plane bearer with the SGSN, and does not establish a control plane bearer with the MSC. The PS to CS switch including the RAU is described below. Referring to FIG. 13, another switching control method in this embodiment may include:

1301 ~ 1302 can be the same as steps 301 ~ 302, and will not be described here.

1303. The MME selects an MSC, and sends a PS to CS handover request message to the MSC, where the message may carry the VOIP EPS bearer ID of the UE-A, and the GTP-C F-TEID and the GTP-U F- of the UE-A corresponding to the SGW. TEID, of course, can carry other information.

1304 ~ 1305 can be the same as steps 304 ~ 305.

1306. The MSC notifies the MME of the GTP-U F-TEID of the UE-A corresponding to the MGW.

1307 ~ 1310 can be the same as steps 310 - 313;

The MSC sends a bearer modification request message to the SGW, where the message carries the GTP-U F-TEID of the UE-A corresponding to the MGW and the VOIP EPS bearer ID of the UE-A;

Wherein, if the control plane bearer information corresponding to the SGW corresponding to the UE-A and the SGW corresponding correspondence are not obtained before UE-A's VoIP GTP-U F-TEID, step 1214 may not be performed.

1312. The MME sends a handover command message to the ENB, where the handover command message may include CS resource information prepared by the target BSS/RNS.

1313. The ENB sends a handover command message to the UE-A, where the handover command message includes resource information prepared by the target BSS/RNS.

1314. The UE-A accesses the 2G/3G network according to the resource information prepared by the target BSS/RNS, and may send a handover complete message to the target BSS/RNS.

1315. The UE-A sends a location update message to the target SGSN to initiate a location update.

1316. The target SGSN sends a context request message corresponding to the UE-A to the MME, requesting to acquire context information of the UE-A.

1317. The MME sends a context response message corresponding to the UE-A to the SGSN, where the MME carries the context information of the UE-A and the GTP-U F-TEID information of the UE-A corresponding to the MGW.

1318. The SGSN sends a bearer modification request message to the SGW, where the message carries the GTP-C F-TEID of the UE-A corresponding to the SGSN and the GTP-U F-TEID of the obtained UE-A corresponding to the MGW.

The SGW may send a bearer modification response message to the SGSN, where the SGW carries the GTP-U F-TEID of the VoIP corresponding to the UE-A; the SGW sends a bearer modification request message to the PDW, and updates the related bearer;

1319. The SGSN sends a context response confirmation message to the MME, where the SGW carries the GTP-U F-TEID of the VoIP of the UE-A. If the SGW changes, the new SGW corresponds to the GTP-U F-TEID of the UE-A and is fed back to the MSC through the MME.

1320. The MME notifies the MSC of the obtained GGW-U F-TEID of the VoIP of the UE-A to the MSC;

The MSC further sends the GTP-U F-TEID of the VoIP corresponding to the UE-A to the MGW, and the user plane of the VoIP corresponding to the UE-A between the MGW and the SGW is established bidirectionally.

The target BSS/RNS may send a handover complete message to the target MSC; the target MSC may send a handover complete message to the MSC; the target MSC may further send an ISUP response message to the MSC to complete the bearer establishment between the MSCs.

The MSC sends a PS domain to the CS domain handover complete message to the MME, to notify the MME that the handover is complete. 1323. Optionally, the MSC initiates location update to the HSS.

So far, both the CS service and the PS service of the UE-A are switched to the 2G/3G network, and the SGW corresponding UE-A only establishes a control plane bearer with the SGSN, and does not establish a control plane bearer with the MSC.

It will be understood that the foregoing method embodiments are described as a series of combinations of actions for the sake of brevity, but those skilled in the art will appreciate that the present invention is not limited by the described order of actions. Because in accordance with the present invention, certain steps may be performed in other sequences or concurrently. For example, the process of initiating bearer modification by the MSC, the MME, and the SGSN may be any time after the MME initiates the PS to CS handover procedure, and is not limited to the sequence described in the foregoing method embodiments.

It should also be noted that the MGW can also obtain information such as the codec of the VOIP, the packet interval, and the value of the RTP payload type before the session transfer is completed. These parameters can be obtained by modifying the session transfer process. Specifically, the MSC sends an INVITE message to the SCC AS; the SCC AS sends the SDP parameter of the VOIP to the MSC, and the MSC sends the parameters to the MGW. The MSC then sends a RE-INVITE or UPDATE message to the SCC AS, and the SCC AS performs a remote update operation.

Further, an embodiment of the present invention further provides an apparatus for implementing the foregoing solution. Example nine

Referring to FIG. 14, the mobile switching center 1400 of the ninth embodiment may include: a receiving module 1410, a sending module 1420, and a notifying module 1430.

The receiving module 1410 is configured to receive a first message from the mobility management entity MME, where the first message carries the VoIP EPS bearer ID of the first user equipment, the control data bearer information corresponding to the first UE of the packet data gateway PGW, and the PGW corresponding to the first message. User plane bearer information of the VoIP of the UE;

The sending module 1420 is configured to send, according to the control plane bearer information of the PGW corresponding to the first UE, a bearer modification request message to the PGW, where the bearer modification request message carries the VoIP EPS bearer ID of the first user equipment and the media gateway MGW corresponding to the first User plane bearer information of the VoIP of the UE, and updating the user plane bearer corresponding to the VOIP of the first UE to the MGW;

The notification module 1430 is configured to notify the MGW of the user plane bearer information of the VoIP corresponding to the first UE by the PGW, and update the user plane bearer of the VOIP corresponding to the first UE by the MGW to the PGW. Example ten

Referring to FIG. 15, a mobility management entity 1500 of Embodiment 10 may include: a receiving module 1510, an obtaining module 1520, and a sending module 1530. The receiving module 1510 is configured to receive an attach request message or a PDN activation request message from the first UE.

The obtaining module 1520 is configured to obtain address information of the MSC.

The sending module 1530 is configured to send a GTP-C message to the SGW, where the GTP-C message carries the address information of the MSC, and triggers the SGW to establish a control plane bearer corresponding to the first UE with the MSC. Embodiment 11

Referring to FIG. 16, a mobile switching center 1600 of Embodiment 11 may include: a first receiving module 1610, an obtaining module 1620, and a first sending module 1630.

The first receiving module 1610 is configured to receive a first session setup request message from the SGW to establish a control plane bearer corresponding to the first UE, and establish a control plane bearer corresponding to the first UE of the SGW. The acquiring module 1620 is configured to be used by the MSC. Obtain the address information of the PGW;

The first sending module 1630 is configured to send a second session setup request message to the PGW, and establish a control plane bearer corresponding to the first UE with the PGW.

The mobile switching center 1600 can also include:

a second receiving module, which receives a packet domain exchange from the corresponding first UE of the MME to a circuit switched domain handover message;

a second sending module, configured to send a bearer modification request message to the PGW, where the second bearer modification message carries user plane bearer information of the VoIP corresponding to the first UE of the MGW;

The notification module is configured to notify the MGW of the user plane bearer information of the VoIP corresponding to the first UE by the PGW, and update the user plane bearer of the VOIP corresponding to the first UE by the PGW to the MGW. Example twelve

Referring to FIG. 17, a mobility management entity 1700 of Embodiment 12 may include: a third sending module 1710, configured to send a second message to the MSC, where the second message carries a user plane bearer corresponding to the VoIP of the first UE by the SGW. Information

The receiving module 1720 is configured to receive a third message from the MSC, where the third message carries information about the user plane of the VoIP corresponding to the first UE of the MGW;

The fourth sending module 1730 is configured to send a bearer modification message to the SGW, where the bearer modification message carries the user plane bearer information of the VoIP corresponding to the VoIP of the first UE, and updates the user plane of the VoIP corresponding to the first UE to the MGW. . Example thirteen Referring to FIG. 18, a mobility management entity 1800 of Embodiment 13 may include: a fifth sending module 1810, configured to send a fourth message to the MSC, where the fourth message carries a user plane bearer corresponding to the VoIP of the first UE by the SGW. information;

The third receiving module 1820 is configured to receive a fifth message from the MSC, where the fifth message carries user plane bearer information of the VoIP corresponding to the first UE by the MGW;

The sixth sending module 1830 is configured to send, by the MME, a sixth message to the SGSN, where the sixth message carries the user plane bearer information of the VoIP corresponding to the first UE by the MGW. Embodiment 14

Referring to FIG. 19, an SGSN 1900 of Embodiment 14 includes:

The receiving module 1910 is configured to receive a sixth message from the MME, where the sixth message carries user plane bearer information of the VoIP of the MGW corresponding to the first UE.

The sending module 1920 is configured to send a bearer modification message to the SGW, where the bearer modification message carries the user plane bearer information of the VoIP corresponding to the first UE of the MGW, and updates the user plane bearer of the VoIP corresponding to the first UE to the MGW.

It is to be understood that the functions of the foregoing apparatus embodiments may be implemented according to the method of the foregoing method embodiments, and details are not described herein again.

A person skilled in the art can understand that all or part of the process of implementing the above embodiment method can be completed by a computer program to instruct related hardware, and the above program can be stored in a computer readable storage medium, and the program is executed. At the time, the flow of the embodiment of each method as described above may be included. The foregoing storage medium may be a read-only memory (Read-Only Memory,

ROM), Random Access Memory (RAM), disk, CD, etc.

The method and device for the voice call back to the circuit switched domain provided by the embodiment of the present invention

It is to be noted that the description of the above embodiments is only for helping to understand the method and the core of the present invention, and the idea; at the same time, for the person skilled in the art, according to the idea of the present invention, in the specific embodiment and the scope of application There are variations, and in summary, the contents of this specification are not to be construed as limiting the invention.

Claims

Rights request

A switching control method, comprising:

The mobile switching center MSC receives the first message from the mobility management entity MME, where the first message carries the Internet Protocol Telephony VoIP Evolved Packet System EPS bearer ID of the first user equipment, and the packet data gateway PGW corresponds to the control plane bearer of the first UE. The information and the PGW correspond to the user-side information of the VoIP of the first UE;

Notifying the MGW of the user plane bearer information of the VoIP corresponding to the first UE to the MGW, and updating the user plane bearer of the VOIP corresponding to the first UE to the PGW.

2. A handover control method, characterized in that it comprises:

Obtaining the address information of the MSC;

3. A PS to CS switching control method, comprising:

The MSC obtains the address information of the PGW;

4. The method according to claim 3, further comprising:

The MSC receives the packet domain switching to the circuit switched domain switching message of the corresponding first UE from the MME, and sends a bearer modification request message to the PGW, where the second bearer modification message carries the user plane bearer information of the VoIP corresponding to the VoIP of the first UE. ;

Notifying the MGW of the user plane bearer information of the VoIP corresponding to the VoIP of the first UE,

The PGW corresponds to the user plane bearer of the VOIP of the first UE to update to the MGW.

5. A handover control method, comprising: The MME sends a second message to the MSC, where the second message carries the user plane bearer information of the VoIP corresponding to the first UE of the SGW;

6. A handover control method, comprising:

7. A handover control method, comprising:

The SGSN receives the sixth message from the MME, where the sixth message carries the user plane bearer information of the VoIP corresponding to the MME of the first UE;

8. A mobile switching center, characterized in that:

9. A mobility management entity, comprising: a receiving module, configured to receive an attach request message or a PDN activation request message from the first UE, where the acquiring module is configured to obtain address information of the MSC;

10. A mobile switching center, comprising:

a first receiving module, configured to receive a first session setup request message from the SGW to establish a control plane bearer corresponding to the first UE, and establish a control plane bearer corresponding to the first UE corresponding to the SGW;

An obtaining module, configured to acquire, by the MSC, address information of the PGW;

The mobile switching center according to claim 10, further comprising: a second receiving module, configured to receive a packet domain switched to circuit switched domain switching message from a corresponding first UE of the MME;

The notification module is configured to notify the MGW of the user plane bearer information of the VoIP corresponding to the PDCCH of the first UE, and update the user plane bearer of the VOIP corresponding to the first UE to the MGW.

12. A mobility management entity, comprising:

13. A mobility management entity, comprising:

a sixth sending module, configured to send, by the MME, a sixth message to the SGSN, where the sixth message carries The MGW corresponds to the user plane bearer information of the VoIP of the first UE.

14. A service general packet service support node, comprising:

a receiving module, configured to receive a sixth message from the MME, where the sixth message carries user plane bearer information of the VoIP of the first UE corresponding to the MGW;

15. A communication system, comprising:

A device according to any one of claims 8 to 14.