KR20130112486A - Paging system, apparatus for providing voice service on heterogeneous network and method thereof - Google Patents

Abstract

In the present invention, to provide a voice service in a heterogeneous network, when providing a voice service in connection with the second mobile communication network in the first mobile communication network to transmit the paging to both the communication network where the incoming call request terminal is located and the communication network to be moved. This increases the paging success rate for voice services.

Description

Paging system, apparatus and method for providing voice service in heterogeneous networks {PAGING SYSTEM, APPARATUS FOR PROVIDING VOICE SERVICE ON HETEROGENEOUS NETWORK AND METHOD THEREOF}

The present invention is to provide a voice service in a heterogeneous network, and in particular, when providing a voice service in connection with a second mobile communication network in a first mobile communication network, paging is transmitted to both a communication network in which an incoming call request terminal is located and a communication network to be moved. The present invention relates to a paging system, an apparatus, and a method for providing a voice service in a heterogeneous network that can increase a paging success rate for a voice service.

3rd Generation Partnership Project (3GPP) mobile communication systems based on Wideband Code Division Multiple Access (WCDMA) radio access technology are widely deployed around the world. HSDPA (High Speed Downlink Packet Access), which can be defined as the first evolutionary phase of WCDMA, provides 3GPP mobile communication system with highly competitive wireless access technology in the mid-term future.

However, as the requirements and expectations of users and operators continue to increase and competition for developing wireless access technologies continues, there is a need to evolve new technologies in 3GPP mobile communication systems in order to gain competitiveness in the future. Reduced cost per bit, increased service availability, the use of flexible frequency bands, simple structure and open interface, and adequate power consumption of the terminal are demanding requirements. In addition, prevention of unnecessary latency at the network node and efficient use of network resources can also promote the technology evolution in 3GPP.

In 3GPP Release 8, a Network Architecture called Evolved Packet Core (EPC) is described as one of mobile communication systems for meeting the above-mentioned requirements. EPC is a set of network nodes for 3GPP LTE (Long Term Evolution) system. The EPC evolves the core network of the existing 3GPP system architecture to support Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN), which is an evolved RAN, And has an efficient network structure that simplifies the network node.

Meanwhile, as described above, EPC or LTE, which is a fourth generation mobile communication, must implement IMS-based VOIP technology in order to provide a voice service as a base of a mobile communication service as a data-only network.

However, due to issues such as lack of completeness of VOIP technology, initial LTE network investment, and cannibalization of existing mobile telephony voice call import model resulting from the introduction of VOIP, WCDMA for voice transmission or reception of LTE terminal devices proposed by 3GPP Circuit switched fallback (CSFB) technology is used to transition to the network and receive service.

That is, when a subscriber camped on the LTE network attempts to make a voice call, the network provides a service by inducing the corresponding terminal to move to the WCDMA network. In addition, when a voice call is received to a subscriber camped on the LTE network, the HLR manages where the WMSC is located in the subscriber's area and routes the call to the WMSC. The WMSC receives the VLR signal indicating that the subscriber is on the LTE network. It checks through (managed through subscriber's SGS-STATE field as shown in Figure 3) and requests incoming call, ie paging, to LTE network. In LTE, which has received the incoming request paging, similarly, the destination terminal makes a paging response after transiting the WCDMA network to enable voice receiving service in the WCDMA network. For the voice call service, the SGs interface between the WMSC and the MME, the LTE Core device, is configured and the above service is provided through the SGs AP protocol communication between heterogeneous networks.

1 illustrates a paging signal processing procedure of a CSFB voice service for a subscriber located in a conventional WCDMA network.

First, when a voice call is received from the terminal device 110 camped on the EPC network, the HLR determines where the MSC of the WCDMA network in the region where the terminal device 110 is located is located, and sends the corresponding MSC 100 to the MSC 100. Routing the incoming call to the terminal device 110 provides (routing) (S10). Then, the MSC 100 receiving the voice call searches for a visitor location register (VLR) and recognizes that the terminal 110 is in the EPC network when the SGs-state is in the SGs Associated state, and the MME 104 of the EPC network. Incoming request, that is, paging request (S12). As such, when receiving an incoming request from the MSC 100 of the WCDMA network, the MME 104 requests paging to the eNode B 106 (S14), and the eNode B 106 again to page the corresponding terminal device 110. The request is made (S16).

Then, the terminal device 110 transmits a paging response to the RNC 102 in response to the paging request (S18), and the RNC 102 transmits a paging response to the MSC 100 of the WCDMA network so that the incoming call is performed. (S20).

2 illustrates a paging signal processing procedure of a CSFB voice service for a subscriber located in a conventional WCDMA network.

First, when a voice call is received from the terminal device 110 camped on the EPC network, the HLR determines where the MSC of the WCDMA network in the region where the terminal device 110 is located is located, and sends the corresponding MSC 100 to the MSC 100. Routing the incoming call to the terminal device 110 is provided (S30). Then, the MSC 100 receiving the voice call searches for a VLR (visitor location register) and recognizes that the terminal 110 is in the WCDMA network when the SGs-state is in the SGs Null state. The request, that is, the paging request (S32).

Then, the RNC 102 requests a paging to the corresponding terminal device 110 for its cell area (S34), and the terminal device 110 transmits a paging response to the RNC 102 in response to the paging request. In operation S36, the RNC 102 transmits a paging response to the MSC 100 of the WCDMA network so that the incoming call is performed (S38).

Republic of Korea Patent Publication No. 10-0948689 Date of registration March 24, 2010 discloses a technology for the connection control in a dedicated wireless connection state of the mobile communication system. Korean Patent Laid-Open Publication No. 10-2009-0079224 discloses a technique for optimizing handoff of a user device between a packet switched network and a circuit switched network on July 21, 2009.

However, in performing the CSFB voice service in the conventional EPC network as described above, the WCDMA network exchanger checks the SGs-state information in the VLR to determine whether the called terminal is located in the LTE network or the WCDMA network. Even in the case of transmitting the paging, when the terminal device in the EPC network moves to the WCDMA network or the terminal device in the WCDMA network suddenly moves to the EPC network at the time of transmitting the paging, paging for voice service fails. There was a problem.

Accordingly, the present invention increases the paging success rate for the voice service by transmitting the paging to both the communication network where the incoming call request terminal is located and the communication network to which the incoming terminal is located when providing the voice service in connection with the second mobile communication network in the first mobile communication network. To provide a paging system, apparatus and method for providing a voice service in a heterogeneous network.

The present invention described above is a paging system for providing a voice service in a heterogeneous network, comprising: a location information providing unit for providing location information on a terminal device, and the location information providing unit upon receiving a voice call incoming request for the terminal device; And a voice / packet switching unit configured to receive the location information and simultaneously transmit paging to a first mobile communication network and a second mobile communication network where the terminal device is located.

The present invention also provides a paging device for providing a voice service in a heterogeneous network, comprising: a communication unit for transmitting a paging signal to a terminal device that has received an incoming call when receiving an EPC-WCDMA network call request; and an HLR when receiving the voice call incoming request. Receiving the location information of the terminal device from the control unit for transmitting the paging at the same time to the MME of the EPC network in which the terminal device is located and the RNC of the WCDMA network.

The control unit may simultaneously transmit paging to an MME stored in a VLR and an RNC of a WCDMA network when the terminal device exists in an EPC network at the time of a voice call reception.

In addition, the control unit, when the terminal device is present in the WCDMA network at the time of the voice call to the terminal device receives the MME to be moved by the terminal device from the HLR and simultaneously transmits the paging to the RME of the MME and WCDMA network Characterized in that.

The controller may determine that the terminal device is located in the EPC network or the WCDMA network at the time of the reception by referring to the SGs-state information in the VLR for the terminal device.

The present invention also provides a paging method for providing a voice service in a heterogeneous network, the method comprising: receiving a voice call incoming request to a terminal device moving between EPC-WCDMA networks, and at the time of the voice call incoming, the terminal device to the EPC network; If present, identifying the MME in which the terminal device is located with reference to the VLR, and simultaneously transmitting paging to the MME in which the terminal device is located and the RNC of the WCDMA network in which the terminal device is located.

The present invention also provides a paging method for providing a voice service in a heterogeneous network, the method comprising: receiving a voice call incoming request to a terminal device moving between EPC-WCDMA networks, and at the time of the voice call incoming, the terminal device to the WCDMA network; And if present, receiving the MME to which the terminal device will move from the HLR, and simultaneously transmitting paging to the MME to which the terminal device moves and the RNC of the WCDMA network in which the terminal device is located.

When providing a voice service in a heterogeneous network, the present invention provides a paging success rate for a voice service by linking a first mobile communication network to a second mobile communication network so as to transmit paging to both a communication network where an incoming call request terminal is located and a communication network that is to be moved. There is an advantage to increase.

1 is a flowchart illustrating a paging signal processing for providing a CSFB voice service to a subscriber located in a conventional EPC network.
2 is a flowchart illustrating a paging signal processing for providing a CSFB voice service to a subscriber located in a conventional WCDMA network;
3 is a network configuration diagram of a heterogeneous mobile communication hybrid system using a WCDMA network and an EPC network to which an embodiment of the present invention is applied;
4 is a format diagram of MME information in an ISD message according to an embodiment of the present invention;
5 is a detailed block diagram of an MSC according to an embodiment of the present invention;
6 is a flowchart illustrating a paging signal processing procedure for providing a CSFB voice service to a subscriber located in an EPC network according to an embodiment of the present invention;
2 is a flowchart of paging signal processing for providing a CSFB voice service to a subscriber located in a WCDMA network according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the present invention. In the following description of the present invention, if it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a diagram illustrating a network configuration of a heterogeneous mobile communication hybrid system using a first mobile communication network (EPC network) and a second mobile communication network (WCDMA network) to which an embodiment of the present invention is applied.

In FIG. 3, reference numerals 310 to 380 denote EPC networks as examples of the first mobile communication network, and 210 to 280 denote WCDMA networks as examples of the second mobile communication network.

The WCDMA network includes NodeB 210, RNC (Radio Network Controller) 220, SGSN 230, HLR 240, GGSN 250, CG (Charging Gateway) 260, MSC / VLR (Mobile Switching Center / Visitor Location Register (270), Short Message Service Center (SMS) 280, and the like.

Here, NodeB 210 and RNC 220 correspond to a radio access network area, and SGSN 230 and GGSN 250 correspond to a packet switched core network.

The HLR 240 is a line-based subscriber information database that stores a service profile of mobile subscriber information, and includes a terminal identification number (MIN) and a terminal unique number (ESN) of the terminal device 110. Number) and service type information to store subscriber information.

In addition, in case there is no subscriber information for the terminal equipment of the EPC network that needs to perform paging for voice service in the MSC of the WCDMA network, the HLR 240 is voiced to the MSC 270 according to an embodiment of the present invention. Provides information on the MME 330 of the EPC network in which the user element (UE) 110 to which the call is received exists. That is, the HLR 240 records the MME information recently registered by the terminal 110 in the MAP_PRN as shown in FIG. 4 and provides it to the MSC 270.

Referring to FIG. 4 above, the HLR 240 sends an ISD (Insert_Subscriber_Data) message transmitted in response to a restore_data message received from the MSC 270 according to a call processing procedure with the MSC 270. MME-NAME received through combined EPS and IMSI Attach through the existing EPC network can be transmitted as an extension. At this time, the MME-NAME as shown in FIG. 4 follows the Fully Qualified Domain Name (FQDN) format.

The MSC 270 stores visitor location information, performs switching control for voice communication, and provides a connection function between various other devices and an external network.

In addition, according to an embodiment of the present invention, the MSC 270 receives an ISD message received from the HLR 240 when a paging signal for voice service using CSFB is transmitted to a terminal device belonging to the EPC network through interworking between the WCDAM network and the EPC network. After analyzing the MME-NAME information included in the MME 330 of the EPC network in which the terminal device to transmit the paging signal is located, and transmits the paging signal to the WCDMA network and the EPC network at the same time to prevent the paging failure.

The SMSC 280 provides a short message service, which is not related to data call processing according to an embodiment of the present invention, but is shown for reference.

In the radio access network area, a function of efficiently using limited radio resources is provided to provide a high speed packet data service and satisfy various quality of service (QoS) requirements in a multimedia system.

The SGSN 230 and the GGSN 250 belonging to the packet switched core network area may interwork with an IP-based protocol to match the packet data network (PDN) 410 such as the Internet so that the terminal device 110 may receive a packet switched service. To provide.

To this end, the SGSN 230 is connected to several RNCs 220 to manage the mobility and packet session management of the subscriber station 110, establish a PDP context with the GGSN 250, and perform tunneling. To carry out the protocol data unit. In addition, the SGSN 230 may perform IP routing and interact with location registration of the terminal device 110.

In addition, when a data call is requested from the terminal device 110, the SGSN 230 requests a subscriber profile from the HLR 240, receives a subscriber profile including plan information from the HLR 240, and the terminal device 110 receives the subscriber profile. It is determined based on the subscriber profile whether the subscriber is the subscriber of the WCDMA network or the EPC network, and the terminal device 110 transmits a data call message to the GGSN 250 when the terminal device 110 is a subscriber of the WCDMA network. In the case of subscribers of the EPC network, the plan information is stored in the form of provision values and preset values provided by the HLR 240, and transmits a data call message to the PDN GW 350 of the EPC network.

The GGSN 250 is a gateway that directly connects with the PDN 410 to maintain routing information between the SGSN 230 and the external network, and performs tunneling and IP routing functions. Meanwhile, the GGSN 250 sets a billing data transfer message or an accounting request including the radio resource usage time information and the usage information of the terminal device 110 and transmits the accounting request to the CG 260. In addition, the GGSN 250 allocates an IP to the terminal device 110 according to the data call message transmitted from the SGSN 230.

EPC network is eNodeB (310), S-GW (320), MME (330), HSS (340), PDN GW (350), PCRF (Policy & Charging Rule Function) (360), OFCS (OFline Charging System) (370) ), An online charging server (OCS) 380, and the like.

The eNodeB 310 is a device supporting next-generation technologies and services such as LTE, and performs functions such as radio frequency (RF) transmission and reception of signal strength and quality, baseband signal processing, and channel card resource management. To perform.

The S-GW 320 is a session control and user plane node that processes payload traffic according to a set session. The S-GW 320 interworks with the eNodeB 310 through an S1-U interface and inter- LTE / 3GPP hand. It supports the over, configures the PDN GW 350 and EPS bearer (Evolved Packet System bearer) and delivers a packet data unit (PDU) using tunneling.

The PDN-GW 350 allocates IP of the terminal device 110 and performs routing control with the S-GW 320 and the external network for packet service as a session control and user plane that interworks with an external Internet network and a non-3GPP network. Maintains tunneling and IP routing functions. In addition, it delivers the PDU to the S-GW 320 and the external network.

The MME 330 is a node that manages subscriber information and mobility of the terminal device 110 and is responsible for session management, idle subscriber management, paging, and subscriber authentication functions. That is, the MME 330 processes the control signal when there is a join request or a radio bearer setup request from the terminal device 110 or another network node such as the PDN GW 350 or the S-GW 320. It is responsible for various functions of a control plane such as a control plane, and performs functions such as setting up EPS bearer or IP tunnel and mobility management.

The HSS 340 is a network node including a database containing subscriber information for a wireless communication system. The HSS 340 stores profile information, authentication, and location data of a service subscriber, and the HSS 340 is an MME. In response to the request of 330, the subscriber profile including the plan information is transmitted to the MME 330.

The PCRF 360 provides dynamic QoS and charging rules according to the service data flow to perform communication policy and charging processing in the communication network.

The OCS 380 receives the billing information of the subscriber who needs the real time billing information and provides a credit management function such as a limit service. Then, EPC GW (Evolved Packet Core GateWay) generates the charging information of the packet flow (packet flow) based on the charging information provided by the OCS (380).

OFCS 370 collects the billing information generated by the EPC GW, processes and transmits the billing data required by the billing system (BS). In addition, OFCS 370 accommodates various charging protocols such as Radius, Diameter, and GTPP to provide a unified BS interface.

5 illustrates a detailed block configuration of the MSC 270. The MSC 270 includes a switch unit 500, a communication unit 504, a control unit 502, a VLR 506, and the like.

The VLR 506 is a device for storing visitor information and manages information of the terminal device 110 that has moved to the MSC 502, and when the terminal device 110 exists in the EPC network, The SGs-state field is represented by, for example, SGs-associated.

The switch unit 500 connects incoming calls, such as voice calls, received by the terminal device 110 to the corresponding terminal devices, thereby forming a call path between the terminal devices.

The communication unit 504 performs an interface for a wireless signal transmitted and received between the terminal device 110 and the MSC 270, such as transmitting a paging signal indicating the reception of the incoming call when the incoming call is received by the terminal device 110.

The controller 502 stores visitor location information, performs switching control for voice communication, and provides a connection function between various other devices and an external network according to an operation program stored in the memory unit 508. Controls the overall operation of the MSC 270.

In addition, the control unit 502 is an ISD message received from the HLR 240 when the paging signal for voice service using the CSFB to the terminal device belonging to the EPC network through interworking between the WCDAM network and the EPC network according to an embodiment of the present invention After analyzing the MME-NAME information included in the MME 330 of the EPC network in which the terminal device to transmit the paging signal is located, and transmits the paging signal to the WCDMA network and the EPC network at the same time to prevent the paging failure.

FIG. 6 illustrates a paging signal processing procedure of a CSFB voice service using simultaneous paging of a first mobile communication network (EPC network) and a second mobile communication network (WCDMA network) according to an embodiment of the present invention.

When a voice call is received from the terminal device 110 camped on the EPC network, the HLR determines where the MSC of the WCDMA network in the region where the terminal device 110 is located is located, and the terminal is connected to the MSC 270. The device 110 provides the routing call to the incoming call (S60).

Then, the MSC 270 receiving the voice call searches for a visitor location register (VLR) and recognizes that the terminal 110 is in the EPC network when the SGs-state is SGs Associated, and the MME 330 of the EPC network. In this case, the paging is failed when the terminal device 110 is not located in the EPC network due to a sudden movement, as described above.

Accordingly, in the embodiment of the present invention, the MSC 270 requests paging to the MME 330 of the EPC network where the terminal device 110 is located, and also requests paging to the RNC 220 of the WCDMA network ( S62). That is, such a paging request is simultaneously transmitted to the MME 330 and the RNC 220.

First, referring to the paging procedure in the EPC network, when receiving a paging request from the MSC (270) (S64), the MME 330 makes a paging request to the eNodeB (310) located in its cell area. Then, the eNodeB 310 receives the paging request and requests paging again to the terminal device 110 (S68). In this case, if the terminal device 110 moves to the WCDMA network, the eNodeB 310 receives a paging response from the terminal device 110. It will not receive, causing paging to fail.

Next, referring to the paging procedure in the WCDMA network, when receiving a paging request from the MSC (270) (S70), the RNC 220 of the WCDMA network to the paging to the terminal device 110 located in its cell area The request is made (S72). At this time, when the terminal device 110 is moved from the EPC network to the WCDMA network, the terminal device 110 transmits a paging response to the RNC 220 in response to the paging request (S74), the RNC 220 ) Transmits the paging response to the MSC 270 of the WCDMA network so that the incoming call is performed (S76).

7 illustrates a paging signal processing procedure of a CSFB voice service using simultaneous paging to a WCDMA network and an EPC network according to another embodiment of the present invention.

When a voice call is received from the terminal device 110 camped on the EPC network, the HLR determines where the MSC of the WCDMA network in the region where the terminal device 110 is located is located, and the terminal is connected to the MSC 270. The device 110 provides an incoming call by routing (S80).

Then, the MSC 270 receiving the voice call searches for a VLR (visitor location register) and recognizes that the terminal 110 is in the WCDMA network when the SGs-state is SGs Null, and the RNC 220 of the WCDMA network is recognized. In this case, as described above, there is a problem that paging fails when the terminal 110 is not located in the WCDMA network due to a sudden movement.

Therefore, in the embodiment of the present invention, the MSC 270 requests paging to the RNC 220 of the WCDMA network where the terminal device 110 is located, and also requests paging to the MME 330 of the EPC network ( S82).

First, a paging procedure in the WCDMA network, when receiving a paging request from the MSC (270) (S84), the RNC 220 of the WCDMA network to request the paging to the corresponding terminal device 110 located in its cell area If the terminal device 110 moves to the EPC network at this time (S86), the terminal device 110 does not receive a paging response from the terminal device 110, causing the paging to fail.

Next, referring to the paging procedure in the EPC network, when receiving a paging request from the MSC (270) (S88), the MME 330 makes a paging request to the eNodeB (310) located in its cell area (S90). ). Then, the eNodeB 310 receives the paging request and requests the paging back to the terminal device 110 (S92).

At this time, when the terminal device 110 is moved from the WCDMA network to the EPC network, the terminal device 110 transmits a paging response to the RNC 220 in response to the paging request (S94), the RNC 220 ) Transmits the paging response to the MSC 270 of the WCDMA network so that the incoming call is performed (S96).

As described above, in the CSFB voice service linked to the WCDMA in the EPC network, when configuring the SGs interface between the MSC of the WCDMA network and the MME of the EPC network, and receives an incoming request from the MSC of the WCDMA network to the terminal device, the SGs interface information By confirming that the paging is transmitted to both the communication network and the communication network located in the incoming terminal device to increase the paging success rate for the CSFB voice service.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention should not be limited by the described embodiments but should be defined by the appended claims.

In the present invention, in the CSFB voice service associated with the WCDMA in the EPC network, the MSD information of the terminal device is included in the ISD message between the HLR-MSC, and to prevent the paging failure between the WCDMA network and the EPC network to the EPC network and WCDMA network Simultaneously, the paging success rate for CSFB voice service can be increased by transmitting paging, which can be applied to an EPC network.

210: NodeB 220: RNC 230: SGSN
240: HLR 250: GGSN 260: CG
270: MSC / VLR 280: SMSC 310: eNodeB
320: S-GW 330: MME 340: HSS
350: PDN-GW 360: PCRF 370: OFCS
380: OCS

Claims (7)

A location information providing unit for providing location information on the terminal device;
A voice / packet switching unit that receives the location information from the location information provider and simultaneously transmits paging to the first mobile communication network and the second mobile communication network where the terminal device is located when receiving a voice call incoming request to the terminal device.
Paging system for providing a voice service in a heterogeneous network comprising a.
A communication unit which transmits a paging signal to a terminal device that has received an incoming call upon receiving an EPC-WCDMA voice call incoming call request;
Control unit for receiving the location information of the terminal device from the HLR when receiving the voice call incoming request and simultaneously transmits the paging to the MME of the EPC network in which the terminal device is located and the RNC of the WCDMA network
Paging device for providing a voice service in a heterogeneous network comprising a.
3. The method of claim 2,
The control unit,
Paging device for providing a voice service in a heterogeneous network, characterized in that when the terminal device is present in the EPC network at the time of the voice call to the terminal device to simultaneously transmit the paging to the RME of the MME and WCDMA network stored in the VLR .
5. The method of claim 4,
The control unit,
When the terminal device exists in the WCDMA network at the time of the voice call reception for the terminal device, the terminal receives MME information to be moved by the terminal from the HLR and simultaneously transmits paging to the MME identified from the MME information and the RNC of the WCDMA network. Paging device for providing a voice service in a heterogeneous network, characterized in that.
The method according to claim 3 or 4,
The control unit,
A paging device for providing a voice service in a heterogeneous network, characterized in that the terminal device is located in an EPC network or a WCDMA network at the time of the reception by referring to SGs-state information in the VLR for the terminal device.
Receiving a voice call incoming request to an EPC-WCDMA network moving terminal device;
Identifying the MME where the terminal device is located with reference to a VLR when the terminal device exists in the EPC network at the time of the voice call;
Simultaneously transmitting paging to the MME where the terminal is located and to the RNC of the WCDMA network where the terminal is located;
Paging method for providing a voice service in a heterogeneous network comprising a.
Receiving a voice call incoming request to an EPC-WCDMA network moving terminal device;
Receiving MME information to which the terminal device will move from an HLR when the terminal device exists in a WCDMA network at the time of the voice call;
Simultaneously transmitting paging to an MME to which the terminal device is to move and to an RNC of a WCDMA network in which the terminal device is located;
Paging method for providing a voice service in a heterogeneous network comprising a.

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